This is a background issue in any study of the past: history, archaeology, genealogy. There's "true" in the absolute sense, as in what would you have seen had you been there. That's not really attainable. The kind of truth that's left in studies of the past is the consensus model reconstructed from the records, and that's always full of controversies.
When new evidence suggests otherwise. All theories are based on our best evidence and we absolutely don't have all the evidence for anything. See, Structure of Scientific Revolution.
>That does not mean that this person contributed to the DNA of anyone living today, he added. It is possible that the jawbone belonged to a previously unknown population of Homo sapiens that departed Africa and then died off.
As far as I can tell, the entire "Out of Africa" model taken for granted within the MSM is being treated with increasing skepticism/nuance by scientists actually studying the facts on the ground, leading to these odd & increasingly ancient "first modern out of Africa" stories which may be confusing the public more than they're illuminating the history of human populations.
Razib Khan had a good short primer on this topic a little while back [1], excerpt:
The data for non-Africans is rather unequivocal. The vast majority of (>90%) of the ancestry of non-Africans seems to go back to a small number of common ancestors ~60,000 years ago. Perhaps in the range of ~1,000 individuals. These individuals seem to be a node within a phylogenetic tree where all the other branches are occupied by African populations. Between this period and ~15,000 years ago these non-Africans underwent a massive range expansion, until modern humans were present on all continents except Antarctica. Additionally, after the Holocene some of these non-African groups also experienced huge population growth due to intensive agricultural practice.
To give a sense of what I’m getting at, the bottleneck and common ancestry of non-Africans goes back ~60,000 years, but the shared ancestry of Khoisan peoples and non-Khoisan peoples goes back ~150,000-200,000 years. A major lacunae of the current discussion is that often the dynamics which characterize non-Africans are assumed to be applicable to Africans. But they are not.
And of course on these time scales people can easily walk all over the place. We only see remnants of larger populations lone wanderers are extremely unlikely to leave any evidence behind.
You can read John Hawks, quoted in this post's linked NYT article, with his own take on recent findings[1], echoing many of the points made by Razib Khan. Even Chris Stringer, one of most vocal & staunch advocates for a simple Out of Africa has recently walked that back [2]
If you are reading experts still standing behind a simplistic Out of Africa model after all the recent findings of archaic admixture and incredibly deep splits in human populations, I'd be very curious to see some links to papers/articles.
There is one massive clue pointing to Africa: more genetic diversity there. This doesn't rule out interesting additions from other populations that left earlier than others, went further than we thought, etc; but it is the elephant in the room.
https://www.ncbi.nlm.nih.gov/pubmed/24984772
Can you recommend a good primer on what we know about evolution and the history of our species, and the supporting evidence?
I thought The Selfish Gene would be this, but it seemed primarily focused on more abstract/philosophical questions, like group selection vs. gene selection. I'm more interested in concrete information about what our DNA and the fossil record can credibly establish. I want to know what facts are indisputably known, and which are more speculative.
It sounds like there's precious little certainty to be had [1]:
So far, nobody has recovered ancient DNA from archaic human skeletal remains in Africa. The 2000-year-old Ballito Bay boy is not the oldest, but there are no DNA results from truly archaic specimens, like the Kabwe skull from Zambia. As a result, we don’t have the kind of record within Africa that geneticists have built for Neanderthals and Denisovans in Eurasia...
Morphology does not tell the story of modern human origins...Did short faces and rounded braincases really make a difference to the survival and success of modern humans? Maybe they were chance legacies of the population that gave rise to our gene pool. We don’t know.
Conclusion:
We have to discover more fossils. That’s the way that we will start to solve these new problems and shed light on old mysteries.
Every time I see someone talk about "the MSM" as a pejorative like this, I laugh, mostly at you, because the alternative is literally conspiracy theorists and, of course, the far right.
Why can't there be a human kind that doesn't "lie all day every day"?
