Modern human tool assemblages under and above the Toba ash in India.

After spotting this story on anthropology.net, I traced down the old pdf.

HUMAN OCCUPATION, ADAPTATION AND BEHAVIORAL CHANGE IN THE PLEISTOCENE AND HOLOCENE OF SOUTH INDIA: RECENT INVESTIGATIONS IN THE KURNOOL DISTRICT, ANDHRA PRADESH

The most interesting part of this (from my POV) was this  (page 42)

The depositional position of the tephra in the Jurreru River Valley, to gether with new chronometric and geochemical evidence, indicates that the ash is a product of the 74,000 year old YTT event (Petraglia et al., 2007). The recovery of Middle Paleolithic assemblages in dated deposits below and above the ash provides the first firm archaeological association, helping to resolve some of the uncertainty about archaeological associations in India. The recovery of Middle Paleolithic industries without major technological changes after the ashfall, indicate that populations survived the super-eruption. We have suggested, based on a variety of datasets, that modern humans were present in the Indian sub continent before the super-eruption, and that these populations survived this event.

I’ve observed that the 60k OOA date is a non-starter based on the arrival of people in Australia ( with TL dates of 55-60k); a pre Toba date is supported for the OOA. I’m still a bit curious why so many seems insistent on a more recent date.  There are modern human sites in Israel dating from 120k (Skhul) to 100k. Not to mention that not the age estimate for the separation of African and non African populations comes to around 140k ago (Cavalli Sforza and at least one other). The moral of this is… never trust a date based on a genetic ‘clock’ unless you can check it with ADNA or archaeological data. The mismatch between the dates on the Paglicci mt DNA (H) and the estimated age of mtDNA type H on one paper should be an example. You’d think they’d start checking against known archaeological dates for population movements/ADNA to improve the accuracy of the estimates.

I have to comment that the estimated ages for expansions in NE Africa in the past few years (about 22-24k for the expansion of M1 from the Nubia area, and 6k for a Chadic expansion) are starting to come close enough to be acceptable, although Y chr dates will probably always be unreliable. Maybe someone should go over all the data for the dates of Eurasian mt DNA to see if they are still getting that pre-Toba date from the mt DNA. I suspect they won’t. There’s a the hint from what’s been published that some of the TL dates in India are now over 100k, which would be interesting if true (no firm source as yet), just this. It would mean that the expansion from Africa would have been fairly rapid into the tropical areas (similar climate, minimal adaptation time) if true.

A few related links, in no particular order so I for my own reference. I hate not being able to find stuff.

http://www.caves.org/pub/journal/PDF/V58/V58N1-Prasad.pdf

http://www.ox.ac.uk/media/news_releases_for_journalists/100222_1.html

http://www.eva.mpg.de/evolution/staff/premo/pdf/premo_hublin_2008.pdf

http://toba.arch.ox.ac.uk/confabs.pdf

The X chromosome in population genetics

The X chromosome in population genetics

Something I’m posting a link to for later reference, in case I see any more X chr studies. The bit I want to find quickly is…

Taken together, these studies indicate an Out of Africa origin for modern humans. Individually, however, the studies point to diverse conclusions. For example, two studies reconstructed haplotypes in introns of X chromosome-linked genes, using chromosomes drawn from many populations around the world. The first study7 found a pattern that was strongly indicative of a recent expansion (and subsequent isolation by distance) of humans from a single geographical source. The chromosomes showed two common, old (200,000–800,000 years) haplotypes with worldwide distribution, as well as many younger, derived haplotypes (~100,000 years old) with limited geographical distribution.Africa was identified as the probable source for the expansion on the basis of the higher genetic diversity there, and by the continued presence of the ancestral human haplotype (as  determined by comparison with other primates). The second study44, on the other hand, found a pattern that was more consistent with multiregionalism.

Intelligence Predicts Health and Longevity, but Why?

Intelligence Predicts Health and Longevity, but Why?

