Evolution by popular genetics

Question 1

2 observations that led Darwin to his theory of natural slection

Answer 1

1. A population doesn’t over population because of limited resources
2. The struggle of life creates a completion amongst organisms to ensure that only the fittest remain

Question 2

Populations

Answer 2

Consists of organisms of the same species that live in the same area
- mating takes place within populations

Question 3

Evoultion and natural selection on a population

Answer 3

Evolution acts on populations and natural slection acts on indivusals

Question 4

Population gentics

Answer 4

The science that focused on evolution within populations

Question 5

Gene pool

Answer 5

The sun of all the alleles and all of the genes in all of the indivusals in a population

Question 6

Allele frequency

Answer 6

How often an allele occurs in a gene pool relative to the other alleles for that gene

Question 7

Evolution

Answer 7

Due to the change in allele frequency’s in a population over time
- unit of evolution = population

Question 8

Micro evolution

Answer 8

Occurs over a short period of time within a population
Ex: the beak sizes fo Darwin’s finches

Question 9

Macroevolution

Answer 9

Occurs over a geologic time above the level of the species
Ex: the fossil record

Question 10

The forces of evoultion

Answer 10

Mutations, gene flow, gentic drift, and natural selection

Question 11

Mutations

Answer 11

Changes int he dna sequences that are inevitable
If mutations occur in the gametes of sexually reproducing organism than the mutation can be passed down to the offspring
- muations alone dont have. A hug affect on alleles frequencies but they do provide new allies and gentic variation that the other forces need

Question 12

Gene flow

Answer 12

Occurs when individuals move into or out of a population
0 migration between populations can alter the distribution of alleles in differnt gene pools
Migration can allow Benifical alleles to spread

Question 13

Gentic drift

Answer 13

Random change in allele frequencies that occurs in a small population
- smaller populations are more vulnerable to gentic drift because they dont have the # to sustain their populations during hard times
- tends to reduce gentic variability in small populations and increase it in other populations

Question 14

Bottleneck effect

Answer 14

Occurs when a population suddenly gets much smaller due to a natural disaster such as a forest fire
- allele frequencies of the survivors may differ form the original population and it reduces gentic variability because some alleles are forcever lost

Question 15

Founder effect

Answer 15

Occurs when a few indivusals start are found a new population
- alleles frequencies of the founders may be drastically differnt form the alleles frequencies of the original population they left

Question 16

Natural slection

Answer 16

Occurs When there is a difference in fitness amongst members of a population
- changers in alleles frequency as some indivusals are more fit and reproduce than others
- it is the 1 thing that putts pressure on organisms to evolve
- acts on indivusals

Question 16

Malaria

Answer 16

A deadly tropical disease caused by a parasite/ enters the hosts blood though the bite of an infected mosquito and infects the red blood cells which can cause fevers

Question 17

Sickle cell anemia

Answer 17

(Ss) a harmful autosomal resscive disease that is caused by a mutation and resultes in sickle shaped red blood cells that can clog tiny blood vessels and cause pain

Question 18

Stabilizing selection

Answer 18

Occurs when the phenotype at both extremes of the graph are slected against/ favors the mean value and narrows the range of variation
EX: birth weight

Question 19

Disruptive slection

Answer 19

Occurs when phenotypes int he middle range are slected against which reuslts in 2 overlapping phenotypes

Question 20

Directional slection

Answer 20

Occurs when 1 of the 2 extreme phenotypes are slected for/ shifts twoards that 1 extreme
EX: giraffe necks/ antibiotic resistance

Question 21

Non random matting by sexual selection

Answer 21

Mating is based on phenotypes which will alter the allele frequency’s in the population
- the female picks the most fit male to mate with and certian traits will not be selected for which is similar top natural selection

Question 22

Hardy Weinberg principle

Answer 22

Shows that allele frequency’s do not change over time if certian condtions are not met

Question 23

Hardy Weinberg equilibrium

Answer 23

• no mutations (reuslts in no new alleles)
• no migration ( no one is moving into or out of the population)
• very large populations (can withstand natural disasters and have members left to reproduce)
• random mating (females wont be selective or males based on phenotypes)
• no natural selection (members will have an equal chance to reproduce)
  When conditions are met allele and genotype frequencies remain the same