speciation (final)

Question 1

biological species concept

Answer 1

• group of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups

Question 2

problems w/ bsc

Answer 2

• does not apply to many types of
  organisms that don’t reproduce
  sexually (asexual)
• can’t observe mating behavior of extinct species

Question 3

speciation

Answer 3

• when a new, distinct species forms from a single ancestral lineage, driven by reproductive isolation that prevents gene flow, leading to genetic divergence and the inability to interbreed, creating biodiversity

Question 4

allopatry

Answer 4

• populations become geographically isolated
• “different-homeland”

Question 5

sympatry

Answer 5

• speciation that occurs even though populations live within the same geographic area
• “together-homeland”

Question 6

internal events

Answer 6

• polyploidy
• autopolyploid
• allopolyploid

Question 7

polyploidy

Answer 7

• presence of extra sets of chromosomes due to accidents during cell division

Question 8

autopolyploid

Answer 8

• more than 2 chromosome sets, derived from a single species

Question 9

allopolyploid

Answer 9

• multiple sets of chromosomes derived from different species

Question 10

reproductive isolating mechanisms

Answer 10

• prevent individuals of diff species from mating and producing viable offspring

Question 11

prezygotic isolating mechanisms

Answer 11

• occur before fertilization

Question 12

postzygotic isolating mechanisms

Answer 12

• occur after zygote is formed

Question 13

ecological isolation

Answer 13

• prezygotic
• diff habitats

Question 14

temporal isolation

Answer 14

• prezygotic
• diff breeding times

Question 15

behavioral isolation

Answer 15

• prezygotic
• courtship behaviors (mating dances, etc)

Question 16

mechanical isolation

Answer 16

• prezygotic
• physical incompatibility

Question 17

gametic isolation

Answer 17

• prezygotic
• gamete incompatibility

Question 18

hybrid inviability

Answer 18

• postzygotic
• hybrid fails to develop

Question 19

hybrid sterility

Answer 19

• postzygotic
• hybrid cannot produce gametes (ex: donkeys, ligers)

Question 20

hybrid breakdown

Answer 20

• postzygotic
• f2 hybrid has reduced survival or fertility

Question 21

extinction

Answer 21

• the death of the last individual in a species or last species in a lineage

Question 22

background extinction

Answer 22

• natural rate of extinction as environments change

Question 23

mass extinction

Answer 23

• large numbers of species and lineages die out over short time period

Question 24

the anthropocene

Answer 24

• proposed current geological epoch where humans are the primary cause of permanent planetary change
• marked by co2 emissions, sea level rise, global mass extinction of species, transformation of land by deforestation