Biology Evolution Terms

Abiogenesis

The hypothesis that life arose from non-living chemical substances

Spontaneous generation

The incorrect idea that living organisms arise from non-living matter

Primordial soup

Early Earth oceans containing simple chemicals that formed organic molecules

RNA World Hypothesis

Theory that RNA was the first genetic material capable of storing information and catalyzing reactions

Ribozyme

RNA molecule that acts as an enzyme

Coacervate

Droplet-like structure formed from organic molecules acting as early protocell model

Panspermia

Theory that life or its building blocks came from space

Amino acid

Building block of proteins

Prebiotic chemistry

Chemical processes that formed organic molecules before life existed

Inorganic compounds

Substances without carbon-hydrogen bonds

Organic molecules

Carbon-based molecules such as proteins

Miller-Urey experiment

Experiment showing organic molecules can form from inorganic gases under early Earth conditions

Evolution

Change in inherited traits of populations over time

Darwin

Scientist who proposed natural selection as mechanism of evolution

Haldane-Oparin

Scientists who proposed early chemical evolution of life

Miller-Urey

Experiment supporting origin of organic molecules from inorganic substances

Pasteur

Scientist who disproved spontaneous generation

Cell theory

Theory stating all living things are made of cells

Adaptation

Trait that improves survival or reproduction

Descent with modification

Species change over time and share common ancestors

LUCA (Last Universal Common Ancestor)

Most recent common ancestor of all life

Mutations

Random changes in DNA that create variation

Variations

Differences in traits within a population

Meiosis

Cell division producing gametes

Crossing over

Exchange of genetic material during meiosis

Independent assortment

Random distribution of chromosomes into gametes

Law of segregation

Alleles separate during gamete formation

Sexual reproduction

Reproduction involving fusion of gametes

Jean-Baptiste Lamarck

Scientist who proposed evolution through acquired characteristics

Acquired characteristics

Traits developed during lifetime that are not inherited

Charles Lyell

Scientist who proposed geological uniformitarianism

Geology

Study of Earth’s structure and processes

Biogeography

Study of species distribution across Earth

Thomas Malthus

Scientist who proposed population growth outpaces resources

Plate tectonics

Movement of Earth’s plates influencing evolution and distribution

Selective breeding (artificial selection)

Human-controlled breeding for desired traits

Natural selection

Process where organisms with advantageous traits survive and reproduce

James Hutton

Scientist who proposed gradual geological change over time

Phylogenetic tree

Diagram showing evolutionary relationships

Survival of the fittest

Individuals best adapted survive and reproduce

Inheritance

Passing of traits from parents to offspring

Founder effect

Genetic drift in a new population started by few individuals

Russell Wallace

Co-discoverer of natural selection

Microevolution

Small changes in allele frequency in a population

Macroevolution

Large-scale evolutionary change over long time

Genetics

Study of heredity and genes

Gene pool

All genes in a population

Fossils

Preserved remains or traces of organisms

Index fossil

Fossil used to date rock layers

Transitional fossil

Fossil showing intermediate traits between species

Genetic drift

Random changes in allele frequencies

Gene flow

Movement of genes between populations

Bottleneck effect

Sharp reduction in population size causing loss of genetic variation

Sexual selection

Selection based on mate choice

Non-random mating

Mate choice based on traits

Random mating

Mating without preference

Cladogram

Branching diagram showing evolutionary relationships

Comparative anatomy

Study of structural similarities between organisms

Homologous structures

Same evolutionary origin

Analogous structures

Same function

Vestigial structures

Reduced or unused structures

Coevolution

Two species evolving in response to each other

Convergent evolution

Unrelated species evolve similar traits

Divergent evolution

Related species evolve different traits

Parallel evolution

Similar evolution in related species independently

Adaptive radiation

Rapid evolution into many species from one ancestor

Selection pressure

Environmental factor that affects survival and reproduction

Comparative physiology

Study of functional similarities between organisms

Comparative embryology

Study of embryos to show common ancestry

Evolutionary genetics

Study of genetic basis of evolution

Directional selection

One extreme trait is favored

Stabilizing selection

Average trait is favored

Disruptive selection

Both extremes are favored

Archaeopteryx

Transitional fossil between dinosaurs and birds

Tiktaalik

Transitional fossil between fish and land animals

Gradualism

Slow continuous evolutionary change

Punctuated equilibrium

Long periods of stability with sudden rapid change

Symbiotic relationships

Close relationships between species

Mutualism

Both species benefit

Parasitism

One benefits

Commensalism

One benefits

Antagonistic interactions

Predator-prey relationships

Competitive interactions

Organisms compete for resources

Primate homology

Shared traits among primates due to common ancestry

Hominin evolution

Evolution of human lineage