Lecture 25 Human Evolution 2

Question 1

3-5 coexisting

Answer 1

Species of Homo in the late Pleistocene

Question 2

DNA evidence pointed to close relationship, but distinct species, of

Answer 2

Homo sapiens and Neanderthals

Question 3

Mitochondrial DNA shows no evidence of Neanderthal mtDNA among modern humans, but

Answer 3

Nuclear genes say there was some interbreeding after humans dispersed into Asia

Question 4

2-3% of the genomes of non-Africans derived from

Answer 4

Nenderthals

Question 5

Probably introgression of human mtDNA into

Answer 5

Neanderthals

Question 6

Denisovans represent a

Answer 6

Third co-existing species of Homo along with modern humans (Homo sapiens) and Neanderthals

Question 7

Denisovans appear to have had a

Answer 7

Neanderthal-like build, dark pigmentation (as did most human populations)

Question 8

4-5% of “Melanesian” genomes derived from

Answer 8

Denisovans

Question 9

Human split from (Neanderthal plus Denisovans)

Answer 9

550-750k yrs ago

Question 10

H. Neanderthals is more

Answer 10

Closely related to us because through interbreeding the Homo sapiens mitochondrial DNA got transferred to H. Neanderthal and it swept through population completely

Question 11

Testing predictions for the origin of modern Homo sapiens

Answer 11

1. Location of ancestor (inferred from molecular Phylogenies and fossils) supports African replacement
2. Divergence time (120,000-220,000) supports African replacement
3. Greater genetic diversity in Africa supports African replacement

Question 12

Two competing hypotheses for the origin of modern Homo sapiens

Answer 12

African replacement
Multiregional theories

Question 13

African replacement is supported but with more complexity

Answer 13

Leaky Replacement (sets of neutral alleles), with 2-3 introgressions events
Also low genetic diversity in humans suggests a bottleneck or small founding population

Question 14

Language requires ability for

Answer 14

Complex vocalization (lacking in other apes) in addition to symbolism combined with syntax

Question 15

Study of Eurasian reveals the Europeans were

Answer 15

Dark skinned until after the influence of agriculture and influx of farmers from Turkey

Question 16

Humans and Neanderthals show an expressions of

Answer 16

Amylase genes (used to start digestion of starch) relative to other great apes, suggesting that fire and cooking was in use by 500,000 yrs ago

Question 17

H. Floresiensis

Answer 17

A dwarf island species, possibly descended from H. Erectus or just and odd population of Homo sapiens, lived just 18,000 yrs ago