chapter 13

Question 1

who proposed the theory of natural selection

Answer 1

Darwin & Wallace

Question 2

what are the four characteristic features of natural selection

Answer 2

**overpopulation–> more organisms are produced than can possibly survive

**inherited variations within species–> without variations, survival would be a matter of chance

**competition–> because of overpopulation, there will not be enough space, food etc leading to competition

**survival of the fittest–> some variations make individuals better competitors than others which will give rise to more successful variations in the next generations

Question 3

how is fitness measured

Answer 3

biological fitness measures the relative reproductive success of an individual relative to others in the population

Question 4

what is taxonomy

Answer 4

the diversity of organisms in different groups by how they are related to common ancestor

Question 5

who developed the binomial system & what are the two parts of a scientific name

Answer 5

Linnaeus
Genus–>first name of the binomial system
Epithet–>second name of the binomial system

Question 6

what is the unit of evolution

Answer 6

microevolution

Question 7

what is the evolutionary role of mutations

Answer 7

they are the original source of genetic variations

Question 8

what is genetic drift & what are two examples of genetic drift

Answer 8

random changes in a gene pool of a small population due to chance;;;

–>bottleneck effect–> size of a population reduced drastically by natural disasters such as volcanic eruptions;

–>founder effect –> when a few individuals colonize a new habitat, genetic drift is likely to occur

Question 9

what are directional, stabilizing, and diversifying selection, what are examples of each

Answer 9

all operate on the same principle that individuals with certain forms of a trait tend to survive and reproduce better than other individuals with different forms of that trait;;;;;

**directional–>favors variants of one extreme

**stabilizing–>intermediate variants by selecting against extreme variants

**disruptive[diversifying]–>favors bot extreme variants over the intermediate variants

Question 10

what is balanced polymorphism & what is an example of balanced polymorphism

Answer 10

balanced polymorphism–>maintenance of harmful genes at unexpectedly high frequency;

a phenomenon in which the loss of the harmful recessive gene through the deaths of the homozygotes is balanced by the grain from larger number of offspring produced by the favored heterozygotes