MULTI-REGIONALISM THREAD
I will start with basic explanation of my views on the origins of modern humans, I will come back and branch out with more evidence and detail later.
writing it all out in short tweets with no plan will be a challenge, give me time!
the genetic variation among modern humans is significant, which in other species would be defined as sub species level diversity at least, but it exists more on a gradient due to admixture between groups.
I am certain that if humans were bred like dogs concentrating and isolating certain groups over time they would show much more variation than dog breeds, mostly because of how recent dog domestication was from a few sources compared to the formation of modern humans
every unmixed dog breed is essentially like a little bottle neck which is then thrown out in a different direction from other breeds sort of like the native Americans being a product of that bottle neck in beringia then spreading out away from other human groups.
humans have more heterozygousity than chimpanzee groups, this study is very poor because dog breeds are by design bred over generations to concentrate particular traits. which reduces their connection to other dog breeds due to founder effect.
"Our overarching aim is to elucidate the spatial and temporal dynamics of the Out-of-Africa II dispersal"
ah that's why
well of course if your aim is to just reinforce OOA you can ignore the data that contradicts it
its pretty fucking amusing that the study when accounting for ancient samples finds clear evidence for east asian continuity in dental traits. but still say it supports an east african dispersal lmao
have they just ignored this in their conclusions somehow
I think thats the whole story in terms of eurasia and africa, sharing a basal homo route, having intermittent genetic flow since then. if we had more ancient african genomes of particularly archaics that would be amazing.
staying in africa, this story is also complex because africa is huge and sustained large and numerous populations of homos which were occasionally connected via gene flow and occasionally separated.
it was likely not specialised like the descendants in early homo, so not as big bodied as ergaster, less robust face, maybe a shorter habilis like face and generally gracile. in africa theu would diversify into habilis, ergaster, Rudolphensis.
skhul and qafzeh are sort of like an african + Neanderthal kind of mix, the middle east generally has had plenty of contact with east africa.
naledi? no clue really, something early in homo that survived in southern africa for a while.
I'm not sure how many posts I have left in this thread but I havent even got back to africa yet. but if this basal homo made it to east asia, maybe it explains the small bodies in Floresiensis and luzonensis as well as their basal traits that are pre erectus most likely.
Neanderthals diversify as they spread across the middle east and some coming back east into the altai, likely contributing to some Neanderthal traits in east asia such as xuchang and xujiayao. they also experienced a series of genetic bottle necks that led to their demise.
in east asia around 300 to 100kya we see modern humans arise in southern china, eventually spreading south into sahul meeting those ngandong populations, as well as west and north to make west eurasians etc. creating the eurasian macro clade genetically of modern humans
around 300kya there is a demographic event in denisovans which leads to northern denisovans (longi clade) and the two southern denisovans (soloensis or ngandong replacing and mixing with Java erectus and narmadensis in india) based on genetic evidence.
I have been working a new family tree for homo with this information in mind, I will explain my general thoughts and hopefully create a diagram some day. keep in mind these arent strict diverging branches, gene flow is expected
New Yunxian thread!
it is important to acknowledge when you were wrong about something and I was wrong about the Yunxian age, thanks to @JeanPeugeot1 for pointing this out. the 1.77mya age is much more likely to be the correct one, the 1mya is not.