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What Neandertal DNA can teach about race, autism, and more

And by extension we should also consider the relationship of the entire Great Ape family tree in the sphere of human occupation. If we can lump in the Neandertal group as a subspecies of the homo group with a lineage that dates back hundreds of thousands of year and still call them possible ancestors, then why do we not honor the same relationship with our ancestral lines from the other Great Apes. This provides a strong argument for the recognition of rights that should be conveyed to our Great Ape brethren. If we now, as modern humans, can recognize the silliness of separation because of race within the species, we can also do the same when considering the relationship of DNA within others in our family tree. Species matter little, just as much as race.

As we continue to examine the DNA of all living forms, a pattern emerges that suggests an interconnected web of life that argues for a continuum of relatedness among all living organisms. One of the distinguishing characteristics between humans and other animals is the choice of conscience that is involved with our decision to be compassionate to all other living creatures. By sanctifying life we honor our ancestors as well as our fellow life forms. An argument can be made that war and killing, including both inter and intra-species, are antithetical to the continuing existence of our species. A spirit of peaceful coexistence within the entire animal kingdom is possibly the key to a future that will allow our own continuation as a species. Otherwise, Neandertal might not be the only extinct subspecies within the homo group.

WHAT rights "should be conveyed to our Great Ape brethren", in your opinion? Personally, I find the term "brethren" applied to great apes to be insulting and ridiculous, but am not opposed to animal cruelty laws tailored to different species/genera/families/classes/etc., based upon the animals' cognitive abilities. Laws governing animal-based medical research should additionally, IMHO, take into account the human need. To give two examples: I'm opposed to the routine blinding of rabbits to test new formulations of mascara. (But then, I think mascara is ridiculous, so I guess I'm biased.) However, I would not be opposed to final testing of an artificial pancreas using chimps, especially if they were 1) bred for the purpose (rather than captured from the wild); 2) otherwise treated humanely; and 3) allowed to live out their lives if the operation worked.
These are judgment calls. Granting human rights to animals (as some activists demand) would be wrong, for many reasons.

I'd go most of the way with you, except where you say "However, I would not be opposed to final testing of an artificial pancreas using chimps,". It would not be a final test is it used chimps. I can see no justification for using animals in any tests that cannot benefit (even if it may be unlikely) the animals tested themselves. A 'final' test of an artificial human pancreas would require a human participant. There's no shortage of people already needing their pancreas replaced, and given the chance, I'm sure you'd have no shortage of volunteers. So why involve chimps at all?

Great article, John. It's amazing to think of human related species living so relatively recently in the past.

A just as fascinating side note - Simcha Jacobovici (The Naked Archaeologist) posits that stories in the Old Testament handed down through ancient oral traditions relate to a race of people called Nephilim. In an episode on the subject, Simcha visits a cave that purports to show evidence that moderns and Neanderthals lived together.

ASDs (autism spectrum disorders) are hypothesized as one of many adaptive human cognitive variations that have been maintained in modern populations via multiple genetic and epigenetic mechanisms. Introgression from "archaic" hominids (adapted for less demanding social environments) is conjectured as the source of initial intraspecific heterogeneity because strict inclusive fitness does not adequately model the evolution of distinct, copy-number sensitive phenotypes within a freely reproducing population.

Evidence is given of divergent encephalization and brain organization in the Neanderthal (including a ~1520 cc cranial capacity, larger than that of modern humans) to explain the origin of the autism subgroup characterized by abnormal brain growth.

Autism and immune dysfunction are frequently comorbid. This supports an admixture model in light of the recent discovery that MHC alleles (genes linked to immune function, mate selection, neuronal "pruning," etc.) found in most modern human populations come from "archaic" hominids.

Mitochondrial dysfunction, differential fetal androgen exposure, lung abnormalities, and hypomethylation/CNV due to hybridization are also presented as evidence.

https://docs.google.com/open?id=0B3dPqM3qgNSiY3p5TmFRMjhSekdyaV8wWUw0MTZiUQ

A short video introduction: http://www.youtube.com/watch?v=Jk_85vNaSMA

The full 2-hour video presentation: http://www.youtube.com/watch?v=r6-6Naz-C0M

Note:

Evidence of transgenerational epigenetic effects due to recent environmental exposures to novel complex molecules also supports this hypothesis. Atavism may be advantageous when it's restricted to a small number of individuals, but deleterious when the mechanisms maintaining this subpopulation are altered in a way that isn't immediately apparent in the genome.

The puzzlingly heterogeneous (yet statistically undeniable) components of autism might thus be united through a better understanding of epigenetics.

