Evolution

Question 1

Creationism

Answer 1

a higher being created life on earth as we know it today

Question 2

Selection Pressure

Answer 2

• When resources are scarce, competition for resources occur and natural selection takes place
• Under high selection pressure, only the fittest survive

Question 3

Divergent Evolution

Answer 3

• The large scale evolution of a group into many different forms
• RIMs isolate population then gradually genetic differences accumulate
• homologous structures

Question 4

Convergent Evolution

Answer 4

• The evolution of similar traits in distantly related species that evolve under similar types of selection pressure
• analogous structures

Question 5

Parallel Evolution

Answer 5

-Two similar, genetically related species changing in similar ways but away from the ancestral type

Question 6

Isolation

Answer 6

-A population of a species cannot mate with any other populations of the same or similar species to produce viable offspring due to environmental factors such as distance or factors such as incompatible mating habits

Question 7

Adaptive Radiation

Answer 7

-Many different species develop from a common ancestor

Question 8

Gene Pool

Answer 8

-The complete set of all alleles contained within a population

Question 9

Genetic Variation

Answer 9

• The number of differences in alleles within a population
• The greater the variation, the more likely the chances of species survival in the event if a drastic change in the environment

Question 10

Gene Frequency

Answer 10

-Refers to the proportion of alleles that are of a particular type

Question 11

Mutation

Answer 11

-An alteration in an individual that differentiates it from the rest of the species in a way that may or may not be advantageous

Question 12

Genetic Drift

Answer 12

• The change in allele frequencies of a population due to chance
• Action on gene pool - random change in small gene pool due to sampling error in propagation of alleles

Question 13

Gene Migration

Answer 13

• The movement of genes in and out of a population due to chance
• Action on gene pool - change in gene pools due to immigration or emigration of individuals between populations

Question 14

Founder Affect

Answer 14

• A species is introduced to a new environment by a few members of the species
• The individuals survive and reproduce and a new population is formed
• can cause speciation

Question 15

Bottleneck

Answer 15

A large population undergoes a decrease in size so that relatively few individuals remain

Question 16

Single Gene Mutation

Answer 16

With mistakes in replication; one nucleotide switch may cause a change in a protein (eg. sickle cell anemia)

Question 17

Gene Duplication / Deletion

Answer 17

Error in DNA replication may cause a gene to repeat or be deleted
The new combination may lead to a variant form of the original protein

Question 18

Recombination

Answer 18

During meiosis, “crossing over” occurs between chromosomes which vares the combination of genes going together into separate gametes

Question 19

Adaptation

Answer 19

an inherited trait or set of traits that improve the chances of survival and reproduction of organisms

Question 20

Structural Adaptation

Answer 20

Adaptations which involve the modification of the composition or structure of an animal or plant

Question 21

Physiological Adaptation

Answer 21

Adaptations which involve the modification of chemical / enzyme production in an animal or plant

Question 22

Behavioral Adaptation

Answer 22

Adaptations which involve the modification of the actions of an animal or plant

Question 23

Non-Random Mating

Answer 23

inbreeding or selection of mates for specific phenotypes (assortative mating) reduces frequency of heterozygous individuals

Question 24

Natural Selection

Answer 24

individuals with the more desirable variations will survive and pass them on to future generations

Question 25

What is the Hardy-Weinberg equation?

Answer 25

p^2 + 2pq + q^2 = 1

Question 26

Directional selction

Answer 26

Occurs in response to an environmental stimulus which favors one form of a trait (peppered moth)

Question 27

Stabilizing selection

Answer 27

selection that favors the intermediate trait (birth mass fr humans)

Question 28

Disruptive selection

Answer 28

selection that favors phenotypes of both extremes (eg. butterflies changing to be orange or white to mimic poisonous butterflies)

Question 29

Sexual selection

Answer 29

- competition for mates (non-random mating) | - examples: mating calls, bright colours, fighting

Question 30

Palezoic era

Answer 30

590 - 250 MYA Cambrian period extensive diversification of life all fossils from this era are from the sea by the end of Ordovician period many modes of life had evolved including bottom feeders, scavengers, carnivores, and colonies

Question 31

What occurred during the invasion of land?

Answer 31

- only few phyla made it successfully to land - plants evolved from photosynthetic protists (green algae) - plant success is because of adaptations that protect against desiccation and provide support - success of insects due to body plan, structures for conserving water and exchanging gases - vertebrates invaded 360 million years ago - earliest were the amphibians - the ozone layer formed

Question 32

Mass Extinctions

Answer 32

- 5 major extinctions - the 4th / most drastic extinction occurred in the Permian period - 96% of all species of marine animals may have became extinct - the 5th major extinction occurred 65 MYA this was when the dinosaurs became extinct

Question 33

What were the causes of the extinctions?

