evolution and natural selection

Question 1

4 aspects of biological evolution

Answer 1

1. heritable (descent w/ modification)
2. genetic change (common ancestry)
3. over generations (time)
4. at population-level

Question 2

natural selection

Answer 2

1 mechanism that drives biological evolution

Question 3

phenotypic plasticity

Answer 3

phenotypic ability to acclimate to environments (NOT evolution)
- ex: over time adjust to high elevation

Question 4

3 types of selection

Answer 4

directional, stabilizing, disruptive

Question 5

directional selection

Answer 5

favors 1 extreme range of variation
- either favors left or right

Question 6

stabilizing selection

Answer 6

favors moderate/middle range trait

Question 7

disruptive selection

Answer 7

favors both extremes
- right and left but NOT center

Question 8

homologous traits

Answer 8

similar appearance due to common ancestry; shared genotype
- not caused by environmental pressure

Question 9

analogous traits

Answer 9

similar appearance due to independent evolution but similar environmental pressures; shared phenotype
- brought about by convergent evolution

Question 10

convergent evolution

Answer 10

process that brings about analogous traits
- species develop similar appearances due to similar environmental pressures NOT common ancestry

Question 11

mechanisms for evolution (4)

Answer 11

1. natural selection
2. genetic drift
3. sexual selection
4. horizontal gene transfer

Question 12

genetic drift

Answer 12

change in allele frequency due to chance
- common in small populations
- ↓ diversity

Question 13

2 types of genetic drift

Answer 13

founder and bottleneck effects

Question 14

founder effect

Answer 14

small portion of population leaves and starts a new population
- ↓ genetic variation = ↓ genetic diversity

Question 15

bottleneck effect

Answer 15

extreme reduction in population size due to bottleneck event (environmental disasters)
- ↓ genetic variation = ↓ genetic diversity

Question 16

genetic drift always causes…

Answer 16

↓ genetic variation = ↓ genetic diversity

Question 17

extirpation

Answer 17

localized extinction
- at least 1 population goes extinct

Question 18

sexual selection

Answer 18

1 sex chooses partner based on specific traits

Question 19

2 types of sexual selection

Answer 19

intErsexual, intrAsexual

Question 20

intErsexual selection

Answer 20

members of 1 sex choose a mate by preference
- usually females selecting males
- “female mate choice”

Question 21

intrAsexual selection

Answer 21

members of same sex compete w/ others for sexual access to members of other sex
- (usually competition b/w males)

Question 22

why do females usually choose (intErsexual selection)?

Answer 22

they have a larger investment (pregnancy) and have to choose most successful male (males don’t even always know whose their offspring)

Question 23

sexual dimorphism

Answer 23

difference in appearance b/w females and males in secondary sex characteristics (related to sex; ex: puberty changes)

Question 24

sexual dimorphism is a result of ____

Answer 24

intrAsexual selection

Question 25

example of sexual dimorphism

Answer 25

males are larger than females

Question 26

sexual dichromatism

Answer 26

difference in coloration or plumage b/w males and females

Question 27

sexual dichromatism is a result of ___

Answer 27

intErsexual selection

Question 28

example of sexual dichromatism

Answer 28

male peacock feathers/colors

Question 29

horizontal gene transfer

Answer 29

non-sexual movement/transfer of genes b/w genomes - 2 organisms "swap" genetic material through cell walls - material replaces/introduces new genes

Question 30

horizontal gene transfer can occur between...

Answer 30

members of related AND unrelated species

Question 31

rotifers

Answer 31

example of horizontal gene transfer; take up genetic info (DNA) from bacteria in new location before un-hibernating

Question 32

microevolution

Answer 32

genetic changes w/in a population; mechanisms for evolution

Question 33

macroevolution

Answer 33

evolution leading to speciation - population becomes new species - lots of micro- leads to macro-

Question 34

3 drivers/types of speciation

Answer 34

allopatric, parametric, sympatric

Question 35

allopatric speciation

Answer 35

speciation due to vicariance (geo isolation)

Question 36

vicariance

Answer 36

geographic separation (isolation) driven by continental drift (Pangea separating)

Question 37

parapatric speciation

Answer 37

(similar to allopatric) but has a narrow overlap of land - inter-mating occurs but ↓ fitness - drives isolation

Question 38

which drivers of speciation are the slowest/fastest?

Answer 38

(slowest): sympatric > parapatric > allopatric (fastest)

Question 39

sympatric speciation

Answer 39

speciation occurs w/in larger population; occupy the new range - random mutations = new behaviors = behavioral isolation --> 2 diff species - no geographic isolation = most hybridization

Question 40

which driver of speciation leads to the most hybridization?

Answer 40

sympatric speciation

Question 41

species concepts

Answer 41

ways species are defined

Question 42

morphological species concept

Answer 42

morphometrics- measuring and comparing appearances

Question 43

which species concept was the most dominant historically?

Answer 43

morphological

Question 44

pros of morphological species concept

Answer 44

fossils records and asexual species

Question 45

cons/downfalls of morphological species concept

Answer 45

natural variation, sub-species, subjective (human observed), convergent evolution

Question 46

biological species concept

Answer 46

"lumpers"; if 2 individuals from 2 populations can mate and have viable offspring (can reproduce) = same species

Question 47

which species concept is most used today?

Answer 47

phylogenetic species concept

Question 48

cons of biological species concept

Answer 48

doesn't consider asexual selection (no mate for reproduction), what if two populations are so isolate they will never meet?

Question 49

phylogenetic species concept

Answer 49

"splitters"; uses DNA and genetic code to determine species - species should be "diagnosably similar" w/ __ % DNA in common

Question 50

which species concept is generally used for sub-species?

Answer 50

biological species concept

Question 51

cons of phylogenetic species concept

Answer 51

vague, how much % similar DNA = enough to be same species? - taxonomic inflation?

Question 52

taxonomic inflation

Answer 52

inflating too many species; over speciation- can be good for awareness (less there are, more important it feels to save them)

Question 53

adaptive radiation

Answer 53

lineage rapidly diversifies w/ new lineages w/ new adaptations - short period of time = ↑ diversity = ↑ # of species in 1 population

Question 54

3 instances/causes of adaptive radiation

Answer 54

1. mass extinctions (new/empty niches) 2. invasion of under-used/un-used land and resources 3. development of key innovations to a species (ex: bird wings)