Lecture 5

Question 1

neo-darwinism aka the modern synthesis

Answer 1

combination of the understanding of natural selection + genetic basis of inheritance in the 1930’s & ’40’s, before understanding of structure and behaviour of dna

Question 2

evolution within a species

Answer 2

change in the frequencies of alleles in a population between generations

Question 3

population

Answer 3

localized group of individuals of same species, population can evolve but individual cannot

Question 4

5 factors affecting allele frequencies

Answer 4

1. mutation
2. natural selection
3. genetic drift
4. gene flow
5. extinction

Question 5

mutation

Answer 5

change in individual’s dna, caused by error in replication or structural damage, passed down if affected dna is in gametes

Question 6

macromutations

Answer 6

mutations in genes that control development

Question 7

3 ways selection can affect allele frequencies

Answer 7

1. directional - mean changes
2. diversifying/disruptive - variance gets larger
3. stabilizing - variance gets smaller

Question 8

fitness

Answer 8

production of offspring that themselves survive to

reproduce

Question 9

sexual selection

Answer 9

within natural selection, intersexual or intrasexual

Question 10

genetic drift

Answer 10

change in a population’s allele frequencies due to chance rather than selection, can be due to small random fluctuations in reproductive success, bottleneck, or founder effect

Question 11

gene flow

Answer 11

occurs when individuals interbreed or migrate among populations, can introduce drift, counteract variation, slow local adaptation, or reduce phenotypic diversity

Question 12

extinction

Answer 12

removes part or all of a species diversity

Question 13

extirpation

Answer 13

local extinction

Question 14

speciation

Answer 14

in between micro and macroevolution

Question 15

biological species concept (BSC)

Answer 15

species defined as population or group of populations whose individuals are capable of interbreeding and
producing viable fertile offspring (works for most animals, does not work for asexual organisms and many plants)

Question 16

DNA barcoding

Answer 16

648 base-pair sequence from mitochondria (barcode) shows little variation within species and clear differences between species (only works for 85% of animals)

Question 17

2 patterns of origin of species

Answer 17

1. anagenesis

2. cladogenesis

Question 18

anagenesis

Answer 18

gradual transformation from one species into another

Question 19

cladogenesis

Answer 19

splitting of ancestral species into two or more species

Question 20

2 possible rates of speciation

Answer 20

1. gradualism

2. punctuated equilibrium

Question 21

2 ways by which species are reproductively isolated

Answer 21

1. prezygotic (habitat, timing, behavioural, mechanic, gametic)
2. postzygotic (hybrid die, hybrid infertile, hybrid offspring unable to produce viable offspring)

Question 22

speciation via hybridization

Answer 22

in plants, hybrids may be fertile among themselves, but reproductively isolated from parents

Question 23

speciation via polyploidy

Answer 23

in plants, mutation doubles/triples number of chromosomes in seed, resulting plant may be self-compatible, but isolated from parents

Question 24

evidence of speciation

Answer 24

fossil record, geographic differentiation, lab experiments