New papers on human evolution

[dilettante layman]

Computer simulation of scavenging by hominins and giant hyenas in the late Early Pleistocene

Abstract
Consumption of animal-sourced food is an important factor in broadening the diet of early hominins, promoting brain and body growth, and increasing behavioural complexity. However, whether early hominins obtained animal food by scavenging or hunting large mammals remains debated. Sabre-toothed felids have been proposed to facilitate the expansion of early Homo out of Africa into Europe 1.4–0.8 Ma by creating a niche for scavengers in Eurasia as the carcasses abandoned by these felids still contained abundant edible resources. In contrast, it has been argued that the niche for a large scavenger was already occupied in Eurasia by the giant hyena, preventing hominins from utilising this resource. This study shows that sabre-toothed felids generated carcasses rich in edible resources and that hominins were capable of competing with giant hyenas for this resource. The simulation experiments showed that maintaining an optimum group size is essential for the success of the hominin scavenging strategy. Early hominins could outcompete giant hyenas only if they could successfully dispute carcasses with them. Thus, in the presence of a strong competitor, passive scavenging is essentially the same as confrontational scavenging.

https://www.nature.com/articles/s41598-023-39776-1

[VladMC]

Parallel signatures of Mycobacterium tuberculosis and human Y-chromosome phylogeography support the Two Layer model of East Asian population history

Abstract
The Two Layer hypothesis is fast becoming the favoured narrative describing East Asian population history. Under this model, hunter-gatherer groups who initially peopled East Asia via a route south of the Himalayas were assimilated by agriculturalist migrants who arrived via a northern route across Eurasia. A lack of ancient samples from tropical East Asia limits the resolution of this model. We consider insight afforded by patterns of variation within the human pathogen Mycobacterium tuberculosis (Mtb) by analysing its phylogeographic signatures jointly with the human Y-chromosome. We demonstrate the Y-chromosome lineages enriched in the traditionally hunter-gatherer groups associated with East Asia’s first layer of peopling to display deep roots, low long-term effective population size, and diversity patterns consistent with a southern entry route. These characteristics mirror those of the evolutionarily ancient Mtb lineage 1. The remaining East Asian Y-chromosome lineage is almost entirely absent from traditionally hunter-gatherer groups and displays spatial and temporal characteristics which are incompatible with a southern entry route, and which link it to the development of agriculture in modern-day China. These characteristics mirror those of the evolutionarily modern Mtb lineage 2. This model paves the way for novel host-pathogen coevolutionary research hypotheses in East Asia.
https://www.nature.com/articles/s42003-0...88-8#Sec17

[dilettante layman]

First direct evidence of lion hunting and the early use of a lion pelt by Neanderthals

Abstract
During the Upper Paleolithic, lions become an important theme in Paleolithic art and are more frequent in anthropogenic faunal assemblages. However, the relationship between hominins and lions in earlier periods is poorly known and primarily interpreted as interspecies competition. Here we present new evidence for Neanderthal-cave lion interactions during the Middle Paleolithic. We report new evidence of hunting lesions on the 48,000 old cave lion skeleton found at Siegsdorf (Germany) that attest to the earliest direct instance of a large predator kill in human history. A comparative analysis of a partial puncture to a rib suggests that the fatal stab was delivered with a wooden thrusting spear. We also present the discovery of distal lion phalanges at least 190,000 old from Einhornhöhle (Germany), representing the earliest example of the use of cave lion skin by Neanderthals in Central Europe. Our study provides novel evidence on a new dimension of Neanderthal behavioral complexity.


https://www.nature.com/articles/s41598-023-42764-0

[Ebizur]

Parallel signatures of Mycobacterium tuberculosis and human Y-chromosome phylogeography support the Two Layer model of East Asian population history

Abstract
The Two Layer hypothesis is fast becoming the favoured narrative describing East Asian population history. Under this model, hunter-gatherer groups who initially peopled East Asia via a route south of the Himalayas were assimilated by agriculturalist migrants who arrived via a northern route across Eurasia. A lack of ancient samples from tropical East Asia limits the resolution of this model. We consider insight afforded by patterns of variation within the human pathogen Mycobacterium tuberculosis (Mtb) by analysing its phylogeographic signatures jointly with the human Y-chromosome. We demonstrate the Y-chromosome lineages enriched in the traditionally hunter-gatherer groups associated with East Asia’s first layer of peopling to display deep roots, low long-term effective population size, and diversity patterns consistent with a southern entry route. These characteristics mirror those of the evolutionarily ancient Mtb lineage 1. The remaining East Asian Y-chromosome lineage is almost entirely absent from traditionally hunter-gatherer groups and displays spatial and temporal characteristics which are incompatible with a southern entry route, and which link it to the development of agriculture in modern-day China. These characteristics mirror those of the evolutionarily modern Mtb lineage 2. This model paves the way for novel host-pathogen coevolutionary research hypotheses in East Asia.
https://www.nature.com/articles/s42003-0...88-8#Sec17

The MRCA of K2-M526 is estimated to have lived approximately 48948 (95% CI 36027 <-> 53266) ybp (Karmin et al. 2022).

