Evolution and Natural Selection Flashcards

Flashcards about Evolution.

Biological Species Concept

Organisms that can interbreed and produce fertile offspring are considered the same species.

Morphological Species Concept

Organisms that look alike (have the same morphological traits) are members of the same species.

Phylogenetic Species Concept

Organisms that share identical gene sequences are the same species.

Macroevolution

The study of Evolutionary changes at the level of anatomical features.

Microevolution

The study of Evolutionary changes at the genetic (molecular) level.

Do individuals evolve?

Evolution occurs at the population level, not the individual level.

Population Genetics

The study of microevolution at the population level.

What is Population Genetics?

The study of how populations change genetically over time.

Modern Synthesis

Integrates Mendelian genetics with the Darwinian theory of evolution by natural selection.

Population

A localized group of individuals capable of interbreeding and producing fertile offspring.

Gene Pool

The total aggregate of genes in a population at any one time.

Hardy-Weinberg Theorem

Describes a population that is not evolving.

What does the Hardy-Weinberg theorem state?

Frequencies of alleles and genotypes in a population’s gene pool remain constant from generation to generation.

What preserves genetic variation in a population?

Mendelian inheritance preserves genetic variation in a population.

What can remove variation from a population?

Selection can remove variation from a population.

What happens if Extremely large population size rule is broken?

Evolution example: genetic drift

What happens if No Gene Flow rule is broken?

Evolution example: introduction of new alleles from one population into another that did not have them

What happens if No Mutations rule is broken?

Evolution example: postzygotic isolation

What happens if Random Mating rule is broken?

Evolution example: sexual selection

What is Genetic Bottleneck?

A Genetic Bottleneck is Drift that occurs because of massive mortality of most of the mating population

What results from Natural Selection?

Natural selection results from success in reproduction and accumulation of habitat-specific traits in a population.

What are the two types of reproductive barriers?

Prezygotic and Postzygotic

What results from descent with modification?

Descent with modification results from adaptation to the natural environment due to the process of natural selection.

What are modern living species descendants of?

Modern living species are descendants of older often extinct species.

What are the key points that Darwin provided overwhelming evidence for during his time in history?

Adaptation AND Natural selection

What did The Origin of Species challenged?

Challenged a worldview that had been prevalent for centuries.

What is Darwin’s Descent with modification?

Modern organisms are descendants of ancient organisms that can be different from the modern ones - Descent with modification.

Define evolution

Change over time, natural selection takes place because organisms must adapt to their environments to survive.

What created by The Galapagos Islands rose out of the sea because of Volcanic Activity?

A new habitat for animals to colonize

What causes adaptive radiation can occur?

When an ancestral species colonizes a new habitat.

What produce descent with modification?

Human selective breeding over the last 10,000 years has also produced descent with modification

What is One result of natural selection?

Populations become adapted for their habitats.

What is convergent evolution?

Sometimes the same selective pressures cause similar adaptive traits in different lineages

What are Homologous Characters?

Homologous characters are characters that descended with modification from a common ancestor

Descent with Modification

The phrase refers to the view that all organisms are related through descent from an ancestor that lived in the remote past.

What is Natural selection?

Differential success in reproduction.

Inference 1 (from Observations 1-3)

Production of more individuals than the environment can support leads to a struggle for existence among individuals of a population, with only a fraction of their offspring surviving each generation.

Inference 2

Survival depends in part on inherited traits. Individuals whose inherited traits give them a high probability of surviving and reproducing in a given environment have higher fitness and are likely to leave more offspring than less fit (adapted) individuals.

Inference 3

This unequal ability of individuals to survive and reproduce will lead to a gradual change in a population with favorable characteristics accumulating over generations.

What does Natural selection results from?

Natural selection results from change in the environment that favors adaptive traits from a population that has natural variation among individuals.