Wednesday, February 21, 2024

The Population Genetics Of India

A new preprint has no really shocking results, but provides many refinements to our previous understanding of historical genetics in India. Credit where credit is due for acknowledging the existing of early waves of modern humans in India even though they haven't left much of a genetic trace in modern populations. It also seems that there was secondary Neanderthal admixture in South Asia in addition to the admixture that took place in the Middle East.
India has been underrepresented in whole genome sequencing studies. We generated 2,762 high coverage genomes from India––including individuals from most geographic regions, speakers of all major languages, and tribal and caste groups––providing a comprehensive survey of genetic variation in India. With these data, we reconstruct the evolutionary history of India through space and time at fine scales. 
We show that most Indians derive ancestry from three ancestral groups related to ancient Iranian farmers, Eurasian Steppe pastoralists and South Asian hunter-gatherers. 
We uncover a common source of Iranian-related ancestry from early Neolithic cultures of Central Asia into the ancestors of Ancestral South Indians (ASI), Ancestral North Indians (ANI), Austro-asiatic-related and East Asian-related groups in India. 
Following these admixtures, India experienced a major demographic shift towards endogamy, resulting in extensive homozygosity and identity-by-descent sharing among individuals. 
At deep time scales, Indians derive around 1-2% of their ancestry from gene flow from archaic hominins, Neanderthals and Denisovans. By assembling the surviving fragments of archaic ancestry in modern Indians, we recover ∼1.5 Gb (or 50%) of the introgressing Neanderthal and ∼0.6 Gb (or 20%) of the introgressing Denisovan genomes, more than any other previous archaic ancestry study. Moreover, Indians have the largest variation in Neanderthal ancestry, as well as the highest amount of population-specific Neanderthal segments among worldwide groups. 
Finally, we demonstrate that most of the genetic variation in Indians stems from a single major migration out of Africa that occurred around 50,000 years ago, with minimal contribution from earlier migration waves
Together, these analyses provide a detailed view of the population history of India and underscore the value of expanding genomic surveys to diverse groups outside Europe.
Elise Kerdoncuff, et al., "50,000 years of Evolutionary History of India: Insights from ∼2,700 Whole Genome Sequences"  (February 17, 2024). https://www.biorxiv.org/content/10.1101/2024.02.15.580575v1

Aztec Human Sacrifice

"For the re-consecration of the Great Pyramid of Tenochtitlan in 1487, the Aztecs reported that they killed about 80,400 prisoners over the course of four days. According to Ross Hassig, author of Aztec Warfare, "between 10,000 and 80,400 persons" were sacrificed in the ceremony."
From Wikipedia.

Recall that this city had a population of 200,000 non-prisoner residents, which while huge for the time, is only about three times greater than the number of people sacrificed.

Monday, February 19, 2024

The XENONnT Dark Matter Experiment

The XENONnT dark matter experiment will have about ten times more sensitivity to WIMPS (a type of dark matter candidate) than the previous XENON1T. 

I fully expect that it will produce a null result without detecting any traces of dark matter that don't turn out to be false positives in the end.

The Black Hole - Galaxy Mass Correlation

The mass of the central supermassive black hole of a galaxy and the inferred mass of its dark matter halo (and the total mass of a galaxy) are correlated, although not terribly tightly. 

Some of the scatter in the relationship may be due to measurement error as central supermassive black hole mass, inferred dark matter halo mass, and galaxy total mass are all challenging to measure.

Orichalcum

Archaeologists have finally found examples of and deciphered a Bronze Age alloy associated with the lost city of Atlantis called "Orichalcum."

This insight, in my view, this is quite consistent with my leading candidate for Atlantis which is the capital city of Tartessos. Their Paleo-Hispanic language is by default an isolate but seems closer to Basque than to any Indo-European language, despite some Celtic borrowings and the use of a Phoenician derived script and their culture's adoption of Phoenician religious practices.

A group of naval archeologists has uncovered two hundred ingots spread over the sandy seafloor near a 2,600-year-old shipwreck off the coast of Sicily. The ingots were made from orichalcum, a rare cast metal that ancient Greek philosopher Plato wrote was from the legendary city of Atlantis.

A total of 39 ingots (metal set into rectangular blocks) were, according to Inquisitr, discovered near a shipwreck. BBC reported that another same metal cache was found. 47 more ingots were found, with a total of 86 metal pieces found to date.

The wreck was discovered in 1988, floating about 300 meters (1,000 ft) off the coast of Gela in Sicily in shallow waters. At the time of the shipwreck Gela was a rich city and had many factories that produced fine objects. Scientists believe that the pieces of orichalcum were destined for those laboratories when the ship sank.

Sebastiano Tusa, Sicily’s superintendent of the Sea Office, told Discovery News that the precious ingots were probably being brought to Sicily from Greece or Asia Minor.

Tusa said that the discovery of orichalcum ingots, long considered a mysterious metal, is significant as “nothing similar has ever been found.” He added, “We knew orichalcum from ancient texts and a few ornamental objects.”

According to a Daily Telegraph report, the ingots have been analyzed and found to be made of about 75-80 percent copper, 14-20 percent zinc and a scattering of nickel, lead, and iron.

The name orichalucum derives from the Greek word oreikhalkos, meaning literally “mountain copper” or “copper mountain”. According to Plato’s 5th century BC Critias dialogue, orichalucum was considered second only to gold in value, and was found and mined in many parts of the legendary Atlantis in ancient times.

Plato wrote that the three outer walls of the Temple to Poseidon and Cleito on Atlantis were clad respectively with brass, tin, and the third, which encompassed the whole citadel, “flashed with the red light of orichalcum”.

The interior walls, pillars, and floors of the temple were completely covered in orichalcum, and the roof was variegated with gold, silver, and orichalcum. In the center of the temple stood a pillar of orichalcum, on which the laws of Poseidon and records of the first son princes of Poseidon were inscribed.

For centuries, experts have hotly debated the metal’s composition and origin.

According to the ancient Greeks, orichalcum was invented by Cadmus, a Greek-Phoenician mythological character. Cadmus was the founder and first king of Thebes, the acropolis of which was originally named Cadmeia in his honor.

Orichalcum has variously been held to be a gold-copper alloy, a copper-tin, or copper-zinc brass, or a metal no longer known. However, in Vergil’s Aeneid, it was mentioned that the breastplate of Turnus was “stiff with gold and white orachalc” and it has been theorized that it is an alloy of gold and silver, though it is not known for certain what orichalcum was.

Orichalcum is also mentioned in the ‘Antiquities of the Jews’ (1 st century AD) – Book VIII, sect. 88 by Josephus, who stated that the vessels in the Temple of Solomon were made of orichalcum (or a bronze that was like gold in beauty).

Today, some scholars suggest that orichalcum is a brass-like alloy, which was made in antiquity the process of cementation, which was achieved through the reaction of zinc ore, charcoal and copper metal in a crucible.

The latest discovery of the orichalcum ingots that had laid for nearly three millennia on the seafloor may finally unravel the mystery of the origin and composition of this enigmatic metal.

From Archaeology World