G23

Question 1

give an example of a physical barrier to gene flow

Answer 1

different species found on either sie of the florida peninsula
get gulf and atlantic species of black sea bass, seaside sparrow and horsehoe crab
lineages cna be seen

Question 2

give an example of behavioural barriers to gene flow

Answer 2

natal homing in turtles

Question 3

what does mutated CCR4 gene in northern europe prevent?

Answer 3

deletion prevents infection by HIV

not found in africa = not evolved

Question 4

give an example of allopatric speciation

Answer 4

island splits diff species evolve on each island

Question 5

give an example of parapatric speciation

Answer 5

hybrids found in middle, usually less fit.

Question 6

what is vicariance

give an example of this being used

Answer 6

looks for relationship between taxa and geographic regions they inhabit, continental drift reflected in midge phylogeny.

Question 7

what is a cophylogeny

give an example

Answer 7

comparing phylogenies, genes and organism, parasitesa nd hosts and organisms and areas.
cophylogeny of gophers and chewing lice shows cospeciation between lice and gopher,
cross overs are likely to be due to host switching or horizontal transmission

Question 8

what is tree reconciliation

Answer 8

explaining why two different trees dont match up

can only be sure of the parts of the tree which do match up

Question 9

what do alleles coalesce back to?

Answer 9

the most recent common ancestor.

smaller populations coalesce faster