Chapter 24 Vocab

Question 1

Speciation

Answer 1

The origin of new species

Question 2

Microevolution

Answer 2

Changs confined to a single gene pool

Question 3

Macroevolution

Answer 3

Refers to evolutionary change above the species level

Question 4

Biological species concept

Answer 4

Defines a species by a population or group of populations whose members have the potential to interbreed in nature and produce viable offspring but can’t produce viable offspring with other populations

Question 5

Reproductive isolation

Answer 5

The presence of biological barriers that keep two different species from creating hybrid offspring

Question 6

Prezygotic barrier

Answer 6

Prohibits mating of different species by preventing fertilization of ova or impedes mating

Question 7

Postzygotic barrier

Answer 7

Prevents the hybrid offspring from developing into a viable, fertile organism

Question 8

Habitat isolation

Answer 8

Two species are kept from creating offspring because while they live in the same region, they live in different parts and rarely cross paths

Question 9

Temporal isolation

Answer 9

Species that breed at different times of day, different seasons, or different years cannot mix gametes

Question 10

Behavioral isolation

Answer 10

Courtship rituals to attract mates and other behaviors are unique enough to keep even closely related species from mating

Question 11

Mechanical Isolation

Answer 11

Morphological differences prevent reproduction

Question 12

Gametic Isolation

Answer 12

Sperm of one species can’t fertilize the other

Question 13

Reduced hybrid viability

Answer 13

The parent’s genes may hinder its ability to develop

Question 14

Reduced hybrid fertility

Answer 14

Differences in parent gametes prevent the organism from reproducing, making them sterile

Question 15

Hybrid breakdown

Answer 15

Some hybrid offspring are not as viable and robust as their parents

Question 16

Morphological species concept

Answer 16

Characterizes species by body, shape, size, and features

Question 17

Paleontological species concept

Answer 17

Focuses on morphologically discrete species based solely on fossils

Question 18

Ecological species concept

Answer 18

Characterizes species based on its role in its environment

Question 19

Phylogenetic species concept

Answer 19

Defines species by their genetic histories and differences

Question 20

Allopatric speciation

Answer 20

Gene flow is interrupted when species are broken up into two geographical populations

Question 21

Sympatric speciation

Answer 21

Speciation takes place in geographically overlapping populations

Question 22

Polyploidy

Answer 22

Accidents during cell division that result in extra sets of chromosomes

Question 23

Autopolyploid

Answer 23

An organism that has two chromosomes sets, all originating from a single species

Question 24

Allopolyploid

Answer 24

Having two or more complete sets of chromosomes derived from different species.

Question 25

Adaptive radiation

Answer 25

The evolution of many diversely adapted species from a common ancestor upon introduction to new environmental opportunities and challenges

Question 26

Punctuated equilibrium

Answer 26

Periods of apparent stasis of a species punctuated by sudden change

Question 27

Exaptations

Answer 27

Structures that evolve in one context and become co-opted for another function

Question 28

Heterochrony

Answer 28

The evolutionary change in the rate or timing of developmental events

Question 29

Allometric growth

Answer 29

The proportioning that helps give a body its specific form

Question 30

Paedomorphosis

Answer 30

Reproductive elements accelerate compared to somatic development, causing the sexually mature age of a species to retain juvenile structures

Question 31

Homeotic genes

Answer 31

Genes that determine where and how limbs and features are placed and attached

Question 32

Hox genes

Answer 32

Genes that provide positional information in an embryo

Question 33

Species selection

Answer 33

The species that endure the longest and generate the most new offspring species determine the direction of major evolutionary trends