Chapters 13 and 14

Question 1

pre-Darwin Ideas

Answer 1

early Greek philosophers: Simpler life forms preceded more complex ones
Aristotle: Species are fixed and do not evolve
Judeo-Christian biblical view: All species were individually designed by a divine creator

Question 2

supporting ideas regarding Darwinian evolution

Answer 2

Buffon: Earth older than 6,000 years
Lamarck: inheritance of acquired characteristics
Lyell: geological processes that shape Earth are uniform through time

Question 3

what did Darwin observe on the HMS Beagle?

Answer 3

1. there are variations amongst species
   
   2. organisms are well suited to their environments
   3. organisms adapt to surroundings
   4. differences in organisms according to environments they inhabited

Question 4

how do fossils provide evidence for evolution?

Answer 4

they document changes that life has undergone over time

they show the transitional forms

Question 5

comparative anatomy

Answer 5

homologous structures
analogous structures
vestigial structures

Question 6

homologous structures

Answer 6

similar in structure, but in different organisms have different functions

Question 7

analogous structures

Answer 7

similar in function but not in origin

Question 8

vestigial structures

Answer 8

remnants of structures that had a function in an early ancestor

Question 9

comparative embryology

Answer 9

similarities in early development

Question 10

molecular biology

Answer 10

DNA/amino acid/protein comparisons

homeobox genes

Question 11

homeobox genes

Answer 11

master control genes, regulate groups of other genes during development

Question 12

artificial selection

Answer 12

1. supports the idea of natural selection

2. nature provides the variation, humans select favorites thus playing the role of the environment

Question 13

biogeography

Answer 13

1. geographical distribution of living species

2. supports common ancestry

Question 14

what is the significance of mutations?

Answer 14

Can create new alleles

Only mutations in cells that produce gametes can affect a population’s gene pool

Question 15

what is the significance of sexual recombination?

Answer 15

generates variation by shuffling alleles during meiosis

Question 16

population

Answer 16

individuals of a species that live in a given area at the same time

Question 17

gene pool

Answer 17

total collection of genes in a population at any one time

Question 18

microevolution

Answer 18

the change in the relative frequency of alleles in a population over several generations

Question 19

what are the five conditions of the Hardy-Weinberg principle?

Answer 19

1. very large
2. isolated (no migration)
3. no mutations in alleles
4. mating is random
5. no selection (ALL individuals = in reproductive success)

Question 20

what does p represent in H-W equation?

Answer 20

p = dominant allele

Question 21

what does q represent in H-W equation?

Answer 21

q = recessive allele

Question 22

genetic drift

Answer 22

change in gene pool of a population due to chance (the smaller the population the higher the impact)

Question 23

bottleneck effect

Answer 23

event that drastically reduces population size (natural disaster)

Question 24

founder effect

Answer 24

colonization of a new location by a small number of individuals (Darwin’s finches)

Question 25

gene flow

Answer 25

migration between populations reducing differences between populations current human populations

Question 26

evolutionary fitness

Answer 26

relative contribution an individual makes to the gene pool of the next generation best fit are those producing most fertile offspring selection indirectly adapts a population to its environment by acting on phenotype

Question 27

what are the types of selection?

Answer 27

stabilizing selection directional selection disruptive selection

Question 28

stabilizing selection

Answer 28

favors intermediate phenotypes

Question 29

directional selection

Answer 29

acts against individuals at one of the phenotypic extremes

Question 30

disruptive selection

Answer 30

favors individuals at both extremes of the phenotypic range

Question 31

why do no perfect organisms exist?

Answer 31

organisms are limited by historical constraints – come from ancestral forms. adaptations are often compromises. chance, natural selection, and the environment interact. selection can only edit existing variations.

Question 32

speciation

Answer 32

origin of new species

Question 33

species

Answer 33

population whose members interbreed naturally and produce fertile offspring

Question 34

hybrid

Answer 34

offspring of two different species

Question 35

reproductive barrier

Answer 35

biological feature preventing interbreeding

Question 36

prezygotic

Answer 36

prevent mating or fertilization

Question 37

prezygotic situations

Answer 37

``` habitat temporal behavioral mechanical gametic ```

Question 38

habitat (reproductive barrier)

Answer 38

lack of opportunities to meet

Question 39

temporal (reproductive barrier)

Answer 39

breed at different times

Question 40

behavioral (reproductive barrier)

Answer 40

failure to send/receive mating signals

Question 41

mechanical (reproductive barrier

Answer 41

physical imcompatibility

Question 42

gametic (reproductive barrier)

Answer 42

molecular incompatibility

Question 43

what is the difference between macroevolution and microevolution?

Answer 43

macroevolution is Darwinism - the big picture over millions of years microevolution is looking at the genes - it’s the DNA that changes that makes those big changes over time

Question 44

why can it be difficult to differentiate between two different species?

Answer 44

sometimes they may have similar features and still not able to reproduce sometimes two different species can reproduce

Question 45

postzygotic

Answer 45

operate after hybrid zygotes are formed

Question 46

reduced hybrid viability

Answer 46

interaction of parental genes impairs hybrid’s development/survival

Question 47

reduced hybrid fertility

Answer 47

hybrids develop/survive but are sterile

Question 48

hybrid breakdown

Answer 48

hybrids develop/survive but their offspring are weak or sterile

Question 49

convergent evolution

Answer 49

independent evolution of similar features in unrelated species analogous structures

Question 50

divergent evolution

Answer 50

species with common ancestry evolve differently | homologous structures