Evolution

Front 1

Evolution

Back 1

A change in a gene pool over time

Populations change, individuals do not

Front 2

Scientific Theory

Back 2

Anexplanation that is well founded with evidence

Front 3

Lamark's Theory

Back 3

-Evolution by acquired characteristics

- A giraffes neck becomes longer overtime because individuals stretch their necks to get food and pass this acquired characteristic onto their offspring

Front 4

Darwin's Theory

Back 4

-Darwin proposed evolution due to natural selection

- Differences in survival and reproduction among individuals due to environmental conditions

-Natural selection occurs when there are more individuals than the environment can support

- Interactionsbetween environment and variability within the population

-Mutation is by chance, natural selection is NOT by chance

-environmentis tree length, variability is giraffe neck length. The giraffes with longernecks eat more and survive and reproduce

Front 5

Four Postulates of Natural Selection

Back 5

1. Individuals within a population vary in their traits (genetic variation)

2. Some of these variations are heritable

3. A population can produce more individuals than can survive (limited resources, survival of the fittest)

4. Individualswith advantageous traits can survive and reproduce (Evolution occurs as advantageous traits accumulate)

Front 6

Biogeography

Back 6

Species that are closer in proximity are more closely related (marsupials in Australia)

Front 7

Comparative Anatomy

Back 7

Homologous structures have the same structural design (cats, humans, whales arm structure)

Front 8

Vestigial Organs

Back 8

Remnants of structures that may have had important functions in an ancestral species, but have no clear function in modern descendants. (hip bones in whales).

Front 9

Fossil Evidences

Back 9

Fossils show transitional species (show organism evolving between ancestral form and that of its descendants)

Front 10

Comparative Embryology and Development

Back 10

More closely related species have embryological development that are more similar

Front 11

Cellular and Molecular Evidence

Back 11

Closely related species have similar molecular structure (human amino acids vs monkey amino acids) and similar cellular processes

Front 12

Sexual Reproduction in evolution

Back 12

Increases genetic variation

Front 13

Mutation

Back 13

Increases variations in gene pool by randomly creating new alleles

Front 14

Gene Flow

Back 14

The exchange of genes between populations (immigration and emigration)

Front 15

Genetic Drift

Back 15

Random changes in allele frequency occurring in small populations through the bottleneck effect (change in size changes the distribution of alleles)

Front 16

Founder Effect

Back 16

When individuals that colonize a new area do not accurately represent the genetic frequency of the parent population

Front 17

Divergent Evolution

Back 17

One common ancestor evolves into two or more species (whales and humans)

Front 18

Convergent evolution

Back 18

Two distinct species become more similar overtime due to similar environments (solutions become the same)

Front 19

Coevolution

Back 19

Two groups evolve in response to one another (newt and garter snake)