AP BIO CH 19 & 21

What did Malthus do?

theorized that populations can grow faster than resources are made

What did Darwin observe?

differences among island species

What are antibiotics?

medicines that kill or slow down the growth of bacteria

What is genetic drift?

random change in allele frequency

what is natural selection?

The idea that the fittest survive and pass along their traits to their offspring.

What is gene flow/migration?

Movement of individuals of a species from one population to another

What is Hardy-Weinberg equilibrium?

states that allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences.

what does homologous mean?

having the same structure

What is a vestigial structure?

A structure that was once used in earlier descendants but lost its use over time

Evidence of Evolution

• fossils
• similar structures
• geographic distribution

What does terrestrial mean?

Land based

what is needed for evolution to occur?

variation, , selection, time

What is the founder effect?

small group from a population colonizes a new area

in a sickle cell, individuals who are homozygous dominant are more likely to suffer from malaria (T OR F)

True

what is the original source of genetic variation?

mutations

what is genetic variation?

differences that occur in individuals within a species

What is the bottleneck effect?

A change in allele frequency following a dramatic reduction in the size of a population

What is directional selection?

when individuals at one end of the curve have higher fitness than individuals in the middle or at the other end

What is stabilizing selection?

when individuals near the center of the curve have higher fitness than individuals at either end

What is artificial selection?

The breeding of plants and animals to produce desirable traits

darwins view on heritable traits

Characteristics acquired during an organisms life are not passed on through genes.

lamarks views on heritable traits

Characteristics acquired during an organisms life are passed on through genes. The idea of use and disuse as a selective measure

Why is Charles Darwin noted for his work in natural selection and evolution?

Devised a mechanism for evolution that was supported by evidence.

What are the principles guiding the idea of natural selection?

-the best-adapted individuals tend to leave the most offspring.
-individuals who survive longer tend to leave more offspring than those who die young.
-populations tend to produce more individuals than the environment can support.
-genetic variation exists within populations.

what does natural selection act on?

phenotypes

What can evolve?

population (not individuals)