16: Macroevolution

Question 1

Macroevolution

Answer 1

evolution at the large scale

• as species originate,
• adapt to their environment,
• and possibly become extinct

Question 2

Biological Species Concept

Answer 2

• group of organisms that interbreed with each other & share the same gene pool
• group of organisms that produce fertile offspring

Question 3

Reproductive barriers

what does it prevent?

Answer 3

• aka isolating mechanisms
• must occur in order for species to be reproductively isolated
• prevents gene flow

Question 4

Prezygotic Isolating Mechanisms

Answer 4

prevent reproduction & make fertilization unlikely

Question 5

Habitat Isolation

Answer 5

When organisms cant reproduce bc they are in different habitats

Question 6

Temporal Isolation

Answer 6

if the reproductive cycles of organisms occurs at different times

Question 7

Behavioral Isolation

Answer 7

unique courtship patterns displayed by organisms that prevent mating

Question 8

Mechanical Isolation

Answer 8

when the genitalia are structurally incompatible

Question 9

Genetic Isolation

Answer 9

when the fertilization does not occur, even when sperm and egg are brought together

Question 10

Postzygotic isolating mechanisms

Answer 10

prevent hybrid organisms from developing (zygote mortality) or reproducing (hybrid sterility)

Question 11

Allopatric Speciation

Answer 11

ancestral population is geographically isolated

• results in evolution of separate species.

Question 12

Sympatric speciation

Answer 12

involves speciation without a geographic barrier

Question 13

Adaptive radiation

Answer 13

involves the evolution of several new species from an ancestral species

• occurs as natural selection drives members of the ancestral species to adapt to several different environments