The Origin of Species

Question 1

Microevolution

Answer 1

Changing allele frequencies in a population

Question 2

Speciation

Answer 2

The process by which one species splits into two or more species

Question 3

Speciation forms conceptual bridge between ____________ and ____________

Answer 3

Speciation forms conceptual bridge between microevolution ( change over time in allele frequencies in a population) and macroevolution (broad pattern of evolution above the species level)

Question 4

Evolutionary theory

Answer 4

Must explain how new species originate in addition to how populations evolve

Question 6

Reproductive isolation

Answer 6

The existence of biological factors (barriers) that impede members of two species from interbreeding + producing viable, fertile offspring

Question 7

Prezygotic barriers

what anf 5 types

Answer 7

Prevents fertilization
1. Habitat isolation
2. Temporal isolation
3. Behavioral isolation
4. Mechanical isolation
5. Gametic isolation

Question 8

Mechanical isolation

Answer 8

Similar species have structural differences in their reproductive organs

Question 8

Temporal isolation

Answer 8

Similar species reproduce at different times

Question 8

Habitat isolation

Answer 8

Similar species reproduce in different habitats

Question 9

Behavioral isolation

Answer 9

Similar species have distinct courtship behaviors

Question 10

Gametic isolation

Answer 10

Gametes of similar species are chemically incompatible

Question 11

Postzygotic barriers

what + 3 types

Answer 11

Reduce viability or fertility of hybrid
1. Hybrid inviability
2. Hybrid sterility
3. Hybrid breakdown

Question 12

Limitations of the biological species concept

Answer 12

can’t be applied to
1. Organisms about which little is known regarding the reproduction
2. Organisms that reproduce asexually all or most of the time (prokaryotes)

Question 12

The morphological species concept

Answer 12

Characterizes a species by body shape and other structural features

Question 13

Hybrid sterility

Answer 13

Hybrid survives to adulthood but is unable to reproduce

Question 13

Hybrid inviability

Answer 13

Hybrid dies at early stage of embryonic development

Question 14

Hybrid breakdown

Answer 14

Offspring of hybrid are unable to reproduce successfully

Question 15

The ecological species concept

Answer 15

Views of species in terms of its ecological niche

Question 17

The phylogenetic species concept

Answer 17

Defines a species as the smallest group of individuals that share common ancestor

Question 18

Speciation

Answer 18

development of a new species

Question 19

Speciation can occur in 2 ways

Answer 19

1. Allopatric speciation
2. Sympatric speciation

Question 20

Allopatric speciation

(3)

Answer 20

• Geographic barrier that separates populations
• Different selective pressures and differing environments act on two populations
• mutations arise and genetic drift alters frequencies

Question 21

Polyploidy - common for who

Answer 21

Far more common in plants than animals

Question 21

Symmetric speciation

Answer 21

Occurs in geographically overlapping populations when biological factors (chromosomal changes + non-random rating) reduce gene flow

Question 22

Polyploidy

Answer 22

Accident during cell division that results in extra sets of chromosomes

Question 23

Symmetric speciation

3 tpyes

Answer 23

1. Polyploidy
2. Habitat differentiation
3. Sexual selection

Question 24

Habitat differentiation

Answer 24

subpopulations within a single geographic area adapt to different ecological niches within their habitat

Question 25

Sexual selection

Answer 25

• increase in the efficiency of females in discriminating among males
• Mate choice based on male breeding coloration → main reproductive barrier that keeps them separate

Question 26

Rates of evolutionary change

2 types + explain

Answer 26

1. Gradualism: Evolution has a fairly constant rate
2. Punctuated equilibria: Periods where species appear suddenly, persist for a period, and then go extinct