Friday, November 4, 2011

How Many Homo Erectus In Asia?

The best estimates of peak Neanderthal population are about 70,000 (census population, not effective population). This translates into roughly one Neanderthal for the entire duration of the species for each modern human alive in their former range today.

Homo erectus was undoubtedly less impressive than Neanderthals in almost every way. They had less advanced tools, particularly in Asia (although some speculate that the lack of stone tool evidence could be due to the development of bamboo tools that weren't preserved). They were smaller. They had less language ability. It isn't obvious that they were apex predators.

Given that more advanced modern humans appear to have had much higher population densities than Neanderthals, even at the hunter-gatherer stage. One recent estimate comparing Neanderthal and modern human strata at the same location in immediate succession put the modern human population density to the Neanderthal population density ratio at 9:1 or 10:1. Given all of this, it isn't unreasonable to guess tht Homo Erectus might have had lower population densities even than Neanderthals. The ratio might be a factor of two, or less, and probably wouldn't be more than the factor of 10:1 of modern humans to Neanderthals.

The size of the geographic range of Homo Erectus in Asia (and by Asia in this context I mean to the east of India) was on the same order of magnitude as the size of the geographic range of the Neanderthals.

So, the census population size of Homo Erectus may have been on the order of 7,000 to 35,000 over this rather vast territory, at any one time, broken up into perhaps 700 to 3,500 separate small bands, no larger than the modern human or Neanderthal bands, and quite possibly a bit smaller as weaker communication skills may have limited their group size.

Now, Homo Erectus was probably in this part of Asia about ten times as long as Neanderthals. But, from a genetics perspective, this may have caused them to be mutationally limited. The number of new mutations in the total population is a function of the number of births that take place. Smaller populations produce fewer mutations. Larger populations produce more mutations. There is no good reason to think that the number of selectively beneficial mutations isn't relatively fixed relative to the total number of mutations. So, Homo Erectus may have had a similar number of selectively beneficial mutations over their 2,000,000 years in Southeast and East Asia and the vicinity as the Neanderthals did in their 200,000 years or so in Europe and the vicinity.

Moreover, one might actually expect that balance to favor the Neanderthals. The likelihood that a new selectively beneficial mutation that has not reached fixation will be lost in a population slump is greater when the population is smaller than it is when the population is larger. And, the likelihood of new mutations having benefits for the Neanderthals, who were living in an environment quite different from that where hominins evolved in Africa, may have been greater than for Asian Homo Erectus who were living in an environment closer to the one that their African ancestors were already optimized to live in through millions of years of selection. The better a fit one is to one's environment, the less likely it is the a new mutation will provide selective benefit relative to the non-derived part of the genome.

Thus, we might expect that Homo Erectus in 2,000,000 years in Asia, with a lower population density in an environment closer to the one that they were adapted to in Africa might actually have evolved less than Neanderthals did in Europe in 200,000 years with a higher population and an environment quite different from their ancestors.

Now, none of this is definitive. It is a toy model of evolution. Perhaps Asia was a more welcoming environment than Europe and could support a larger population as a result. Perhaps smaller individuals allowed for greater population numbers. Perhaps at the biochemical and immune system level that most of the genome is devoted to (more of our genome goes towards providing instructions to building various subparts of our bodies like proteins and tissues than to the large scale morophology of our bodies), Africa and Asia aren't so similar.

But, the notion that hominin evolution may have been slower for archaic hominins because their small populations caused them to be mutationally limited, i.e. not able to give rise to many beneficial mutations to allow those mutations to be selected positively for, could be important to making sense of the pace of evolution.

Also, if one relies on the rule of thumb that it takes 75-100 individuals to support a sustainable population of a species without intentional outside intervention, and consider that the total population of Neanderthals or Homo Erectus at far less than their peak populations when modern humans come on the scene, it becomes easier to see how modern humans could fragment these archaic hominin populations to below a tipping point and wipe them out without embarking on a full scale, Nazi-like deliberate campaign of continent-wide genocide.

15 comments:

Maju said...

East Asia, the range of H. erectus, is as large as the rest of Eurasia... or as Africa. I see no disadvantage in this aspect for H. erectus.

What I do see is that all colonizing populations, including ours (non-African modern humans), experienced bottlenecks of some sort (founder effect) and that largely limits the available diversity, potentially providing genes for the future.

Also some strategical developments happened in some populations and not others. H. erectus (unlike Neanderthals to some extent) could never compete with us (nor with Neanderthals surely either): their brains, even if highly developed in relation to chimpanzees or australopithecines, were just too small in comparison.

mike gibbs said...

I think H. Erectus who controlled his environment for 2 MILLION YEARS may have been smarter than you give credit for. Brain size as a measure of smarts is questionable. Nueral connections might be the driving force behind innovation and "the human spark"

Maju said...

