Chapter 14: Origin Of Species Flashcards Preview

Biology > Chapter 14: Origin Of Species > Flashcards

Flashcards in Chapter 14: Origin Of Species Deck (19):
1

Reproductive Barrier

A biological feature of the organism itself to prevent individuals of closely related species from interbreeding when their ranges overlap

2

Temporal Isolation

Occurs when species breed at different times

3

Habitat Isolation

2 species live in the same general area but not in the same kinds of places

4

Behavioral Isolation

Little to no sexual attraction between males and female of different species

5

Mechanical Isolation

Male and female sex organs are not compatible

6

Genetic Isolation

The make and female copulante but the hamsters do not form a zygote

7

Pre-Zygotic Barriers:

Prevent mating or fertilization between species

8

Post-Zygotic Barriers:

Prevents the hybrid from being fertile

9

Reduced Hybrid Viability

Hybrids fail to develop

10

Reduced Hybrid Fertility

Hybrids fail to produce functional gametes

11

Hybrid Breakdown

Offspring of hybrids are weak or infertile

12

Allopathic Speciation

The initial block to gene flow seems to have been a geographic barrier that isolated a population

13

Sympatric Speciation

A new species arises within the same geographic area as a parent species

14

Hybrid Zone

Regions in which species meet and mate, producing hybrids

15

Possible outcomes for a hybrid zone over time

Reinforcement
Fusion
Stability

16

Reinforcement

When hybrids are less fit than members of both parent species, we expect natural selection to reinforce reproductive barriers, thus reducing formation of unfit hybrids

17

Fusion

When the reproductive barriers between the two species are not strong. So much gene flow may occur that the Speciation process reverses, causing the two hybridizing species to fuse into one

18

Stability

Many hybrid zones turn out to be stable in the sense that hybrids continue to be produced. The two hybridizing species also maintain their integrity

19

Adaptive Radiation

Evolution of many diverse species from a common ancestor