A Notable Life In Quantum Physics

Chien-Shiung Wu was one of the pioneers of quantum mechanics and high energy physics, and was a female Chinese physicists in an era where women still made up only a tiny percentage of scientists in the field. 

If something remembers you with a speech like this, one hundred and ten years after you were born, when you have long passed away, then you did something right in life.

In 1950, Chien-Shiung Wu and her student published a coincidence experiment on entangled photon pairs that were created in electron-positron annihilation. This experiment precisely verified the prediction of quantum electrodynamics. 

Additionally, it was also the first instance of a precisely controlled quantum entangled state of spatially separated particles, although Wu did not know about this at the time. 

In 1956, Wu initiated and led the so-called Wu experiment, which discovered parity nonconservation, becoming one of the greatest experiments of the 20th century. 

As Chen Ning Yang said, Wu's experiments were well known for their precision and accuracy. Experimental precision and accuracy manifested Wu's scientific spirit, which we investigate here in some detail. 

Yu Shi, "Scientific Spirit of Chien-Shiung Wu: From Quantum Entanglement to Parity Nonconservation" arXiv:2504.16978 (May 31, 2022) (This paper is the translated transcript of the speech the author made at the International Symposium Commemorating the 110th Anniversary of the Birth of Chien-Shiung Wu, on May 31, 2022 in Chinese. The above abstract is the translation of the original abstract of the speech.)

She earned her undergraduate degree in physics (which had a thesis requirement at the time) in China in 1934, prior to the Maoist Revolution, and earned a PhD working under a professor only three years older than her who had studied under Madame Curie, and under the first female PhD in Physics in China, who earned that degree at the University of Michigan (where I also earned my graduate degree). Wu earned her PhD at the University of California at Berkley in 1940 (thirty years before my father earned his PhD at Stanford).

Wu was admitted by the University of Michigan to study at her own expense, and was financially supported by her uncle. On her way to Michigan, Wu visited Berkeley, where she was so impressed, especially by Ernest O. Lawrence’s cyclotron, that she wanted to stay in Berkeley. The cyclotron had been invented by Lawrence, so it was an ideal place for studying physics. Another important factor that influenced Wu’s decision was that she cared a lot about gender equality, and there was gender discrimination at the University of Michigan. In addition, there were a lot of Chinese students at the University of Michigan at the time, and Wu didn’t want her socializing be dominated by fellow Chinese students. So she stayed in Berkeley. Her decision reflected her devotion to physics as a woman.

She then taught at Smith (from which my sister-in-law graduated), and then Princeton, and then she worked at Columbia University as part of the Manhattan Project. 

She was highly productive (publishing more than fifty papers in the early 1950s when a huge share of U.S. women were homemakers in the Baby Boom), and her early post-war research agenda involved the verification of Fermi’s theory of β decay.

Chien-Shiung Wu served as the President of the American Physical Society from 1975 to 1976.

James W. Cronin, who won the 1980 Nobel Prize for his discovery of charge conjugation-parity (CP) nonconservation, once said, “The great discovery of Chien-Shiung Wu started the golden age of particle physics.” 

She continued to publish through at least 1980, and died in February of 1997. The author of the paper had met her.

My Cues For Identifying Unhelpful Physics Papers (And Interesting Ones)

I skim the preprints at arXiv in astrophysics, general relativity, HEP-experiment, HEP-Lattice, and HEP-phenomenology almost every single day (going back to look at days I missed when I can't) and have done so for years.

There are lots of papers published, that in my personal, subjective, educated layman's view, are barking up the wrong tree in a line of research that I find to be unlikely to reflect reality and in that sense dubious. 

I mean this without denigrating the fact that these papers are mostly written by legitimate professional PhD physics researchers and represent predominately accurate and good faith efforts to apply their knowledge to unsolved problems in physics. These parts are often good enough if one makes the assumptions associated with that subfield, but I simply don't think that these subfields and the assumptions or conjectures behind them are correct.

Some of this is driven purely by my own informed intuition, even though I can't rigorously establish that these lines of inquiry are wrong. Others have been long disfavored by observational evidence that the authors choose to ignore or overlook for some reason. And, capricious as I am, sometimes something else about a paper that would generally seem unhelpful cause it to capture my attention anyway, usually in some aspect of the paper unrelated to the unhelpful parts.

I'll call these "unhelpful" physics papers. Also, to be clear, there are plenty of papers that are not in the "unhelpful" category, but simply aren't in an area of physics that I'm particularly interested in. 

For example, astronomy searches for exoplanets or analysis of how exoplanets form (that don't implicate new physics) are perfectly legitimate "helpful" papers, but I simply don't care much about the search for exoplanets or the process by which they form, since my main area of interest is the question to improve our understanding of the laws of physics themselves. Similarly, I am rarely interested in papers that recount new astronomy data without any meaningful analysis of it (it may be important, but I'm not skilled enough to analyze it without professional astronomer assistance). Likewise, HEP-experiment papers that discover and characterized new hadrons whose existence and properties are predicted by the Standard Model are "helpful" but just not all that interesting given my core interests.

Another class of papers which I largely ignore, although they are also not "unhelpful" in this sense, are papers discussing proposed new physics experiments that haven't reached the construction phase. Similarly, I don't pay much attention to highly technical instrumentation upgrade papers (in astronomy as well as HEP).

I identify "interesting papers" mostly by process of elimination, although some classes of papers, like measurements of Standard Model physical constants, analyses of the nature of scalar and axial vector mesons, modified gravity explanations of dark matter and dark energy phenomena, and mirror gravity cosmology papers are presumptively interesting.

One class of papers that hovers between the unhelpful and uninteresting category is the class of papers focusing on gravity and modified gravity theories in the very strong field regime (e.g. near black holes and neutron stars). I suspect that old fashioned classical GR does a very good job in this context, and in general, I'm just not all that interested in black holes.

What are some of the cues I use to determine that a preprint or paper is "unhelpful." Some papers have multiple "unhelpful" flags.

* Papers that discuss a see-saw mechanism for neutrino mass. See, e.g., here.

* Papers that analyze Majorana mass for neutrinos theoretically. See, e.g., here.

* Papers that propose "right handed" and/or "sterile" neutrinos. See, e.g., here and here.

* Papers that propose new GeV scale or more massive dark matter candidates. See, e.g., here and here.

* Papers that think we need new post-Big Bang physics to explain the baryon asymmetry of the universe. See, e.g., here.

* Supersymmetry models. See, e.g., here.

* String theory models. See, e.g., here.

* Lie Group based GUT and TOE models.

* Papers proposing new Higgs bosons in addition to the Standard Model Higgs boson (although papers ruling them out in some new parameter space deserve a passing glance). See, e.g., here.

* Papers exploring cosmological inflation models.

* Papers that propose leptoquarks. See, e.g., here.

* Papers discussing theories that give rise to proton decay.

* Papers that analyze "naturalness". See, e.g., here.

* Papers that propose non-sphaleron violations of baryon number or lepton number conservation (e.g. flavor changing neutral currents).

* Papers about quark stars and/or boson stars.

* Papers about macroscopic wormholes.

* Papers about magnetic monopoles.

* Papers about tachyons.

* Papers proposing more than five dimensions.

* Papers proposing tiny "rolled up" dimensions.

* Papers about Kaluza-Klein gravitons.

* Papers about Proca models.

* Papers about QCD Peccei-Quinn axions and/or the "strong CP problem". See, e.g., here.

* Papers proposing violations of the combined CPT symmetry.

* Papers proposing faster than light communication or information transfer.

* Papers about cosmological bounce models.

* Papers about "tired light" models.

* Papers that attempt to explain a discrepancy between experimental measurements of muon g-2 and the Standard Model value of it with new physics.

* Papers that take the new CDF W-Boson mass anomaly seriously. See, e.g., here.

* Papers that employ anthropic reasoning.

* Papers proposing theories where different generations of a particle have different properties (such as couplings) that are not coded in the particle's mass or its CKM/PMNS matrix couplings.

* Papers proposing fourth generation fundamental fermions. See, e.g., here.