Latest thing is that primates have much smaller neurons than other mammals, so we can pack more brainpower into less size, but let's not overdo it. Also guess who has even smaller neurons (although also smaller brains)? Birds! Birds and presumably dinosaurs have even smaller neurons than any mammal, so their brains are extremely compact ("dense" but in an oddly good sense of "dense").

mike gibbs said...

had read about birds but haven't really studied . Mr. Maju you are an interesting fellow. Thanyou for your post

also thanks for response to my original question ....how many Homo erectus. I asked that because my real interest is in the peopling of the Americas ....by who, when, how, where ? I follow two anthropologists(or I did) who claimed Homo erectus in the americas IN Brazil to be specific .. Maria Beltrauo and Neida codon iVwe wondered to myself if that could be possible and if so then probable. ? I found evidence of the possibility in a download from the US Park Service describing the Bering land bridge opening to 4 and 2 legged animals and guessed it not too far a reach for H Erectus to have entered the americas during ice age times when water levels opened the bridge.

Have you ever heard this?

mike gibbs said...

also thanks for response to my original question ....how many Homo erectus. I asked that because my real interest is in the peopling of the Americas ....by who, when, how, where ? I follow two anthropologists(or I did) who claimed Homo erectus in the americas IN Brazil to be specific .. Maria Beltrauo and Neida codon iVwe wondered to myself if that could be possible and if so then probable. ? I found evidence of the possibility in a download from the US Park Service describing the Bering land bridge opening to 4 and 2 legged animals and guessed it not too far a reach for H Erectus to have entered the americas during ice age times when water levels opened the bridge.

Have you ever heard this?
my email is KLGLPG@gmail.com

Maju said...

As far as we can tell, no archaic Homo ever arrived to America. I know that there is one speculation based on some "foot imprints" but, as, they say, exceptional claims require exceptional evidence and it is extremely strange that not a single tool or bone has been found ever in the Americas before c. 17,000 years ago, when Homo sapiens did overcome the Beringian barrier, either overland or more likely via coastal navigation, and settled the double continent (probably c. 15,000 for arrival to South America). IF evidence would pile up then we would have a completely different scenario but so far there's really no evidence whatsoever excepted those alleged footprints that could really be anything. While other Homo species did show surprising ability to adapt to hostile conditions (Siberia) and even in some cases to do some lesser navigation (Flores, Luzon), reaching North America apparently required a combination of both adaptations that only our speceies was able to achieve, very possibly thanks to a rather humble and often overlooked invention: the sewing needle, which allowed for multilayer clothing, sorta the "astronaut suit" of the Stone Age. This invention is first documented some 40-50,000 years ago (early Upper Paleolithic).

mike gibbs said...

interesting on sewing needle didn't know that. Again thanks....Im learning things . I read about a ancient fish hook in Okinawa involved a hole in a seashell ( drilled or nature made I don't know) photos of the footprints in Mexico look like footprints to me. I get the point that tools or related fossils were not found ...But, those footprints were made as people were moving and probably very quickly to escape the volcanic eruption. I would think a small group would abandon lots of un needed items

other evidence? What about Cerrutti (San Diego ) mastodon?
Monte Verde
Calico Early man site ( Luis LEAKY is supposed to have reviewed the tools there and said they were exactly what he found in Africa
Meadow croft

By the way Luzonensis might have walked to where they were found. The China sea was a dry bed or shallow bed during the Ice age.

I hope Im not pestering you but for an amateur like me Its hard to find someone willing to explain things

One more question. It appears to me that elongated craniums existed at some point before modern humans . can you elaborate on that?

mike gibbs said...

Mexico foot prints and Cerrutti (San diego) mastodon both published by Nature magazine . I assumed that meant Peer Review and general acceptance of findings. True? or not?

Other sites
Meadowcroft, Monte Verde, Calico (Barstoe Calif)

by the way Luzonensis may have walked to Luzon caves. The china Sea dried up or was very low level in Ice age.

mike gibbs said...

other evidence? What about Cerrutti (San Diego ) mastodon?
Monte Verde
Calico Early man site ( Luis LEAKY is supposed to have reviewed the tools there and said they were exactly what he found in Africa
Meadow croft

By the way Luzonensis might have walked to where they were found. The China sea was a dry bed or shallow bed during the Ice age.

I hope Im not pestering you but for an amateur like me Its hard to find someone willing to explain things

One more question. It appears to me that elongated craniums existed at some point before modern humans . can you elaborate on that?

Maju said...

Monte Verde is within the c. 17,000 BCE arrival to North America frame even with recalibration. It could push a bit towards the past the arrival of HOMO SAPIENS to America, and particularly to South America, but it's still within the paradigm.

