Exam 1

Question 1

Homologous species

Answer 1

indicative of evolution from a common ancestor.

Question 2

analogous species

Answer 2

Evolve to look & function the same through convergent evolution.

Question 3

convergent evolution

Answer 3

same solution to similar selection pressures.

Question 4

rudimentary structures

Answer 4

unused, left over from the previous ancestry

Question 5

comparative embryology

Answer 5

evolution of development, similarities in embryos

Question 6

conserved molecular characteristics

Answer 6

dna, rna, proteins, specific enzymes & enzyme pathways

Question 7

evolution

Answer 7

change/time in allele frequency of a population

Question 8

Darwin & Wallace independently concluded evolution in…

Answer 8

1859

Question 9

natural selection

Answer 9

non-random, unequal reproductive success (reproduction of the fittest)

Question 10

Darwin’s observations:

Answer 10

• organisms have the capacity to produce exponential population growth
• populations tend to remain stable ( w fluctuation) not exponential
• resources are limited
• some variation is heritable
• better adapted individuals leave more offspring

Question 11

Earth’s operating conditions

Answer 11

• sunlight
• water
• gravity
• limits & boundaries
• dynamic equilibrium
• cyclic processes

Question 12

adaption

Answer 12

trait that increases the fitness of an individual

Question 13

evolutionary fitness

Answer 13

relative contribution of an individual in a population to the next generation (reproductive output)

Question 14

r selected

Answer 14

lots of offspring with low investment and low survival rates

Question 15

k selected

Answer 15

few offspring with high investment & high survival rates

Question 16

directional selection

Answer 16

selection against 1 extreme, shifting toward the other extreme. Graph just slides down

Question 17

diversifying selection

Answer 17

shift away from intermediate to both extremes. Graph turns into an M shape (could lead to speciation)

Question 18

Stabilizing selection

Answer 18

selection against both extremes. Graph narrows.

Question 19

sexual selection

Answer 19

natural selection that results in adaptions that directly influence reproductive success.
Inter-sexual = between sexes
Intra - sexual = with in sexes

Question 20

Genetic Drift

Answer 20

variation in the relative frequency of different genotypes in a small population, owing to the chance disappearance of particular genes as individuals die or do not reproduce.

Question 21

GD: bottle neck effect

Answer 21

Catastrophic reduction in population. Original population -> chance survivors -> new population

Question 22

GD: founder effect

Answer 22

a few individuals from a population start a new population with a different allele frequency than the original population

Question 23

Gene flow

Answer 23

immigration/migration of individuals between populations that result in change in population allele frequencies.
- more gene flow between 2 populations makes them more similar
- less gene flow means they’re more diverged
- not totally random

Question 24

mutations

Answer 24

random change to DNA
- introduce new alleles to a population
- adds diversity
- natural selection acts on mutations to eliminate mal-adaptive options

Question 25

non- evolving population

Answer 25

- very large population size (no genetic drift) - no gene flow (no immigration/migration) - no mutations - no selection, all individuals are equal in reproductive success

Question 26

Hardy- Weinburg Theorum

Answer 26

there is no evolutionary change just via reproduction...a force must ensure that at least 1 of 5 parameters must be broken for evolution to occur

Question 27

Species

Answer 27

based on the ability to interbreed. If interbreeding is possible then speciation is not complete. - biological species concept is based on infertility rather than physical similarity

Question 28

Prezygotic barriers

Answer 28

- before zygote = a fertilized egg - behavioral isolation (mating dance0 - mechanical isolation (bees only being able to pollinate flowers shaped a certain way) - gametic isolation (surface proteins on the gametes are incompatible)

Question 29

Postzygotic barriers

Answer 29

- hybrid inviability = they die before they fully develop - hybrid sterility = they're not able to produce viable gametes & reproduce - hybrid breakdown = fizzling out after a couple generations

Question 30

Genetic isolation can lead to new species

Answer 30

it is the blocking connection between populations

Question 31

genetic divergence can lead to new species

Answer 31

it is becoming incompatible genetically

Question 32

macroevolution

Answer 32

mutation, gene flow, genetic drift, natural selection, + 3.8 billion years

Question 33

LUCA

Answer 33

last universal common ancestor

Question 34

allopatric speciation

Answer 34

geographic separation, scale and type of movements, migration, & dispersal can be key factors Example: pollen blown by wind, ground squirrels on either side of the grand canyon, adaptive radiation

Question 35

adaptive radiation

Answer 35

divergent evolution compares and contrast with convergent evolution

Question 36

convergent evolution

Answer 36

creating analogous structures through similar selection pressures (often founder effect involved)

Question 37

sympatric speciation

Answer 37

by autopolyploidy in plants causes instant new species

Question 38

autopolyploidy

Answer 38

self-duplication of chromosome numbers - plants tolerate extra chromosome sets, flexibility & plants can self pollinate

Question 39

ecological isolation

Answer 39

through behavioral/geographical

Question 40

allopolyploidy

Answer 40

hybridization with meiotic nondisjunction (no separation of homologous chromosomes) + self fertilization