Evolution Part 1 School Test

Question 1

Theory of evolution

Answer 1

-states that all species are descendents of ancient species that were different from those that exist today
-refers to changes in characteristics of populations (occurring gradually) over many successive generations

Question 2

Animal characteristics

Answer 2

-aka “traits” controlled by genes
-each gene has two or more versions called alleles

Question 3

What is a gene pool

Answer 3

all of the alleles in all individuals of a specific population and shifts occur in evolving populations of species

Question 4

Mutation

Answer 4

The ultimate source of all genetic variation
• first step of evolution → creates new alleles
• 3 types: neutral, harmful beneficial
Change in DNA in an organism

Question 5

What is neutral mutation

Answer 5

Provide no benefit or harm to individual
(e.g. human hair colour)

Question 6

Harmful mutation

Answer 6

Reduce the reproductive success of the organism; therefore, less likely to accumulate in future generations (e.g. cystic fibrosis)

Question 7

Beneficial mutation

Answer 7

Gives the individual a better chance of survival (e.g. antibiotic resistance in bacteria or sickle-cell anemia in humans)

Question 8

Why do populations evolve?

Answer 8

to adapt to changing environments
• characteristics that are well suited to the environment are more likely to be passed on to future generations → results in shift in gene pools

Question 9

What were early ideas about evolution in early 400 bce?

Answer 9

-Europeans believed that Earth and all living things were created in Present forms
- it was believed that life was unchangable that the Earth was younge

Question 10

Who is James Hutton?

Answer 10

was the first to challenge the notion that Earth is young
• proposed Theory of Uniformitarianism which supported the idea that the earth was old and was formed by very slow moving process

Question 11

Who’s Jean-baptiste Lamarck?

Answer 11

-was the first to offer a possible mechanism for evolution
2 ways to distinguish Lamarck mechanism
-principal of use and disuse
-principle of acquired characteristics

Question 12

Principle of use and disuse

Answer 12

-Lamarks
-structures an individual uses become stronger, while structures that are not used become weaker
(Birds wings stronger—> offspring strong muscles)

Question 13

Principle of acquired characteristics

Answer 13

-Lamarks
-Individuals can pass on acquired characteristics to their offspring
e.g(if an adult giraffe stretches its neck during its lifetime, its offspring will be born with longer necks)

Question 14

What’s are some flaws with Lamarks theory?

Answer 14

-Organisms can acquire characteristics but many features do not change in response to use
-Features that change are not normally heritable because your DNA does not change in response to environmental pressures over time

Question 15

Who’s Georges Cuvier?

Answer 15

-conducted first detailed studies of fossils
-found fossils of complex organisms only at shallow depths
-fossils of simple organisms at all depths found that fossils at shallow depths resembles living species

Question 16

What were Cuviers conclusions

Answer 16

-gave strong support for theory that life evolved from simple to more complex forms over time
-lead to his theory of catastrophism global catastrophes caused caused widespread extinction
-accounted for different grouped of species in each layer, but did not account for why each layer included progressively more complex forms

Question 17

Who’s Charles Lyell

Answer 17

• expanded on James huttons ideas of uniformitarianism earth was changes by the same processes in the past that occur present
  -geological change is slow and gradual, rather than fast and catastrophic

Question 18

Who is Thomas Robert Malthus?

Answer 18

-stated that population size is limited by the environment and food supply
-helped Darwin come to the conclusion that members of the same species complete for their resources

Question 19

What did Darwin observed?

Answer 19

1. Species vary globally
2. Species vary locally
3. Species vary over time

Question 20

Species vary globally

Answer 20

-Darwin observed
-some areas have unique organisms not found anywhere else in the world(e.g kangaroos are found only in Australia)

Question 21

Species vary locally

Answer 21

-related species that occupy different habitats express different features; more obvious on islands(e.g tortoises of the Galapagos)

Question 22

Species vary locally

Answer 22

-related species that occupy different habitats express different features; more obvious on islands(e.g tortoises of the Galapagos)

Question 23

Darwins voyage

Answer 23

-began at age 22
-lasted t years(1831-1836)
-primary mission to survey ans map coastal waters of South America

Question 24

What is the climate of Isabela island?

Answer 24

-Higher above sea level
-greater rainfall
-abundant vegetation close to ground

Question 25

What is the climate at Espanola island?

Answer 25

-hot -dry -nearly barren with sparse vegetation higher up from the ground

Question 26

Species vary over time

Answer 26

-species living today resemble fossils of extinct species (e.g modern armidilow—> extinct glytodon)

Question 27

What are the two main points of Darwin’s book on the origin of species?

Answer 27

1. Descent with modification 2. Natural selection

Question 28

What is Natural selection?

Answer 28

the process by which individuals with inherited characteristics well suited to their environment leave more offspring than do individuals with adaptations less suited to the environment

Question 29

What is Descent with modification

Answer 29

all species today are descended from ancestral species

Question 30

What are some elements of natural selection?

