Evolution Study Guide Flashcards

This set of vocabulary flashcards covers essential concepts from the Evolution Study Guide, including theories by Darwin and Lamarck, mechanisms of evolution, population genetics, and evidence for evolutionary relationships.

Lamarck's Theory

The idea that traits organisms develop in their lifetime can then be passed on to their offspring.

Darwin's Theory

The theory that populations have variations and the "fittest" organisms survive the struggle for survival to reproduce and adapt the population.

Modified Descendants

The common idea shared by both Lamarck and Darwin that organisms seen today are altered versions of fossil ancestors.

Beagle

The name of the ship Charles Darwin sailed on for $5$ years around the world.

Variation

The raw material on which natural selection acts, which can include wing color ranging from vibrant bright blue to muted pale blue.

Mutation

A source of variation that does not happen often but has the potential to create a new trait.

Recombination of DNA

A source of variation involving crossing over and meiosis that packages new traits together that did not exist before.

Sexual reproduction

A source of variation caused by the random fertilization of specific egg and sperm cells.

Fitness

In an evolutionary sense, the ability of an organism to survive and REPRODUCE, thereby influencing evolution.

Gene pool

The total set of alleles for a population, such as the $150$ white (W) alleles and $50$ brown (w) alleles in a group of $200$ moths.

Allele frequency

The measure of how often an allele appears in a population, expressed as a percentage like $W = 75\%$ or $w = 25\%$.

Genetic equilibrium

A state where allele frequencies remain constant; this is unlikely to be maintained if environmental changes like pollution occur.

Migration (Gene flow)

The exchange of genes between two populations which can introduce new alleles into a gene pool and increase variation.

Genetic Drift

A random event that can destroy an entire genotype by chance, affecting small populations significantly more than large ones.

Stabilizing Selection

A type of natural selection that favors the average phenotype.

Directional Selection

A type of natural selection that favors one extreme phenotype.

Disruptive Selection

A type of natural selection that favors both extreme phenotypes.

Species

Organisms that look similar and can reproduce to have fertile offspring.

Geographic isolation

A form of isolation where species are separated by physical barriers, such as a rift valley.

Reproductive isolation

A form of isolation where mating times do not align or populations become active at different times, such as being nocturnal.

Fossils

Preserved remains or traces of ancient organisms.

Homologous structures

Structures with different functions but similar internal anatomy.

Analogous structures

Structures with similar functions but different anatomical origins.

Vestigial structures

"Useless" features that were functional in an organism's ancestors.

Embryological similarities

Similarities found in the early developmental stages across different species.

Molecular similarities

Similarities in DNA, RNA, or protein sequences, considered the best evidence for evolution.

Macromolecules

DNA, RNA, and proteins used to provide a quantity of differences to determine how LONG it has been since two species shared a common ancestor.

Cladogram

A diagram showing evolutionary relationships, such as how birds are most closely related to crocodiles or humans relate to frogs.