Evolution and Natural Selection Exam Review

Flashcards created to help review key concepts from the lecture notes on evolution and natural selection.

Natural Selection

The process whereby organisms better adapted to their environment tend to survive and produce more offspring.

Genetic Drift

A mechanism of evolution due to random fluctuations in the frequencies of alleles from one generation to the next.

Gene Flow

The transfer of alleles or genes from one population to another, which can increase genetic diversity.

Speciation

The formation of new and distinct species in the course of evolution.

Phylogenetic Tree

A diagram that represents evolutionary relationships among various biological species based on similarities and differences in their physical or genetic characteristics.

Homozygous

An organism that has two identical alleles for a trait.

Heterozygous

An organism that has two different alleles for a trait.

Codominance

A genetic scenario where both alleles in a heterozygote are fully expressed.

Disassortative Mating

A mating pattern where individuals with dissimilar phenotypes mate with one another more frequently than would be expected.

Müller’s Ratchet

A process by which the genomes of asexual populations accumulate deleterious mutations in an irreversible manner.

Sexual Dimorphism

Differences in appearance between male and female members of the same species.

Fraternal Birth Order Effect

A phenomenon where the likelihood of a male being homosexual increases with the number of older brothers he has.

Red Queen Hypothesis

A theory that suggests that organisms must constantly adapt and evolve to survive against ever-evolving opposing organisms.

Ultimate Causes of Same-Sex Behavior

The evolutionary reasons why a trait or behavior, such as homosexuality, may persist in a population despite being non-reproductive.

Parental Investment

The time and resources that parents provide to their offspring to ensure their survival.

Sexual Selection

A form of natural selection where individuals with certain traits are more likely to obtain mates than others.

Allele Frequency

The relative frequency of an allele (variant of a gene) at a genetic locus in a population.

Transcription

The process of copying a segment of DNA into RNA.

Translation

The process in which cellular ribosomes create proteins based on the genetic instructions carried by mRNA.