FoundationalConceptsNeuroscience

into biology by proposing that all life is deeply related—having devel-
oped over vast expanses of time from common origins—and the great
diversity of living organisms can be understood as resulting from pro-
cesses of variation and selection.
Darwinian evolution posits that there must be some underlying
source of variation—something that is capable of changing—
producing variant organisms that can be selected by natural (or do-
mestic) processes. This variation is associated with how information
is stored and passed on from one generation to the next in living
organisms. Gregor Mendel (1822-1884), a Catholic Augustinian friar
and eventual abbot of his monastery, had a deep interest in scien-
tific approaches to understanding the world. Although he studied
astronomy and meteorology and taught physics at his monastery,
Mendel is known today for his experiments on inheritance in plants.
In his monastery’s garden, he investigated inheritance in pea plants,
observing that various traits of pea plants (such as shape and texture
of the seed, color of the seed, color and shape of the pea pod, color of
the flower, and size of the plant) parceled out in an orderly fashion
during breeding from one generation to the next. This led to the idea
that information needed to build an organism is packaged into units
associated with specific traits. Though Darwin and Mendel were
contemporaries, they apparently did not know of one another’s work.
And although Darwin’s ideas achieved widespread dissemination
both during his lifetime and after, Mendel’s discoveries were relatively
obscure, not widely known during his lifetime, and not appreciated
by the scientific community until several decades after his death.
Thus, it came to be believed that inheritance involved fundamental
units or packets of information. The scientific study of inheritance
acquired the name genetics (Greek genesis = origin, birth), and the fun-
damental unit of heredity came to be called a gene. The words genetics