At www.hhmi.org/news/clovis-people-spread-central-and-south-america-then-va… … DNA evidence of the spread of Clovis people determined they had disappeared 9000 years ago – replaced by a new group of people in North America. It now emerges from DNA of the Clovis people that had spread into Central and South America, that they too disappeared around 9000 years ago. The research was done by David Reich and colleagues and published in the journal Cell. This is a biological journal that has apparently become geneticist friendly. See also https://doi.org/10.1016/j.cell.2018.10.027 … but you may note they disappeared long after the Younger Dryas boundary event. They were replaced by another group which also had origins in North America, according to the genetic research. Reich is now asking archaeologists to help solve the puzzle.
At www.pnas.org/content/117/46/28555 … an article on the Overkill hypothesis of disappearing megafauna at the end of the Ice Age raises some interesting objections to the human hunting theory for the extinction. It seems not all the megafauna survived into the Clovis period [roughly coinciding with the Alleroed in Europe] and could not have therefore been killed by Clovis people. Also, it is calculated that there were hundreds of millions of herbivores at the time of Clovis, yet only 16 occurrences have been found of a human kill, or scavenger, site, with remains of megafauna in association with human activity – such as stone points in carcasses. In addition, humans are known to have existed in North America prior to Clovis – yet there is no evidence of kill or scavenging sites associated with them. Apparently, overkill authors and researchers ignore this fact as they have hung their theory on the Clovis point. That did not exist in Siberia but a lot of megafauna died out there. There is strangely, even during the Clovis period, plenty of evidence of kill and scavenging sites of animals that did not become extinct, such as bison, elk, moose, deer etc. Some 90 kill sites, in fact. They did not become extinct and went on to thrive during the Holocene. OIther animals that did not go extinct would not have been hunted by Clovis, such as the dire wold, big cats, and armadillos, tortoise, and some species of snakes for example. Not only that there is distinct evidence that animals began to adapt, becoming smaller, after the end of the Late Glacial Maximum. The authors here prefer climate change as an explanation – not mentioning that climate change can be induced by catastrophic events.