Is supported by and makes sense of any osbservation

Theory

Homologous to ancestors, or common ancestors

Vestigial

Unique to a geographic area

Endemic species

Is a graded change in a trait along geographic areas

Cline

consists of the movement of alleles among populations
Alleles can be transferred through the movement of fertile individuals or gametes (for example, pollen)

Gene Flow

describes how allele frequencies fluctuate unpredictably from one generation to the next
tends to reduce genetic variation through losses of alleles

Genetic Drift

Sudden reduction in a population do to the environment changing

Bottle neck effect

Few individuals from a larger population become isolated from that larger group and start there own population

Founder Effect

Form of natural selection in which individuals with a certain inherit gene mate with another of the same have have successful mating

Sexual Selection

Makes the difference between the sexes, in the secondary sexual characterstics

Sexual Dorphism

Better chance at survival, and is most closely related to stabilizing selection

Heterozygous advantage

The regular occurrence of geological or meteorological disturbances

Catastrophism

Studied Fossil record with catastrophism

Cuvier

What did Darwin Study?

A mechanism for evolution that was supported by evidence

Why have giraffes developed longer necks over time?

Because trees got taller, and evolution to adapt with the environment

What is natural selection based on?

Genetic variation exists within the population, best adopted longer lives is more offspring,(Individuals with favorable traits are more likely to survive and reporduce)

Why is MRSA an example of artificial selection?

Because humans synthesis methacilin and create environment in which bacteria frequently come into contact with methicilin

How would can you explain the fact that human arms, bat wings, and dolphin flippers contain many of the same bones and have developed from very similar embryonic tissues?

Common ancestors and homologos selection

Why is acceptable to say all life on earth comes from a common origin?

All organisms are essentially the same genetic code

Why are old fossils found vs newer fossils?

Deeper in the rock

What are the three mechanisms that cause allele/gene frequency change?

Natural Selection, Genetic drift, and gene flow

What in an Organisms genes is most likely to help the organism respond properly to changes in its environment?

Natural Selection

is 52% of loci are heterozygous on average how many are homozygous?

48%

Why can't natural selection fashion perfect organisms?

1.Selection can only act on existing variations
2.Evolution is limited by historical constraints
3. Adaptions are often compromises
4. Chance, Natural selection, and the environment interact

Briefly explain what Hardy-Weinberg equilibrium means and what type of population it describes.

1.There are no Mutations
2.The mating is random
3.No natural selection
4. Large population
5. No gene flow
It Describes a Hypothetical Population that is not evolving

List and Describe the various mechanisms help to preserve genetic variation in a population.

Heterozygous advantage-Maintains two alleles between individuals
Diploids-holds chromosones
Natural Selection- genes that help mating good offspring

List and describe the 3 modes of selection

1. Directional selection- favors individuals at one end of the phenotype range
2. Disruptive selection- favors both individuals at the extreme ends of the phenotype
3. Stabilizing selection- favors intermediate phenotypes and acts against the extremes

Favors Indivudals at one end of the phenotpye range

Directional Selection

favors both individuals at the extreme ends of the phentype

Disruptive selection

favors the intermediate phenotypes and acts against the extreme phenotypes

Stabilizing selection

Evolutions above the species level

Macroevolution

Region in which members of different species reproduce hybrid offspring

Hybrid zone

group of a population, that from 1 split into 2

Speciation

List and describe the species concepts

States a species is a group of populations whose members have the potential to interbreed in nature and reproduce fertile offspring

Punctuated equilibrium model

describes the periods of apparent stasis punctuated by a sudden change

what are the Prezygotic Barriers?

habitat isolation
temporal isolation
behavioral isolation
mechanical isolation
gametic isolation

Two species encounter each other rarely, or not at all, because they occupy different habitats, even though not isolated by physical barriers

habitat isolation

Species that breed at different times of the day, different seasons, or different years cannot mix their gametes

Temporal isolation

Courtship rituals and other behaviors unique to a species are effective barriers

behavioral isolation

Morphological differences can prevent successful mating

Mechanical isolation

Sperm of one species may not be able to fertilize eggs of another species

Gametic isolation

What is the possible outcome when closely related species meet in the hybrid zone?

They reinforce the hybrids and diffuse into a single population

Analogous structures that evolve independently

Homoplasy

Much evolutionary change in genes and has no effect on fitness and is not influence by selection

neutral theory

What are the taxonomical levels

domain, kingdom. phylum, class, order, family, genus, species

What would the best classification system be based on?

Evolutionary History

what did the use of computers and software enable scientist to better study in the field of phylogeny?

The research of trees that are parsimonious and likely

In a cladistic approach to systematic, what is the most important for classification?

Shared derived characteristics

Why would species that are not closely related and that do not share many anatomical similarities still be placed together on the same phylogentic tree?

Homologous genes that are highly conserved

What would allow a gene to act as a molecular clock? which would not allow a gene to act as a molecular clock?

When its not acted upon and when it is mutated

Come from a common ancestor

Homology

Homoplasy, analogous structures

Homoplasies

Similarities and convergent evolution

analogous

decent with modification

evolution

modified other species by selecting and breeding individuals with desired traits

artificial selection

Consists of all the alleles for all loci in a population

gene pool

Differential success in reproduction results in certain alleles being passed to the next generation in greater proportions
For example, an allele that confers resistance to DDT increased in frequency after DDT was used widely in agriculture

Natural Selection

is the contribution an individual makes to the gene pool of the next generation, relative to the contributions of other individuals

Relative fitness

the fitness of a phenotype declines if it becomes too common in the population

Frequency-dependent selection