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Flashcards in Test 1 Deck (72):
1

what is science

-guided by natural phenomena
-objective explanations based on data
-feasible predictions
-iterative and self correcting
-complementary across disiplines

2

confirmation bias

seek out the evidence that supports our own view

3

cell concept/theory

all cells come from preexisting cells

4

assumptions of Hardy-Weinberg

no microevolutionary processes(genetic drift, gene flow, selection, mutation, nonrandom mating),, needs infinite population size, random mating is REQUIRED for HW

5

genetic drift

changes in gene pool due to random chance, increases with decreasing sample size, more likely with smaller populations, causes bottleneck and founder effect

6

bottleneck effect

disasters reduce population size resulting in a non-representative sample of gene pool

7

founder effect

colonization of a new habitiat by a few or single individuals decreases genetic variation

8

gene flow

genetic exchange of fertile individuals, new indiviudals moving in and out alter allele frequency, increases genetic variation

9

natural selection

only adaptive microevolutionary process, variations of traits result in better survival of individuals

10

mutation

random, point mutations are rare,- 10^9 per base pair

11

non random mating

interbreeding, may cause accumulation of hurtful alleles(interbreeding depression)

12

names of the 3 types of selection

stabilizing selection, directional selection, disruptive selection

13

stabilizing selection

middle forms have higher fitness and are favored by selection, does not change average value for trait but decreases variance... ex: baby size in child birth, don't want too small or do not want too big

14

directional selection

extreme forms at one of the ends of the distribution has higher fitness ...... ex: birds under a bridge

15

disruptive selection

both ends of distribution have higher fitness than the middle, no change in average but increases variance, vary rare

16

intersexual selection

females select males with specific triats

17

intrasexual selection

traits provide males with advantage in contests for access to females

18

runaway selection

creates exaggerated traits through a positive feedback look with female choice for males with extreme traits

19

discrete traits

categorical (dominant and recessive), (AA and Aa would have advantage)

20

quantitative/continuous traits

continuous variation, follow normal distribution, polygenic traits (steady decrease of advantage going from AA to Aa to aa)

21

epistasis

aka polygenic traits, multiple loci acting on a single trait (height, colors, patterns)

22

neutral theory

most mutations are neutral- genetic drift important bc random process

23

purifying selection vs positive selection

purifying-when there are more synonymous mutations, phenotype is maintained..
positive- more non synonymous mutations, so certain phenotypic traits are advantageous

24

Mullers ratchet

accumulation of deleterious mutations in gene linkages increases in non-recombining organisms

25

pseudogenes

functionless copies of entire gene

26

heterchrony

changes in the rates of development (ontogeny)

27

allometry

minor changes that regulate development can result in large changes in phentype

28

allometric growth

difference in growth rates for different parts of the body, (ex: human head is negative allometry)

29

heterotopy

changes in a regulatory gene results in a change of expression......Ex: ubx gene in insects(Distalless genes initiates leg development but Ubx mutation inhibits leg formation)

30

how do ducks get their webbed feet?

more Gremlin causes more webbing, gremlin expression inhibits BMP4

31

morphological species concept

based on taxonomy...morpholical, physiological and bicheical differences, difficult to define precisely

32

biological species concept

population or group of populations interbreed and create viable offspring

33

lineage species concept

new species begin at branching points and has an ancestor-descendant history

34

polymorphism

some species have more than one form although they are the same species

35

ring species

continuous gene flow can occur throughout the range but the two ends do not interbreed

36

allopatric speciation

geographic barriers isolate populations and function as barriers to gene flow

37

vicariance

splitting of populations by geologic events

38

peripatric speciation

aka dispersal, gene flow, or migration

39

sympatric speciation

separation of population is not a physical barrier, but differences in local environment or behavior

40

polyploidy, autopolyploidy, allopolyploidy

poly=increase in chromosomes
auto=same species produce 2n gametes
allo=2 species resulting in (2n+X) offspring

41

disruptive selection

natural selection is stronger than the effect of gene flow

42

incipient species

two populations/morphs on the verge of achieving reproductive isolation (still breed, but slowly separating)

43

prezygotic barriers

prevent fertilization and the formation of a zygote, spatial/habitat isolation, temporal isolation, mechanical isolation, gametic isolation

44

postzygotic mechanisms/barriers

prevent zygote from developing to a fertile adult, low hybrid zygote viability, hybrid infertility

45

temporal isolation

breeding at different times of the year...Ex; eastern and western spotted skunk

46

mechanical isolation

genital has evolved to not interbreed

47

gametic isolation

failure to form a zygote...ex: aquatic species sperm in water

48

low hybrid zygote viability

developing zygote dies due to genetic incompatibility

49

hybrid infertility

f1 hybrids are not fertile (ex: mules)

50

reinforcement

mechanisms that maintain the integrity of a species via reproductive barriers

51

Derived features

features that arose within the group, apomorphies

52

shared-derived charactersitcs

synapomophies(caused by homology)

53

homoplasy

similarity in function due to convergent evolution (independent events that have led to similar phenotypes)

54

parsimony

most likely explanation is one that implies the least amount of state change

55

monophyletic, paraphyletic, and polyphyletic groups

mono=contains ancestors and all decendants
para=does not contain all decendants of an ancestor
poly=more than one common ancestor

56

petrification

minerals in the groundwater seep into tissues of fossils

57

molecular fossils

retain organic material, provide DNA, ex: amber, freezing, mummificaiton

58

trace fossils

foot prints, burrows, leaf impressions....can infer behavior and ecology

59

absolute dating

radiometric isotope dating

60

relative dating

fossils from shallow, younger strata are more similar....fossils from deeper and older strata are more similiar

61

Mass extinctions

1-late ordovician
2-late Devonian
3-end Paleozoic (Permian)
4-late Triassic
5-Cretaceous-Tertiary
6-modern day

62

toxin in puffer fish

tetrodotoxin- blocks sodium channels

63

difference between Darwin and Lamarck

both presented convincing cases, but only Darwin was convincing on HOW it occured

64

sexual recombination

results in the elimination of harmful mutations

65

bioprospecting

search for plant and animal species which medicine and drugs can be obtained

66

how did differences in marine and freshwater sticklebacks arise

changes of a transcription factor

67

Jacobs notion of evolution as a tinkerer

nearly all evolutionary innovations are modifications of previously existing structures

68

what genes distinguish insects from arthropods

Insect UBX inhibits expression of Distalless whereas the Ubx of some arthropods activated Distalless expression

69

how could snakes develop hindlimbs

gain expression of sonic hedgehog

70

Ernst Mayr

most closely related to the biological species concept

71

Dobzhansky-Muller model of speciation

combinations of chromosomal rearrangements, interactions of genes, genetic divergence, different mutations occur in each of two descendant lineages

72

sequence in allopatric isolation

geographic barrier, genetic divergence, reproductive isolation