The MRCA of K2a-M2308 is estimated to have lived approximately 48040 (95% CI 34839 <-> 52277) ybp (Karmin et al. 2022).

The MRCA of NO-M214 is estimated to have lived approximately 41750 (95% CI 30597 <-> 46041) ybp (Karmin et al. 2022).

The MRCA of K2b1-PR2099/Y25867 is estimated to have lived approximately 48215 (95% CI 34802 <-> 52382) ybp (Karmin et al. 2022).

48948 - 41750 = 7198, so there should be only approximately 7,200 years between the MRCA of K2-M526 (i.e. the most recent common ancestor of K2a-M2308 plus K2b-M1221) and the MRCA of NO-M214 (i.e. the most recent common ancestor of N-M231 plus O-M175).

7,200 years is plenty of time for K2a-M2308 to have migrated to East Asia (where it hypothetically would have produced N-M231 and O-M175) via North Asia and K2b1-PR2099/Y25867 to have migrated to Sundaland and/or Sahul (where it hypothetically would have produced M-P256 and S-B254) via South Asia, so the authors' hypothesis is not implausible, but is it really significant (even if one assumes it to be correct; in reality, basal branches of K2a(xNO) and O2-M122(xF36) have been found in the south rather than in the north)?

There are also the very important but difficult questions of where C2-M217 (formed 50729 [95% CI 47095 <-> 54293] ybp, TMRCA 34548 [95% CI 31158 <-> 38199] ybp according to Karmin et al. 2022) and P-P295 (formed 49037 [95% CI 46341 <-> 51678] ybp, TMRCA 48627 [95% CI 45956 <-> 51322] ybp according to Karmin et al. 2022) have originated and how they have spread.

[dilettante layman]

Early Homo erectus lived at high altitudes and produced both Oldowan and Acheulean tools

Abstract
 Africa, the scarcity of hominin remains found in direct association with stone tools has hindered attempts to link Homo habilis and Homo erectus with particular lithic industries. The infant mandible discovered in level E at Garba IV (Melka Kunture) on the highlands of Ethiopia is critical to this issue due to its direct association with an Oldowan lithic industry. Here, we use synchrotron imaging to examine the internal morphology of the unerupted permanent dentition and confirm its identification as Homo erectus. Additionally, we utilize new palaeomagnetic ages to show that (i) the mandible in level E is ca. 2 million-years-old, and represents one of the earliest Homo erectus fossils, and (ii) that overlying level D, ca. 1.95 million-years-old, contains the earliest known Acheulean assemblage.

[/url][url=https://www.science.org/doi/10.1126/science.add9115]https://www.science.org/doi/10.1126/science.add9115

https://www.smithsonianmag.com/science-n...180983073/

[dilettante layman]

Chimpanzees make tactical use of high elevation in territorial contexts

Abstract
Tactical warfare is considered a driver of the evolution of human cognition. One such tactic, considered unique to humans, is collective use of high elevation in territorial conflicts. This enables early detection of rivals and low-risk maneuvers, based on information gathered. Whether other animals use such tactics is unknown. With a unique dataset of 3 years of simultaneous behavioral and ranging data on 2 neighboring groups of western chimpanzees, from the Taï National Park, Côte d’Ivoire, we tested whether chimpanzees make decisions consistent with tactical use of topography to gain an advantage over rivals. We show that chimpanzees are more likely to use high hills when traveling to, rather than away from, the border where conflict typically takes place. Once on border hills, chimpanzees favor activities that facilitate information gathering about rivals. Upon leaving hills, movement decisions conformed with lowest risk engagement, indicating that higher elevation facilitates the detection of rivals presence or absence. Our results support the idea that elevation use facilitated rival information gathering and appropriate tactical maneuvers. Landscape use during territorial maneuvers in natural contexts suggests chimpanzees seek otherwise inaccessible information to adjust their behavior and points to the use of sophisticated cognitive abilities, commensurate with selection for cognition in species where individuals gain benefits from coordinated territorial defense. We advocate territorial contexts as a key paradigm for unpicking complex animal cognition.

https://journals.plos.org/plosbiology/ar...io.3002350

[Piquerobi]

East-to-west human dispersal into Europe 1.4 million years ago
Published: 06 March 2024