I only blog a small percentage of the articles that I flag as interesting and bookmark (by subject area). Sometimes, they are too incremental or too technical or similar to papers on similar subjects that I've blogged before, and sometimes, I'm just not moved to write about them.

This Year's Nobel Prizes In STEM

The Nobel Prize in Physics for 2024 was awarded to John J. Hopfield and Geoffrey E. Hinton for their work in using machine learning methods (specifically, neural networks, a form of artificial intelligence) to solve physics problems. 

Both my son and his girlfriend currently work in the AI industry (and my brother and my daughter both work in the larger IT industry), so this is highly relevant to me personally. The large language models (LLMs) used in my own industry, law, are getting dramatically better by the year, but are still not ready for prime time and are prone to making things up and reaching absurd conclusions.

The prize in Physiology or Medicine went to Victor Ambros and Gary Ruvkun for their discovery of microRNA, which helps determine how cells develop and function. 

The Nobel prize in chemistry will be awarded tomorrow.

How Do People Decide Which Scientists To Believe?

Examining and resolving in my own mind disputes between scientists is pretty much the essence of what I do on a daily basis, especially, but not only, at this blog. So, this study caught my attention. I suspect that my methods are more analytical and sourced than average, and view myself as kindred to "superforecasters" in my methods.

Uncertainty that arises from disputes among scientists seems to foster public skepticism or noncompliance. Communication of potential cues to the relative performance of contending scientists might affect judgments of which position is likely more valid. We used actual scientific disputes—the nature of dark matter, sea level rise under climate change, and benefits and risks of marijuana—to assess Americans’ responses (n = 3150). 

Seven cues—replication, information quality, the majority position, degree source, experience, reference group support, and employer—were presented three cues at a time in a planned-missingness design. The most influential cues were majority vote, replication, information quality, and experience. Several potential moderators—topical engagement, prior attitudes, knowledge of science, and attitudes toward science—lacked even small effects on choice, but cues had the strongest effects for dark matter and weakest effects for marijuana, and general mistrust of scientists moderately attenuated top cues’ effects. 

Risk communicators can take these influential cues into account in understanding how laypeople respond to scientific disputes, and improving communication about such disputes.

Branden B. Johnson, Marcus Mayorga, Nathan F. Dieckmann, "How people decide who is correct when groups of scientists disagree" Risk Analysis (July 28, 2023).

The Willow In Slavic Folklore

My birth surname, "Willeke", is a derivative of "Willow Tree" in some early modern dialect of German. 

Also, while my ancestry on my father's side is German (well, Prussian, anyway), my Y-DNA patriline probably derived from the Balkans from which my ancestors integrated themselves into migrating populations of steppe men in the early Bronze Age or late Copper Age, and made their way to the northwest.

Naturally, a blog post at the Old European Culture blog about the Willow in Slavic Folklore caught my eye (the source is full of wonderful images and links to related articles, so please, click through and check it out).

The Willow is associated with Slavic spring fertility rituals and summer magical rituals. 

Saturday before Palm Sunday is in Serbia known as Vrbica (Willow day). On that day kids and young women make and wear wreaths made of willow twigs and flowers. On that day, willow twigs with young leaves and flowers, like these, known in English as Pussy Willow are brought to the church where they are blessed the next day, Palm Sunday, which is in Serbia known as Cveti (Flowers day). According to the church, this whole willow business is the consequence of the fact that there are no palms in Serbia, and people replaced palm branches with willow branches...Move on, nothing so see here...

There are few problems with this explanation...Vrbopuc (Willow burst) is an expression which in Serbia means "part of spring during which willow starts growing new green shoots"... In Serbia in the past people believed that during this time of the year women become very horny and very fertile...So this was the best time to make babies...🙂 Vrbopuc is also a term used in Serbia for the period of sudden surge of sexual hormones in teenage boys and girls...

Basically willow was directly linked with human fertility...Which is why in the past in Serbia, girls used to make belts from willow twigs (wrap willow twigs around their bellies), and wear them going to the rivers to perform ritual baths... This ritual bathing was performed on Cveti (Flowers day) but also on Djurdjevdan (St George's day), the old Yarilo day, the old day of the young sun, the old celebration of the beginning of summer...Known also as Beltane... At the same time on St Georges day, while girls were wearing willow belts and bathing, boys and men were blowing into willow horns to "scare the witches away"... It is interesting that this ritual bathing was done before sunrise and willow belt had to be taken off as soon as the sun rose...And that blowing into the willow horns was also done during the night.... I didn't pay much attention to this until I remembered that willow was directly linked with water, water divination....Dodole, young women which took part in rain bringing magic rituals performed during hot summers also wore willow twig belts...

Mother Earth = Yin = Winter, Cold, Wet, Night, Down = Female fertility

Father Sun (Sky) = Yang = Summer, Hot, Dry, Day, Up = Male fertility

Which is why rain, water magic is female magic... And which is why willow, the tree which grows next to water, is associated with rain, water and female fertility, female sexuality...Hence ritual whipping of teenage girls by teenage boys using willow whips, performed in the Czech Republic, Slovakia on Easter Sunday... If men arrive at women's houses after 12 o'clock, women throw a bucket of cold water on them. In some regions the men also douse girls with water... The man first sings a a ritual song about spring, bountifulness and fertility, and the young woman then turns around and gets few whacks on her backside with the willow whip...This was done "so girl would be healthy, beautiful and fertile throughout the following year"...

In Serbia willow was also linked with female coming of age rituals, also performed on Willow day...On that day, young unmarried girls, wearing willow twig belts and willow and flower wreaths walked around the village land and blessed the nature... They would first go to a spring where they would sing and dance and would then wish good morning to the spring water. Spring water is in Serbia called "živa voda" (live water, water of life) and is believed to have magic properties...

Spring is seen as a place where fertile Mother Earth releases her "water of life" in the same way that a fertile woman releases her menstrual blood, female "water of life". In this way the spring water is magically linked with the menstrual blood... So no wonder that the spring is the first stop of the Lazarice group, the group of girls whose "water of life has started to run" (who got their period). BTW they are called Lazarice "because Willow day is by Christians also known as Lazarus day"... After this ritual, the girls would go to meadows to pick wild flowers. They would use these flowers to make wreaths which they would wear on their heads during their procession through the village land and the village... They would then walk through the fields, forests, meadows belonging to the village, and would sing fertility songs wishing nature to be fertile and bountiful.... Young girls, Spring Earth, Female fertility, Earth fertility, water...Willow...

That the belief in the link between willow and fertility was once probably Europe wide, can be seen from this English belief: "Striking an animal or a child with a willow twig will stunt their growth!" This is a great example of Christianity at work...

In Serbia it is actually the opposite...On Willow day, children and animals are whipped with willow twigs so they grow like willow and are healthy and fertile...Which is what you would expect after everything I have presented so far... Willow twigs, particularly the ones cut around St George's day are considered to be most potent when it comes to growing magic...Willow was in the mind of the Slavs definitely linked to growth and fertility... 

So imagine my surprise when I came across this information: Willow contains two very interesting chemicals: indolebutyric acid (IBA) and salicylic acid (SA)... Indolebutyric acid (IBA) is a plant hormone that stimulates root growth. It is present in high concentrations in the growing tips of willow branches... Salicylic acid (SA) is a plant hormone which is involved in the process of “systemic acquired resistance” (SAR) – where an attack on one part of the plant induces a resistance response to pathogens (triggers the plant’s internal defences) in other parts of the plant...

Soooo...The first hormone makes the plant grow...The second hormone makes the the plant healthy...And these hormones can be extracted from the willow shoots and used to help your plants grow and be healthy...

Salicylic acid is also an acne treatment, something young men and women often need to keep themselves looking beautiful.

23 and Me Korea-Japan Glitch Fixed

When the home genetic testing firm 23andMe first provided reports for my wife, her parents, her sister, my children, and my nice and nephew who are children of her sister, the reports showed a significant share of Japanese ancestry. 

This would be a scandalous fact, if true, as it would indicate, in all likelihood, a child born from a Japanese father during Japanese occupation (from 1910 to 1945), or from a Korean man collaborating with the Japanese in that era who married a Japanese woman in connection with that event, something that came be to seen as dishonorable. 

