chapter 12: the origin and diversification of life on earth

Question 1

shortcomings of the biological species concept

Answer 1

1. classifying asexual species
2. classifying fossil species
3. determining when 1 species has changed into another
4. classifying ring species
5. classifying hybridizing species

Question 2

ring species

Answer 2

2 non-interbreeding populations may be connected by gene flow
- no exact point where 1 species stops and another begins

Question 3

hybridization

Answer 3

interbreeding of closely related species

Question 4

morphological species concept

Answer 4

characterize species based on physical features such as body size and shape
- choice is subjective: can be used to classify asexual species
- doesn’t require knowledge of whether individuals can interbreed

Question 5

specification

Answer 5

process by which 1 species splits into 2 distinct species
1st phase: reproductive isolation
2nd phase: genetic divergence

Question 6

genetic divergence

Answer 6

2 populations evolving separately accumulate physical/behavioral differences

Question 7

allopatric separation

Answer 7

occurs when a geographic barries cause one group of individuals in a population to be reproductively isolated from another group

Question 8

sympatric speciation

Answer 8

speciation that results not from geographic isolation but from polyploidy/hybridization/alloloyploidy

Question 9

polyploidy

Answer 9

doubling number of sets of chromosomes

Question 10

systemics

Answer 10

modern approach to classification
- goal of reconstructing evolutionary history(phylogeny) of orgnaisms

Question 11

specification event

Answer 11

point in evolutionary history at which a given population splits into independent evolutionary lineage

Question 12

modes

Answer 12

point on evolutionary tree at which species diverge from a common ancestor

Question 13

monophyletic

Answer 13

describe any group in which all individuals are more closely related to each other than to any individuals outside group (birds and crocs)

Question 14

convergent evolution

Answer 14

occurs when populations of different organisms live in similar environments and so experience similar selective forces

Question 15

analogous traits

Answer 15

characteristics that are similar because they were produced by convergent evolution

Question 16

homologous features

Answer 16

features that are inherited from a common ancestor
- result of natural selection not relatedness

Question 17

macroevolution

Answer 17

evolutionary changes involving origins of entirely knew groups of organisms

Question 18

microevolution

Answer 18

changes in allele frequencies within a population

Question 19

punctuated equilibrium

Answer 19

theory about the tempo of evolution, long periods of relatively little evolutionary change interrupted by brief periods of rapid evolutionary changes (opposite is creep)

Question 20

adaptive radiation

Answer 20

occurs when small number of species diversify into larger number of species

Question 21

3 phenomena trigger adaptive radiation

Answer 21

1. mass extinction events
2. colonization events (new place new resources)
3. evolutionary innovations

Question 22

extinction

Answer 22

complete loss of all individuals in a species population

Question 23

mass extinctions

Answer 23

large number of species become extinct over a short period of time due to extraordinary and sudden environmental change

Question 24

background extinctions

Answer 24

occur at lower rates during times other than mass extinction

Question 25

microbes

Answer 25

microscopic organisms : between plants and animals

Question 26

3 domains

Answer 26

bacteria; archaea; eukaryote

Question 27

horizontal gene transfer

Answer 27

transfer genetic material directly into another species (bacteria)

Question 28

viruses

Answer 28

4th group but not included because they’re not technically living

Question 29

5 groups of archaea

Answer 29

1. thermophiles
2. halophiles
3. high and low pH tolerant archaea
4. high pressure tolerant archaea
5. methanogens

Question 30

protists

Answer 30

consists of all single-celled eukaryotes

Question 31

7 classifications of animals

Answer 31

kingdom; phylum/division; class; order; family; genus; species