Chapters 16-18

Question 1

evolution

Answer 1

genetic change in a line of descent over generations

Question 2

comparative morphology

Answer 2

study of similarities/differences in body plans between major groups

Question 3

Georges Cuvier

Answer 3

examined fossils; saw abrupt changes in fossil line; extinctions in history

Question 4

Jean Lamarck

Answer 4

environmental pressures and internal needs force changes in body form/fxn

Question 5

Charles Lyell

Answer 5

examined geology and saw earth formed by slow changes at worth

Question 6

Wallace

Answer 6

independently promoted evolution in a letter

Question 7

Malthus

Answer 7

said humans run out of resources when they reproduce beyond nature’s capacity to sustain life

Question 8

Darwin’s theory of evolution by natural selection

Answer 8

a population can evolve when individuals differ in at least one heritable traits responsible for differences in survival and reproduction

Question 9

population

Answer 9

• group of indiv. of same species occupying given area - charac by morph, phys, & behav traits

Question 10

gene pool

Answer 10

pool of genetic resources that is shared by all members of a population and then their offspring

Question 11

5 events shaping outcome of alleles in gametes

Answer 11

1. gene mutation 2. crossing over at meiosis I 3. indep assort. at meiosis I 4. fertilization 5. change in chrom#/structure

Question 12

genetic equilibrium

Answer 12

1. no mutations 2. no allele freq change at given gene locus stable for generations 3. very large population 4. isolated population from other species 5. gene has no effect on survival 6. mating is random

Question 13

factors changing allelic freq

Answer 13

natural selection gene flow genetic drift

Question 14

Hardy-Weinberg rule

Answer 14

p2 [AA] + 2pq [Aa] + q2 [aa] = 1 (sum of genotype freq = 1)

Question 15

Natural selection

Answer 15

diff. in survival & reproduction among indiv. of a population that differ in heritable traits; increased fitness

Question 16

5 Types of Natural selection

Answer 16

directional (allelic freq shift 1 direction) stabilizing (intermed favored) disruptive (extremes favored) balancing (all frms that maintain 2+ alleles) sexual (favor reprod success; dimorphism: persistence in phenotype)

Question 17

gene flow

Answer 17

• change in allelic freq as indiv leave/enter a population - immi/emigration - largest unit (species)

Question 18

genetic drift

Answer 18

random fluctuation in allelic freq over time due to chance alone - greater effect in small pop. (sampling error) - fixation -bottleneck, founder effect, inbreeding

Question 19

fixation

Answer 19

1 kind of allele remains; all indiv. are homozygous for it

Question 20

bottleneck

Answer 20

severe reduction in population size bc intense selection pressure or some calamity - founder eff: indiv establish elsewhere

Question 21

inbreeding

Answer 21

nonrandom mating among closely related individuals - form of genetic drift; homozygous condition - Ellis-van Creveld syndrome

Question 22

biological species concept

Answer 22

species is 1+ populations of indiv. that are - interbreeding naturally & producing fertile offspring - reproductively isolated from other populations

Question 23

speciation

Answer 23

where daughter species forms from population of parent species; gene flow must end

Question 24

pre-zygotic isolation mechanisms

Answer 24

temporal (times) mechanical (physical incomp) behavioral (missed sex cues) ecological (diff. places)

Question 25

gamete incompatability

Answer 25

reproductive cells meet, but not fertilization occurs

Question 26

post-zygotic isolation

Answer 26

hybrid inviability (hybrid embryos die early) hybrid sterility (can’t make fxnl gametes)

Question 27

allopatric speciation

Answer 27

most common speciation mechanism geographic barriers prevent gene flow between populations of a species interbreeding won’t occur even if indiv make contact later

Question 28

sympatric speciation

Answer 28

reproductive isolation of individuals in same home range; e.g. polyploidy

Question 29

parapatric speciation

Answer 29

adjacent populations give rise to new species while in contact; “hybrid zone”

Question 30

cladogenesis

Answer 30

branching lineages

Question 31

anagenesis

Answer 31

genetic and morphological change in unbranched lineage

Question 32

gradualism

Answer 32

slight changes over long time

Question 33

punctuated speciation

Answer 33

short time periods of change; bottlenecks and founder

Question 34

adaptive radiation

Answer 34

burst of divergences from a single lineage giving rise to new species; extensive branching

Question 35

microevolutionary processes

Answer 35

• mutation (original source of alleles) - gene flow (preserves species cohesion) - genetic drift (erodes species cohesion) - natural selection (depends on environ. pressures)

Question 36

macroevolutionary processes

Answer 36

• genetic persistence (basis of unity of life) - genetic divergence (basis of life’s diversity branching, radiation) - genetic disconnect (extinction)

Question 37

development of nuclear envelope

Answer 37

2 prok cells merged; envelope kept genomes separate

Question 38

endosymbiosis

Answer 38

by Lynn Margulis; a symbiont lives inside a host and the interaction supports one or both of them - mitochondria & chloroplasts evolved

Question 39

morphological divergence

Answer 39

comparable body parts modified in diff. lines of descent; homologous structures

Question 40

morphological convergence

Answer 40

dissimilar body parts evolved independently; analogous structures

Question 41

characteristics of prokaryotic cells

Answer 41

1. no membrane-bound nucleus 2. single chromosome 3. cell wall in most species 4. reproduction by prokaryotic fission 5. great metabolic diversity