The bite was particularly cutting in this case because my wife's mother's family, in particular, was part of the big business economic elite of the pre-Korean War Korean nation, and would have had lots of economic and social ties to members of the Japanese occupation elites as a result.

But while it wasn't absolute impossible that there was cryptic Japanese ancestry in the family, her parents family ancestry was know to them to be exclusively Korean in their parents and grandparents generations, at a minimum, so the percentages shown were impossible. Also, pretty much all other Koreans we knew who had done consumer genetic testing, were seeing the same thing.

The reality was a methodological artifact rooted in a historical reality that blind cluster analysis performed by computers couldn't grok. 

The modern Japanese people are the admixed product of the indigenous Japanese Jomon people (mostly with a sedentary fishing village based economic foundation) whose ancestors arrived on these islands on the order of 8,000 to 16,000 years ago, and the Yayoi soldier-rice farmers who arrived around 2,300 years ago by sea from Korea and conquered the Jomon and their land.

Modern Japanese people are 9-13% Jomon in origin (measured by autosomal genetics), although modern Japanese men are about 1/3rd Jomon in Y-DNA and a significantly smaller share of modern Japanese people are Jomon in mtDNA, which is inherited from mother to child. 

This mix of uniparental markers is quite surprising. Usually more maternal than paternal uniparental DNA survive by introgression into a conquering people from the people who conquerer them, as male soldiers or pioneers or explorers take local wives. The fact that there is virtually no Jomon linguistic substrate in the Japanese language also limits to the scope of the possible narratives that could cause this unual uniparental DNA marker mix to arise. The cultural process by which this happened in Japan starting around 2,300 years ago is still not well understood. 

A best guess would be that Yayoi soldiers recruited and then thoroughly assimilated local Jomon boys into their army who would leave few linguistic substrates due to their superior youthful language learning abilities. Then, the Yayoi brought wives for all of its soldiers and veterans, including Jomon boy recruits, from Korea, which was not far away, rather than taking local wives. Given the overall percentage of Jomon automsomal ancestry in the Japanese, most Japanese Jomon autosomal DNA probably derives from Jomon origin fathers rather than Jomon origin mothers. But, this is little more than an educated guess. 

Anyway, the bottom line is that modern Japanese people are predominantly Korean in remote genetic origin. Admittedly, the genetic makeup of Korea 2300 years ago was somewhat different than it is today. Also, there was significant later Chinese genetic introgression into Japan via wives imported from China to Japan for elite Japanese men for many centuries after the initial ethnogenesis of the Japanese people. This happened because Chinese wives were considered prestigious because China had the most sophisticated civilization in East Asia at the time. Strong ties to China also did have significant linguistic impact on the Japanese language.

But because the 23andMe database has more Japanese samples than Korean samples, and because there is heavy overlap between the two populations, a computerized blind cluster analysis by 23andMe assumed that many Koreans had Japanese admixture. 

In reality, however, unless someone has a significant minority of Jomon origin genes in their genome as a whole, someone with genes found in both Japanese people and Korean people almost certainly has no Japanese admixture, even if they have many genes that are common in Japanese people.

Eventually 23andMe figured this out, and in a December 2020 update, it now reports that my wife's parents and their descendants all have 100% Korean ancestry (even though my wife's father's Y-DNA haplogroup, O-CTS723 which is a subclade of O-M268, is one that was common among the Yayoi).

Now, the handling of their Korean origins still isn't perfect. 23andMe says that everyone in the family has localized Korean origins that are most likely in Seoul, South Korea. And, this is true as of the post-Korean War era in the 1950s. My wife's parents emigrated there during the Korean War (i.e. June 25, 1950-July 27, 1953) in their tweens or teens about fifteen years before moving to the United States. But, her parents lived the first half of their Korean lives in North Korea, where they were born, as did at least a couple of generations of their ancestors. Yet, 23andMe states that they have 0% North Korean origins. 

Still, two cheers for progress.

My Genetic Ancestry In A Nutshell

23 and Me and updated its ancestry algorithm. In my case, any changes from the previous estimates in this report were very subtle. 

I have Y-DNA haplogroup E-V13 (from my father) and mtDNA haplogroup H1b (from my mother). My autosomal ancestry using the regional assignment algorithm of the service is as follows:

The trace ancestry is from Southern India:

The service says this about that population:

Home to the Malayali (meaning “people of the mountains”), Kerala has been at the heart of a thriving international spice trade for millennia, becoming one of India’s most diverse and prosperous states. This genetic signature reaches high levels among Christian communities who live in Kerala, a large number of whom immigrated to the United States during the last century.

I suspect that this trace ancestry is a false positive. 

The reports assigns time depths to these major ancestry components in addition to localizing some of them.

The lion's share of my non-Finnish ancestry (including all of the Scandinavian ancestry) is from my father who is genetically, something of a Northern European mutt. I do have genealogically confirmed Irish ancestry on my father's side from a marriage that took place in Northwest Ohio, although I don't know precisely where in Ireland. My father's predominant ancestry according to genealogical sources is proximately from Lutheran Germany (it was called Prussia in 1847 at the time my patrilineal ancestor migrated to the U.S. to avoid being conscripted into the military). The relatively small amounts of Italian and Scandinavia admixture are traceable to pre-emigration admixture event in Europe, probably during the 18th century.

The regional localization of my Finnish ancestry (which is all on my mother's side) is quite striking as it is very close to the place from which my actual ancestors in Finland originate a little later in the 19th century. It looks more recent than the known date of immigration of my Finnish ancestors because my mothers ancestors all come from an endogamous Finnish community in the Upper Peninsula of Michigan that was a subset of the community in Finland from which they originally migrated to the U.S.

I have less than 2% Neanderthal DNA, but I still have more Neanderthal DNA than 78% of 23 and Me customers. 

I previously made a deep dive into what kind of narrative is likely to be associated with Y-DNA E-V13 at this blog, which can be found here.

My mtDNA haplogroup H1b is common in the 23 and Me sample (one in 130 customers). According to the service:

Your maternal line stems from a branch of H1 called H1b. The common ancestor of haplogroup H1b lived approximately 5,000 to 7,000 years ago in southwestern Europe. Her maternal-line ancestors had been among the former inhabitants of continental Europe, but massive glacial ice sheets during the last great peak of the cold at the end of the Ice Age pushed them out of the continental interior. They sheltered for thousands of years in warmer refuges along the Mediterranean. Then, as the Ice Age faded away, they re-emerged and migrated north.

While the woman who gave rise to H1b probably lived in southern France or the Iberian Peninsula, her descendants are most frequently found among eastern Europeans. Women carrying H1b journeyed eastward from southwestern Europe, passed north of the Italian Alps and entered present-day Slovakia. From there, H1b spread north throughout the region surrounding the Baltic Sea and the Volga-Ural area of Russia. Members of H1b also moved into southeastern Europe to Ukraine, the Balkans, and the Caucasus Mountains.

Previous posts on my personal genome from April 27, 2015, and April 6, 2015.

My Wife

My wife is 99.9% Japanese and Korean, with a possible 0.1% trace ancestry from Central and South Asia (from her mother's side). 

Both her parents immigrated from what is now North Korea (the partition was a recent event when they migrated to the U.S. in the 1960s) and have deep ancestry there. Notwithstanding this fact, 23 and Me states that South Korean ancestry is a "Highly Likely Match" and states that North Korean ancestry is not detected. This obvious fail is no doubt due to the small number of North Korean samples in the database.

The service also suggests that my wife has 7.6% Japanese ancestry (75% from her father suggesting that my wife would have a single great-great grandparent on his side, and 25% from her mother, suggesting that my wife would have a Japanese ancestor a generation or two more remote than that on her mother's side). This ancestry, according to the service, dates to sometime in the range from 1760 to 1850. At least some of this is probably an artifact of flaws in the ancestry matching algorithm, related to the fact that the non-Jomon ancestors of the Japanese very likely originated in the Korean Peninsula but Japan makes up more of the sample than Korea, although those flaws are significantly less severe than they used to be.