“Stone tools stratified in alluvium and loess at Korolevo, western Ukraine, have been studied by several research groups since the discovery of the site in the 1970s. Although Korolevo’s importance to the European Palaeolithic is widely acknowledged, age constraints on the lowermost lithic artefacts have yet to be determined conclusively. Here, using two methods of burial dating with cosmogenic nuclides, we report ages of 1.42 ± 0.10 million years and 1.42 ± 0.28 million years for the sedimentary unit that contains Mode-1-type lithic artefacts. Korolevo represents, to our knowledge, the earliest securely dated hominin presence in Europe, and bridges the spatial and temporal gap between the Caucasus (around 1.85–1.78 million years ago) and southwestern Europe (around 1.2–1.1 million years ago). Our findings advance the hypothesis that Europe was colonized from the east, and our analysis of habitat suitability suggests that early hominins exploited warm interglacial periods to disperse into higher latitudes and relatively continental sites—such as Korolevo—well before the Middle Pleistocene Transition”.
https://www.nature.com/articles/s41586-024-07151-3

[VladMC]

Evolutionary Trends of Polygenic Scores in European Populations From the Paleolithic to Modern Times

Published online by Cambridge University Press: 06 March 2024

Abstract

This study examines the temporal and geographical evolution of polygenic scores (PGSs) across cognitive measures (Educational Attainment [EA], Intelligence Quotient [IQ]), Socioeconomic Status (SES), and psychiatric conditions (Autism Spectrum Disorder [ASD], schizophrenia [SCZ]) in various populations. Our findings indicate positive directional selection for EA, IQ, and SES traits over the past 12,000 years. Schizophrenia and autism, while similar, showed different temporal patterns, aligning with theories suggesting they are psychological opposites. We observed a decline in PGS for neuroticism and depression, likely due to their genetic correlations and pleiotropic effects on intelligence. Significant PGS shifts from the Upper Paleolithic to the Neolithic periods suggest lifestyle and cognitive demand changes, particularly during the Neolithic Revolution. The study supports a mild hypothesis of Gregory Clark’s model, showing a noticeable rise in genetic propensities for intelligence, academic achievement and professional status across Europe from the Middle Ages to the present. While latitude strongly influenced height, its impact on schizophrenia and autism was smaller and varied. Contrary to the cold winters theory, the study found no significant correlation between latitude and intelligence.

https://www.cambridge.org/core/journals/...8E37D9273D

[AimSmall]

This is intriguing...

"Moreover, Indians have the largest variation in Neanderthal ancestry, as well as the highest amount of population-specific Neanderthal segments among worldwide groups."

[old europe]

Quote from the paper

The Indian cline has previously been shown to reflect variable proportions of ancestry from two ancestral groups: the Ancestral North Indians (ANI) who harbor large proportions of ancestry related to West Eurasians, and the Ancestral South Indians (ASI) who are distantly related to West Eurasians

What type exactly of western eurasian dna ANI are made of? and when did it reach India? It si something related to Iranian Neo/CHG or is it more ancient like Dzudzuana?

[Kale]

This is intriguing...

"Moreover, Indians have the largest variation in Neanderthal ancestry, as well as the highest amount of population-specific Neanderthal segments among worldwide groups."

Keeping in mind India is a huge country with diverse ancestry streams, and (from my superficial observations) less significant bottlenecking events than most of the world, while it is intriguing, I don't think it should be overly surprising.

[Merriku]

Quote from the paper

The Indian cline has previously been shown to reflect variable proportions of ancestry from two ancestral groups: the Ancestral North Indians (ANI) who harbor large proportions of ancestry related to West Eurasians, and the Ancestral South Indians (ASI) who are distantly related to West Eurasians

What type exactly of western eurasian dna  ANI are made of? and when did it reach India? It si something related to Iranian Neo/CHG or is it more ancient like Dzudzuana?

It is absurd that they are still clinging to ASI-ANI BS in 2024. It's clear that west Eurasian ancestry in South Asians is from at least 2 different sources - west Eurasian donor to IVC (I personally don't buy Rai-Shinde's basal IranHG hypothesis) and proto Indo aryans

[Jalisciense]

Quote from the paper

The Indian cline has previously been shown to reflect variable proportions of ancestry from two ancestral groups: the Ancestral North Indians (ANI) who harbor large proportions of ancestry related to West Eurasians, and the Ancestral South Indians (ASI) who are distantly related to West Eurasians

What type exactly of western eurasian dna  ANI are made of? and when did it reach India? It si something related to Iranian Neo/CHG or is it more ancient like Dzudzuana?

Steppe pastoralists descendants.

ANI is supposed to had high Steppe DNA, Iran N and not too much AASI, I read somewhere people claiming that they would have been in average around 50% Steppe, 25% Iran N and 25% AASI.

About the dates:

"Some time in the first half of the second millennium BCE, descendants of Steppe pastoralists entered South Asia from the north"

https://www.google.com/amp/s/m.economict...556277.cms