(1) "lie" has intent. You can't prove intent on the scale you accuse.
(2) "The media" is amorphous. Ask any two people and they won't identify the exact same group. Ironically, this is the same problem with the concept of "race", "species", and a few other similar concepts of population.
(3) The suffix "establishment" in this context is ridiculously vague to the point of being a No True Scotsman fallacy.
IMHO people complaining about "the mainstream media" have no historical anchor. Things were an order of magnitude worse when Hearst was actively running his "yellow journalism" outlets and when governments had monopolies on media coverage.
Media literacy is hard now because there is more than one choice for news. I choose not to get my news from the impulse isle or from {TMZ, E! Television, Fox News, MSNBC, local television affiliates}. There are still thousands if not millions of media outlets that don't "lie all day every day", the only difference is now there is more onus on the reader to be able to distinguish journalism from opinion from sponsored stories from entertainment from outright fraudulent stories.
I think the point is that Kahn, as a regular contributor to explicitly racist websites, is not likely to be a good source from which to obtain an objective summary of the latest news in paleogenetics.
> For all of this, dismissing Khan as a crank would be a mistake. While his associations are extremist, his science is not, and very little of what he writes about human genetics falls outside the pale of ordinary scientific discourse.
> Most scientists will object to this application of their work, but the illiberal challenges to scientific scholarship, perhaps now more than ever, seem destined to come not just from creationists and neo-skinheads, but from self-styled hyper-rationalists, too — from people who adhere to what they consider a “science-first” worldview, who often ignore history and social context, and who are predisposed to drawing troubling, and sometimes patently racist conclusions based on otherwise dispassionate science.
> In other words, they’ll come from people who sound a lot like Razib Khan.
My critique is that there is only one demographic in the US that attacks with the term "MSM" and then leads right into referencing this guy. "Mainstream media" used like this is a fingers-in-your-ears right wing in-group catch phrase and has been for probably more than two decades. And when a person using that secret handshake references something like this, it leads the observant to wonder.
The question isn't whether a scientist should drop work if racists like it, but rather whether a scientist would work diligently to associate with racist publications without aligning motive.
> included a letter he had written in 2000 to VDare, a white-nationalist website, suggesting among other things that black people are innately less intelligent than white people. Later that week, a spokeswoman for The Times issued a statement saying “after reviewing the full body of Razib Khan’s work, we are no longer comfortable using him as a regular, periodic contributor.”
Do you think there's science backing up that "black people are innately less intelligent than white people"?
I wouldn't have said "shit source", but I think he's better viewed as a reasonable populariser than a proper source. He is up with the literature (in the sense that the day after a new paper is published, he blogs about it), but he's not an authority in any way, and some of what he writes about e.g. the gendered aspect of IE migrations is a bit florid and unsupported by facts, as far as I can tell. You'd never find a reputable scientist in the field (lets say someone from Reich or Willerslev's labs) pushing lines like that.
Regarding the Out of Africa (OoA) model, that is definitely still the consensus model. What is becoming clearer is that subsequent to the OoA event, there was substantial admixture within OoA populations, backflow into Africa, and introgression from Archaic Humans (i.e. interbreeding with Neanderthals etc). Razib refers to this as the "Braided streams" model, rather than a model where populations split and then remained isolated.
The real revolution in understanding seems to me to be the role played by human migrations in hte formation of modern populations (i.e. the refutation of the "pots not people" view popular since the 60s.
Melanated people (aka Africans, which is a European term) were the first Hebrews and Arabs. "Africans" who migrated East to China, then back migrated after they went through mutation, and mixed with the original people. But of course, no one would believe it unless, well, you already know. Hopefully all the "pseudo-scholars" who spread this knowledge can rest easy now. Most of them died broke while these "discoverers" will die wealthy and famous. Of my post is perceived as racist, so what. I didn't hurt nothing but feelings.
At what point is the theory just wrong?