40S Unit 4 - Evolution

Question 1

what is evolution

Answer 1

the permanent genetic change in a population that occurs over successive generations

Question 2

define microevolution

Answer 2

the small-scale changes within gene pools over generations

Question 3

define macroevolution

Answer 3

the large-scale changes in form as viewed in the fossil record, involving whole groups of species and genera

Question 4

do populations evolve or do individuals evolve

Answer 4

populations evolve, not individuals

Question 5

what are the 7 evidences for evolution

Answer 5

1. paleontology
2. comparative anatomy
3. biogeography
4. embryology
5. artificial selection
6. biochemistry
7. molecular genetics

Question 6

define paleontology

Answer 6

the dating of fossils which gives us some of the most direct evidence of evolution

Question 7

define comparative anatomy

Answer 7

the study of the morphology of different species which shows trends in bone structure and function

Question 8

define biogeography

Answer 8

the study of geographic distributions which can indicate where species may have originally arisen

Question 9

define embryology

Answer 9

the study of embryonic development in different organisms which shows many trends in development of different species

Question 10

define artificial selection

Answer 10

selective breeding of plants and animals has shows that the phenotypic characteristics of species can change over generations as particular traits are selected in offspring

Question 11

define biochemistry

Answer 11

similarities and differences in the biochemical make-up of organisms can closely parallel similarities and differences in appearance

Question 12

define molecular genetics

Answer 12

sequencing of DNA and proteins indicates the degree if relatedness between organisms

Question 13

what is the central idea of biological evolution

Answer 13

all life on earth shares a common ancestor

Question 14

define divergent evolution

Answer 14

the process in which an ancestral species gives rise to new species that are adapted to different environmental conditions

Question 15

define an unopened ecological niche

Answer 15

the parts of the environment that have no species

Question 16

define homologous structures

Answer 16

similar structures that have changed overtime to be suited to the species current environment

Question 17

define adaptive radiation

Answer 17

common ancestor giving rise to several species suited to unique ecological niches

Question 18

define convergent evolution

Answer 18

unrelated species occupy the same environment and are subjected to similar environmental pressures. as they encounter similar environmental pressures, the organisms often develop analogous structures

Question 19

define analogous structures

Answer 19

structures that have the same function but come from different ancestors

Question 20

define vestigial structures

Answer 20

structures that once served a function in the species

Question 21

give examples of some vestigial structures

Answer 21

1. tailbone
2. wisdom teeth
3. inside corner of human eye
4. goose bumps
5. palmar grasp reflex

Question 22

state the 4 points of Darwin’s Theory of Natural Selection

Answer 22

1. organisms produce more offspring than can survive, leading to competition
2. variation is evident in populations and this is passed down to offspring
3. individuals suited to the environment survive to produce more offspring
4. change is slow and gradual

Question 23

define overproduction

Answer 23

more offspring are produced by an organism than can possibly survive

Question 24

define competition

Answer 24

high birth rates cause a shortage of life’s necessities leading to competition between organisms

Question 25

define variation

Answer 25

each individual differs from all other members of its species, some differ more than others

Question 26

define adaptation

Answer 26

allows organisms to become better suited to their environment

Question 27

define natural selection

Answer 27

the most fit (best adapted) organisms survive and reproduce

Question 28

define speciation

Answer 28

the formation of new species from ancestral species by means of natural selection

Question 29

what does it mean for an organism to be fit

Answer 29

organisms that are better adapted to their environment

Question 30

what are the types of adaptations

Answer 30

behavioral adaptations physiological adaptations structural adaptations

Question 31

define behavioural adaptations

Answer 31

the behavioral response a species has to their environment

Question 32

define physiological adaptations

Answer 32

when a species has a unique metabolic or physiological process that has adapted to suit the environment

Question 33

define structural adaptations

Answer 33

these affect the shape or arrangement of physical features of an organism

Question 34

define mimicry

Answer 34

allows one species to resemble another

Question 35

define camouflage

Answer 35

allows an organism blend into the environment to allow for survival

Question 36

what are the factors that may increase or decrease allele frequencies in a population leading to evolutionary change

Answer 36

1. mutations 2. gene flow 3. genetic drift (founder effect/bottleneck) 4. non random mating and & sexual selection

Question 37

define mutations

Answer 37

they introduce new alleles and variations into a population. the more the genetic variation, the greater the chance of a selective advantage in a changing environment

Question 38

define gene flow

Answer 38

the movement of alleles from one population to another through migation

Question 39

define genetic drift

Answer 39

a random increase or decrease in alleles often resulting from a small population

Question 40

define founder effect

Answer 40

when allele frequencies in a group of migrating individuals are not the same as that of their population of origin

Question 41

define the bottleneck effect

Answer 41

when populations undergo a dramatic decrease in size often due to a weather event, human impact, disease or predation

Question 42

define sexual selection

Answer 42

competition between males and mates

Question 43

what are the 3 types of natural selection

Answer 43

1. directional selection 2. stabilizing selection 3. disruptive/diversifying selection

Question 44

define stabilizing selection

Answer 44

individuals with common phenotypes ad favored and selected against those with extreme phenotypes

Question 45

define directional selection

Answer 45

individuals with rare phenotypes are favoured against common phenotypes

Question 46

define disruptive/diversifying selection

Answer 46

individuals with extreme phenotypes are favoured against the average