Natural Selection Notes Biology

What is natural selection?

Natural selection is the process by which organisms that are better adapted to their environment survive and reproduce more.

What is an adaptation?

An adaptation is a change or trait that helps an organism survive in its environment and reproduce successfully.

What does fitness mean in biology?

Fitness is the ability of an organism to survive and reproduce more offspring compared to others in the population.

What is genetic variation?

Genetic variation is the genotypic and phenotypic differences among individuals in a population.

Why is genetic variation important?

Genetic variation is important because it increases the chance that some individuals will survive when the environment changes.

What is a beneficial adaptation?

A beneficial adaptation is genetic variation that helps an organism survive and reproduce.

How does natural selection work?

Natural selection works when the environment selects organisms with favorable traits, allowing them to survive and reproduce more.

What does natural selection cause?

Natural selection causes evolution to occur over time.

Who is the selective agent in natural selection?

The environment is the selective agent because it determines which traits are helpful.

How does population variation help a species?

Population variation increases the chance that a species will survive changing environmental conditions.

What does 'survival of the fittest' mean?

It means organisms with the best traits for the environment are more likely to survive and reproduce.

Who was Charles Darwin?

Charles Darwin was the scientist known as the Father of Evolution who proposed natural selection.

What did Darwin contribute to science?

Darwin proposed the mechanism for evolution called natural selection.

What is descent with modification?

Descent with modification means species change over time and develop traits that help them survive.

What does natural selection act on?

Natural selection acts on existing variation and phenotypes.

What is evolution?

Evolution is the change in the genetic makeup of a population over time as a result of natural selection.

What are the four steps of Darwin's theory of natural selection?

The four steps are overproduction, variation, competition, and selection.

What is overproduction?

Overproduction is when species produce more offspring than can survive.

Why do species overproduce offspring?

Species overproduce because not all offspring will survive to adulthood.

What is variation?

Variation is genetic differences among organisms within a population.

Why is variation important in a species?

Variation is important because it helps species survive environmental changes.

Why is more variation in a habitat helpful?

More variation means at least some species are likely to survive changes.

What is competition in natural selection?

Competition happens when organisms fight for limited resources like food, water, space, and mates.

What resources do organisms compete for?

Organisms compete for food, water, space, and mates.

Why do not all individuals survive to adulthood?

Not all individuals survive because of competition and environmental challenges.

What is mutualism?

Mutualism is a relationship where both organisms benefit.

What is commensalism?

Commensalism is a relationship where one organism benefits and the other is unaffected.

What is parasitism?

Parasitism is a relationship where one organism benefits and the other is harmed.

What is interspecific competition?

Interspecific competition is competition between organisms of different species.

What is intraspecific competition?

Intraspecific competition is competition between organisms of the same species.

What is selection in natural selection?

Selection is when individuals with the best traits survive and pass those traits to offspring.

Does natural selection act on genotype or phenotype?

Natural selection acts on phenotype, which is physical appearance.

What is genotype?

Genotype is the genetic makeup of an organism.

What is phenotype?

Phenotype is the physical appearance or traits of an organism.

When does evolution occur?

Evolution occurs when helpful traits build up over generations and harmful traits are removed.

What is ecosystem stability?

Ecosystem stability refers to how constant or changing an environment is.

How does a stable environment affect evolution?

A stable environment causes a slow rate of evolution.

How does a fast-changing environment affect evolution?

A fast-changing environment causes a fast rate of evolution.

What are biotic factors?

Biotic factors are living things in an environment, such as plants, animals, and bacteria.

What are abiotic factors?

Abiotic factors are nonliving things in an environment, such as water, temperature, and atmosphere.

What is directional selection?

Directional selection favors one extreme trait and selects against the other extreme.

Give an example of directional selection.

An example is favoring very tall plants while selecting against short plants.

What is stabilizing selection?

Stabilizing selection favors moderate traits and selects against both extremes.

What is disruptive selection?

Disruptive selection favors both extreme traits and selects against moderate traits.

What is artificial selection?

Artificial selection is the process where humans breed organisms for desired traits.

Give examples of artificial selection.

Examples include dog breeds and wild cabbage being bred into different vegetables.

Why does the environment matter in natural selection?

The environment determines which traits are helpful for survival.

Why are organisms with favorable traits more likely to reproduce?

They survive longer and have more chances to produce offspring.

What happens to unfavorable traits over time?

Unfavorable traits become less common as individuals with them die or reproduce less.

Why is natural selection important?

Natural selection is important because it explains how populations evolve and adapt over time.