Bio Midterm

Front 1

Speciation requires

Back 1

Genetic isolation and genetic divergence

Front 2

Hardy Weinberg predicts:

Back 2

Random mating (gametes from gene pool combine at random, no choice in mate), No selection (all members of parental generatoin survive. Equal numbers of gametes to gene pool, no matter the genotype), No Genetic Drift (Alleles picked in exact frequencies, not different for random causes), No Gene flow (No nnew alleles are added by imigration or lost to emigration, all offspring alleles come from original gene pool), No Mutation (No new alleles in gene pool)

Front 3

Offspring genotype frequencies:

Back 3

P^2 + 2pq +q^2 = 1

Front 4

Allele frequencies;

Back 4

(P^2 + 1/2 pq genotypes)/total

Front 5

Evolution is:

Back 5

A change in allele frequencies

Front 6

If variation is low and environment changes

Back 6

Good chance of available alleles will enable survival and reproduction under new conditions but average fitness down)

Front 7

Purifying selection

Back 7

Disadvantageous alleles lower in frequency

Front 8

Directional stability

Back 8

Low fitness at one extreme of trait pushes average fitness in other direction). Variation down. Could lead to a freq of 1 and 0 at extremes

Front 9

Stabilizing selection

Back 9

Reduces both extrees, reduces variation but no change in average trait

Front 10

Disruptive selection

Back 10

Eliminates phenotype @ average, favors extremes. Increases variation and could lead to speciation)

Front 11

Balancing selection:

Back 11

No single alleles have a distinct advantage.

Front 12

Heterozygote advantage

Back 12

Causes balancing selection

Front 13

Frequency dependent selection

Back 13

Causes balancing selection, certain alleles favored when rare but not when common

Front 14

Selection always:

Back 14

improves fitness and leads to adaptation

Front 15

Aclimization

Back 15

Doesn't exist. Individuals don't change genotype over time

Front 16

Why to control:

Back 16

Affects dependent variable, elimiates outside variability, ,if we didn't we wouldn't know whether pre-controlled variable or independent caused results)

Front 17

Founder affect

Back 17

Kind of drift, uninhabited place occupied by new population whose allele frqeuncy is probably different from the source population.

Front 18

Bottleneck event

Back 18

Kind of drift, sudden reduction in the diversity of alleles in population. (probably environmental)

Front 19

Sacrificing for the good

Back 19

Would just select against itsself, no evolutionary sense \

Front 20

Population control

Back 20

Doesn't make evolutionary sense, it doen'st think ahead

Front 21

Inbreeding:

Back 21

Non random mating: Increases homozygosity and decreases heterozygosity (only heterozygote f1 produces heterozygote 1:2:1 ratio, and decreases every generation). Does not cause evolution becaue allele frequencies don't change (genotype frequencies do), but speeds up rate of evolutionary change (increases rae at which selection eliminates recessive deleterious alleles fromp pop)

Front 22

Selfing/Self-Fertilization

Back 22

Most extreme form of inbreeding

Front 23

Inbreeding depression

Back 23

Decline in average fitness that may take place when homozygosity increases and heterozygosity decreases because: Many recessive alleles represent loss of function mutations (most loss of function alleles exist in heterzygous individiuals). Homozygous recessive individuals are selected against

Front 24

Sexual selection

Back 24

Non-random mating: females actively choose certain males and/or males compete among themselves. Leads to changes in allele frequencies in the population and increases fitness (form of natural selection)

Front 25

Genetic drift

Back 25

causes allele frequencies to drift up and down randomly over time due to Blind luck (sampling error). Occurs in every population, in every generation, especially in small populations. Over time can lead to random loss or fixation of alleles.

Front 26

Genotype freq to allele freq in 3 alleles (6 genotypes)

Back 26

3 allele frequencies: Fr[P1] = (P1P1 + (1/2)P2P1 + 1/2 P1P3). Same for all, add homo + half of hetero

Front 27

Respond to change in environment

Back 27

Increase variation again by sexual reproduction maybe, or anything that would increaase likely hood of resistance increasting

Front 28

Gene Flow

Back 28

Movement of alleles between populations (individual leaves 1 population, joins another, and breeds). Equalizes allele frequencies etween source population and recipient population, become more alike (homoginizes). Presence or absenece of gene flow important for in threatened/endangered species. Affects fitness differently depending on situation

Front 29

Hamilton's rule:

Back 29

Br>C, B = benefit to recipient, C = fitness cost of the altruistic act to the actor, r = coefficient of relatednewss (how closely related they are). Altruistic behavior most likely when: Fitness benefits are high for recipient (high B), altruist and recipient are close relatives (high R), or fitness costs to the altruist are low (low C)

Front 30

Kin selection

Back 30

Selection that acts through benefits to relatives at the expense of the indivitual. Decreases direct fitness of individual but increases overall increase in inclusive fitness

Front 31

Biological Species concept

Back 31

Species can inter breed, different species if they can't produce fertile offspring. Hard to apply in populations that don't overlap geographically).

Front 32

Morphospecies concept:

Back 32

Identification evolutionarily by differences in size, shape, or other morphological features. Distinguishing features are most likely to arise if populations are independent and isolated from gene flow. Applicable to sexual, asexual, or fossil species. May lead to naming of two or more species when there is only one polymorphic species with diff phnotypes, doesn't identify cryptic species which differ in traits other than morphology, and morphological features are subjective. Different researchers caworking on the sae populations may disagree on the characters that distinguish species.

Front 33

Phylogenetic species concept

Back 33

Identifies species based on the evolutionary history of populations. (species related by common ancestry). Synapomorphy is a trait that is found in certain groups of of organisms and their common ancestor, which identify monoyletic groups (anscestral population and all of its descendants)

Front 34

Geographic isolation occurs

Back 34

In dispersal or vicariance (physical splitting of habitate)

Front 35

Chi-Squared test

Back 35

Overall probability that the observed and expected values are the same.

Front 36

Linear regression

Back 36

compares 2 continuous variables, calculates the line of best fit.

Front 37

Standard error

Back 37

Standard deviation estimated from sample.

Front 38

Test static

Back 38

Number that quantifies the magnitiude of difference between group. The larger the value the alrger the difference..

Front 39

R^2?

Back 39

Measure of how well regression line approximates the real data points. R^2 of 1 indicates the regression perfectly fits the data.

Front 40

T-Test

Back 40

Asses whether the means of two groups are statistically different from each other. Category vs Continuous