CH3: Evolution by Natural Selection

Vocabulary flashcards covering key terms and concepts related to evolution by natural selection, based on Professor Pitcher's BIOL-2142 lecture notes.

Evolution by Natural Selection

A process where the proportion of different traits in a population changes over time due to individuals with certain traits having differential reproductive success.

Variation

Members of the population vary in the traits they display.

Inheritance

Offspring tend to resemble their parents, meaning variations among individuals are passed from parents to offspring.

Differential Reproductive Success

Individuals with certain traits are more successful than others at surviving and reproducing in their environment.

Fitness

The ability of an individual to survive and reproduce in its environment.

Adaptation

A trait or characteristic of an organism that increases its fitness relative to individuals without the trait.

Mutations

Generate variation and are a major source of variation on which natural selection acts, occurring randomly with respect to the needs of the organism.

Traits

The physical, behavioural, genetic, or physiological characteristics of an organism that are the object of explanation in evolutionary studies, focusing on how they change or remain constant over time.

Population Change

Natural selection is a process by which the traits of a population change over time, not those of an individual.

Genotype-Environment Interaction (GxE)

The interplay between an organism's genotype and its environment, which produces the phenotype that natural selection acts upon.

Phenotype

The observable characteristics of an organism, which are a product of its genotype interacting with the environment, and are directly acted upon by natural selection.

Reaction Norm

Describes how flexible or sensitive an organism's traits are to environmental changes, illustrating that a genotype can produce a range of phenotypes under different environmental conditions.

Model Systems for Natural Selection

Organisms frequently used to study natural selection, including Darwin Finches, Oldfield mouse, Trinidadian guppies, Sticklebacks, Drosophila, and E. coli.

Evolution in a bottle

A term used to describe laboratory evolution experiments, such as those with E. coli, designed to observe natural selection over many generations in a controlled environment.

Constraints on Natural Selection (Genetic Variation)

Limitations on what natural selection can achieve due to the restricted supply of new genetic variation available or an influx of genes from neighboring populations with different selective pressures.

Constraints on Natural Selection (Physical Laws)

Natural selection operates on physical structures and is thus constrained by the same physical laws that govern the material world.

Natural Selection (Lack of Foresight)

The characteristic of natural selection that it cannot anticipate the future; it favors changes that are immediately favorable in the present, not those that might be useful later, and has no predetermined goal.