Evolution

Front 1

Evolution: definition of term

Back 1

- a change in the genetic makeup of a population over time is termed EVOLUTION.

Front 2

Evidence of Evolution:

6 parts

Back 2

- Fossil Record

- Comparative Anatomy

- Comparative Embryology

- Comparative Biochemistry (Physiology)

- Vestigial Structures

- Geographic Barriers

Front 3

Evidence of Evolution: Fossil Record

fossil types (4)

Back 3

- terms:
> petrification - proces which minerals replace cells of organism.
> Imprints - impressions left by organisms
> molds - form in hollow spaces of rocks, org. within decays.
> casts - formed by minerals deposited in molds.

Front 4

Evidence of Evolution: Comparative Anatomy

Back 4

1. Homologous structures
> similar structure
> same origin

2. Analogous Structures
> similar structure
> different origin
> cannot be used as a basis for classification

Front 5

Evidence of Evolution:Comparative Embryology

human embryology?
> how similar to hydra (cnidaria) structure?
> how similar to flatworm (platyhelminthes)?
> how similar to fish?

Back 5

- human: 3 layers of gastrula (endo, ecto, and meso)derm
> similar to hydra because of 2 layer gastrula
> similar to flatworm because of 3 layer gastrula
> embryo has gill slits, indicate common ancestry.

- suggest common ancestry and development history
> not identical early development.

Front 6

Evidence of Evolution: Comparative Biochemistry (Physio.)

what structures/processes are very similar between organisms?

Back 6

- metabolic processes
> require same nutrients, same energy storage, similar enzymes.

- respiratory processes,
> similar enzymes

Front 7

Evidence of Evolution: Vestigial Traits

human

horse

python/whale

Back 7

- appendix and tail

- splints - remains of two side toes

- reduced or useless bones embedded in the sides of the adult.

Front 8

Evidence of Evolution: Geographic barriers

its in the title

Back 8

- barriers, seperated evolution, migration, blah blah

Front 9

Evidence of Evolution: Systematics and Cladistics

Back 9

- field of study that constructs and studies evolutionary relationships.
> phylogeny

- is used to classify organisms based on their phylogenetic relationships.
> cladograms are constructed to predict how an ancestor has evolved into its proposed descendants.
> clade: each subtree of the cladogram, members share a distinguishing characteristic.

Front 10

Theories of Evolution: Lamarckian Evolution

Back 10

- discredited theory

- evolution based on use or disuse of organ

- poor understanding of genetics

Front 11

Theories of Evolution: Darwin's Theory of Natural Selection

general definition

agents of evolution

Back 11

- pressures in the environment select for the organism most fit to survive and reproduce.

agents:
> Overpopulation
> Variations
> Competition
> Natural Selection
> Inheritance of the variations
> evolution of new species

Front 12

Darwin's Theory: Agents of Evolution (1 & 2)

Overpopulation

Variations

Back 12

- not enough resources/room, too many offspring = death

- offspring show differences in their characteristics compared to PARENTS.
> MUTATIONS

Front 13

Darwin's Theory: Agents of Evolution (3 & 4)

Competition

Natural Selection

Back 13

- developing pop. must compete for life needs.
> many young die
> adult population stays about constant

- some organism have variations that give them an advantage over others.

Front 14

Darwin's Theory: Agents of Evolution (5 & 6)

Inheritance of variations

Evolution of the species

Back 14

- organisms that survive live to adulthood, reproduce, pass traits to offspring. genes begin to dominate gene pool.

- advantageous variations in a species begins to accumulate, new species born.

Front 15

Forces of Evolution:

3 types

Back 15

- Population Genetics

- Microevolution

- Speciation

Front 16

Forces of Evolution: Population Genetics

gene pool? gene frequency?

p? q?

Back 16

- sum total of all alleles for any given trait in a population
- decimal fraction representing the presence of an allele in a population.

- p represents the frequency of the dominant allele

- q represents the frequency of the recessive allele

- p + q = 1 for a given locus.

Front 17

Forces of Evolution: Hardy-Weinberg Principle

Back 17

- large pop., no mutation, no migration, gene neutrality, random mating,

- p^2 + 2pq + q^2 = 1
(TT) (Tt) (tt) -------frequencies

Front 18

Forces of Evolution: Microevolution

agents of microevolution?

Back 18

- represents real populations

- agents:
> Natural selection
> Mutation
> Assortive Mating
> Genetic Drift
> Genetic Flow

Front 19

Microevolution: Agents (1 & 2)

Natural Selection

Mutation

Back 19

- favorable genotype variations selected, frequency of these genes increases. other genotypes disappear

- gene mutations change allele frequency in pop.

Front 20

Microevolution: Agents (3, 4, 5)

Assortive Mating

Genetic Drift aka founders effect

Genetic Flow

Back 20

- mates are not randomly chosen, they are chosen on criteria of phenotype and proximity, genotype ratio's affected.

- changes in composition of the gene pool due to chance.
> more in small populations

- migration of individuals btwn pop.'s will result in loss or gain of genes. changes gene pool.

Front 21

Forces of Evolution: Speciation

5 parts

Back 21

- Demes

- Development of New Species

- Adaptive Radiation

- Evolutionary History

- Isolation

Front 22

Speciation: Demes

Back 22

- small local population of interbreeding organisms of same species

- members of demes affected by the same environmental factors and selective processes.

Front 23

Speciation: Development of New Species

Back 23

-gene pools become different within species significantly

- two individuals cannot mate and make fertile offspring.
> two species have developed.

Front 24

Speciation: Adaptive Radiation

Back 24

- emergence of a number of lineages from a single ancestral species.

Front 25

Speciation: Evolutionary History

convergent evolution?

parallel evolution?

Back 25

- groups on different branches develop in similar ways when exposed to similar environment

- two species experience similar, yet different geographical environments

Front 26

Speciation: Genetic Isolation

divergent evolution?

Back 26

- results often from geographic isolation of a population in two groups
> no gene flow.

- any differences from mutations or new combinations of genes will be maintained in the isolated population.