Mechanisms of Evolution: phylogenetic trees

Question 1

Evolution

Answer 1

accounts for shared characteristics across living systems/diversity: have evolved via genetic change/natural selection

Question 2

Natural Selection occurs`

Answer 2

organisms in a population vary, some variation –> offspring, not all individuals survive, some variation increase probability of survival

Question 3

Sexual selection

Answer 3

natural selection: mate-finding and reproductive behavior: risk factor (behaviors that attract mates attract predators)

Question 4

Allelic/genetic drift

Answer 4

Random loss of alleles from (small populations); can lead to “fixation” (loss of alleles): leads to loss of diversity

Question 5

Founder effect

Answer 5

Allele drift type: new populations established by a few founding individuals –> gene frequencies different from those in parent population: Lake Maracaibo + Huntington’s disease –> trace back ancestry to 1 woman

Question 6

Bottleneck effect

Answer 6

Allele drift type: loss of alleles as population size plunges suddenly (major environmental changes, no selective bias)

Question 7

Allele Flow

Answer 7

Random movement of alleles among populations (carried by individuals)

Question 8

Evolutionary mechanisms beyond natural selection

Answer 8

mutation/other variations, natural selection, allelic drift, allele flow

Question 9

Phylogeny

Answer 9

study of evolutionary relationships/lineages through time

Question 10

speciation events

Answer 10

branch points on phylogeny tree

Question 11

speciation

Answer 11

formation of a species; population isolation + divergence contribute to: allele flow must stop

Question 12

species

Answer 12

group of individuals that can interbreed in nature + produce viable/fertile offspring

Question 13

Biological species Concept

Answer 13

1 Approach to defining species: distinct species do not interbreed + form fertile offspring in nature