Those early hominids
It’s pretty well-established that early humans outside of Africa mated with Neanderthals. For example, through DNA testing, I learned that I have an only slightly less-than-average share of Neanderthal myself.
Now we learn that people of west African heritage have a trace of a different and unknown early hominid:
Using whole-genome data from present-day West Africans, scientists have found a small portion of genetic material that appears to come from this mysterious lineage, which is thought to have split off from the human family tree even before Neanderthals.
Today, it’s thought (although still being debated) that anatomically modern humans originated in Africa, and that once these populations migrated to Europe and Asia, they interbred with closely-related species like Neanderthals and Denosovans.
As such, modern West Africans, like populations in Yoruba and Mende, do not possess genes from either of these ancient species, but that doesn’t mean there was no intermixing. In fact, recent evidence suggests the genetic past of West Africans may contain a similarly juicy narrative.
When I was in school, things were thought to be much simpler. But I did read texts that indicated some anthropologists believed humans had bred with Neanderthals, although it was an unpopular view at the time. It appealed to me, though, and I continued to believe it might be true. Later it turned out that DNA evidence confirmed it.
According to my sister’s 23andMe report she has 81% more Neanderthal DNA than the average 23andMe client. So I assume I am in that ballpark as well and I couldn’t be more pleased.
From what I can tell we all came out of Africa — some earlier, some later. But it’s a pretty complicated story.
Hail to our ancestors!
“scientists have found a small portion of genetic material that appears to come ”
The operative word is appears. Thus there is a leap to a conclusion from an “appearance”, and that is quite unscientific.
George Booth, cartoon: Ip Gissa Gul
Works for Valentine’s Day, too.
It has always seemed to me that if Cro-Magnon, Neanderthal, and Denosovan interbred, and their offspring were fertile, then they weren’t actually different species, were they?
I have always been fascinated by this aspect of human history.
https://www.npr.org/sections/krulwich/2012/10/22/163397584/how-human-beings-almost-vanished-from-earth-in-70-000-b-c
Because once in our history, the world-wide population of human beings skidded so sharply we were down to roughly a thousand reproductive adults. One study says we hit as low as 40.
This story or one very like it first appeared several years ago but was circulating as far as I could tell only on anthropological or specialist blogs. That may have involved partial crania discoveries as well.
It was a rather sensitive issue at the time as the hypothesized mystery “ancestor” appeared, to those positing it, to have been rather more primitive a specimen than, say, the Neanderthal.
I don’t actually know if this current report is related that same report, or confirmations of it, now reaching mass media, or not.
I suppose I should look up some old files and sites.
This type of thing… http://dienekes.blogspot.com/2016/02/archaic-introgression-in-pygmies.html
sdferr, Ip Gissa Gul! That cartoon was on my fridge for years, and has made it into my family’s vocabulary — we still say “hom tont ho” when puzzled, and one of these days I’m going to name a dog “Huppy Dod.”
The operative word is appears. Thus there is a leap to a conclusion from an “appearance”, and that is quite unscientific.
Science has evolved (i.e. chaotic process) as a sociopolitical art of the plausible.
inferences
Created knowledge.
I followed your link, to its link. And there I saw the same two authors who were mentioned in this 2018 preprint. https://www.biorxiv.org/content/10.1101/285734v1.full
Arun Durvasula, Sriram Sankararaman
doi: https://doi.org/10.1101/285734
March 21, 2018
Apparently it has now been issued in peer reviewed form.
Kate. Maybe an outlier, but if you pair up a horse and a donkey — specifically a male donkey and female horse– you get a mule. While horses and donkeys are both “equine” creatures, they are different species…. as is their offspring, the mule.
And that gives me a chance for a “gotcha” question: What animal can you eliminate completely from the face of the earth and then begin producing them again the next day? The mule.
And I have often heard the opinion the men and women a different species that just happen to be sexually compatible.
Andy on February 13, 2020 at 5:52 pm said:
… One study says we hit as low as 40.
* * *
Unfortunately, that link just went to the generic NPR site.
However, there was a post on this topic, with a little more information.
https://www.npr.org/2020/02/12/805237120/ghost-dna-in-west-africans-complicates-story-of-human-origins
I’m curious about how they distinguish something that’s “not modern” from something that is.
And when did scientists start saying “hominins” instead of “hominids”?
The Internet knows!
https://www.smithsonianmag.com/science-nature/whats-in-a-name-hominid-versus-hominin-216054/
Another Mike, that’s what I meant. Mules don’t reproduce. Those ancient Neanderthal/Denosovan/Cro-Magnon mixes did reproduce, because we’re carrying their genes, or I am, as a European-ancestry person. The same is true for the African genetic material referred to in this post. And I note that populations separated by tens of thousands of years or more began reproducing as soon as there was contact in the modern era, producing fertile offspring.
