On the Origin of Species

Charles Darwin’s 1859 book argues that species change over time through natural selection and descend from common ancestors. It supports this account with evidence from organisms, fossils, geography, and domestication.

Natural selection: The process by which heritable traits that improve reproductive success become more common across generations. Darwin’s central mechanism explains how favorable variations accumulate without foresight.
Variation of organisms: Differences in traits among individuals of the same species or population. Selection can act only when individuals differ in traits that affect survival or reproduction.
Charles Darwin: An English naturalist who developed the theory of evolution by natural selection. Darwin assembled the book’s argument from decades of observation and research.
Evolutionary biology: The branch of biology that studies the origins, histories, and changes of populations and species. Darwin’s framework became a foundation for explaining biological diversity and adaptation.
Common descent: The hypothesis that different species descend from shared ancestral populations. The book’s branching account of life depends on species sharing ancestors.
Struggle for existence: Competition and environmental pressures that limit survival and reproduction in populations. Darwin used limited resources to explain why not all individuals leave offspring.
HMS Beagle: A British survey ship on which Darwin traveled around the world from 1831 to 1836. Observations made during the voyage supplied evidence and questions later developed in the book.
The Descent of Man: Charles Darwin’s 1871 book applying evolutionary theory to human origins and sexual selection. Darwin later extended evolutionary reasoning to humans and their behavior.
Artificial selection: The breeding of organisms by humans to increase desired heritable traits. Darwin used domesticated breeds to show how selection can transform populations.
Adaptation: An inherited trait that improves an organism’s performance in a particular environment. The book treats fit between organisms and conditions as an outcome of selection.

Linked from 25 pages