Her mtDNA haplogroup C5 is atypical for a Korean where it is found in 0.1% of tested Koreans (a point discussed here), although I suspect that the frequency is higher in North Korea, which is closer to the geographical homeland of that mtDNA haplogroup. My working hypothesis, given the relevant historical context and her mother's family background, is that she has a remote Mongol Princess matrilineal ancestor, from ca. 1250 CE, which may also be the source of trace Central Asian ancestry.

Hard Science Isn't Immune To Current Events

Both of the defining events of 2020 have had an impact on arXiv, the repository of free, open access, scientific journal pre-prints that I scour several times a week.

What Would Have Been Different If The Persians Had Defeated The Greeks? UPDATED

Feel free to discuss and consider this proposition in the comments. 

I will briefly comment that during a visit to Greece, and in particular, some tours in Athens last summer, the Greco-Persian War was vibrantly alive in the hearts and minds of the Greek people and still felt relevant today.

Of all the many counterfactuals, those “what-ifs” posed by history, perhaps the most arresting, if only because the most sweeping, asks: "what if the Persians had defeated the Greeks in the Greco-Persian War of 490–479 B.C.?" 

Had this happened, there might have been no Plato, no Aristotle, no Roman Empire, no Christianity, no Western Civilization. A Great King, a lineal descendant of Darius, might still rule the world. All might worship the Zoroastrian god Ahura Mazda, with men going about in turbans, women remaining at home or in harems. But that, as every counterfactual invariably ends—generally accompanied by a sigh of relief—didn’t happen.

From this book review reviewing Peter Green, Xerxes at Salamis (1970, reissued as The Greco-Persian Wars).

I'll also note that the answer is multi-faceted. 

One aspect of the question is a question of what matters in terms of historical causation.

If you are believer in the "Great Men" and "key moments" theory of history, events like this really can make an immense difference. 

But, if you think that history is largely a function of big, long term fundamental forces like climate and technology and inevitable secular trends (an approach often associated with Marxist historical interpretation but by not means so ideologically bound), you may be inclined to say that if the Persians had defeated the Greeks in the Greco-Persian War of 490–479 B.C., the fortunes of the parties probably would have been reversed in a second Greco-Persian War of 453-444 B.C., without leaving the world notable changed in the long run.

In this view, "Great Men" may change the finer grained details of history, but only rarely the overarching long term trends that matter in the long run. The alternative history would surely be different in some respects, because history does not repeat itself, but it would rhyme with the world we live in, taming our utopian and dystopian instincts.

In the language of mathematics, historical causation is a "chaotic" process, i.e. one in which small changes in the conditions in one moment are capable of producing big differences in outcome down the line due to the non-linear processes involved in how events unfold. But, historical trajectories have an "attractor" to which the non-linear processes' developments tend to gravitate, although the strength of these attractors is not a matter upon which there is a strong consensus, even when it is possible to meaningful define or describe that strength with more than a mere gut feeling. 

Even then, however, a question like this opens up the question of what is really fundamental, and what is window dressing.

An absence of Plato and Aristotle does not imply that the Persian tradition might have offered us equally formidable philosophers and proto-scientists. Cf. Hindu philosophy was mathematical. Indeed, some non-Western figures readily present themselves as alternatives. 

We might not have "Western Civilization" but that is not to say that Persian civilization under the different conditions it would have encountered in the scenario suggested would have been all that different in the ways that matter. Surely, an ascendant global Persian civilization would have still been more similar to our "Western Civilization" than the civilizations of India, China, Japan, the expansionist Bantu tribes of Africa, or the Aztecs.

A Persian Empire, had it extended to Hadrian's Wall, would probably have turned out more similar to the Roman Empire than the Persian Empire of our history books, but it would surely also have been quite distinct in myriad particulars. The notion that "A Great King, a lineal descendant of Darius, might still rule the world", likewise, seems about as plausible as the notion that because the Greeks won, a Roman Emperor still rules the world.

The Roman Empire with late Iron Age technology, was not sufficient robust to survive to the modern day, and neither would a Persian Empire.

Arguably, the therapeutic deism of the typical layman with little training in religious doctrine, who is nominally Christian, is actually closer, doctrinally, to Zoroastrianism than to Christianity or Judaism understood at the level of the doctrines that matter to educated elites.

It could be that 19th century businessmen might have ended up wearing turbans rather than bowler hats or beaver caps and silk neckties, if this had come to pass. But, anyone who thinks that fashion has much intrinsic value vastly overestimates the importance of function over form.

And, the suggestion that in world where the Persians rather than the Greeks prevailed that we would have women remaining at home or in harems, misapprehends the extent to which women's roles are functions of economics more than culture. 

King Solomon is a household name to every small town Christian and Jew in America, and he generally has a very high favorability rating. But, that doesn't mean that modern Americans maintain vast harems in order to follow his allegedly wise example. And, women remained at home to a much greater extent than they do today as recently as the 1950s and early 1960s Baby Boom in the United States.

IMPORTANT UPDATE (July 6, 2020):

One noteworthy aspect of Zoroastrianism is that, in contrast to other ancient religions (including Judaism, and later, Christianity), Zoroastrianism appears to have banned slavery on spiritual grounds. This is important to bear in mind in the context of discussing the Persian War, below. The Greeks thought of the war as the defense of their glorious traditions, including the political participation of citizens in the state, but it was the Greeks who controlled a society that was heavily dependent on slavery, whereas slavery was at least less prevalent in Persia than in Greece (despite the religious ban, slavery was clearly still present in the Persian Empire to some degree).

From here.

23andMe On My Y-DNA With Conjectures Regarding Indo-European Linguistics

Overview

I learned a bit about my Y-DNA from the 23andMe summary. But, I read their sources and researched more. This gave rise to some insights and conjectures.

* My Y-DNA haplogroup E-V13 spread across Europe as part of the Indo-European expansion in the Bronze Age, not as part of the Neolithic expansion of farmers from Anatolia (or at some other time).

* E-V13 is found at low frequencies everywhere that multiple distinct waves of Indo-European expansion reached. It is found in European Corded Ware derived populations where the expansion was dominated by Corded Ware haplogroups of Y-DNA R1a-M458. It is found in similar percentages in European Bell Beaker derived populations where the expansion was dominated by Bell Beaker haplogroups of Y-DNA R1b-L51. It is found at quite high percentages among the Greeks. It is found among Indo-European language speakers in the Caucuses. It is found in similar percentages in Indo-Iranian (like Iranians and the Kurds) peoples dominated by R1a-Z93 and R1b-Z2103. E-V13 has been found as far away as central Siberia, near the Altai, a region also known to have been settled by Bronze Age Indo-Europeans, which could have sources from either Indo-Iranians or Tocharians. But, it is not found among linguistically Indo-Aryan populations, even though these languages are often considered a sub-family of Indo-Iranian languages with otherwise similar Y-DNA profiles - a fact that can, in theory, shed light on the paternal ancestry diversity, and likely size within wide error bars, of the male founding population of Indo-Aryans in absolute terms and relative to the entire Indo-Iranian population.

* The two of the defining mutations of E-V13 date to ca. 3500 BCE and 2100 BCE (the date for TMRCA) and those mutations are shared by all living members of E-V13 in all of these places. The expansions that E-V13 was a part of probably took place from 2100 BCE to 1800 BCE. This means that E-V13 men must have assimilated into each of these expanding Indo-European populations (to an extent greater than other Indo-European populations did with each other), rather than just one of them. 

* E-V13 differentiated from E-M78 its parent haplogroup ,which was common in the pre-Neolithic and Neolithic Levant, no earlier than the beginning of the Holocene era (8000 BCE), and probably quite a bit later.

* The distribution of E-V13 in Anatolia and the vicinity, interpreted in light of the larger historical context, can help us evaluate and compare different proposals regarding the timing and character of the Anatolian language family's origins and its relationship to the larger Indo-European language family. E-V13 is found at much higher frequencies in Western Anatolia than in Central Anatolia. But, it is found among Kurds, in the Caucasus region, and in Iran. 

