Homo sapiens

Homo sapiens (meaning wise ape) is the only living member of the hominin lineage. They gradually evolved from Homo erectus ~190,000 years ago in Africa, but migrated from there ~50,000 years ago and now live across the earth and even beyond.

 

Biology

• Physically they are generalists, able to tolerate a wide variety of environments and diets.

• There is variation in jaw shape amongst humans and not all of this has a genetic basis.

• They have one of the largest brains, compared to their body size, on the planet.

• Their belly buttons accrue fluff, possibly because stomach hair funnels it there.

 

 

Behaviour

• Humans have a suite of “modern behaviours” that might not be so modern.

• Despite engaging in extensive food sharing, hunter-gatherers aren’t very egalitarian.

• Humans decide what to do in an uncertain situation in the same way monkeys do.

• They had started to bury their dead by ~100,000 years ago, showing they were religious by this point.

• They are attracted to mates of a similar height to their parents, although they don’t “imprint” on their parents.

• Monogamy and polygamy are just variations within normal human behaviour.

• They had started to change the environment by as early as ~40,000 years ago.

• In Europe they were living in distinct ethno-linguistic groups by ~30,000 years ago.

• Complex societies arose before agriculture, allowing large temples to be built relatively early.

 

 

Evolution

• The first humans are highly variable. The red deer cave people appear to be long lived examples of such variety.

• They engage in inceptive niche construction, which exposes them to novel environments and means they are still be evolving.
  • Taller woman have lower infant mortality. Since doctors reduce infant mortality size is no longer a factor, so selection for shorter and more fertile is dominant.

• Sexual selection appears to be acting on human populations, although further research is needed to know for sure.
  • An artificially sex typical voice is not attractive, preventing substandard mates from putting on a more sex typical voice t appear higher quality.

• Different populations have evolved different skin colours to balance UV protection with vitamin D production.

• The Out of Africa model, which suggests humans migrated out of Africa 60,000 years ago, could be wrong.

 

 

Technology

• Humans were wearing hard soled shoes by the Upper Palaeolithic.

• Humans use prosthetics to replace missing body parts. This started between 1,000-500 BC.