Chapter 24

Question 1

why is it important to identify species

Answer 1

• endangered species
• medicine (malaria, etc.)
• biodiversity conservation effects

Question 2

how do we distinguish species?

Answer 2

1. morphological traits
2. the ability to interbreed
3. molecular features
4. ecological factors
5. evolutionary relationships

Question 3

microevolution

Answer 3

evolution on the small scale in allele freq. in a population

Question 4

macroevolution

Answer 4

• evolutionary changes that produce new species + groups of species
• predicted to take thousands to millons of years

Question 5

speciation

Answer 5

an ancestral species gives rise to one or more dependent species

(the point at which micro turns into macroevolution

Question 6

species concept

Answer 6

a way of defining a concept of a species, and providing an approach to differentiate 20 different concepts

Question 7

subspecies

Answer 7

2 or more geographically restricted groups of the same species display 1 or more traits that are different

However, not enough difference to be different species

Question 8

biological species concept

Answer 8

used to distinguish species, a species is a group of individuals whose members have the potential to interbreed with one another in nature to produce viable, fertile offspring but cannot successfully interbreed with members of other species.

Question 9

cryptic species

Answer 9

species whose differences are not physical; could be genetic, behavorial, or physiological

Question 10

evolutionary lineage concept

Answer 10

used to distinguish species; states that a species is derived from a single distinct lineage and has its own evolutionary tendencies and historical fate.

uses DNA

Question 11

ecological species concept

Answer 11

used to distinguish species; considers a species within its native environment and states that each species occupies its own ecological niche.

Question 12

general lineage concept

aka phlogentic concept

Answer 12

A widely accepted approach used to distinguish species; states that each species is a population of an independently evolving lineage.

Question 13

allopatric speciation

Answer 13

a form of speciation that occurs when a population becomes geographically isolated from other populations and evolves into one or more new species.

Question 14

sympatric speciation

Answer 14

a form of speciation that occurs when members of a species that initially occupy the same habitat within the same range diverge into two or more different species even though there are no physical barriers to interbreeding.

Question 15

habitat isolation

Answer 15

species occupy different habitats, so they never come into contact with each other

Question 16

temporal isolation

Answer 16

species have different mating or flowering seasons or times of day or become sexually mature at different times of the year.

Question 17

behavioral isolation

Answer 17

sexual attraction between males and females of different animal species is limited due to differences in behavior or physiology

Question 18

mechanical isolation

Answer 18

morphological features such as size and incompatible genitalia prevent 2 members of different species from interbreeding

Question 19

gametic isolation

Answer 19

gametic transfer takes place, but the gametes fail to unite with each other. This can occur because the male to female gametes fail to attract

Question 20

hybrid inviability

Answer 20

the egg of one species is fertilized by the sperm from another species, but the fertilized egg fails to develop past the early stages

Question 21

hybrid sterility

Answer 21

an interspecies hybrid survives, but it is now sterile

Question 22

hybrid breakdown

Answer 22

the F₁ species is viable and fertile but F₂ and so on become inviable over time

Question 23

secondary contact

Answer 23

formerly diverged population/species come back into contact with one another.
a.) hybridization returns all individuals to 1 population or species
b.) hybridization to create a new species in the hybrid zone
c.) reinforcement of the previous separation

Question 24

polyploidy

Answer 24

the condition in which a cell/organism has 3 or more sets of chromosomes

this is a gentic change that can cause immediate reproductive isolation

Question 25

polyploid hybrid speciation

Answer 25

genome is multiplied during hybridization, offspring can no longer interbreed with parental species, only with polyploids

Question 26

homoploid hybrid speciation

Answer 26

ploidy levels stays the same in offspring following hybridization

Question 27

gradualism

Answer 27

the rate of new species formation is relativley constant