evolution

Question 1

biological evolution definition

Answer 1

heritable change in a population across one or more generations determined by genes caused by environment

requires genetic diversity

abiotic and biotic factors play a role in deciding if a trait will succeed in a particular environment

DOES NOT CREATE NEW TRAIT it selects and advantages those already existing

Question 2

microevolution vs macro

Answer 2

micro: small changes, but still same species
macro: lots of small changes leading to different species (or big change)

Question 3

ecological selection vs sexual

Answer 3

eco: survival is determined more by ecology than sexual reproduction

sex: survival determined more by sexual characteristics than eco

natural selection encompasses both

Question 4

morphological vs physiological vs behavioural

Answer 4

morpho: how it looks
physio: its function
behavioral: its in the name

Question 5

fossil

Answer 5

evidence of past life and their era of living
info about morphology or mammal usually and parts that dont decompose easily and only external
gives info on when they went extinct through the stratigraphic layers

Question 6

homologous features

Answer 6

similar structure, but different functions, hypothesized to come from common ancestor

Question 7

analogous structures

Answer 7

structures of organisms with seperate ancestries that adapt in similar ways because they have similar environments, comes from convergent evolution (evolution of features similar in distant groups)

Question 8

evolution tree

Answer 8

phylogenetic trees (hypothesis)

Question 9

vestigal structures

Answer 9

loss of fucntion of a feature because of adaptation to different modes of life

Question 10

horizontal gene transfer

Answer 10

gene trasnfer in bacterias for example, from individual to indvidual, as opposed to vertical gene trasnfer, from generation to generation

Question 11

population

Answer 11

a population is considered so if it can only reproduce with itself (due to geographic “isolation”)

Question 12

gene pool

Answer 12

all the alleles present in a population

Question 13

genetic equilibrium

Answer 13

frequency of alleles and gentype in a population’s gene pool remains constant

a sexually reproducing population will be at genetic equilibrium if all are met:
1-natural selection is not occuring
2-mating is random
3-no net mutation
4- large population (small ones tend to genetically drift)
5-no migration between populations

Question 14

fitness

Answer 14

ability to survive, find a mate, produce an offspring, and leave genes in next generation
How well adapted to environment

Question 15

natural selection

Answer 15

adaptive, adapts to the environment

Question 16

Sexual selection

Answer 16

Non random mat
Direct: two competitors fight
Indirect: attract partner

May have costs, such as energy consuming and attracting predator

Also non random mating that’s not adaptive, when similar genotypes are attached to each other, reduces variability genetic variation

Question 17

Non adaptive factors leading to evolution

Answer 17

Non random mating that’s not adaptive
Mutations
Genetic drift (bottleneck, founder effect)
Gene flow

Question 18

Genetic mutation

Answer 18

Random
Must be in gametes to be passed down
In eukaryotes, rates are low
Microorganism more often because of high speed of reproduction (binary fission)
Add variability, if no variability, no evolution

Point mutation: one nucleotide change
Chromosomal mutation: deletion, duplication, usually harmful

Question 19

Genetic Drift

Answer 19

Change in allele frequencies occurs from a random event that occurs in small population

Small populations more likely to change by random fluctuations

Question 20

Bottleneck

Answer 20

Sudden decrease in population size cause by adverse environment factors

Reduction in genetic diversity

Question 21

Founder effect

Answer 21

Individuals leave the original population and start a new one

New population has less genetic variability

Question 22

Gene flow

Answer 22

Transfer of alleles from one population to another (same species)
Recipient gains alleles, donor may lose alleles
Results from a movement of fertile individual gametes

Ex: horizontal gene flow

Can happen between different species, for example with prokaryotes, can rarely happen with eukaryotes