The Human Diaspora

Rife with spelling and grammar errors, as I don't look at the screen when I typed this.

There are 21 different ancestry groups, as described by the Baker et. al paper. No one person is just one ancestry group — most humans have evidence of at least six ancestry groups in their genomes.

When a field is brand new, it enters a hypothesis generation stage — the stage that human genome research is in.

Y DNA and mtDNA data shows that at one point, the human population experienced a bottleneck. It restricted genetic variation, sometime around 50k years ago.

One theory postulates that 74k years ago, a giant volcano erupted and led to years of volcanic ash, perhaps causing a decline in human populations.

Regardless of the volcanic eruption, there was nevertheless a lot of global termperature oscillations, the volcanic eruption happened as we were heading to an ice age.

There are two populations that account for a lot of the genetic cariation in euro[eans and asians today, the Basal Eurasioans/Ancient North Eurasians.

What we know about the group

• This group had no Neanderthal admixture. There were no genetic affinities.

• There was a major and distinctive population that seems to have actually had many subpopulatiions. It was a stable and major population center for himans.

• We don't know who these people were, there isn't really an old enough skeletons to represent someone from that time.

• We know they existed because there are traces of them in the genome, but we don't have any of their actual DNA.

We think that they might be related to a people than the Natufians, a people who were around much later than the Basal Eurasians.

"Ghost population of Ancient North Eurasian" population, we only know they existed because of evidence in modern genomes.

Gravettians

Made Venus vigurines, did cave art, and were very prolific hunters. They even had oil lmaps that were made out of stone. As the last ice age got into swing, they Gravettians had to move out of Europe.

Magdalaneans

Around 24k years ago, there was a shift in temperature, around 5 deg C avg drop. There was less precipitation, more desert, less tropical rainforest. Grobal productivity is estimated to been hjalf what is postglacial;ly. Sea level dropped about 120 meters. Around 19k, 14k years ago, the ice started to recede.

These people, the magadalaneans, had taken resgure on the ibearian population dring the last ice age. AS the ice sheets receded, this populaiton expended north and east. They were associated with teh extinction of some species of mammothy.

They had bone and ivory tools, and did art.

We trhink that there was a warming event called the bolling allerod warming event. With this dramatic climatological event, human culture

The Beginning of Algriculture

Humans started domsticated aminals — dogs, sheep, piigs, cattle, horses, llamas. Rice was domesticated in asia, wheat and oats in europe, beans, grounds, maize in North America. In multiple regions around the world, people were figuring out what they could do with the plants and animals around them.

At this point, enarly 42 percent of regions oppupied by humans had some form of agriculture.

How do we know that a plant is domesticated? There are morphological differences between the ears of wild and domestic wheat. YOu can see indications of grains being broken off rather than naturally falling off — these are visible in the archaeological record.

Surplus food supplies allowed larger civilizations to be established. More energy allowed people to develop monoliths like the Stonehenge.

As agriculture spread across Europe, hunter-gatherers meshed into the farmer groups.

Horses

The Scythians were one of the first examples of the domestication of horses — and would even bury the horses. There were also wagons, allowing people to move a lot of things at once. There were several cultural groups active in the start of thedomestication of horses. This helped with human genetic variation befcause there was more potential for movement.

Yamnaya

The Yamnaya were a people with no permanent settlements. The evidence that we had of them were their burial mounts, where people were buried with wagons and their horses. They are also associated with the corded ware culture — named after the way they would decorate their pottery.

Evidence of their genome appears across asia as well as Europe.

The Ancient North Eurasians

The people who lived at Mal'ta left behind bone carvings as well as figurines. Archaeologists found the remains of a baby 24,000 years ago. His genomic variation had an admixture graph rooted with the modern Europeans and Native Americans.

This ghost population intertwines people in Europe with the people in the Western Hemisphere.

The Ancient Beringians

During the last glacian maximum Beringia occupied a unique position and had unclac9iated land whose temperature only droppped a little but.

Archaeological expedition showed that there was a region of shrub tundra that was isolated from other areas by an ice sheet and a mesic tundra. This shrub tundra was a refuge — an area of biological productivity in an ice age.

The Beringian standstill analysis states that a population out of the Ancient North Eurasians took refuge in beringia during the last glacial maximum, and lived in genetic isolation during the ice age.

This indicates that ratehr than a roiute or a bridge, it was a center of population dispersal. People lived in the region, and when climate changed, people dispersed back into asia and back into the western hemisphere.