Large epidemiological studies of almost an entire population in Scotland have found that intelligence (as measured by an IQ-type test) in childhood predicts substantial differences in adult morbidity and mortality, including deaths from cancers and cardiovascular diseases. These relations remain significant after controlling for socioeconomic variables. One possible, partial explanation of these results is that intelligence enhances individuals’ care of their own health because it represents learning, reasoning, and problem-solving skills useful in preventing chronic disease and accidental injury and in adhering to complex treatment regimens.

A Gottfredson pdf just full of useful bits of information about the influence of IQ on mortality. A few of the most interesting bits…

a drop of 1 standard deviation in IQ was associated with a 27% increase in cancer deaths among men and a 40% increase in cancer deaths among women (Deary, Whalley, & Starr, 2003). The effect was especially pronounced for stomach and lung cancers, which are specifically associated with low socioeconomic status (SES) in childhood.

For each standard deviation increase in IQ, there was a 33% increased rate of quitting smoking. Adjusting for social class reduced this rate only mildly, to 25%. Thus, childhood IQ was not associated with starting smoking (mostly in the 1930s, when the public were not aware of health risks), but was associated with giving up smoking as health risks became evident.

When all other variables were statistically controlled, each additional IQ point predicted a 1% decrease in risk of death. Also, IQ was the best predictor of the major cause of death, motor vehicle accidents. Vehicular death rates doubled and then tripled at successively lower IQ ranges (100–115, 85–100, 80–85; O’Toole, 1990).

A low IQ increases the risk of heart attack

Does IQ predict cardiovascular disease mortality as strongly as established risk factors? Comparison of effect estimates using the West of Scotland Twenty-07 cohort study

Objective
To compare the strength of the association between intelligence quotient (IQ) and cardiovascular disease (CVD) mortality with the predictive power for established risk factors.

Design
Population-based cohort study of 1145 men and women with IQ test scores, a range of established risk factors, and 20-year mortality surveillance.

Results
When CVD mortality was the outcome of interest, the relative index of inequality (sex-adjusted hazard ratio, 95% confidence interval) for the most disadvantaged relative to the advantaged persons was (in descending order of magnitude for the top five risk factors): 5.58 (2.89, 10.8) for cigarette smoking; 3.76 (2.14, 6.61) for IQ; 3.20 (1.85, 5.54) for income; 2.61 (1.49, 4.57) for systolic blood pressure and 2.06 (1.07, 3.99) for physical activity. Mutual adjustment led to some attenuation of these relationships. Similar observations were made in the analyses featuring all deaths where, again, IQ was the second most powerful predictor of mortality risk.

Conclusion
In this cohort, lower intelligence scores were associated with increased rates of CVD and total mortality at a level of magnitude greater than most established risk factors.

There’s also a paper from 2008 by the same man that comes to a similar conclusion after studying  4,166 US soldiers. This one concluded

The main finding was that, in age-adjusted analyses, lower IQ scores in both early adulthood and middle age were related to total and CVD mortality at a level of magnitude greater than many traditional risk indices.

What I did find amusing was reading through what the media had to say on this recently, trying to tell people that they could boost IQ with education (hasn’t been done with any lasting effect yet, and many have tried).

 Higher IQ has been associated with better outcome for disease in other studies, with explanations from following a healthier lifestyle (smokers have a much lower average IQ, 7.5 points lower) and being better able to manage medical conditions and medication.

Genetic Influences on the Overlap Between Low IQ and Antisocial Behavior in Young Children

Genetic Influences on the Overlap Between Low IQ and Antisocial Behavior in Young Children

The well-documented relation between the phenotypes of low IQ and childhood antisocial behavior could be explained by either common genetic influences or environmental influences. These competing explanations were examined through use of the Environmental Risk Longitudinal Twin Study 1994–1995 cohort (Moffitt & the E-Risk Study Team, 2002) of 1,116 twin pairs and their families. Children’s IQ was assessed via individual testing at age 5 years. Mothers and teachers reported on children’s antisocial behavior at ages 5 and 7 years. Low IQ was related to antisocial behavior at age 5 years and predicted relatively higher antisocial behavior scores at age 7 years when antisocial behavior at age 5 years was controlled. This association was significantly stronger among boys than among girls. Genetic influences common to both phenotypes explained 100% of the low IQ–antisocial behavior relation in boys. Findings suggest that specific candidate genes and neurobiological processes should be tested in relation to both phenotypes.

