Human evolution Flashcards
humans vs chimpanzees
- protein sequences are 98.5% similar ~6% of human genes not found in chimps, >1400 genes in humans not found in chimps
- Replicate copies of some genes in humans not found in chimps
- This difference in protein sequences translates a greater dissimilarity in amino acid sequences
what are hominins?
all species on the human side of the family tree after the split from the branch that became modern chimps
when did hominins brach off from apes
6.0Ma
what is the foramen magnum
the hole in the skull where the spinal chord comes through; directly below skull in hominins and in the rear of ape/chimp skulls
what is the age of Australopithecus
around 4.0-1.8 Ma: restricted to southern and east Africa
dental arcades of Australopithecus
semi parabolic: parabolic like hominins and rectangular like chimps
when did genus homo split form australopithecus
around 2.5 Ma
homo erectus
Large brain, bipedal, and more carnivorous
Expanded geographic range to include Africa, Middle East and South Asia
homo Neanderthalensis
230 kyr to 30 kyr (Europe, West & Central Asia, Middle East)
Cold adapted with heavy built and muscular bodies Modern humans of non-African descent have 1-4% Neanderthal DNA
when did anatomically modern humans (h. Sapiens) evolve
200 thousand years ago
homo floresiensis
Flores Island, Indonesia: 94,000 – 13,000 years ago;
- “hobbits” only ~3 feet tall
- They also used tools
what are the trends in human evolution
bipedalism dental arcade becomes more parabolic w/ reduced canines body size increases brain size tripled in 3 million years less body hair
what are some advantages of being bipedal
Good for carrying behavior
Reduction of heat stress: more surface area therefore easier to cool down
Energy efficient for travelling
Better vision
Possible defense against predators (extra hands to carry weapons)
