Natural Selection

Question 1

Logical theory that can be derived by the four testable postulates

Answer 1

1. individuals of a population differ from one another
2. the differences are, at least in part, passed from parents to offspring
3. some individuals are more successful at surviving and reproducing then others
4. the more successful individuals are not merely Lucky; they succeed because of the variant traits they have inherited and will pass to their offspring.

Question 2

Natural selection put in other words

Answer 2

• organisms produce more offspring than can be supported
• there is a constant struggle for to survive and reproduce
• individuals in populations vary in phenotypes, which are manifested of genotypes.
• some phenotypic variation is heritable (genotypes)
• individuals best adapted to current conditions are likely to survive and reproduce themselves (to adapt it must be to the environment and the biotic and abiotic conditions that have an impact on individuals ability to survive.
• if they adaptation are heritable , they will be passed on to their offspring

Question 3

What does natural selection act on?

Answer 3

Directly on phenotypes, only if there is a change in allele frequency in population, then evolution occurs

Question 4

population genetics

Answer 4

the study of allele and genotype frequencies, variation in frequencies across space and time and evolutionary factors that explain variation.

Question 5

Darwinian Evolution

Answer 5

if postulates hold true then the population will change gradually over time

Question 6

Evolution in a population results from

Answer 6

natural selection on individuals

Question 7

what kind of thinking does evolution require?

Answer 7

Statistical thinking - change in the frequency distribution of a trait in a population

Question 8

Fitness

Answer 8

ability of an individual to survive and reproduce in its environment

Question 9

How is fitness estimated?

Answer 9

1. counting the offspring of the individuals over their lifetime
2. determining the ability of individuals to survive some natural even/environmental condition. it doesn`t captures the lifetime reproductive success but their fitness in that moment

Question 10

How is fitness a relative term?

Answer 10

it is relative to fitness of other member of the population
a person with the higher level of fitness pass on more alleles to the next generation

Question 11

loci or locus

Answer 11

location, some place in the genome and doesn’t mean its a gene though it could.

Question 12

Gene

Answer 12

protein coding sequence

Question 13

Alleles

Answer 13

variants of a gene

Question 14

Adaptation

Answer 14

trait that increase the ability of an individual to survive and reproduce compared with individuals without that trait

Question 15

trait

Answer 15

any characteristic of an individual ranging from outward appearance to molecular

Question 16

Medium Ground Finch

Answer 16

peter and rosemary are accredited for this test of theory
- size of the beak is an adaption for them to eat and pick up the seeds, but the seed size is a function of the size of the beak

Question 17

Darwins Finches

Answer 17

• studied in the galapagos islands
  14 species of finches with different shape and sizes of beaks, these were adapted to their prey.

Question 18

Migration

Answer 18

seasonal movement

Question 19

Dispersal

Answer 19

movement away from the place it was born

Question 20

scientific benefits of species and area

Answer 20

1. dispersal is minimal, hardly do species move between between islands
2. population is small enough to be studied exhaustively

Question 21

Postulate 1

Answer 21

Individuals of a population differ from on another
- this is seen in finches, there is a range of beak sizes from 6-14mm

Question 22

Postulate 2

Answer 22

the differences are at lease in part, passed from parents to offspring
- variability in a train may be due to the environment, genetics or both

Question 23

Heritability

Answer 23

Proportion of the variability in a trait that is due to variation in the genetics among individuals
the finches when plotted would give a scatter plot if beaks depth did not depend on genetics, but if it did then the beak would be very close to a slope of one

Question 24

Postulate 3

Answer 24

some individuals are more successful at surviving and reproducing then others. in the finches there was a dry year, but 200 species did survive… what are the differences with those species?

Question 25

postulate 4

Answer 25

successful individuals have variant traits they inherited and will pass to offspring - for finches the average beak depth increase by a mm, there was still variation but more birds had larger beaks after the drought later years it returned to normal

Question 26

what are the differences with that were not fit enough to survive those species?

Answer 26

- the reason was the seeds did not grow due to drought and ones that were produced were larger and harder. - only finches with larger beaker were more likely to survive as they can consume the seeds