Remembering the outrage the last time I posted material of this nature, I shall stick to snipping the more interesting bits of text out and not add my own comments.

The exclusion of children who received a diagnosis of ADHD had no effect on our findings regarding the gender difference in the strength of the association between low IQ and antisocial behavior.

 Furthermore, it is important to note that once children with ADHD diagnoses were excluded from the sample, the low IQ–antisocial behavior correlation in girls was attenuated to almost nonsignificance. These findings suggest that the low IQ–antisocial behavior relation in girls is largely an artifact of comorbid ADHD.

The population prevalence of early-onset antisocial behavior that is life-course persistent is low (5% among men, less than 1% among women); however, these individuals account for more than their share of crime (Robins, 1966). Low IQ predicts the chronicity of antisocial behavior (Lahey et al., 1995); therefore, the children in our study who are boys, have low IQs, and have high levels of early antisocial behavior are at high risk for becoming life-course persistent antisocial individuals. This antisocial subtype is at the highest risk for myriad negative outcomes in adulthood, including mental health problems, substance dependence, financial problems, drug-related violent crime, and violence against women and children (Moffitt, Caspi, Harrington, & Milne, 2002). Genetic influences on IQ and antisocial behavior suggest that the parents of these vulnerable children are also likely to have low IQ and to be antisocial. Such parents are at risk for creating family environments that aggravate rather than ameliorate their children’s vulnerabilities. Thus, the families of young boys with low IQ who exhibit high levels of antisocial behavior should be targeted for early intervention.

One of the pieces of info I picked up from this was that … The prevalence of this research diagnosis of ADHD was 8% (70% boys; 30% girls). Also that the genders scored the same for IQ. I can’t help wondering if the abscence of these lower IQ antisocial boys from school during their teen years might not be part of the reason for the occasional finds of slightly higher IQ’s in the boys- the misssing lower IQ males boost the male average (tucked away in specialist schools, or just absent due to truancy or abandoning school at an early age.

Bayesian phylogenetic analysis of Semitic languages identifies an Early Bronze Age origin of Semitic in the Near East

Bayesian phylogenetic analysis of Semitic languages identifies an Early Bronze Age origin of Semitic in the Near East

The evolution of languages provides a unique opportunity to study human population history. The origin of Semitic and the nature of dispersals by Semitic-speaking populations are of great importance to our understanding of the ancient history of the Middle East and Horn of Africa. Semitic populations are associated with the oldest written languages and urban civilizations in the region, which gave rise to some of the world’s first major religious and literary traditions. In this study, we employ Bayesian computational phylogenetic techniques recently developed in evolutionary biology to analyse Semitic lexical data by modelling language evolution and explicitly testing alternative hypotheses of Semitic history. We implement a relaxed linguistic clock to date language divergences and use epigraphic evidence for the sampling dates of extinct Semitic languages to calibrate the rate of language evolution. Our statistical tests of alternative Semitic histories support an initial divergence of Akkadian from ancestral Semitic over competing hypotheses (e.g. an African origin of Semitic). We estimate an Early Bronze Age origin for Semitic approximately 5750 years ago in the Levant, and further propose that contemporary Ethiosemitic languages of Africa reflect a single introduction of early Ethiosemitic from southern Arabia approximately 2800 years ago. pdf

While I know this is old news, I’m  having an Afro-Asiatic weekend, and I missed this last year. This isn’t a million miles away from the conclusion I got from examining the reconstructed proto words of proto Semitic a while ago; only about 750 years different (based on the presence of silver and antimony). 

