Theory of Natural Selection: Vocabulary Flashcards

Vocabulary flashcards covering key terms and concepts from the notes on natural selection, Darwin, Wallace, and 19th-century intellectual context.

Charles Darwin

British naturalist who developed the theory of natural selection; extensively studied during the voyage of the H.M.S. Beagle (1831–1836).

Alfred Russel Wallace

Naturalist who independently conceived natural selection; prompted Darwin to publish after sharing ideas in 1858.

H.M.S. Beagle (1831–1836)

Darwin's surveying voyage whose observations contributed to the development of evolutionary theory.

Independent discovery

Two scientists (Darwin and Wallace) independently arriving at the idea of natural selection.

Plato's Theory of Forms

Belief in perfect, unchanging essences; influenced views of fixed, non-evolving natural kinds.

Aristotle's Scala Naturae

Hierarchical ladder of life, implying fixed order and progress toward humans; predecessor to the Great Chain of Being.

Great Chain of Being

Another name for Scala Naturae; a rigid, ordered view of nature with fixed species.

Natural Theology

19th-century worldview assuming a young Earth and that all species are separately created and fixed.

Argument from Design (Watchmaker Argument)

Paley's claim that biological complexity indicates a designer, analogous to a watch implying a watchmaker.

Bishop William Paley

Proponent of the Design argument; argued complexity implies a divine creator.

Catastrophism

Geological theory that Earth's features result from sudden, catastrophic events causing extinctions and repopulations.

Georges Cuvier

Proponent of catastrophism; explained fossil layers by successive catastrophes and mass extinctions.

Uniformitarianism

Idea that present geologic processes operated in the past; implies an ancient Earth and slow change.

James Hutton

Geologist who advocated gradualism; helped establish deep geological time.

Charles Lyell

Author of Principles of Geology; influential advocate of uniformitarianism and long Earth history.

Gradualism

Change arises through slow, steady processes over long time spans.

Lamarck

Early evolutionary thinker proposing drive toward complexity and inheritance of acquired characteristics.

Drive toward Complexity

Lamarckian idea of an innate force pushing lineages up the scala naturae toward greater complexity.

Adaptive force

Lamarck's idea that organisms change in response to needs and those changes are inherited by offspring.

Inheritance of Acquired Characteristics

Lamarck's flawed notion that traits gained during life can be passed to offspring.

Essay on the Principle of Population

Thomas Malthus's work noting that population tends to grow faster than food supply, leading to competition.

Thomas Malthus

Economist whose observations on population growth influenced Darwin and Wallace.

Struggle for Existence

Competition for limited resources; not all individuals survive and reproduce.

Pattern of Survival

Observation that some individuals are better suited to the environment and survive to reproduce.

Fitness

Reproductive success of an individual relative to others in a population; a measure of advantageous traits in a given environment.

Variation

Differences among individuals in a population that provide material for natural selection.

Heritability

The extent to which trait differences are passed from parents to offspring (genetic basis).

Three conditions for evolution by natural selection

Variation; differential survival/reproduction; heritability.

Peppered Moth (Biston betularia)

Classic example where color variation (genotype-influenced) shifts allele frequencies due to predation.

Descent with Modification

Darwin and Wallace's phrase for evolution: species change over time from common ancestry.

Evolution (modern definition)

A change in the genetic composition (allele frequencies) of a population over time.

Allele Frequencies

Relative frequencies of different alleles in a population; shifts indicate evolution.

Spontaneous Generation

Discredited idea that living organisms arise from nonliving matter.

Adaptation

Heritable trait that improves an organism's survival and reproduction in its environment.