Encyclopedia of Evolution.pdf - Online Reading Center

languages of the immigrants. One of the few surviving languages
of people who lived in Europe before the arrival of
the Indo-Europeans is Basque, spoken by natives of the Pyrenees
Mountains that separate France and Spain. A later
wave of immigrants brought agriculture across Europe from
the Middle East (see agriculture, evolution of). Among
the earliest agricultural cities in the Middle East are Jericho
(Israel) and Çatal Höyük (Turkey). The transformation of
Cro-Magnon into modern civilization involved an increasing
rapidity of technological, cultural, and artistic innovation and
increasing geographical variation.
Further Reading
Hitchcock, Don. “Cave Paintings and Sculptures.” Available online.
URL: http://donsmaps.com/cavepaintings.html. Accessed March
23, 2005.
Lewis-Williams, David. The Mind in the Cave. London: Thames and
Hudson, 2002.
O’Neil, Dennis. “Early Modern Human Culture.” Available online.
URL: http://anthro.palomar.edu/homo2/sapiens_culture.htm. Accessed
March 23, 2005.
cultural evolution See evolution.
Cuvier, Georges (1769–1832) French Biologist, Paleontologist
Georges Cuvier was born on August 23, 1769. He
made contributions to the understanding of animal anatomy
and the history of the Earth that allowed the later development
of evolutionary science. Cuvier’s main contributions
were to establish the science of comparative anatomy and the
fact that extinctions have occurred during the history of the
Earth.
In 1795 French biologist Étienne Geoffroy Saint-Hilaire
invited Cuvier, who was then a naturalist and tutor, to come
to Paris. While Geoffroy started Cuvier’s career, the two men
were later to split over fundamental scientific issues. Soon
Cuvier became a professor of animal anatomy at the Musée
National d’Histoire Naturelle (National Museum of Natural
History), established by the Revolutionary government.
Not only did Cuvier stay at his post when Napoleon came to
power, but Napoleon appointed him to several government
positions, including Inspector-General of Public Education.
Cuvier held government positions under three French kings
thereafter. Cuvier may have been the only public figure to
have held French government leadership positions under Revolutionary,
Napoleonic, and monarchical regimes.
Cuvier’s careful studies of the anatomy of invertebrate
and vertebrate animals allowed him to develop the science
of comparative anatomy. The function of one organ within
an animal could only be understood as it related to the other
organs; all organs fit and functioned together perfectly.
Because of this, Cuvier had the famous ability to reconstruct
organisms from the most fragmentary of fossil remains.
When more complete fossils were later found, Cuvier’s reconstructions
turned out to be amazingly accurate. A corollary
of this principle was that no part of an animal could change
without destroying its ability to interact with all the other
parts. This is one reason that Cuvier did not accept any evo-
Cuvier, Georges 0
lutionary theories, such as that proposed by his fellow French
scientist Lamarck (see Lamarckism). Another reason is that
when Cuvier studied the mummified cats and ibises that had
been brought to France from Napoleon’s conquest of Egypt,
he found that they were no different from modern cats and
ibises. From this Cuvier concluded that animals did not
undergo evolutionary change.
Cuvier was one of the first to recognize that groups of
animals had fundamental structural differences. He classified
animal life into four branches or embranchements: the vertebrates,
the articulates (arthropods and segmented worms),
mollusks, and the radiates (cnidarians and echinoderms) (see
invertebrates, evolution of). These embranchements
correspond roughly to modern evolutionary classifications,
although echinoderms have bilaterally symmetrical larvae
even if adult starfish have external radial symmetry. Because
all organs must work together, the organs of animals in one
embranchement would not work with organs of animals in
another; therefore Cuvier considered evolutionary transformations
among the embranchements to be impossible.
Because he recognized the separate embranchements of
animal life, Cuvier opposed the theories of contemporaries
such as Buffon (see Buffon, Georges), Lamarck, and Geoffroy,
all of whom suggested or championed some form of
evolutionary transformation. Cuvier pointed out that vertebrates
have a central nerve cord along the back (dorsal) surface
of the body, while articulates have a nerve cord along the
front (ventral) surface, and that no transformation is possible
between them. Geoffroy’s response, which was at the time
unsupported by evidence, was that vertebrates might have
developed as upside-down articulates. Geoffroy’s view was
not vindicated until the discovery of Hox genes (see developmental
evolution). One of these genes, found both in
flies and frogs, affected the ventral surface of fly embryos but
the dorsal surface of frog embryos. Furthermore, Buffon and
Geoffroy claimed that vestigial characteristics were evolutionary
leftovers. Cuvier claimed that all organs were perfectly
designed, and a vestigial organ was one whose function
had not yet been discovered.
Cuvier was not the first to believe that extinction had
occurred, but his studies removed all reasonable doubt. Fossilized
mammoths had been found in Italy and the United
States. Some scientists claimed that the Italian bones were
merely those of elephants that had died during Hannibal’s
invasion of Rome. American President Thomas Jefferson
believed that mammoths were still alive somewhere in the
American wilderness; one of the purposes of the Lewis and
Clark Expedition was to find them. Cuvier’s careful study
of living elephants and of mammoth and mastodon bones
proved that Indian and African elephants were different species,
and that mammoths and mastodons were not elephants.
He also studied the skeletons of the Irish elk, a kind of deer
with huge antlers, and demonstrated that they were unlike
any existing animal. Cuvier explained extinction as having
resulted from “revolutions” during Earth history. He
avoided the word catastrophe because of its supernatural
overtones, but his view was similar to that of the supporters
of catastrophism.