Evolution test

Evolution

the process by which animals, plants, and other living organisms are transformed into different forms by the accumulation of changes over successive generations

Artificial selection

the process where humans intentionally choose specific plants or animals to breed based on desirable, inherited traits, such as higher yield, flavor, or appearance

disruptive/diversifying selection

a type of natural selection that favors both extreme variations of a trait over intermediate (average) ones. (It increases genetic diversity by selecting against the average individual, often leading to a population splitting into two distinct groups)

Hutton

suggests that slow, continuous changes over millions of years created Earth's current features

Natural selection

The organism with traits better suited to the enviornment will survive

Lyell

Stabilizing Selection

a type of natural selection that favors average, intermediate phenotypes rather than extreme variations, reducing genetic diversity within a population

Malthus

If population growth is not kept in check, it will outstrip food production, leading to a crisis (famine, war, disease) that kills off part of the population and restores a lower standard of living

Adaptation

a heritable trait—structural, physiological, or behavioral—that enhances an organism's survival and reproduction in a specific environment

fitness

(often called Darwinian or evolutionary fitness) measures an organism's success at passing its genes to the next generation relative to others in its population

genetic drift

each new generation tends to become more alike, with less variety of alleles. This is similar to inbreeding, and it makes the population more genetically uniform. Genetic drift is the name for this loss of variety.

vestigial organs

remnants of bodily structures that served a vital function in an ancestor but have reduced or lost that function in modern species, serving as evidence of evolution. Examples include the human tailbone, appendix, and wisdom teeth, which often have minor or no current utility

The Voyage of the Beagle

Charles Darwin's journal from his five-year expedition (1831-1836) on the HMS Beagle, chronicling his observations in biology, geology, and anthropology across South America and other parts of the world

Lamark’s theory

First person to suggest a mechanism of evolution

Inheritance of acquired traits - the largely discredited theory that physical changes acquired during an organism's lifetime—due to use, disuse, or environmental influence—can be passed to offspring

Lamarck argued that giraffes stretching their necks to reach high leaves caused them to lengthen slightly over their lifetime, passing this longer neck to their offspring

Wallace

Conceived the idea of “natural selection”

Embryology

the study of prenatal development, focusing on the formation and growth of an organism from fertilization to birth

Gene pool

the combination of all the genes (including alleles) present in a reproducing population or species

Speciation

the evolutionary process by which populations evolve to become distinct, reproductively isolated species

inheritance of acquired characteristics (Lamarkism)

a discredited biological theory, often called Lamarckism, proposing that traits developed during an organism's lifetime—due to use, disuse, or environmental influence—can be passed to offspring

Population

the study of how genetic variation within populations changes over time

Charles darwin theory

species change over time through a "struggle for existence," where organisms with heritable traits better adapted to their environment are more likely to survive and reproduce

Homologous parts

Homologous parts (or structures) are physical features in different species that share a common ancestral origin, even if their current functions differ

Behavioral isolation

a prezygotic barrier where species-specific mating rituals, signals, or behaviors prevent interbreeding, even if species live in the same area.

Temporal Isolation

a prezygotic reproductive barrier where two species or populations reproduce at different times—such as different hours, days, seasons, or years—preventing gene flow

ex. specific orchids that bloom in different weeks

Reproductive isolation

Reproductive isolation refers to biological or physical barriers that prevent different species from interbreeding and producing fertile offspring

ex. geographical separation (squirrels separated by the Grand Canyon), temporal differences (species breeding in different seasons)

Geographic isolation

Geographic isolation occurs when physical barriers—such as mountains, rivers, oceans, or deserts—separate populations, preventing interbreeding and leading to distinct evolution, or speciation

Mutation

A mutation is a permanent alteration in the DNA sequence of an organism

Genetic shuffling

Genetic shuffling is the process of creating new combinations of genes in offspring, occurring naturally through reproduction (via meiosis and crossing-over) or artificially in biotechnology to evolve proteins

Directional Selection

a mode of natural selection where a single, extreme phenotype is favored over other phenotypes, causing the allele frequency to shift over time in one direction

founders effect

The founder effect is a type of genetic drift occurring when a new, isolated population is established by a very small number of individuals from a larger population.

ex. the Pennsylvania Amish, who have a high prevalence of Ellis-van Creveld syndrome (dwarfism/polydactyly) due to recessive genes from a small founding couple in the 1700s

On the origin of species

Drawing on his voyage on the HMS Beagle, Darwin argued that species are not fixed but evolve from common ancestors, a concept that revolutionized science and challenged prevailing beliefs about creation