The Philippines were separated from the mainland, South China Sea was a sea and the stratts that separate Philippines from Borneo (then part of the peninsula called Sundaland) still existed, similarly the straits separating the Lesser Sunda islands from Bali and Java (then also part of Sundaland) also existed. Archaic homo must have boated somewhat in order to reach both Luzon and Flores. Similarly Neanderthals must have boated in order to reach some Greek islands and suely our kin (Homo sapiens) must have boated across the Bab el-Mandeb in order to reach Southern Arabia without leaving a trail all the way by land (that doesn't mean they also probably walked to Palestine but different branch almost certainly), our people also must have boated in order to reach Australasia. Boating or rafting is a very ancient human activity even if it was surely limited most of the time to coastal and riverine navigation before the Neolithic (but clearly not always).

Australian legends suggest that people reached the continent following the great saltwater crocodile, and I believe that very plausible: those hunter-gatherers knew their environment and must have realized that crocs were not just heading to the open sea. However there's another way of knowing: climbing mountains and searching the horizon in clear days, the distances in that chain are not remote enough to hide the nearby islands and continent, although step by step, of course.

Calico site has two "evidences": an alleged "rock ring" (probably a natural formation, extremely anomalous artifact among actual human remains) and a clear stone axe or biface, which is dated to c. 14,700 BP (again within the current paradigm). I have great respect for Louis Leakey but I must disagree with his opinion in this case.

You can cling to the Cerrutti site (which I was unaware of) and the alleged footprints but unless there is much more evidence, I will remain skeptic. We know that archaic humans (both Denisovans and Neanderthals) managed somehow to survive in very cold latitudes (Komi, Altai) but this is a bit too far fetched without at least some more clear remains.

mike gibbs said...

Once again Mr Maju I thank you for your measured assessment . I have been clinging to reports that would have "changed everything" which is typical of me to take the side of the underdog.

Thanks again you have a new convert. Although I wouldn't be surprised to see the paradigm change. History of homo is it seems always going further and further back in time from when I started with Lucy and now somebody I think they call ardi pithicus?

I am surprised at your knowledge of Ice Age sea levels . I thought I might be the only person in the world who linked the two disciplines . foolish of me. I had read that the North Sea, the english channel, were dry beds.

what do you know about the elongated craniums and when that change occurred

mike gibbs said...

Once again Mr Maju I thank you for your measured assessment . I have been clinging to reports that would have "changed everything" which is typical of me to take the side of the underdog.

Thanks again you have a new convert. Although I wouldn't be surprised to see the paradigm change. History of homo is it seems always going further and further back in time from when I started with Lucy and now somebody I think they call ardi pithicus?

I am surprised at your knowledge of Ice Age sea levels . I thought I might be the only person in the world who linked the two disciplines . foolish of me. I had read that the North Sea, the english channel, were dry beds.

what do you know about the elongated craniums and when that change occurred

May 21, 2020 at 8:00 AM Delete

mike gibbs said...

Once again Mr Maju I thank you for your measured assessment . I have been clinging to reports that would have "changed everything" which is typical of me to take the side of the underdog.

Thanks again you have a new convert. Although I wouldn't be surprised to see the paradigm change. History of homo is it seems always going further and further back in time from when I started with Lucy and now somebody I think they call ardi pithicus?

I am surprised at your knowledge of Ice Age sea levels . I thought I might be the only person in the world who linked the two disciplines . foolish of me. I had read that the North Sea, the english channel, were dry beds.

what do you know about the elongated craniums and when that change occurred

Maju said...

What "elongated craniums"? https://forwhattheywereweare.blogspot.com/2013/01/frontal-bulge-almost-exclusive.html (it is foreheads, not "elongated craniums" what makes us "sapiens", also related: chins).

Also you should not be surprised: it's all over the place, and by "the place" I mean the Internet, just go to Wikipedia's article on Sundaland and you know what I know about sea levels, at least the basics (I've seen many other references of course but that article and map should suffice).

Underdog is fine... if there are good arguments. But should not be a systematic choice, it should be a critical choice based on evidence.

mike gibbs said...

RE: Chinese reports of Archaic human remains from Hualongdong, China, and Middle Pleistocene human continuity and variation

apparently homo erectus was in east asia 125,000 years ago and at 300,000 years ago. if that's true then H. erectus could have walked into the Americas explaining ALOT Maybe Maria Beltraou was right.
I have read more than one article on how young anthropologists were encouraged not to report findings not consistent with the 15,000 year old paradigm. If that is correct then I think American anthropologists have forsaken science for what? a focus on funding? lifestyle maintenance? Im skeptical of those that constantly refute evidence

it has always made good sense to me that homo would have followed prey along with other predators into the americas.