natural selection and evolution

Natural selection

Evolutionary mechanism in which individuals that are better suited to their environment survive and reproduce most successfully [directly related to the environment and not random]

Artificial slection

Humans interfere in choosing traits that they desire.

Adaptation

Any heritable trait that improves an organism's ability to survive and reproduce in an environment

Variation*

The individuals of a population have many characteristics that differ.

Competition*

There are not enough resources, such as food, water, and shelter, to support an infinite amount of animals. That means environments have carrying capacities; only a certain number of individuals can survive there. {Struggle}

Heritable

how parents pass on some of their traits to their offspring.

Evolution*

the process by which different kinds of living organisms are thought to have developed and diversified from earlier forms during the history of the earth.

Evolutionary Fitness*

an organism's ability to survive and reproduce in its environment, compared to other members of its species

Advantage*

Individuals with advantageous traits will be able to survive better and pass the traits that led to their survival on to their offspring.

Directional selection

Selection of one extreme of a trait over the other in a population. (Shifts over time)

Stabilizing selection

Selection of the average or intermediate traits in a population

Disruptive selection

Selection of both extremes of a trait in a population (Often human behavior)

Causal

When one thing causes another thing to happen

Correlative

When two or more things appear to be related

Gene frequency

The number of copies of a particular allele divided by the number of copies of all alleles in that population. (AA/Aa/aa)

Gel Electrophoresis

a technique used to separate DNA fragments based on their size using an electric field

Phenotype

Visual appearance of gene

Genotype

Letter representing dominant and recessive genes

Overproduction

Every species tends to produce more individuals than can survive to maturity

Asexual reproduction

Direct clone (no variation)

Sexual reproduction

Leads to variation in a population

Biotic

relating to or resulting from living things, especially in their ecological relations.

Abiotic

physical rather than biological; not derived from living organisms.

Species

a group of living organisms consisting of similar individuals capable of exchanginggenes or interbreeding

Mutation

Mess up in DNA sequence sometimes causing disease

Meiosis

Process in differentiating daughter cells

Evolution (Law) : Natural selection (Theory)

Evolution: Over time, organism with these phenotypes (ie alleles/genotypes) will increase in the population.

Natural selection: The environment favors certain phenotypes. Organisms with those phenotypes will live to reproduce.

Environment

the surroundings or conditions in which a person, animal, or plant lives or operates.

Population

A community of animals, plants, or humans among whose members interbreeding occurs

Trait

a genetically determined characteristic.

Offspring

The baby of an animal

Ecosystem

a biological community of interacting organisms and their physical environment

Heterozygus

Having a recessive and dominant allele (Aa)

Homozygus

Having two of the same alleles (AA/aa)

Heterozygous advantage

Heterozygote advantage occurs when an individual possessing two different alleles for a gene has a higher fitness (survival and reproductive success) compared to individuals with two identical alleles (homozygotes)