Ch 26 Evolutionary Genetics

Question 1

genetic change taking place in a group of organisms

Answer 1

evolution

Question 2

does an individual organism evolve?

Answer 2

no, only groups of organisms evolve

Question 3

evolution taking place within a single lineage

Answer 3

anagenesis

Question 4

evolution causing a splitting of a lineage into two new species

Answer 4

cladogenesis

Question 5

describe how the biological species concept defines species

Answer 5

a species is a group of interbreeding individuals and are reproductively isolated from other species

Question 6

what are some problems about the biological species concept?

Answer 6

• can’t determine reproductive isolation from fossils
• can’t be applied to asexually reproducing organisms

Question 7

describe how the morphological species concept defines species

Answer 7

species are based on phenotypic similarities and differences

Question 8

describe how the phylogenetic species concept defines species

Answer 8

species are defined as the smallest recognizable group that has a unique evolutionary history

Question 9

any biological factor/mechanism that prevents gene exchange

Answer 9

reproductive isolating mechanism

Question 10

prevent gametes from different species from fusing and forming zygote

Answer 10

prezygotic reproductive isolating mechanisms

Question 11

reproductive isolating mechanism where species live in different habitats and interact with the environment in different ways

Answer 11

ecological isolation

Question 12

reproductive isolating mechanism where differences in behavior prevent members from interbreeding

Answer 12

behavioral isolation

Question 13

reproductive isolating mechanism where reproduction of species occurs at different times of the year

Answer 13

temporal isolation

Question 14

reproductive isolating mechanism where anatomical differences prevent successful exchange of gametes

Answer 14

mechanical isolation

Question 15

reproductive isolating mechanism where gametes are incompatible

Answer 15

gametic isolation

Question 16

gametes of two species fuse and form zygote, but no gene flow

Answer 16

postzygotic reproductive isolating mechanisms

Question 17

reproductive isolating mechanism where incompatibility between genomes of species prevents hybrid zygote from developing

Answer 17

hybrid inviability

Question 18

reproductive isolating mechanism where hybrid embryos complete development but are sterile

Answer 18

hybrid sterility

Question 19

reproductive isolating mechanism where closely related species can mate and produce viable, fertile offspring, but further crossing of hybrids produce inviable, sterile offsprign

Answer 19

hybrid breakdown

Question 20

process by which new species arise

Answer 20

speciation

Question 21

geographic barrier splits a population into two groups and blocks gene exchange

Answer 21

allopatric speciation

Question 22

a population splits into two groups in the absence of a geographic barrier, due to reproductive isolating mechanisms evolving in a population

Answer 22

sympatric speciation

Question 23

evolutionary relationships among a group of organisms

Answer 23

phylogeny