I find it difficult to believe that ancient populations, whether nomadic or settled should be assumed as less demanding of skills for social interaction. They lacked today's essential distractions like Wii, Angry Birds, etc. and had to work together simply to survive. Granted, the skittishness of some people with ADHD might allow them to more readily detect and kill prey, thus preserving that competitive advantage in our genome, I can't think of any competitive advantage in the case of autistic children. It's not as if ancient populations enjoyed the readily available/dependable resources that we enjoy today, which would (in theory) allow them to ignore shortcomings, real or imagined for an autistic child. Don't blame it on Neanderthals.

Autistic spectrum disorders are seemingly assumed to be genetic in the comments and to a lesser extent in the article. But that can't explain the inexorable rise in conditions identified as within that spectrum, in the recent past. We seem to have something of an epidemic of 'autistic' disorders. I'd be far more inclined to an epigenetic explanation, driven by recent enormous changes in our chemical environment, beginning mainly only 200-300 years ago.

"We show that Neanderthals had significantly larger visual systems than contemporary AMHs (indexed by orbital volume) and that when this, along with their greater body mass, is taken into account, Neanderthals have significantly smaller adjusted endocranial capacities than contemporary AMHs. We discuss possible implications of differing brain organization in terms of social cognition, and consider these in the context of differing abilities to cope with fluctuating resources and cultural maintenance."

http://rspb.royalsocietypublishing.org/content/280/1758/20130168.full

Thank you for your thoughtful and clear article on an important subject.

http://autismtheory.org traces why Neanderthal and Denisovan DNA probably correlates with autism to basic physical facts. The thesis, now over ten years old, is posted at the site in a paper titled The Sparseness Adaptation Syndrome: Adaptation to low population density yields a set of traits correlated with autism and male gender.
Neanderthals and Denisovans lived in regions and habits of relatively low population density.

The paper is here: http://autismtheory.org/sparse1.pdf

From a pure statistical viewpoint, 3.125% of your DNA is inherited from your great, great, great, grandparents from 5 generations ago.
So for 4% of our DNA to be from Neanderthal origins, that would have to be in very stable locations on the genome.

If most of us have 4% of any particular genetic component all our descendents will also have them?

If most of us have 4% of any particular genetic component, all our descendents will also have them.

Can someone please explain to me why if modern humans were a different species than the Neanderthals or Denivosans, we were able to breed with them and inherit their genes? Isn't the definition of species a group that can't successfully breed with another group, they might have a hybrid child, but the hybrid isn't supposed to able to reproduce? Sounds like if we bred with them and descended from them at all, then they count as part of our species, despite genetic variety.

***A simple refutation of that idea has been the proof that the diversity of genetic characteristics within racial groups is greater than the diversity separating them: human races are not well enough defined and different enough to be meaningful biological groups. For that reason, many scientists now argue that race is not a biological concept but rather a social concept that sometimes carries biomedical consequences.***

In that case sub-species in other animals are also just a "social concept"? Note that population genetics studies show that human races are easily defined into major clusters. As Jerry Coyne notes:

"Ive received an email from a researcher who points out that two of my statements are either misleading or incorrect in view of more recent work. Heres the email and links:

In your interesting blog article Are there human races?, you write:As has been known for a while, DNA and other genetic analyses have shown that most of the variation in the human species occurs within a given human ethnic group, and only a small fraction between different races. That means that on average, there is more genetic difference between individuals within a race than there is between races themselves. But this is patently false. I Tal (2012b) I show that pariwise genetic distances, from within- and between-populations, are substantially divergent (in fact, for Fst=0.15, reflecting average intercontinental differentiation from SNPs, the averages differ by almost 50%).

Also, you ask:Im not aware that anybody has tested the accuracy of diagnosing a single indviduals geographic origin from her multilocus genotype; if such studies exist, please let me know. Yes. In Tal (2012a) I develop models that show that classification accuracy approaches 100% even for very close populations, given enough loci. I then analyze recent empirical studies of human populations under this framework.

Tal O, 2012a. The Cumulative Effect of Genetic Markers on Classification Performance: Insights from Simple Models. Journal of Theoretical Biology. Volume 293, 21 January, Pages 206-218.

Tal O, 2012b. Two Complementary Perspectives on Inter-Individual Genetic Distance. In Press, BioSystems.

http://whyevolutionistrue.wordpress.com/2012/02/28/are-there-human-races/

I believe it was Nova program that said Neanderthal DNA has been proved to gave us a part of our brain, but I cannot remember what part it was. Can anyone tell me? I've searched the internet and this was a new finding based on DNA, but have not been able to find what was said on the program. I believe it was the ability to feel feelings, but it was worded differently of course. Anyone?

I have O negative blood type, and there are many among us, (negative blood types), that believe Neanderthal is the origin of negative blood types, since negative blood is not connected to anything on Earth. I have a friend who has charted the people negative blood types originated from, and where they lived, and compared it to Neanderthal and it's almost exact. Makes you think.....

However, I am still trying to find the answer to our DNA that Neanderthal man gave us part of, so if anyone knows, please respond.

Cheers!