Exam 2 Powerpoints

Question 1

Analogous traits

Answer 1

similarities that are independently evolved or convergent

not used in cladograms

Question 2

branch points

Answer 2

speciation events

Question 3

Darwin described…

Answer 3

a “Great tree of Life”- the beginning of phylogenies- linked embryology, genetics, medicine, etc.
Organisms united by shared ancestry

Question 4

Pros & Cons of the Analysis of Fossils

Answer 4

P: Direct
C: fragmentary, hard to interpret

Question 5

phylogenetic analysis

Answer 5

compare similarities of organisms (molecular)

construct cladograms

Question 6

systematics

Answer 6

classification to reflect the phylogeny of organisms

Question 7

monophyletic

Answer 7

shared derived trains

an ancestor and all of its descendant

Question 8

polyphyletic

Answer 8

convergent similarity

analogous structures

Question 9

paraphyletic

Answer 9

an ancestor and some of its descendants

Question 10

Goal of Phylogenetics

Answer 10

monophyletic groups- accurately describe relationships

Question 11

Two Cladistic Methods

Answer 11

1. out group analysis

2. Parsimony

Question 12

taxon

Answer 12

group of similar and related individuals

Question 13

phylogeny

Answer 13

patterns of lineage branching produced by the truth evolutionary history of the organisms being considered

Question 14

cladistics

Answer 14

school of systematics using only homologous, shared derived characteristics

Question 15

clade

Answer 15

monophyletic groups- a group of species that includes an ancestral species and all of its descendants

Question 16

speciation

Answer 16

the origin of new species, is at the focal point of evolutionary theory

Question 17

microevolution

Answer 17

consists of changes in allele frequency in a population over time

Question 18

macroevolution

Answer 18

refers to broad patterns of evolutionary change above the species level

Question 19

species concept

Answer 19

members have the potential to interbreed

some hybridization is i.k. as long as it is natrual

Question 20

ecological

Answer 20

viewed in terms of a niche

Question 21

pre zygotic barriers

Answer 21

prevent formation of a zygote or fertilized egg

Question 22

post zygotic barriers

Answer 22

prevent development of viable or fertile offspring

Question 23

What separates species? (Prezygotic)

Answer 23

1. habitat isolation
2. temporal (timing) isolation
3. behavioral isolation
4. mechanical isolation
5. Gametic Isolation

Question 24

Habitat Isolation

Answer 24

Pre.
may occupy the same range and be potentially able to hybridize, but prefer different habitats so never (or rarely) mate.
(i.e. maggots)

Question 25

Temporal Isolation

Answer 25

Pre. may potentially interbreed, but are :ready" at different times (i.e. breeding times in frogs)

Question 26

behavioral isolation

Answer 26

pre. species may encounter each other, but do not mate because of differences in courtship or other behaviors (i.e. bird courtship & songs, firefly blink pattern)

Question 27

mechanical isolation

Answer 27

pre. differences in anatomy especially in flower and insects

Question 28

Gametic Isolation

Answer 28

pre. | gametes do not recognize each other due to different receptors

Question 29

What separates species post zygotically?

Answer 29

1. reduced hybrid viability 2. hybrid infertility 3. hybrid breakdown

Question 30

reduced hybrid viability

Answer 30

post hybrid offspring do not develop hybrid offspring do not survive as well (i.e. stickleback: Benthics vs. Limnetics)

Question 31

hybrid infertility

Answer 31

post the hybrids are not fertile (i.e. mules, Tigons etc.) *STERILE*

Question 32

hybrid breakdown

Answer 32

post | 1st generation hybrids are fertile, but 2nd generation are sterile or weak (i.e. in some plants)

Question 33

How do differences arise?

Answer 33

1. allopatric speciation | 2. sympatric speciation

Question 34

allopatric speciation

Answer 34

physical barrier divides population (vicariance) (i.e. rise of a mountain range, formation of a river/valley, changes in sea level, or migration to an island or a new habitat)

Question 35

adaptive radiation

Answer 35

(speciation on islands) | evolution of many diversely adapted species from a common ancestor

Question 36

Populations become different due to..

Answer 36

founder effect at outset (especially if one or both of the new populations are small) through genetic drift - natural selection under different conditions. May result in physical or behavioral differences that inhibit breeding even if contact is restored.

Question 37

Reinforcement

Answer 37

hybrid offspring have lower survival, so selection favors assortative mating hybrids gradually cease to form

Question 38

fusion

Answer 38

large areas of hybridization and highly fit hybrids may fuse the two species back into one Re-contact may overwhelm differences acquired in isolation

Question 39

sympatric speciation

Answer 39

no physical barrier separating diverging populations (ecological isolation, auto and allopolyploidy)

Question 40

allopoloploidy

Answer 40

hybridization and errors in meiosis lead to polyploid offspring with chromosomes from 2 different species

Question 41

Evolution is a tinkerer

Answer 41

when evolution gives something a function.... turns a leg into a wing or a part of a jaw into ear pieces

Question 42

macroevolutionary patterns

Answer 42

broad-sale patterns of change, diversification and extinction in the fossil road

Question 43

macroevolutionary patterns

Answer 43

1. gradualism | 2. punctuated equilibrium

Question 44

gradualism

Answer 44

classic darwin generally slow and constant change distinction among fossil species fairly arbitrary claims that gradual change is a predominant pattern

Question 45

punctuated equilibrium

Answer 45

emphasizes periods of stasis interspersed with periods of "rapid" change emphasizes that most change occurs at speciation

Question 46

what causes stasis?

Answer 46

stabilizing selection variable directional selection genetic/ developmental constraints

Question 47

6 origins of evolutionary novelty

Answer 47

1. exaptation 2. duplication 3. serial homology 4. heterochrony 5. lateral gene transfer 6. homeotic genes and pattern formation

Question 48

exaptation

Answer 48

evolution is a tinkerer | (i.e.