* Critically, if Anatolia has some form of Y-DNA R that is associated with Indo-European demic migration, but not E-V13, this suggests that Anatolian languages could have broken off pre-3500 BCE, could have been excluded due to founder effects in a manner similar to that of the Indo-Aryans, or could (especially if Y-DNA R is rare) signal that the Anatolian languages were a product of elite dominance with only slight demic impacts. 

* The analysis is complicated by the fact that we have limited information about the presence of Anatolian languages (or Indo-Europeans more generally based upon archaeology without written language evidence) in Anatolia prior to 1800 BCE. Also, after the Hittite Empire fell, Anatolia spend long periods of time in which it was ruled by Greeks (and to a lesser extent, some other Indo-Europeans), especially in Western Anatolia. Even modern Turkish history, like the Armenian genocide and the expulsion and killing of many Greek speaking Anatolians in the 20th century, complicate trying to make inferences about the prehistory and ancient history from the genetic character of modern Turkish people. Our knowledge of the history of the linguistically Armenian people, whose language doesn't fit neatly into categories for classifying Indo-Europeans languages, which adjacent to the historical area where Anatolian languages were spoken, is even more patchy. It is also complicated by the fact that many of the Turkic people who caused the country of Turkey to speak Turkish also have Indo-Iranian admixture.

The Y-DNA mix in Turkey as a whole is as follows:

• R1b=15.9%
• R1a=6.9%
• E-M35=10.7% (E-M78 and E-M123 accounted for all E representatives in the sample, except a single E-M81 individual). E-V13 is a sub-haplogroup of E-M78.
• G=10.9%
• J2=24% - J2 (M172)
• J1=9%
• I=5.3%
• K=4.5%
• L=4.2%
• N=3.8%
• T=2.5%
• Q=1.9%
• C=1.3%
• R2=0.96% 

Others markers than occurs in less than 1% are H, A, E3a , O , R1*.

The first Neolithic farmer populations of Anatolia (at least in Western Anatolia but probably more broadly) were dominated by Y-DNA G. Y-DNA R1b, R1a and E-M78 were almost surely all intrusive to Anatolia in the post-Neolithic era, and are associated with Indo-Europeans.

My Y-DNA

The ancestry narratives at 23 and Me evolve over time, in part due to new research and in part due to more effort on the company's part.  Generally speaking, the information provided by the company is accurate, albeit simplified. 

Their article also clarifies an issue I had pondered and had not clarified for myself in the literature, which is whether Y-DNA E-V13 spread from the Balkans to the rest of Europe with the first farmers (apparently, it mostly did not) or around the time of the demographic transition that took place around the time of the Indo-European expansion in the Eneolithic Age (i.e. Copper Age) and early to Middle Bronze Age (apparently, it mostly did), or at some later time such as the Iron Age (apparently, it mostly did not). 

This conclusion not too surprising given that my paternal ancestors as of the 1700s to 1847 were from central Germany (near the former West German and East German border and not too far to the North or South along that former border). 

This is an area which experienced in the Bronze Age significant, although not complete, population replacement from the original Linear Pottery Culture derived first farmers of most Anatolian origins who in turn largely replaced the European hunter-gathers that preceded them in the Mesolithic era as Europe was repopulated after the Last Glacial Maximum, while admixing somewhat with them. 

The defining Y-DNA haplogroups of those mass migration and replacement episodes that followed in this area through the Bronze Age were clades within Y-DNA R1a and Y-DNA R1b, but Y-DNA E-V13 was apparently a minor component of that mix that came along for the ride in that wave of migration.

Here is what mine says right now (in part, to provide a baseline and in part, out of general interest, my commentary is in italics and brackets):

Haplogroup A 275,000 Years Ago 

The stories of all of our paternal lines can be traced back over 275,000 years to just one man: the common ancestor of haplogroup A. Current evidence suggests he was one of thousands of men who lived in eastern Africa at the time. However, while his male-line descendants passed down their Y chromosomes generation after generation, the lineages from the other men died out. Over time his lineage alone gave rise to all other haplogroups that exist today.

[Ed. The narrative omits, for simplicity's sake, the emergence of Y-DNA haplogroup B from Y-DNA haplogroup A, and of Y-DNA haplogroup DE from Y-DNA haplogroup B, which gives rise to Y-DNA haplogroup DE (and also to Y-DNA haplogroup CF). It also dodges the issue of the precise location of the B to CF and DE split, and the DE split into Y-DNA haplogroup D, found mostly in the Andaman Islands, Tibet, North Asia, at low frequencies in South Asia, and Japan, and Y-DNA haplogroup E, found mostly in Africa with probably later migrations mostly to Europe via both Western and Eastern and central maritime migrations takes place, and the related controversy of the minority position that Y-DNA haplogroup E back migrated from the Middle East (or beyond) to Africa. 

The map used to illustrate the article suggests, without definitively saying so or being very specific, that the B to DE split took place in the vicinity of Ethiopia and that the DE to E split took place in the vicinity of South Sudan. The map also suggests that the first modern human man emerged in East Africa and that the A to B split also took place in that vicinity.] 

leads to [Ed. I use the words "leads to" in lieu of the line running from top to bottom in the margin of the original.] 

Haplogroup DE-M145 76,000 Years Ago 

leads to 

Haplogroup E-M96 73,000 Years Ago 

leads to 

Haplogroup E-M78 23,000 Years Ago.  

Origin and Migrations of Haplogroup E-M78 

Your paternal line stems from the common ancestor of haplogroup E-M78, a branch of E that dates back approximately 24,000 years. The earliest carriers of the E-M78 lineage likely lived in a population that moved from eastern Africa into northeastern Africa about 14,000 years ago, during the final days of the Ice Age. From northeastern Africa, their descendants expanded to the west between the Sahara and the Mediterranean coastline, and to the east out of Africa into the Middle East, where E-M78 men remain common. 

Today, men bearing this haplogroup are also common in southern Europe, including in the Balkans, Iberia, and Italy. In Greece, Bulgaria, and Albania, between 15% and 30% of men bear haplogroup E-M78. Their ancestors were likely relatively late arrivals to the region. While some branches of haplogroup E were carried into Europe nearly 8,000 years ago, recent research suggests that the major spread of E-M78 occurred in the last 5,000 years or so during the Bronze Age. Bronze Age cultures learned to smelt tin and copper to create beautiful and complex bronze items like hardier tools and weapons. They journeyed along river waterways in the Balkans and spread into east-central Europe. Today, men from Ukraine, Hungary, Romania, and Slovakia all carry E-M78 at levels of nearly 10%. 

While the majority of E-M78 European males trace their recent ancestry to Turkey and the Middle East, some men carrying E-M78 from Spain, Italy and Greece trace their ancestry directly from North African populations, probably within the last 4,000 years. The ancestors of these men must have sailed across the Mediterranean Sea and settled in communities along the European coast. 

leads to 

Haplogroup E-V13 11,000 Years Ago 

Your paternal haplogroup, E-V13, traces back to a man who lived approximately 11,000 years ago. 

[Ed. The 11,000 years ago date is shortly before the advent of the Holocene era which is usually considered to begin with the Fertile Crescent Neolithic Revolution about 10,000 years ago.] 

That's nearly 440.0 generations ago! E-V13 is relatively common among 23andMe customers. Today, you share your haplogroup with all the men who are paternal-line descendants of the common ancestor of E-V13, including other 23andMe customers. 1 in 43 23andMe customers share your haplogroup assignment. 

[Ed. The 23 and Me logo for E-V13 below, is a picture of a small castle on an island in a lake in Slovenia, which is in the Balkans within Southeast Europe.]

References

• Al-Zahery N et al. (2003). "Y-chromosome and mtDNA polymorphisms in Iraq, a crossroad of the early human dispersal and of post-Neolithic migrations." Mol Phylogenet Evol. 28(3):458-72.

• Alonso S et al. (2005). "The place of the Basques in the European Y-chromosome diversity landscape." Eur J Hum Genet. 13(12):1293-302.

• Arredi B et al. (2004). "A predominantly neolithic origin for Y-chromosomal DNA variation in North Africa." Am J Hum Genet. 75(2):338-45.