I finally found my old work that records Ehret’s older date for proto Semitic as being the roughly similar to Proto Cushitic (about 10,500 bp to 10,000 bp). If this isn’t an admission that he’d seriously overestimated the dates in his earlier work on AA, I don’t know what isn’t. It supports my criticism of his dating of proto Cushitic as being about 40% out, considering how slashed the time frame for Semitic is (nearly half). This brings all his dates for AA languages into a Neolithic time frame if you apply the same rule to them as a group. I was amused to see him clinging onto an African origin for PAA like grim death, given that the DNA, archaeology and proximity of Semitic languages to PIE and Sumerian really doesn’t leave this as a viable option anymore. Essentially the ‘African origin’ needs to find a cultural or biological expansion from Africa dating to about 11k ago, and AFAIK so far the only suitable population movement across North Africa in that era goes from Asia into Africa (Capsian culture). Then it needs to find a really good reason why Nubians speak a Nilo Saharan language, when they apparently shared a common culture with Afro-Asiatic speaking upper Egyptians before the Neolithic hit Africa.

Some people (who shall remain nameless) are adamant that the E3b1 Y chr is the Y chr related to the expansion of Afro-Asiatic languages. This is incorrect in at least two cases, as Chadic is not at all associated with this, but with the R1b-V88, which arrived from Asia in the neolithic (or Holocene), and neither is Semitic which is Asian and associated with the spread of J1 (also non-African). Afro-Asiatic languages are associated with the expansion of Neolithic Y chromosomes, not E3b1. I’d also like to add that in expansions of this type, languages appear to be spread patrilinealy, not matrilinealy, the Bantu expansion and observations from other expanding farmers v hunter gatherers don’t have the maternal hunter gatherers language being preserved.

My main objections to an African origin for Proto Afro-Asiatic.

The nouns don’t reconstruct to a ceramic using African hunter gatherer landscape, but to an aceramic West Asian early Neolithic landscape. 

There are no population movements out of Africa known that are recent enough to have carried proto Semitic into Asia. The last one was about 22,000 years ago, traced by the expansion of the M78 Y chr and the Kebaran culture (the Mushabian’s origin is open for debate, but it’s also too early). This is just impossibly old. Anything more than 11,000 years and you can’t be in the same language family. So many accumulated changes will have occurred after that time that they will only bear the same level of relation to each other as two random non related language groups. 

The known population movements between Africa and Asia that could have carried the language between them in the relevant time frame all go into Africa from Asia. 

Proto Semitic shows a proximity to both Sumerian and Anatolian Neolithic proto Indo European, which places it in Asia about 9,000 years ago. Even if you think the Anatolian theory is junk, it has loan words into the later PIE about 5k ago. This leaves a narrow time frame for the movement between Asia and Africa (11k max language age – 9k for AN PIE=2,000 years), and the arrival of Neolithic farmers into Africa via the Sinai sits smack in the middle of this time frame. 

Corrected dating for Afro-Asiatic (see above comments on Ehret) shows its something like a maximum of 11,000 years old. The main supporter for the E3b1/Kebaran scenario, Ehret, is now slicing big chunks of time off his calculated dates. This places AA languages into an essentially late Holocene (if African) or early Asian neolithic scenario. Not a match for the Kebaran/E3b1 expansion.

 Nubian is not Afro-Asiatic. Nubians and upper Egyptians shared a common culture in the Holocene with each other and the western desert ceramic cultures, but they apparently didn’t speak even remotely related languages by the time of state formation in Egypt. This is suggestive of Afro-Asiatic replacing the original pre-Badarian languages, leaving Nubians isolated like an island in a sea of Afro-Asiatic. It also nails the arrival of Afro-Asiatic in upper Egypt to a time after the ceramic Nilo-Saharans got there (which was about 10,500 bp) fixing it to a younger age than this. The only influx after this into the area that we know about is the arrival of the Neolithic from Asia about 7,000 BP in upper Egypt. Nilo Saharan has a very  similar age to Afro-Asiatic (Holocene), and matches pretty well to the spread of the first ceramic using people across the Sahara and down the Nile, including upper Egypt. It’s fragmented distribution is very suggestive of a much wider territory, now occluded by later waves of Afro-Asiatic. The isolation of the Nubian NS language, when using corrected dates, comes into an era when the Neolithic pastoralists arrived from Asia into NE Africa.  

