Human evolution

Question 1

where did all modern humans originate

Answer 1

Africa

Question 2

where was the first evidenceof human migration

Answer 2

Greece and China
but these populations woulda died out and their lineages didnt carry on

Question 3

when was the first dispersal of the humnas that gave rise to modern populations
what couldve caused this dispersal?

Answer 3

~70,000 years ago
left africa, through middle east into other continents

perhaps climate change, so left to find better food and shelter

Question 4

when is our evidence for first human traces in north america and why is this now being questioned?

Answer 4

estimated ~ 12,00 yrs ago humans first travelled to NA

but, recently discovered footprints in New MExico from 20,000 yrs ago

so suggests maybe humans were there earlier

Question 5

heterozygosity def

Answer 5

genetic variation

Question 6

describe how heterzygosity changes with distance from East Africa

Answer 6

largest variation in Africa

as you get further away, variation decreases
cuz as people leave, only small part of the genetic pool leaves and reproduces

so you slowly lose heterozygosity as people move

see graph in onenote

Question 7

Explain why pop size could’ve lead to human extinction ~50,000 yrs ago?

Answer 7

bottleneck of ~12,000 people
could’ve been caused by climate change

so human genetic variablity is very little

so wouldn’t have taken much to wipe them out

Question 8

Neanderthals

Answer 8

400,000-30,000 yrs ago (about 5000 yrs overlap w/ humans)

NOT ancestors, cousins = they left africa before modern humans

lived in family groups, had relationships

Question 9

evidence for neaderthals having human like things and idk stuff

Answer 9

worn down teeth = used as a third hand to prepare animal hides and clothes and stuff

dived for shells and made string

made jewellery - shell and tooth necklaces with holes in it that were drilled in

made cave art - 65,000 yrs ago so humans were in middle east at this time

buried their dead with flowers by their bodies

Question 10

why did neanderthals disappear

Answer 10

we dont know lol

but their populations were very small so easily wiped out

Question 11

what was found when neanderthals genome was sequenced?

Answer 11

humans had interbred with neanderthals

so we’re not a seperate species as humans bred to make fertile offspring

only ~96 amino acid differences between humans and neanderthals

differences between us proably arised from regulatory gene differences

Question 12

how were the Denisovans discovered?

Answer 12

tooth found in Denisova cave, and it deffo didnt belong to humans or neanderthals
and also tiny finger bone
was dated to ~40,000 yrs ago

Question 13

which population have Denisovan genes

Answer 13

modern populations in asia

The EPAS1 allele in tibetans acc came from the denisovans

Question 14

what’s the evidence that denisovans used boats

Answer 14

Wallace’s line

land animals are vry different on either side, cuz couldnt travel across

so only way denisovans could would’ve been using boats

Question 15

evidence that neanderthals and tibetans mated

Answer 15

analysis of bones found in cave showed both genomes

Question 16

what makes us human

Answer 16

plenty of cave art
indonesian cave art when humans first arrived like 40,000 yrs ago

tools
guns
etc etc

modern = inc CO2 levels

Question 17

what is androstenone and how would it smell diff to neanderthals and denisovans compared to us

Answer 17

a pheromone
celery smell

a single base pair change changes how we percieve the smell