Lecture 11

Question 1

species

Answer 1

group of individuals that actually or potentially interbreed in nature
-biggest gene pool naturally

Question 2

biological species concept

Answer 2

species are groups of actually or potentially interbreeding natural populations that are reproductively isolated from other organisms

Question 3

pros of BSC

Answer 3

widely used, species defined this way are real entities

Question 4

cons of BSC

Answer 4

can’t be applies to all species, can’t apply to distinct species, can’t apply to asexual organisms, difficult to assess when species live in different places

Question 5

morphospecies

Answer 5

defined by morphological characteristics- similar characteristics
disadvantages- sexual dimorphism, physical variations. mimcry

Question 6

phylogenetic species concept

Answer 6

defined by unique genetic history, represented by a single tip on a phylogenetic tree

Question 7

speciation

Answer 7

the formation of distinct species by genetic divergence leading to reproductive isolation

Question 8

allopatric speciation

Answer 8

a population of the same species becomes subdivided geographically into separate populations

Question 9

vicariance event

Answer 9

the actual event that causes allopatric speciation

Question 10

sympatric speciation

Answer 10

speciation without geographic separation

initial barrier is biological- genetic, ecological, behavioral

Question 11

polypoidy

Answer 11

difference in chromosome number in somatic cells causes the population unable to breed and creating an instantaneous speciation event
-most common in plants compared to other eukaryotes

Question 12

reproductive isolation

Answer 12

mechanisms to prevent reproduction

Question 13

prezygotic isolation

Answer 13

before the egg is fertilized, prevent mating or fertilization, no hybrid zygotes are formed

Question 14

postzygotic isolation

Answer 14

after the egg is fertilized, fertilization occurs, fertilized ad hybrid zygote forms, sometimes can’t reproduce

Question 15

behavioral

Answer 15

prezygotic, species use different courtship signals

Question 16

ecological (spatial)

Answer 16

prezygotic, species live in same area but in different habitats

Question 17

temporal

Answer 17

pre, species breed at different times

Question 18

mechanical

Answer 18

pre, anatomical differences between individuals prevent mating

Question 19

gametic

Answer 19

pre, gametes meet from two individuals but do not fuse

Question 20

hybrid incompatibility/ inviability

Answer 20

hybrid embryos or juveniles die

Question 21

hybrid sterility

Answer 21

hybrid offspring live, but are unable to reproduce

Question 22

adaptive radiation

Answer 22

a single ancestral species rapidly diversifies into a large number of descendant species

Question 23

autopolyploidy

Answer 23

having more than two haploid sets of chromosomes from the same ancestral species

Question 24

dispersal

Answer 24

the movement of individual organisms from their place of birth to other locations for breeding

Question 25

tetraploid

Answer 25

containing four sets of homologous chromosomes