> Today, H. sapiens doesn’t have the possibility of quickly grabbing a load of diversity by mating with another group: For perhaps the first time in our history, we’re the only humans on the planet. It’s another reason to miss our extinct cousins, says population geneticist Carina Schlebusch of Uppsala University. “To have such a large densely spread species with … so little genetic diversity … is a dangerous situation,” she says.
Now that we have such a huge and interconnected population diversity will fade and adaptation will slow.
https://news.sky.com/story/human-microevolution-sees-more-pe...
It would make sense if she specifically referred to Homo sapiens sapiens, but for Homo sapiens that "other group" would be of a different species and we thus we shouldn't be able to produce fertile offspring with them.
Also Homo sapiens sapiens have plenty of genetic diversity. Even just the number of easily observable environmental adaptions present in populations are countless (Sherpa, Bajau people, etc.)
As for COVID-19, most people are more-or-less unaffected by it. Our genetic diversity is working as intended.
That's one definition of "species" (specifically, it's "the biological species concept"), but like all the other definitions, it doesn't work and does not correspond to most usage of the term. You can read modern genetic work discussing how homo sapiens interbred with hominids of other species. You can also observe how easily different species interbreed today, like wolves (canis lupus, obligatory pack animals) and coyotes (canis latrans, solitary).
Humans aren’t particularly genetically diverse, given our dispersal, though as far as I know there’s some disagreement on _why_.
Since they were purged and exist as remnants in individuals' DNA.
Also, we don't know that most people are more or less unaffected by covid-19. We're only beginning to understand long term affects of even mild cases. Please don't spread misinformation.
I know it's macabre, but I think about human migratory routines and when different groups clashed back when life was so primitive and brutish, they're must've been those tendencies to rape and sexually conquer the opposition.
Surely that is reflected in the genetic ledger of time. What a crazy insight. Genetics is such an interesting field. It's bonkers there's just strings of data that we can read the past through.
It’s full of “and then tribe X invaded and the land of Y, took their women and enslaved their men”. Back and forth for centuries. This behavior was cyclical, inevitable, and universal, until violence was monopolized and institutionalized.
We’ve come a long way, I guess. Still have work to do.
From what I understand, the most common view is that in hunter-gatherer times there was much less inter-group violence than there was after the advent of agriculture, simply because there was much less of a notion of territory and any need to defend it before agriculture was a thing.
Do you mean the Bible?
"Only in the cities of these peoples that the LORD your God is giving you as an inheritance, you shall not leave alive anything that breathes. But you shall utterly destroy them, the Hittite and the Amorite, the Canaanite and the Perizzite, the Hivite and the Jebusite, as the LORD your God has commanded you,...? Deut. 20:16..
https://www.smithsonianmag.com/science-nature/colored-pigmen...
https://en.wikipedia.org/wiki/Earliest_findings_for_hominid_...
There was inevitably conflict, but I'm skeptical of the "tendencies to rape and sexually conquer the opposition" framing. AFAIK there isn't much evidence for large amounts of inter-group violence. A paper like https://onlinelibrary.wiley.com/doi/full/10.1002/ajpa.23751 lays out a contra case that the absence of evidence isn't evidence of absence--but I think it is a reason to be cautious about what we project back on those populations.
I think at some point in the far past though there might have been a wider gap, genetically, between the two forces meeting. I haven't had time to read the whole article in detail, just skimmed it.
Anyhow, thanks. You're right, there's definitely been plenty of mandatory diversification before.
https://history.stackexchange.com/questions/23975/what-was-t...
Why couldn't they have been meaningful relationships?
2. John does not rape.
3. Therefore, John is not a mammal.
I think it's most interesting to think of how fluid what we mean by species really is. We've always known it was fluid, but I think many people never really consider that when thinking about ourselves.
I'd say that for most Sci-Fi Movies/TV there's a couple of reasons:
1. Non-humanoids are less relatable than humanoids;
2. Budgetary restrictions and the relative immaturity of CGI holds us back from creating fairly realistic and relatable alien species.
The act of separation would create new species. Not our drive to bone.
In the case of Neanderthals, isn't that "all" people rather than "many" people?
Neanderthals are believed to have gone extinct 40000 years ago.
But there was an article here the other day about the genetic isopoint [1], which is the most recent time when every human alive then was either an ancestor of every human currently alive or had no descendants that are currently alive.
Most researchers put the genetic isopoint somewhere between about 4000-15000 years ago.
If both of these are true (or even if not, as long as the genetic isopoint is after Neanderthal extinction), then all my ancestors that descended from Neanderthals and were alive at the genetic isopoint are also your ancestors, and so you are also descended from Neanderthals through them.
There seems to be a lot more uncertainty about when the Denisovans went extinct. It seems likely that they were probably also all gone by the isopoint and so "all" rather than "many" probably goes for them too.
Your kids only get half your DNA, their kids only get half their DNA, and so on. You can eventually end up with descendants who have none of your DNA.
If the genetic isopoint really was after the Neanderthals went extinct than everyone in sub Saharan Africa has Neanderthal ancestry even if none of them have Neanderthal admixture.
> ...which involves only three expansions of humans from Africa into Eurasia: an expansion of early Homo at about 1.9 Ma ago, an expansion of neandersovans at about 700 ka ago, and an expansion of modern humans at about 50 ka ago.
The “early Homo” or “superarchaics” are H. erectus and their DNA contribution is inferred since no sequences have yet been extracted. “Neandersovans” is the common ancestor of European Neanderthals and Asian Denisovans.
Interbreeding occurred in Eurasia after the second and third expansion.
