Lecture 27 - Human Evolution

Question 1

Humans (who are we?)

Answer 1

One of the few hominid species
- only homo species left

Question 2

What are humans ancestor?

Answer 2

Hominidae (Family) 15 mya
Homininae (Subfamily) 10 mya
Hominini (Tribe) 5 mya

Question 3

What are the three Homo species

Answer 3

Homo sapiens “Humans”

Homo denisova “Denisovans”

Homo neanderthalensis “Neanderthals”

Question 4

Neanderthals (when, where and climate)

Answer 4

lived 700,000 - 200,000 years ago

mostly found in Europe but also Asia

Neanderthals were well adapted to colder climates (survived through 3 or 4 ice ages)

Question 5

Neanderthals characteristics

Answer 5

Same average height as pre-industrial humans , but with larger brains

broader structures and weighed more than pre-industrial humans

Question 6

Do Neanderthals share genes with Humans?

Answer 6

Yes, known through remains found in the same places and are dated to the same time

evidence that co-existed as Neanderthals genomes have been sequenced and there has been at least one major introgression event between humans and Neanderthals.

Main introgression event occurred around 60,000 years ago when humans migrated to Africa. this is likely the reason that non-sub-saharan Africans all have some Neanderthal DNA in their genomes

Question 7

What is strong correlation in allele frequency plotted on a graph for two populations allele frequencies?

Answer 7

Strong correlation means that if the SNP is high in one population it is also high in the other.

Question 8

What is likely to be seen where there is little to no divergence between populations?

Answer 8

suggests that the evolution has occurred in one population more than the other (points on the graph that stray from the strong correlation diagonal line)

Question 9

Where did EPAS1 allele for altitude adaptation cum from?

Answer 9

it came from Denisovan introgression

Question 10

Current selection in humans:

is there still genetic and phenotypic variation?

is there still heritable variation?

are there still fitness differences

Answer 10

YES

YES

Probably

Question 11

What kind of species are humans, neanderthals, and Denisovans?

Answer 11

These are morphological species

some people say that they are not different species because they can produce viable offspring

Question 12

The retention CCR5-delta 32 in some human population is a result of…

Answer 12

Antagonistic pleiotropy