Human Origins and Evolution Chapter 24 Flashcards
the human lineage branches off of
the great ape
prosimians are
a separate primate group
the humans split from? and when?
chimpanzee lineage
5-7 mya
what is our evolutionary history?
fossils found in Africa
hominins discovered as common ancestor between chimps/humans 7 mya
-ardi 4.4 mya walked upright -but climbed in trees
-lucy fully bipedal 3.2 mya
neanderthals interbred w/ homo sapiens
out of africa hypothesis
humans arose from common african ancestor
which kind of DNA is better to use?
mtDNA b/c no recombination occurs, just sequence variation thru mutation
homo sapiens evolved in
africa
common ancestor for humans is only
200,000 yrs old
when did we become bipedal?
3.5 mya
adult humans share many features with
juvenile chimps-lack of hair, foramen magnum centered, large heads
-our 2 genomes are similar but gene-reg pathway altered during diff step in evolution
1st phase of colonization was when and where?
50,000 yrs ago
15,000 yrs ago we crossed from siberia to north america
the recent spread of modern humans means
there is less genetic variation
natural selection prompted
light skin in eurasians b/c light skin promoted production of vitamin D
what human genes are under selection for resistance to malaria?
SA heterozygotes most protected in mediterranean/africa
- S allele disadvantageous outside of these places
- heterozygotes for G6PD gene mutation have protection against malaria, but susceptible to favism
success of humans is owed to
capacity to innovate and transmit culture
