Adam and Eve: According to the Bible (Genesis 2–3), the first two people are Adam (man) and Eve (life). They inhabit The Garden of Eden, with a Tree of Life and a Tree of the Knowledge of Good and Evil in the center. They are instructed not to eat the fruit of the latter tree, but they do so anyway and are subsequently cursed and expelled from the garden. This forms the basis for the traditional origin myth of Jews, Muslims and Christians.
Adaptation: A fit between the organism and environment.
Allele: A genetic variant.
Blending Inheritance: Heredity conceptualized as a mixture of fluids. Its opposite would be particulate inheritance, where heredity is regarded as the interaction of discrete elements and provides the basis of Mendelian genetics.
Canalization: The tendency of a growing organism to be buffered toward normal development.
Descent with Modification: Darwin’s term for what we now call “evolution,” in which animals and plants look different from their ancestors.
Epigenetics: The study of how genetically identical cells and organisms (with the same DNA base sequence) can nevertheless differ in stably inherited ways.
Epistemes: Fundamental cultural ideas, which organize the world and help to render it meaningful. Similar to paradigm.
Eugenics: An idea that was popular in the 1920s that society should be improved by breeding better kinds of people.
Evo-devo: The study of the origin of form; a contraction of “evolutionary developmental biology.”
Exaptation: An additional beneficial use for a biological feature.
Extinction: The loss of a species from the face of the earth.
Founder Effect: The reduced genetic diversity that results when a population is descended from a small number of ancestors.
Gene: A stretch of DNA with an identifiable function (sometimes broadened to include any DNA with recognizable structural features as well).
Gene Flow: Geographical movement of genes, due to the contact of populations.
Gene Pool: Hypothetical summation of the entire genetic composition of population or species.
Genetic Drift: Random, short-term perturbations to the gene pool, with nonadaptive effects.
Genotype: Genetic constitution of an individual organism.
Hereditarianism: The idea that genes or ancestry is the most crucial or salient element in a human life. Generally associated with an argument for natural inequality on pseudo-genetic grounds.
Homology: Correspondence of parts between species due to the mutual inheritance of a primordial form from a common ancestor.
Inheritance of Acquired Characteristics: The idea that you pass on the features that developed during your lifetime, not just your genes; also known as Lamarckian inheritance.
Monogenism: The idea that all people share a common single origin.
Mutation: An alteration to the base sequence of DNA.
Natural Selection: A consistent bias in survival and fertility, leading to the over-representation of certain features in future generations and an improved fit between an average member of the population and the environment.
Niche Construction: The active engagement by which species transform their surroundings in favorable ways, rather than passively inhabiting them.
Noah’s Ark: According to the Bible (Genesis 6–9), God decides to destroy all life because of the wickedness of people, but he saves a righteous man named Noah, his three sons, and their wives. They build a large boat and preserve pairs of all the animals; the boat eventually lands “on the mountains of Ararat” and the world is subsequently repopulated. Other ancient cultures also have cognate myths about a flood, boat-builder, and animal-saver, with differing details.
Phenotype: Observable manifestation of a genetic constitution, expressed in a particular set of circumstances.
Plasticity: The tendency of a growing organism to react developmentally to its particular conditions of life.
Polygenism: The idea that different peoples have different origins.
Phrenology: The 19th century anatomical study of bumps on the head as an indication of personality and mental abilities.
Punctuated Equilibria: The idea that species are stable through time and are formed very rapidly relative to their duration. (The opposite, that species are unstable and constantly changing through time, is called phyletic gradualism.)
Savage: A dehumanizing term used by pre-modern European scholars to suggest that other cultures were primitive, violent, immoral, and illogical.
Sexual Selection: Natural selection arising through preference by one sex for certain characteristics in individuals of the other sex.
Synonymous Mutation: A change in the DNA sequence that codes for amino acids in a protein sequence, but does not change the encoded amino acid.
Synthetic Theory of Evolution: Explains the evolution of life in terms of genetic changes occurring in the population that leads to the formation of new species.
Species Selection: A postulated evolutionary process in which selection acts on an entire species population, rather than individuals.
Teleological: The explanation of phenomena in terms of the purpose they serve rather than of the cause by which they arise.
Tower of Babel: According to the Bible (Genesis 11), all people once spoke a single language and decided to cooperate to build a giant tower that would stretch into the heavens. For this arrogance, they are made to speak different languages and must give up building the tower. The story’s setting is generally thought to refer to the ancient ziggurats of Babylonia.
Transmutation Hypothesis: The nineteenth century idea that life forms were spontaneously generated and not descended from a common ancestor.
