Origins Flashcards
Human evolution
- opposable thumbs
- long fetal development
- complex thoughts + consciousness
- culture
- language and tools
Why is evolution not a set timeline process
- adaptations build on existing adaptations
- uses gradual adaptations
- a changing environment will provide opportunities to try new/unexpected combinations
Physical changes that provide new adaptive challenges/opportunities
- climate change
- continental drift
- geological changes
- formation of rivers or valleys
Co-evolution, how does it drive diversity
- new ways to benefit from plants, insects for pollen dispersal
Primate characteristics
- Stereoscopic vision
- Versatile limbs
- Large brains
Why is there so much research into the development of humans
- observer bias
- humans have many phenetic adaptions to look at
When was the angiosperm explosion
Diversified around 100 million years ago
Adaptive foraging
The ability to switch between types of food, and to learn to use new types of food
humans did complex foraging with cooking and fire, weapons and hunting, tools and digging, selecting plants
Adaptive looping
Adaptations can reinforce each other
ex.
- Bigger brains may increase selection for adaptive foraging
- Needing to process more types of food may increase selection for clever hands
- More clever hands may increase selection for good stereoscopic vision
- Ability to see and manipulate things in front of you may increase selection for bigger brains
How much genetic difference between chimps and humans
~1% in homologous sequences
about 4% overall
Hominins
People and our upright ancestors
When did modern humans evolve and where
Evolved in Africa around 200 thousand years ago
Getting fed
what is…
Frugivory: eating fruits and flowers
Folivory: eating leaves
Insectivory: eating insects
Eye orbits
The skeletal cavities where eyes are
Sexual dimorphism
Information about differences between males ad females has implications about social structure and mating patterns
more sexual dimorphism in male-centered groups