• Balanovsky O et al. (2008). "Two sources of the Russian patrilineal heritage in their Eurasian context." Am J Hum Genet. 82(1):236-50.

• Barać L et al. (2003). "Y chromosomal heritage of Croatian population and its island isolates." Eur J Hum Genet. 11(7):535-42.

• Beleza S et al. (2005). "The genetic legacy of western Bantu migrations." Hum Genet. 117(4):366-75.

• Bereir RE et al. (2007). "Co-introgression of Y-chromosome haplogroups and the sickle cell gene across Africa's Sahel." Eur J Hum Genet. 15(11):1183-5.

• Bosch E et al. (2001). "High-resolution analysis of human Y-chromosome variation shows a sharp discontinuity and limited gene flow between northwestern Africa and the Iberian Peninsula." Am J Hum Genet. 68(4):1019-29.

• Bowden GR et al. (2008). "Excavating past population structures by surname-based sampling: the genetic legacy of the Vikings in northwest England." Mol Biol Evol. 25(2):301-9.

• Capelli C et al. (2006). "Population structure in the Mediterranean basin: a Y chromosome perspective." Ann Hum Genet. 70(Pt 2):207-25.

• Cinnioğlu C et al. (2004). "Excavating Y-chromosome haplotype strata in Anatolia." Hum Genet. 114(2):127-48.

• Coia V et al. (2004). "Binary and microsatellite polymorphisms of the Y-chromosome in the Mbenzele pygmies from the Central African Republic." Am J Hum Biol. 16(1):57-67.

• Cruciani F et al. (2002). "A back migration from Asia to sub-Saharan Africa is supported by high-resolution analysis of human Y-chromosome haplotypes." Am J Hum Genet. 70(5):1197-214.

• Firasat S et al. (2007). "Y-chromosomal evidence for a limited Greek contribution to the Pathan population of Pakistan." Eur J Hum Genet. 15(1):121-6.

• Francalacci P et al. (2003). "Peopling of three Mediterranean islands (Corsica, Sardinia, and Sicily) inferred by Y-chromosome biallelic variability." Am J Phys Anthropol. 121(3):270-9.

• Hurles ME et al. (2005). "The dual origin of the Malagasy in Island Southeast Asia and East Africa: evidence from maternal and paternal lineages." Am J Hum Genet. 76(5):894-901.

• Karafet TM et al. (2002). "High levels of Y-chromosome differentiation among native Siberian populations and the genetic signature of a boreal hunter-gatherer way of life." Hum Biol. 74(6):761-89.

• Kayser M et al. (2005). "Significant genetic differentiation between Poland and Germany follows present-day political borders, as revealed by Y-chromosome analysis." Hum Genet. 117(5):428-43.

• Luis JR et al. (2004). "The Levant versus the Horn of Africa: evidence for bidirectional corridors of human migrations." Am J Hum Genet. 74(3):532-44.

• Marjanovic D et al. (2005). "The peopling of modern Bosnia-Herzegovina: Y-chromosome haplogroups in the three main ethnic groups." Ann Hum Genet. 69(Pt 6):757-63.

• Nasidze I et al. (2004). "Mitochondrial DNA and Y-chromosome variation in the caucasus." Ann Hum Genet. 68(Pt 3):205-21.

• Onofri V et al. (2007). "Y-chromosome genetic structure in sub-Apennine populations of Central Italy by SNP and STR analysis." Int J Legal Med. 121(3):234-7.

• Pericić M et al. (2005). "High-resolution phylogenetic analysis of southeastern Europe traces major episodes of paternal gene flow among Slavic populations." Mol Biol Evol. 22(10):1964-75.

• Qamar R et al. (2002). "Y-chromosomal DNA variation in Pakistan." Am J Hum Genet. 70(5):1107-24.

• Regueiro M et al. (2006). "Iran: tricontinental nexus for Y-chromosome driven migration." Hum Hered. 61(3):132-43.

• Rosa A et al. (2007). "Y-chromosomal diversity in the population of Guinea-Bissau: a multiethnic perspective." BMC Evol Biol. 7:124.

• Rosser ZH et al. (2000). "Y-chromosomal diversity in Europe is clinal and influenced primarily by geography, rather than by language." Am J Hum Genet. 67(6):1526-43.

• Semino O et al. (2002). "Ethiopians and Khoisan share the deepest clades of the human Y-chromosome phylogeny." Am J Hum Genet. 70(1):265-8.

• Sengupta S et al. (2006). "Polarity and temporality of high-resolution y-chromosome distributions in India identify both indigenous and exogenous expansions and reveal minor genetic influence of Central Asian pastoralists." Am J Hum Genet. 78(2):202-21.

• Shen P et al. (2004). "Reconstruction of patrilineages and matrilineages of Samaritans and other Israeli populations from Y-chromosome and mitochondrial DNA sequence variation." Hum Mutat. 24(3):248-60.

• Tambets K et al. (2004). "The western and eastern roots of the Saami--the story of genetic "outliers" told by mitochondrial DNA and Y chromosomes." Am J Hum Genet. 74(4):661-82.

• Tishkoff SA et al. (2007). "History of click-speaking populations of Africa inferred from mtDNA and Y chromosome genetic variation." Mol Biol Evol. 24(10):2180-95.

• Wells RS et al. (2001). "The Eurasian heartland: a continental perspective on Y-chromosome diversity." Proc Natl Acad Sci U S A. 98(18):10244-9.

• Wood ET et al. (2005). "Contrasting patterns of Y chromosome and mtDNA variation in Africa: evidence for sex-biased demographic processes." Eur J Hum Genet. 13(7):867-76.

Your haplogroup migrated in large numbers from the Balkans into Europe about 4,500 years ago, triggered by the beginning of the Balkan Bronze Age. During this migration, members of your haplogroup mainly followed rivers connecting the southern Balkans to northern-central Europe. Technological leaps often cause lineages to grow dramatically in numbers and in geographic range. The development of Bronze technology may have given men in your lineage a competitive advantage over other men, causing your lineage to proliferate and become widespread.

[Ed. This implies that my patrilineal ancestors were Southeastern European hunter-gathers in smallish semi-nomadic tribes and bands for about 2,000 to 3,000 years. But, Trobetta (2015) which it cites, favors a date that would start the E-V13 split at 8.1 kya which would be at the start of the Balkan Neolithic without a period as Southeastern European hunter-gathers that an 11 kya data would imply, which I am inclined to favor as a better motivated narrative. The key sentence of Trobetta (2015) states that: "The TMRCA of E-V13 chromosomes (8.1 ka; 95% CI: 5.6–10.8 ka) is consistent with a previous hypothesis about a post-Neolithic expansion of this haplogroup in Europe (Cruciani et al. 2004, 2007)." Then, they would have been Neolithic farmers or herders somewhere in the Balkans using the Fertile Crescent Neolithic package of crops, probably linked to the Cardial Pottery Neolithic wave or to earlier culture diffusion of food production technology from Anatolia and the Levant, while living in smallish villages for about 3,500 to 4,500 years. Then 4,500 years ago, they would have joined to Bronze Age wave of migration to the rest of Europe led by Indo-Europeans with ancestry derived from the Pontic-Caspian steppe. This is based mostly on Cruciani (2007) which, making inferences from 517 modern Y-DNA samples states in the abstract that: "A single clade within E-M78 (E-V13) highlights a range expansion in the Bronze Age of southeastern Europe, which is also detected by haplogroup J-M12. Phylogeography pattern of molecular radiation and coalescence estimates for both haplogroups are similar and reveal that the genetic landscape of this region is, to a large extent, the consequence of a recent population growth in situ rather than the result of a mere flow of western Asian migrants in the early Neolithic. Our results not only provide a refinement of previous evolutionary hypotheses but also well-defined time frames for past human movements both in northern/eastern Africa and western Eurasia." Eventually, they would have ended up in what is now central Germany sometime after that. The localization of my French-German ancestry in another part of the 23andMe ancestry report suggests that those ancestors may have started out in Switzerland or nearby in what is now Southern Germany and then made their way north to the point were our family's genealogy records begin in Central Germany, probably sometime in the last 800 years or so, with the more recent 300 years or so of that time frame being favored. For example, they might have been Swiss Protestants who migrated to Protestant Germany for economic opportunity or to flee some uncomfortable scandal in Switzerland. Poznik (2016) adds almost nothing to the analysis.]

