phylogeography

Question 1

what is phylogeography

Answer 1

comparing the evolutionary relationships of genetic lineages to their geographical distribution to try to understand which factors have most influenced their current distributions

Question 2

what is biogeography

Answer 2

investigating the current distribution patterns of a species

Question 3

reasons for studying phlogeography / biogeography

Answer 3

• understand how current biodiversity has evolved
• help predict responses to future environmental change
• species ID for cryptic species
• help identify taxonomic units both within and between species

Question 4

what is a haplotype or haploid genotype

Answer 4

a group of alleles that are inherited from one parent
a different version of that gene

Question 5

what is a haplotype networks

Answer 5

widely used approach for analysing and visualising the relationships among DNA sequences within a population or species

Question 6

what is the role of phylogenetics

Answer 6

infer evolutionary relationships between groups (species, individuals, genes)

Question 7

is a cladogram an evolutionary tree

Answer 7

no

Question 8

what do cladograms assume

Answer 8

a current relationship rather than an ancestral one

Question 9

what is the focus of a phylogram

Answer 9

evolutionary relationships

Question 10

what do the branch lenghts represent in a phylogram

Answer 10

evolutionary distance

Question 11

what does the ‘multi species coalescent’ mean

Answer 11

there are always multiple lineages and dead ends to phylograms that aren’t always shown on the trees

Question 12

what kind of species can be found either side of the Isthmus of Panama and why

Answer 12

species pairs
was not always impassable, now is a barrier to gene flow = allopatric speciation

Question 13

what species would of experienced a reduction in gene flow first during the formation of the Isthmus of Panama

Answer 13

deep-floor sea species

Question 14

explain the idea of ‘molecular clocks’

Answer 14

concept that mutations in a genetic sequence occur at regular intervals

Question 15

what is the molecular clock of mitochondrial markers

Answer 15

2% divergence every million years

Question 16

what effect do mutations in the third base of a codon have

Answer 16

often little effect as they usually code for the same amino acid

Question 17

explain the Bengula Upwelling system, what was it, what problem did it cause and who was affected

Answer 17

cold upwelling system in place for 2 million years
barrier to dispersal for many species due to abiotic (temperature) and biotic barrier
mostly problematic for coastal species, not an issue for oceanic species that can swim around it

Question 18

how is ancient DNA often preserved before it is discovered

Answer 18

in permafrost