U3: C16: Evolution

Question 1

Gene pool

Answer 1

total of all alleles in a population

Question 2

evolution

Answer 2

change in gene pool, via (natural selection, mutation, genetic drift, genetic shift)

Question 3

Theories of evolution x 4

Answer 3

1. Lamarcks: inheritance of acquired characteristics
2. Darwin: natural selection
3. Neodarwin
4. Punctuated equilibrium

Question 4

Inheritance of acquired characteristics

Answer 4

• is a theory of evolution, by Lamarcks.
• it believed that used traits evolved, and unused traits -atrophied.
• this theory is wrong, traits are inherited not acquired

Question 5

Darwin’s natural selection

beliefs

Answer 5

is a theory of evolution

1. few offspring survive and reproduce
2. chance variations due to mutation or recombination, that increase fitness (success for reproduction), will be selected for
3. survival of the fitness leads to increase of those favorable genes in gene pool
4. adaptation to environment cause organisms to separate into different species
5. macroevolution, takes long period of time, and stable

Question 6

Neodarwinism

Answer 6

is a theory of evolution

- that modifies natural selection so that not all traits had to be selected for, instead occur by gene population trends

Question 7

Punctuated equilibrium

Answer 7

is a theory of evolution

- evolution occurs in rapid bursts rather then gradually over time (ex: dinosaurs and mammals)

Question 8

Homologous structures

Answer 8

share common evolutionary origin and similar in structure, but may appear completely different. (ex: bat wings and mammalian arms)

Question 9

Analogous structures

Answer 9

different evolutionary origin but structure serves same function (dolphin fins and shark fins)

Question 10

Vestigial structures

Answer 10

remnant of organs that have lost ancestral function

Question 11

Hardy Weinberg Equilibrium
1. predicts
2. formula
(key pt)

Answer 11

1. phenotypicf allelic frequencies in a nonevolving population
2. p + q = 1, p^2 + 2pq + q^2 = 1 (p = dominant, q = recessive) (pq = heterozygous)
   - there is 2x as many genes as individuals in a population bc each individual has 2 autosomal copies of each gene.

Question 12

5 criteria of Hardy Weinberg Equilibrium

Answer 12

1. large population size
2. no mutations that affect the gene pool
3. mating is random
4. no net migration of individuals into our out of a population
5. genes in a population are all equally successful at reproducing (no natural selection)

Question 13

There is only brown and blue eyes in the population. If blue eyes is recessive and 36% of the population has blue eyes, find the pheonotypic frequency and gene frequency.

Answer 13

36% q^2 therefore q = .6
* q + p = 1, therefore p = .4
1. qq (blue eyes) = 36%
pp (brown eyes) = 16%
pq (heterozygous) = 2pq = 48%
2. 36% bb = 36% b allele, and 0% B allele
16 % BB = 0 % b allele, and 16% B allele
48% bB = 24% b allele, and 24% B allele
therefore 60% b allele, and 40% B allele

Question 14

Microevolution

Answer 14

violates the (Hardy Weinberg)

1. GENETIC DRIFT: random change in gene pool due to chance, it is more pronounced in small populations also referred to as founder effect, results from natural barriers or catastrophic events. (large population size)
2. mutation (no mutations that affect the gene pool)
3. assortive mating (mating is random)
4. GENE FLOW: migration of individuals leading to loss or gain of genes, therefore changing the populations gene pool. (no net migration of individuals into our out of a population)
5. natural selection (genes in a population are all equally successful at reproducing)

Question 15

Natural Selection Modes

Answer 15

change in population over long period of times (1000s-1 million years)

1. Stabilization: elimination of extremes
2. Directional: adaptive pressure lead to emergence of dominance of an initially extreme phenotype
3. Disruptive: both extremes selected for over the norm.
4. Group: natural selection acting on the group not the individual, explains altruism

Question 16

Altriuism

Answer 16

sacrifice the fitness of individual to beneift the group (family), which have similar genes with the individual. When the benefit outweighs the cost, this behavior is selected for.

Question 17

fitness vs inclusive fitness

Answer 17

1. ability to pass your genes, or reproduce

2. # of alleles passes on to the next generation, even if only indirectly through altruistic behavior.

Question 18

In order to be the same species it must meet 3 criteria

Answer 18

1. interbreed
2. produce fertile, viable offspring
3. do this randomly

Question 19

bottleneck

Answer 19

severe reduction i population size (from catastrophes)

Question 20

genetic drift

Answer 20

random changes in allele freq (effect of genetic drift increases as population size decreases)

Question 21

Speciation

Answer 21

different species, bc reproductive isolation

1. prezygotic (no zygote formation)
2. postzygotic (zygote can’t form viable offspring)

Question 22

Name the evolution patterns

Answer 22

what causes similarities bw 2 species

1. divergent
2. parallel
3. convergent

Question 23

divergent evolution

Answer 23

same lineage, evolving apart to be more different

-produces homologous structures (bat wings and horse hoofs)

Question 24

parallel evolution

Answer 24

same lineage, evolving closer together to be similar, using similar mechanisms/ mutations

Question 25

convergent evolution

Answer 25

different lineage, evolving closer together to be similar, using different mechanisms
-produce analogous structures (bat wings and butterfly wings)

Question 26

K selection

Answer 26

Natural selection, Fitness

• producing few number of offspring that mature slowly with lots of parental care
• sigmodial growth curve, carrying capacity (max number of organisms that an environment can maintain) level off

Question 27

R selection

Answer 27

Natural selection, Fitness

• producing large number of offspring that mature rapidly with little parenting care. High brood mortality rate
• population growth curve are exponential, generally found in unpredictable, rapidly chancing environment.

Question 28

Origin of life
Development 
1. organic molecules
2. RNA
3. protocells
4. prokaryotes
5. eukaryotes

Answer 28

1. organic molecules created by atm gases zapped by lightning, which falls into the ocean to make primordial soup. Miller’s experiment proved this in the lab
2. RNA world hypothesis: simple organic molecules formed RNA polymers that can self replicate (having enzymatic activity as well as serving as a template)
3. Protocells: aggregates of RNA, proteins inside lipid envelopes
4. Prokaryotes: first anaerobic heterotrophs bc early atm blocks the light req for photosynthesis, then anaerobic autotrophs that undergoes photosynthesis and makes oxygen, the aerobics that utilize oxygen.
5. Eukaryotas: evolved by endosymbiosis, where a big cell engulfed a smaller cell and then developed a mutualistic relationship. Hetertrophs engulfed mitochondria, autotrophs engulfed chloroplast.