Answer 30

1. Struggle for existence/survival of the fittest 2. Variation 3. The environment

Question 31

Struggle for existence/ survival of the fittest, variation, environment

Answer 31

1. Direct competition among individuals for limited resources—> results in only a small percentage of survivors in each generation 2. Heritable differences exist among members of the same species 3.favours individuals with variations that are best suited for that environment

Question 32

Evidence for evolution

Answer 32

1. The fossil record 2.geological distribution 3. Comparative anatomy 4. Comparative embryology 5. Molecular biology

Question 33

What is the fossil record?

Answer 33

-evidence of extinction -changes of organisms show in rock layers

Question 34

What is geographic distribution?

Answer 34

A)closely related but diff -geographic isolation causes development of adaptations eventually—> new species (eg galapagos tortoises) B)distantly related but similar -eg rodents similar body shapes—> beaver NA capybara SA

Question 35

What is comparative anatomy?

Answer 35

Evidence of evolution -a) homologous structures: similar structures(and origin) but different function (e.g vertebrate forelimbs aka hand to bat wing) -b) analogous structure : different structures (and origin) but similar function (e.g bee wing vs bird wing) -c) vestigial structures: no known structure, resemble ancestors (e.g reduced pelvic bones of whales —>terrestrial ancestors)

Question 36

What is comparative embryology?

Answer 36

Evidence of evolution -embryos of closely related organisms often have similar stages of development (all vertebrate embryos have gill slits and tail due to their common ancestory)

Question 37

What is molecular biology?

Answer 37

Evidence of evolution -two species that have similar amino acid sequences (DNA) likely share a common ancestry( e.g human and gorilla share one amino acid sequence)

Question 38

What is artificial selection?

Answer 38

- it is a captive breeding process whereby humans select specific animals or plants with desirable traits to breed in order to reproduce traits in the offspring - over 10000 years -wild mustard—> brocolli -grey worlf—> domesticated dog -wild tomato—> modern tomato

Question 39

What are the limitations of artificial selection?

Answer 39

-breeders have no control over the diversity that exists and the mutation that arise -e.g there is no gene for blue petal colour, no amount of crossbreeding will make blue rose)

Question 40

What are the two disadvantages of artificial selection?

Answer 40

1. Can reduce genetic diversity within a population-> makes population more vulnerable to disease 2. Some favorable traits are linked to alleles that are detrimental (e.g hip dysplasia in dogs)

Question 41

What is macro evolution?

Answer 41

-large scale evolution resulting in large scale structural and functional changes that lead to the formation of new species ( e.g amphibians evolving ton reptiles)

Question 42

What is micro evolution?

Answer 42

-small scale evolution resulting in changes in gene frequencies/traits within a species (e.g mosquitos evolving to be more resistant to pesticides)

Question 43

What are the mechanisms of micro evolution?

Answer 43

1. Natural selection 2. Sexual selection 3. Artificial selection

Question 44

What are the parts of natural selections?

Answer 44

A) stabilizing selection -eliminates both extreme phenotypes -intermediate phenotypes increases in population -most common type ( e.g average human birth mass =3-4 kg) B) directional selection -eliminates one extreme phenotype C) disruptive/diversifying selection -eliminates intermediate phenotype

Question 45

What are the parts of natural selections?

Answer 45

A) stabilizing selection -eliminates both extreme phenotypes -intermediate phenotypes increases in population -most common type ( e.g average human birth mass =3-4 kg) B) directional selection -eliminates one extreme phenotype C) disruptive/diversifying selection -eliminates intermediate phenotype

Question 46

What is sexual selection?

Answer 46

- favours traits that enhance mating success -may reduce survival ( e.g bright plumage) (E.g sexual dimorphism—> ,ales different from females of same species

Question 47

What is artificial selection?

Answer 47

- allows micro evolution to occur at a very fast pace

Question 48

What are alleles?

Answer 48

-different forms of a gene - every individual carries two alleles for each gene ( 1 paternal and one maternal) (E.g gene for fur colour in mice) B=black b=white

Question 49

What are the 4 factors changing allele frequencies?

Answer 49

Mutation, gene flow, genetic drift,selection - changes in allele frequencies in a population from one generation to the next is evidence of evolution

Question 50

What is mutation?

Answer 50

- a random change in dna base sequence of an organism -source of all new genetic info (only if they occur in gametes) -harmful ones occur frequently —> selected against - beneficial ones rare—> selected for—> accumulate over time

Question 51

What is gene flow?

Answer 51

A factor of changing allele frequency -random migration/ movement of individuals (and alleles) between populations - may be obvious (animals) or subtle ( pollen)

Question 52

What is genetic drift?

Answer 52

- changes in gene pool due to chance or random event -significant in small, isolated populations 2 types

Question 53

What is Bottle neck effect?

Answer 53

A type of genetic drift - severe reduction in population size due to a natural disaster (e.g flood, fire, disease) -most killed-> small assortment of survivors/alleles -e.g current cheetah population

Question 54

What is the founder effect?

Answer 54

A type of genetic drift -small group splits off from main population to start a new, isolated population ( e.g production of new species on Galápagos Islands -( e.g common genetic disorder Ellis-van crevald syndrome in Amish communities )

Question 55

What is selection?

Answer 55

- changes in gene pool due to selection by environment ( natural) or humans (artificial)