The distribution of Afro-Asiatic in Africa has a very strong relationship to the spread of Neolithic Y chromosomes (particularly Chadic and Berber). Asian ones that enter via the Sinai mainly moved into East Africa and Lake Chad. NE African Y chr M81 shows a match to the old spread of Berber languages (from the Nile Delta in the Neolithic) prior to Arabization .

 Proto Cushitic, and all the African and Asian AA languages,  reconstruct with nouns for sheep and goats, Asian animals that don’t even appear in Africa until 8,000 BP. Archaeology tracks these pastoralists moving from the Nile Delta with their herds into North West Africa, East Africa and  Lake Chad, with large chunks of their male ancestry traceable to Neolithic Asia. Using the archaeology to correct the dates for proto Cushitic means it can only be of a Neolithic age, possibly be in the 5k-6k date range. This does not support a Holocene or older date for PAA in Africa, and is more evidence connecting it to the Asian Neolithic.

 So…what are you are left with in support of an African origin? Not a lot really. That there’s more diversity and structure in Africa, but that’s about it. Omotic as a pre-agricultural AA language doesn’t really stand up to scrutiny, with several publications suggesting they originally spoke Nilo Saharan but adopted Afro-Asiatic in the Neolithic, or of it being an off shoot of Cushitic, or not even Afro-Asiatic. The main supporter for an ancient African origin for Afro-Asiatic tied to E3b is slashing huge amounts of time off his estimated dates (about 45% for proto Semitic).

The real issue for anyone claiming an African origin for PAA is to show some population/cultural movement from Africa into Asia about 11,000 to 10,000 years ago, or even any time close. This is the real ‘brick wall’ the claims for an African urheimat run into. Until someone can explain how it managed to ‘swim upstream’ against the arrival of the Capsian and Neolithic arrivals from the Levant, IMO the claims for an African origin for PAA jus don’t fit the biological or archaeological evidence.

Leiterband ceramics and other stray bits of info

More archaeological work in Lower Wadi Howar

A field report I found while looking for info on Leiterband pottery. Most usable quotes for me..

Leiterbandmotifs are the predominant decorative pattern of the earliest pastoral phase of Middle Wadi Howar, but also occur further west in the Chad,

 Leiterbandmotifs, which suggest a date in the fourth or third millennium BC

From a second pdf studying the same area (more interesting than the one above):

On the basis of 15 radiocarbon samples, the Leiterband complex dates chiefly between 5200 and 4000 14C yr

And the sequence goes in Wadi Howar… dotted wavy line (Holocene hunter gatherers) Laqiya (later hunter gatherers), then Leiterband (pastoralist). The oldest Leiterband marked is just a bit younger than 6,000 BP.

The only thing that troubles me mildly is that there is no mention of ovicaprines at the Leiterband sites. Lots of cattle though, and microliths that were probably used to bleed them. However a little digging tells me that ovicaprines were present in 5,500 BP at Al Kadada (which was founded about 6,000 BP), so the animals would have been known to the Leiterband people, just not herded by them. Possibly the lack of ovicaprines was due to the lusher conditions in the Wadi at the time that favoured cattle.

 And another pdf, Aridity, Change and Conflict in Africa, has more information: it seems that small livestock were a slightly later addition (behind by a few hundred years into Northern Sudan).

A look at the geology of the area explains why the Westward migration – Wadi Howar provides a route from the Nile to the West that would still have had water in the Leiterband era.

The development of the pottery design styles in the Wadi Howar region which dates the Leiterband transition to 6,000 BP. This one has the best info on the ceramics and their manufacture .

Well, we have an earliest date of 6,000 BP for the expansion of proto Chadic speakers West along Wadi Howar. So a Neolithic culture is strongly associated with Chadic speakers, which IMO adds more weight to a neolithic date for the expansion of v88 into Africa and it’s ‘marriage’ to L3f3.