References

• Cruciani F et al. (2007). "Tracing past human male movements in northern/eastern Africa and western Eurasia: new clues from Y-chromosomal haplogroups E-M78 and J-M12." Mol Biol Evol. 24(6):1300-11.

• Poznik GD et al. (2016). "Punctuated bursts in human male demography inferred from 1,244 worldwide Y-chromosome sequences." Nat Genet. 48(6):593-9.

• Trombetta B et al. (2015). "Phylogeographic Refinement and Large Scale Genotyping of Human Y Chromosome Haplogroup E Provide New Insights into the Dispersal of Early Pastoralists in the African Continent." Genome Biol Evol. 7(7):1940-50.

The 23 and Me materials and the references that they cite don't discuss ancient Y-DNA E-V13 but there are some examples of it.

A lengthy and well annotated analysis of Y-DNA E-V13 can be found at Eupedia (see below). The narrative portion of that entry which is better reasoned and better sourced suggests a somewhat different history of E-V13.

E-V13 And Indo-European Historical Linguistics

This narrative corroborated by ancient DNA in places, draws from the fact that E-V13 was present a minor subcomponent of at least, the Y-DNA gene pool of the Corded Ware, the Bell Beaker and the Indo-Iranian branches to Indo-European expansion, although apparently not the Indo-Aryan branch, divisions of the Indo-European expansion that each have their own dominant Y-DNA R haplogroups. 

Thus, the assimilation of E-V13 into the Indo-Europeans must have happened in or near the shared homeland of these three Indo-European cultures immediately prior to their respective and roughly contemporaneous expansions, in or near the Pontic Caspian steppe. Indeed E-V13 is good evidence of such a shared pre-expansion homeland. 

The time depth of that is well bracketed by the genetic time depth of E-V13 diversification, since "all the modern members of E-V13 . . . descend from a later common ancestor who carried the CTS5856 mutation. That ancestor would have lived about 4,100 years ago, during the Bronze Age. Almost immediately afterwards, CTS5856 split into six subclades, then branched off into even more subclades in the space of a few generations." So, you are looking at the phase of Indo-European expansion that included E-V13 taking place over a few centuries starting ca. 2100 BCE and mostly having run its course by ca. 1800 BCE.

The Eupedia states with regard to E-V13 that:

Origins & History

Assimilation of Neolithic European E-V13 by the Indo-Europeans 

For many years the vast majority of academics have assumed that E-V13 and other E1b1b lineages came to the Balkans from the southern Levant via Anatolia during the Neolithic, and that the high frequency of E-V13 was caused by a founder effect among the colonisers. This theory has it that E1b1b people were associated with the development of Neolithic lifestyle and the advent of agriculture in the Fertile Crescent and its earliest diffusion to Southeast Europe (Thessalian Neolithic) and Mediterranean Europe (Cardium Pottery culture). The testing of ancient DNA from the Natufian culture (Mesolithic Levant) and Pre-Pottery Neolithic Levant confirmed a high incidence of haplogroup E1b1b in that region. However, out of 69 Y-DNA samples tested from Neolithic Europe, only two belonged to that haplogroup: one E-M78 from the Sopot culture in Hungary (5000-4800 BCE), another E-M78 (c. 5000 BCE), possibly E-V13, from north-east Spain, and a E-L618 from Zemunica cave near Split in Croatia from 5500 BCE (Fernandes et al., 2016). Whether these E-M78 samples came with Neolithic farmers from the Near East or were already present among Mesolithic Europeans is unclear at present. But in any case E-V13 was definitely not the major Neolithic European lineage it was once alleged to be.

Nowadays E-V13 is the only Mediterranean haplogroup consistently found throughout Europe, even in Norway, Sweden, Finland and Baltic countries, which are conspicuous by the absence of other Neolithic haplogroups like G2a (bar the Indo-European G2a-Z1815), J1 and T (except in Estonia). However, since G2a is the only lineage that was consistently found in all Neolithic sites tested to date in Europe, the absence of Neolithic G2a lineages from Scandinavia and the Baltic implies that no Neolithic lineage survives there, and consequently E-V13 does not date from the Neolithic in the region.

In fact, it has been calculated that E-V13 emerged from E-M78 some 7,800 years ago, when Neolithic farmers were advancing into the Balkans and the Danubian basin. Furthermore, all the modern members of E-V13 descend from a common ancestor who lived approximately 5,500 years ago, and all of them also descend from a later common ancestor who carried the CTS5856 mutation. That ancestor would have lived about 4,100 years ago, during the Bronze Age. Almost immediately afterwards, CTS5856 split into six subclades, then branched off into even more subclades in the space of a few generations. In just a few centuries, that very minor E-V13 lineage had started an expansion process that would turn it into one of Europe's most widespread paternal lineages and reach far beyond the borders of Europe itself, also spreading to the eastern edge of the Mediterranean, the Caucasus, Kurdistan, Iran, and even Siberia.

This data suggests that the fate of E-V13 was linked to the elite dominance of Bronze Age society. The geographic distribution of the six main branches show that E-V13 quickly spread to all parts of Europe, but was especially common in Central Europe. The only Bronze Age migration that could account for such a fast and far-reaching dispersal is that of the Proto-Indo-Europeans. At present the most consistent explanation is that E-V13 developed from E-M78 in Central or Eastern Europe during the Neolithic period, and was assimilated by the R1a and R1b Proto-Indo-Europeans around the time that they were leaving the Pontic Steppe to invade the rest of Europe.

What is surprising with E-V13 is that it is as common in R1a-dominant as in R1b-dominant countries. R1a Indo-European tribes are associated with the Corded Ware culture, which spanned across Northeast Europe, Scandinavia and the northern half of Central Europe. R1b tribes invaded the Balkans, the southern half of Central Europe, and joined up with Corded Ware people in what is now Germany, the Czech Republic and western Poland. If E-V13 was found among both groups, it would have needed to be either assimilated in the Pontic Steppe or very near from it (say, in the Cucuteni-Trypillian culture, around western Ukraine, Moldova and Romania), or at the junction between the two groups in central Europe (e.g. around the Czech Republic). 

The distribution and age of E-V13 clades in central and western Europe are consistent with a dispersal by Hallstatt and La Tène Celts, Italic tribes (including a Roman redistribution) and the later influx of Germanic tribes, particularly the Goths, who may have assimilated additional Proto-Slavic E-V13 lineages in East Germany, Poland and Ukraine before entering the Roman Empire. (=> see also the discussions Was E-V13 a major lineage of Hallstatt Celts and Italics? and Ancient East, West and North Germanics had different Y-DNA lineages).

Amorim et al. (2018) tested the ancient DNA from 6th century Italy and Hungary and identified one E-V13 in Collegno (Turin) who was autosomally fully Italian (not a Lombard immigrant like many other samples tested).

The eastern advance of the Corded Ware culture eventually gave rise to the Sintashta culture in the Ural region, which is the ancestral culture of the Indo-Iranian branch of Indo-Europeans. E-V13's presence in this culture would explain why modern Iranians and Kurds possess E-V13, in addition to R1a-Z93 and R1b-Z2103. E-V13 has been found as far away as central Siberia, near the Altai, a region also known to have been settled by Bronze Age Indo-Europeans.

Due to the scarcity of full genomic sequences available from the Balkans, it is not yet clear when E-V13 expanded in that region. The Indo-European migrations would certainly have brought some E-V13 early on, from circa 2500 BCE. But the history of the region is so complex that there might be many separate branches of E-V13 that each came with a different invasion (e.g. Iranic tribes, La Tène Celts, Romans, Goths, Slavs). The first Indo-European migration to Greece was that of the Mycenaeans from c. 1650 BCE. The Dorians from Central Europe followed from c. 1200 BCE. Both could have brought different subclades of E-V13, and a founder effect or the phenomenon of elite dominance among the ruling invaders might have caused a fast growth of E-V13 lineage in Late Bronze Age and Iron Age Greece.