And Andy’s story, above, makes one wonder about the old story of common ancestry from Eve.
Regardless of the twisted journey, our ancestors fought like hell against all odds and all the other contenders and achieved the top prize… top of the food chain… and with sentience thrown in as a bonus.
What a story!
Neocon;
Despite your small deficit of the Neanderthal genome, you probably have more of that genetic trait than Elizabeth Warren has of Cherokee genes.
Therefore, do not fret; you, like most folks can claim full membership in the Neanderthal nation and you should not be discriminated against just because you are mildly Neanderthal “challenged.”
Three cheers for Neocon; “um-galla-galla, um-galla-galla, um-galla-galla”
WRT H. Nean. We’re here and they’re not. Which leads to the conclusion that the mutts were raised in and by the H. Sap band. And likely reproduced therein or with another H. Sap band.
So, we know they weren’t cast out at birth.
How did this happen? Maybe a H. Sap band took in a wandering H. Nean hunter. Could always use the help, right?
Or a woman. In any case,, the kid had about the same chance at life as the pure H. Sap.
I don’t see a H. Sap going walkabout and impregnating a gullible H. Nean woman, and then going back for the kid.
It had to have happened frequently, as life was nasty, brutish, and short–short if you were lucky–and any number of promising starts must have ended before the genes spread beyond just flat stopping.
Those ancient Neanderthal/Denosovan/Cro-Magnon mixes did reproduce
Kate, you make a good point, but it seems that “species” are not so sharply defined by inability to produce fertile offspring, as this piece suggests.
The extremely tenuous and sketchy evidence used to construct the hominid/human evolutionary tree would go right into the toilet if just one set of human or near human bones, much older than anything previously discovered anywhere, were found in , say Uzbekistan or thereabouts.
Think about it; just one discovery of this sort would totally upend the apple cart.
Recall that sea levels at one time (or more than one time) were about 300 feet lower than today. Any “information” now submerged is long gone.
Further, the QUANTITY of hominid bones found oft times amounts to a pinky bone or other small fragments, from which the researchers draw all sorts of conclusions using the “science” of craniometry (for skull fragments) and if possible extracting DNA.
Just check out on Wikipedia the photos of the Denisovan bone fragments discovered and then read what they have inferred.
Sorry, but it’s a real stretch.
Basically the researchers are constructing a human evolutionary tree from remnants of early humans that they, by pure dumb luck, just happened to stumble upon’
They then use this 000000000000000000000001% of the “data” that had originally existed (say 150,000 to 500,000 years ago when early humans walked the earth) to construct their evolutionary model.
Nothing wrong with trying to put the puzzle together, but it’s all conjecture.
Good to know that’s where the notion of I’d hit it came from.
“Whole genome simulations”, “inferences”, and the “suggestions” derived therefrom are not factual. They remain the basis of speculation.
I still remember taking an undergraduate anthropology class, circa 1998 or so. The jury was (then) still out on whether or not modern humans had ever interbred with Neanderthals. In fact, one class assignment was to defend both sides of the issue. (We were also cautioned that our professor had strong opinions on the issue, and thus we should be careful, when talking to him, not to get on his bad side.)
How times have changed, and so quickly!
The comments suggest that all this is unreliable and unscientific. I’m not sure what level of proof they would like before researchers come forward. The mathematical tools used are straightforward and identify that there is something that shouldn’t quite be there, of which mating with a related hominid is the best current possible explanation. If someone thinks that is not so, saying “Pish tosh” is not actually very helpful. What are your alternative hypotheses for these gene variants that shouldn’t be there?
Those who like this sort of thing will like Greg Cochrane’s blog “West Hunter.” He was trained as a physicist and now teaches anthropology – at Utah, I think. Quite brilliant; author of The 10,000 Year Explosion.
AVI:
You say, “statistical inference based on high coverage whole-genome data” is straightforward and ” leads to the best current explanation”. Saying so does not make it so. Current=transient.
Statistics is probability-based, an assessment of chance. It is not a stalwart foundation for truth.
I am reminded of the saying “Lies, damn lies, and statistics”.
“anthropologists believed humans had bred with Neanderthals, although it was an unpopular view at the time.” Would not surprise me a bit. I was in the Navy and found that sailors will breed with anything.
For a great laugh about archeologists deriving civilizations from potshards, read Robert Nathan’s Among the Weans. And paleontology makes archeology look like hard science!
The best view of paleontology.
http://www.cartoonistgroup.com/search/results.php
I’m still holding out for evidence of the “naked ape”.
Jimmy – I had assumed the idea that “species can’t interbreed” was shot down back when they discovered or bred the Liger (and also theTigon).
https://en.wikipedia.org/wiki/Liger