darwin

Species

A group of related organisms that share a distinctive form and, among sexually reproducing species, are capable of interbreeding to produce viable and fertile offspring.

Population

Members of the same species that are likely to encounter each other and thus have the opportunity to interbreed.

Creationism

A pre-Darwinian belief that a god is the absolute creator of heaven and earth, out of nothing, by an act of free will.

Spontaneous Generation

A pre-Darwinian belief that living organisms can arise suddenly and spontaneously from nonliving matter (e.g., mice from rags and grain, maggots from rotting meat).

Anaximander

An ancient Greek philosopher who suggested that organisms evolve over time.

Plato's Theory of Forms

The philosophical idea that objects are temporary reflections of ideal forms.

Aristotle's Scala Naturae

A linear hierarchy in which all living things can be arranged, also known as the 'Scale of Nature' or 'Great Chain of Being'.

Scala Naturae (Great Chain of Being)

A concept establishing man as the dominant and perfect form of life, setting humanity above and apart from nature, and incorporated into religious belief that creatures have not changed since creation.

Erasmus Darwin

Suggested common descent and provided evidence from developmental patterns, artificial selection, and vestigial organs.

John Ray

Conducted the first thorough study of the natural world.

Carolus Linnaeus

Proposed the fixity of species, an ideal structure and function for each species, a place in the scala naturae, and developed the binomial system of nomenclature.

Count George Buffon

Wrote a 44-volume catalog of known plants and animals and suggested that life forms change over time.

Cuvier

The first to use comparative anatomy for classification, proposed catastrophism, was the founder of paleontology.

Catastrophism

Cuvier's theory that local catastrophes in the past caused later strata to have a new mix of fossils, with regions repopulated by species from surrounding areas after each event.

Lamarck

The first biologist to propose evolution and link diversity with environmental adaptation, concluding that complex organisms are descended from less complex ones and proposing the 'Inheritance of Acquired Characteristics'.

Inheritance of Acquired Characteristics (Lamarckianism)

Lamarck's proposed mechanism of evolution where traits acquired during an organism's lifetime in response to environment are passed on to offspring.

Charles Lyell

Proposed Uniformitarianism, suggesting the Earth is subject to slow but continuous cycles of erosion and uplift, and authored 'Principles of Geology'.

Uniformitarianism

Lyell's principle stating that the rates and processes of geological change are constant over time.

Charles Darwin

Served as a naturalist on the HMS Beagle voyage (1831-1836), making observations that led to his theory of evolution by natural selection.

Biogeographical Observations (Darwin)

Darwin's study of the geographic distribution of life forms, where he observed similar species in similar habitats and reasoned that related species could be modified according to the environment.

Galápagos Tortoises (Darwin's Observation)

Darwin observed that tortoise neck length varied from island to island, correlating with differences in vegetation, suggesting speciation.

Galápagos Finches (Darwin's Observation)

Darwin observed 13 different species of finches on various islands and speculated they could have descended from a single pair of mainland finches.

Rev. Thomas Malthus

His 'Essay on the Principle of Population' (1838) influenced Darwin with its concepts of 'struggle for existence' and that reproductive potential is greater than the environment can support.

Struggle for Existence (Malthus)

The concept that reproductive potential in a population is greater than the environment can support, leading to inevitable death, disease, and famine to maintain population stability.

On Origin of Species by Means of Natural Selection

Charles Darwin's groundbreaking book published in 1859, detailing his theory of evolution through natural selection.

Darwin's Theory of Evolution by Natural Selection

Based on observations of variation, heritability, great potential fertility, limited resources, and differential survival and reproduction, leading to adaptations and new species over many generations.

Natural Selection

The process by which varying organisms show differential survival and reproduction, favoring advantageous heritable traits, which gradually produces new adaptations and new species.

Microevolution

Changes in a single gene in a population over time.

Macroevolution

Formation of new species or groups of species.

Evolution

Heritable change in one or more characteristics of a population or species from one generation to the next.

Plato

An ancient Greek philosopher who proposed that objects are temporary reflections of ideal forms ('Essentialism' or 'Theory of Forms').

Aristotle

An ancient Greek philosopher who suggested all living things could be arranged in a linear hierarchy called Scala naturae ('Father of Classic Taxonomy').

Scala Naturae (Scale of Life)

A linear hierarchy proposed by Aristotle, known as the 'Great Chain of Being,' which established man as the dominant and perfect form of life, often incorporated into religious beliefs of special creation.

Fixity of Species

The belief, supported by Linnaeus, that species do not change over time.

Binomial System of Nomenclature

The system for naming species (e.g., Genus species) developed by Carolus Linnaeus.

Paleontology

The study of fossils, founded by Cuvier.

Struggle for Existence

A concept from Malthus, adopted by Darwin, describing the competition among organisms in a population for limited resources necessary for survival and reproduction.

Alfred Russell Wallace

Independently conceived of the theory of evolution by natural selection and co-presented his work with Darwin.