There are at least three distinct sources of E-V13 in Italy. The first would be the Bronze Age Italic tribes from Central Europe, who in all logic would have possessed at least some E-V13 lineages before they invaded the Italian peninsula. Proto-Italics would have been a predominantly R1b-U152 tribe, but also carried a minority of E-V13, G2a-L140 (L13, L1264 and Z1816 subclades) and J2a1-L70 (PF5456 and Z2177 subclades). The second would be the ancient Greeks, who heavily colonized southern Italy from the 9th century BCE until the Roman conquest in the 3rd century BCE. The third are the Goths. As a Germanic tribe they might have carried a small percentage of E-V13. But that percentage very certainly increased after spending several centuries in Central and Southeast Europe and assimilating Proto-Slavs and Balkanic people before invading Italy. The Goths settled over all the Italian peninsula. They would have brought typically Germanic lineages like I1 and R1b-U106, but also the Proto-Slavic R1a-CTS1211, which is now found uniformly in 1 to 2% of the population. Since R1a-CTS1211 is not originally Germanic, it is likely that the Goths also brought a small but noticeable percentage of assimilated lineages from the Balkans, including E-V13 and J2b1 (I2a1b-CTS10228 would have come later from the East Slavic migrations from Ukraine during the Early Middle Ages, hence its absence from Italy, apart from a few coastal areas facing the Adriatic Sea).

An Indo-European dispersal of V13 subclades would not only explain why E-V13 is present in places like Finland, northwest Russia or Siberia, where Neolithic farmers had a negligible impact, but also why E-V13 is so conspicuously lacking from the Basque country and (central) Sardinia, the two regions of Europe with the highest Neolithic ancestry. Sardinia is also the only part of Europe where Bronze Age Steppe ancestry is virtually absent. The low percentage of E-V13 is coastal Sardinia would be better explained by more recent settlements on the island by the Romans, or even the Goths, who also settled in Sardinia.

The small presence of E-V13 in the Near East could be better explained by the extremely long Greek presence in the eastern Mediterranean from the time of Alexander the Great until the end of the Byzantine domination over the region during the Middle Ages. It would be unthinkable that over 1,500 years of Hellenisation and Byzantine rule in Anatolia and the Levant didn't leave any genetic trace. In Anatolia, E-V13 is found mostly in the western third of the country, the region that used to belong to ancient Greece. The absence of E-V13 from Central Anatolia does not concord with a diffusion linked to Neolithic agriculture. There is clearly a radiation from the Greece (where E-V13 makes up approximately 30% of the paternal lineages) to the East Mediterranean (where the frequency drops to under 5%).

E-V13 and the Anatolian Languages.

The distribution of E-V13 also potentially provides some insight into the Anatolian language controversy, although it does not resolve it. This is because according to Eupedia as quoted at greater length above: 

In Anatolia, E-V13 is found mostly in the western third of the country, the region that used to belong to ancient Greece. The absence of E-V13 from Central Anatolia does not concord with a diffusion linked to Neolithic agriculture. 

While this doesn't correspond with Neolithic agriculture (for this and for other reasons), it could be linked to Indo-European Anatolian language speakers, in addition to the Greek that follows. 

Also, the claimed distribution of E-V13 also seems somewhat self-contradictory because the paper also states that Y-DNA E-V13 is found in "the Caucasus, Kurdistan, Iran," with Kurdistan including much of Southern Anatolia and the Northern Mesopotamian basin, that were previously part of the Hittite Empire or adjacent to it.

Kurdish populations are found, in particular, in parts of Anatolia that correspond geographically relatively closely with the range of the historical Luwian language in the Anatolian language family, and with a significant subsection of the Hittite empire, both of which are shown below (although there is some question regarding whether the modern Kurds may have been migrants to the places where they currently reside from someone else in the highlands of West Asia). So, while there might be a deficit of E-V13 in Central Anatolia, if the Kurds have E-V13 (who might be under sampled for political reasons), the case for attributing E-V13 in Anatolia almost entirely to the Greeks is greatly undermined.

Kurdish inhabited areas as of 1992 (from here).

The Anatolian branch of the Indo-European languages include the Hittite language, a group of Indo-Europeans who established a Bronze Age empire that controlled all of Anatolia and adjacent parts of modern Syria, Lebanon and Iraq, part of the Caucuses, and a small part of the far Northeast portion of modern Iran. 

The Hittite Empire at its greatest extent under Suppiluliuma I 

(c. 1350–1322 BC) and Mursili II (c. 1321–1295 BC)

The only other Anatolian languages attested prior to the waning days of the Hittite Empire immediately before or after Bronze Age collapse (when the Hittite Empire fell) were Luwian, spoken in mostly in Southeastern Anatolia, and Paliac spoken in North Central Anatolia.

Area where the 2nd millennium BC Luwian language was spoken.

After the Hittite Empire fell, many Anatolian languages are attested, all in Western Anatolia. These these may have had a relationship to the Hittite language similar to that of the Romance languages to Latin, and the Indo-Aryan languages to Sanskrit. But, they could also have been separate Anatolian languages from an earlier time period.

Anatolian languages attested in the mid-1st millennium BC.

On the other hand, if E-V13 really is found where there was Greek occupation, but is not found at meaningful percentages in places where Anatolian languages were spoken historically this could mean a number of things. At least, three scenarios could explain this:

* E-V13 was low enough in frequency that the same kind of Founder effects that kept it out of the Indo-Aryan founding population, even though it was in an Indo-Iranian founding population, could also have, by random chance, kept it out of the Anatolian founding population.

* The Anatolian languages were indeed, as many linguists assume (but I have argued against on mostly non-linguistic grounds), on the grounds that it is more distinct from other Indo-European languages linguistically, a branch that broke away from the Indo-European languages sooner than the Indo-European languages of Europe, West Asia and South Asia. Particularly if the Anatolian languages broke away prior to ca. 3500 BCE, the source population for E-V13 may not yet have arrived in the vicinity of the Pontic Caspian steppe to assimilate into the Indo-European community. 

There is some archaeological evidence that suggests that people who were culturally Egyptian and from the Levant, where the parent clade of haplogroup E-V13 (i.e. E-M78) was common made their way by boat to the Black Sea where they would have encountered populations ancestral to the Indo-Europeans (or the Proto-Indo-Europeans themselves) in about the right time frame. These people could have vanished by assimilating into the Proto-Indo-Europeans and could have been the source of Indo-European E-V13.

* The Indo-European people who were the source of the Anatolian languages may not have been very numerous and may have brought about language shift mostly through elite dominance (which may have been limited to members of those elites in the early stages) in a manner similar to the way that the Magyars brought language shift to Hungary. The Hattic culture that preceded the Hittite Empire was quite urban and advanced relative to that of many other areas conquered by the Indo-Europeans which were in a state of agricultural collapse and civilizational decay when the Indo-Europeans migrated into this power vacuum. In contrast, contemporaneous Akkadian and Hittite record establish that the expansion of the Hittite Empire was accomplished largely by forcefully seizing existing cities and communities of the Hattic culture, intact, and assimilating their citizens. It also also plausible, although not definitively clear, that there may have been long standing caste-like distinctions between conquered locals and the Hittites who had deeper foreign origins.

This scenario would also be consistent with a scenario in which Indo-European Hittite elites might have migrated en masse from other parts of their former empire to the Anatolian fringe neo-Hittite states of Western Anatolia where Anatolian languages were mostly spoken after the fall of the Hittite empire. This scenario is more plausible if the Anatolian languages were always the languages of a political and cultural elite that could migrate en masse more easily, than it is if language shift from the Hattic languages to the Anatolian languages was widespread even among illiterate peasants and city dwellers, regardless of their ancestry. There are historical examples of language shift following a conquest of a territory limited to elites and of language shift that penetrated more deeply into the general population.

The maps below help to disentangle other Y-DNA E-M35 haplogroups from E-V13 geographically. 

E-M81 has a Berber/Islamic empire conquest of Spain and colonial migration from Algeria to France profile.

The profile of E-M123 is harder to characterize succinctly.

And one more map for a context of the time of E-V13 expansion.