charles_darwin

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Glossary of Selected Terms
Mutation. The process of change in a species. In evolutionary theory, mutation
occurs when genetic information in cells undergoing reproduction
is copied incorrectly.
Naturalism. The idea that natural phenomena can and should only be
explained by laws. In science, these laws must be testable by experimentation.
Natural Selection. A term coined by Darwin to describe the process that
makes evolution occur. Members of a species acquire a new characteristic
that enables them to adapt better to their surroundings than
other species or other individuals in the same species. Those individuals
with the new characteristic survive better, generally by producing
more progeny. The process of adaptation and survival is natural
selection.
Natural Theology. The idea that nature reveals the creative work of God.
Particularly popular among Christians in Europe and the United
States in the eighteenth century, proponents of natural theology
believed people could learn all they needed to know about the character
of God from studying nature.
natura non facit saltum. A Latin phrase meaning ‘‘nature does not make
jumps.’’ This idea was one of the major assumptions of Darwin’s
theory of descent by modification. Darwin argued that species
changed slowly and gradually over a long period of time.
Neo-Darwinism. In the late nineteenth century, Neo-Darwinists were scientists
who argued that natural selection was the only or the primary
means of effecting evolution. In the twentieth century the same term
was used to describe a different theory about evolution. From the
1950s onward, Neo-Darwinism has been the accepted scientific explanation
of evolution. Twentieth-century Neo-Darwinists joined the
genetic theory of heredity with the Darwinian idea of natural selection.
Mutations in genes are passed from parent to progeny; those
mutations that enable a species to adapt better to its environment than
other species or other individuals in the same species are more likely
to survive through natural selection.
Old Earth. Creationists who argued that the Earth was more than six thousand
years old believed in an ‘‘Old Earth.’’
Polymorphic. A term that means ‘‘many forms.’’ Darwin used this term in
its botanical sense referring to plants that produce many varieties
because of distinct differences in physical characteristics, such as the
thickness of the leaf or the length of the stem. Orchids, one of
Darwin’s favorite plants, are polymorphic.
Pre-Implantation Genetic Diagnosis (PGD). Technique developed by molecular
biologists (such as Mark Hughes) and reproductive endocrinologists
(such as Jamie Grifo of New York University) that enables the
genes of an embryo to be identified before implantation in the womb.