Answer 33

- extinctions have multiple causes | - change in environmental conditions played an important role on regional scale

Question 34

Mesozoic Era

Answer 34

- 250 - 65 MYA - time of drought and glaciation - few kinds of marine organisms survived - ones that did began to evolve rapidly - the oldest flowering plant 127 MYA - diversified to become the dominant type of plant - dinosaurs became extinct 65 MYA - mammals appeared 200 MYA

Question 35

Cenozoic Era

Answer 35

- 65 MYA to present - extensive deserts formed in North America, the Middle East, and India - deteriorating climate - sharp differences in habitats - regional evolution - rapid formation of many new species

Question 36

microevolution

Answer 36

the change in allele frequencies within a single species or population

Question 37

Macroevolution

Answer 37

- evolution on a larger scale above the species level eg. flowering plants evolving from seeding plants - most often gradual evolution (stasis) - may be the result of catastrophism, the combined result is a punctuated equilibrium

Question 38

What are the mechanisms of macroevolution?

Answer 38

- stasis - exaptation - mass extinctions - adaptive radiation - co evolution

Question 39

Who came up with the idea of Pangea

Answer 39

Wegener

Question 40

What is the origin of life?

Answer 40

reactions due to hydrogen burning of alpha particles will produce other elements - carbon, oxygen, and nitrogen

Question 41

What were the earliest fossils?

Answer 41

cyanobacteria and stromatalites

Question 42

Process of fossilization

Answer 42

- often in freshwater / marine environments - dead organism is covered in sediment creates and anoxic environment - organic tissues (bone) are replaced by minerals

Question 43

Species

Answer 43

a group of populations that interbreed with each other in nature and produce fertile offspring

Question 44

Reproductive isolation

Answer 44

the end of gene flow between populations

Question 45

What are RIMs

Answer 45

Reproductive Isolating mechanisms that ensure that interbreeding between species is not successful

Question 46

What are the prezygotic isolating mechanisms (5)

Answer 46

1. Behavioral - mating calls differ 2. Temporal - mating seasons differ 3. ecological - mating environments / habitats differ 4. mechanical isolation - lock and key doesn't fit 5. Genetic - sperm wont penetrate the egg because it doesn't have the right chemical composition

Question 47

What are the postzygotic isolating mechanisms (3)

Answer 47

1. zygote mortality - offspring won't develop 2. hybrid in viability 3. hybrid infertility

Question 48

What is a common origin of new species?

Answer 48

- geographical separation - the split populations will likely be in different environments - adaptations will occur in each environment - the groups may encounter RIMs if they reunite after too long

Question 49

Intrinsic isolating mechanism

Answer 49

populations become so genetically different they develop biological characteristics that prevent effective breeding

Question 50

Extrinsic isolating mechanisms

Answer 50

geographical barriers that results in speciation

Question 51

Sympatic speciation

Answer 51

same native land - speciation without separation common in plants

Question 52

Allopatric speciation

Answer 52

the formation of extrinsic isolating mechanisms ex. great wall of China

Question 53

What were the earliest primates

Answer 53

prosimians (tree shrews, lemurs etc.) | -posses traits common to later primates - opposable thumb, acute sense of sight

Question 54

What are anthropoids

Answer 54

all primates other than prosimians, old and new world monkeys etc.

Question 55

Co-evolution

Answer 55

- two species interact so closely with one another, that they evolve together - a change for one will mean death for the other unless it changes as well

Question 56

What is the evidence for evolution?

Answer 56

- Evidence from the fossil record - molecular evidence - same DNA structure, code for amino acids the same way, - anatomy (homologous or analogous) - Vestigial organs (structures with no function ie. appendix)

Question 57

Homologous Structures

Answer 57

structures in different organisms with different functions likely the results of one common ancestor ex. pentadactyl limb

Question 58

Analogous structures

Answer 58

structures in different organisms with similar functions evolved due to similar selection pressures (wings on different animals)

Question 59

What was Darwin Wallaces theory of Natural Selection?

Answer 59

1. variations exist within a population 2. some variations have higher advantage than others (survival or to reproduce) 3. organisms have learned to produce more offspring that can can survive "survival of the fittest" 4. over time offspring of survivors will make up a larger proportion of the population "descent with modification"