Evolutionary Mechanisms Part 2

Question 1

microevolution

Answer 1

change in a population!

Question 2

macroevolution

Answer 2

speciation

-extinction of dinosaurs

Question 3

mutation

Answer 3

• only mechanisms that produce new alleles

- random but natural selection edits them

Question 4

quantitative

Answer 4

• traits on a continuum

- ex. height and weight

Question 5

qualitative

Answer 5

• yes/no traits
• either you have it or you don’t
• dimples, albinism, widow’s peak

Question 6

natural selection

Answer 6

differential survival and reproduction of individuals in a population based on heritable variations in their phenotypes

Question 7

gene

Answer 7

a section of DNA that codes for a trait

Question 8

phenotype

Answer 8

observable traits

Question 9

genotype

Answer 9

genetic make-up

Question 10

allele

Answer 10

versions of a gene

Question 11

gene pool

Answer 11

all genetic information within a population

Question 12

recessive

Answer 12

allele masked by a dominant gene

Question 13

dominant

Answer 13

allele that if inherited, is always expressed

Question 14

population

Answer 14

all individuals of a single species that live together in one place and time

Question 15

species

Answer 15

group that can potentially interbreed and produce viable offspring

Question 16

mechanisms of evolution

Answer 16

• mutations
• gene flow
• genetic drift
• natural selection
• nonrandom mating (sexual selection and artificial selection

Question 17

Genetic drift

Answer 17

a totally random event that causes the allele frequency in a population to change unpredictably

Question 18

genetic drift key point:

Answer 18

• totally random:as opposed to natural selection, which is not random
• although genetic drift is an evolutionary mechanism it doesn’t produce adaptation
• reduces genetic variation
  
  • the fewer copies of an allele present in a population (the more rare the alleles) then the greater effect genetic drift will have

Question 19

True or false:

small population size means the loss of just a small number of alleles means the loss of a large amount in diversity

Answer 19

true

Question 20

circumstances in genetic drift

Answer 20

• founder effect

- bottleneck effect

Question 21

population bottleneck

Answer 21

when the population goes through a huge change that drastically reduces population, there will be a change in the frequency of alleles
-caused by catastrophes, manmade or natural

Question 22

founder effect

Answer 22

a special type of bottleneck when a small number of a population splinter off
-can be a driving force in development of new species

Question 23

gene flow

Answer 23

• the movement of alleles from one population to another
• new genes flow into existing populations
• migration
• pollen dispersal
• one population becomes 2 populations
  
  • natural barriers
  • manmade barriers

Question 24

cladogenesis

Answer 24

evolution that results in the splitting of a lineage

Question 25

anagenesis

Answer 25

evolution within a lineage

Question 26

speciation

Answer 26

the generation of a reproductively isolated species

Question 27

artificial selection

Answer 27

- when humans mess with nature - humans breeding certain plants or animals for certain traits - domesticity, food production, size, type - bred for work

Question 28

inbreeding

Answer 28

breeding of related organisms, tends to multiply recessive

Question 29

out crossing

Answer 29

breeding of completely unrelated organisms

Question 30

line breeding

Answer 30

milder form of inbreeding, a fluid term depending on species

Question 31

hybrid vigor

Answer 31

strength in selective outcrossing

Question 32

sexual selection

Answer 32

non random mating

Question 33

hermaphrodite

Answer 33

both sexes in one organism

Question 34

gender

Answer 34

the behavior, appearance, and life history of a sexed body

Question 35

sex

Answer 35

refers to size of the gametes. - male sperm=small - female egg= big

Question 36

sexual dimorphism

Answer 36

distinct difference in size or appearance between the sexes of an animal in addition to difference between the sexual organs themselves

Question 37

why do organisms have sex?

Answer 37

- facilitates sharing - is used for reconciliation of disputes - helps integrate new members to a society - used to form coalitions - is a commodity that can be traded - used for reproducing

Question 38

how does sex benefit organisms?

Answer 38

- maintains variability in a population - DNA repair - allows for mutation which leads to variations like crossing over, independent assortment, and sexual reproduction

Question 39

2 ways sexual selection is mediated

Answer 39

- intrasexual selection | - intersexual selection

Question 40

intrasexual selection

Answer 40

- fight each other, within one sex - sperm competition to make more sperm - prolonged copulation: stay hooked to females so no other male can get access - sperm is cheap and eggs are to take care of - females can be choosy

Question 41

intersexual selection

Answer 41

interaction between sexes

Question 42

infanticide

Answer 42

kill the other males' offspring

Question 43

copulatory plugs

Answer 43

plug females to prevent other males from copulating

Question 44

alternative strategies to doing it

Answer 44

- small males sneak in and deposit sperm | - males will act like and/or look like a female to sneak past other males

Question 45

hypotheses for choosy females

Answer 45

- sexy son hypothesis: they want their sons to be good looking - good gene hypothesis: their offspring will have a better chance at survival and reproducing