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Hooker, Joseph Dalton
to be inferior. After the acceptance of an evolutionary origin
of humans (see Descent of man [book]), many scholars
simply translated pre-evolutionary racist views into an evolutionary
context by claiming either that darker races had a
separate evolutionary origin from the European race, or that
the darker races represented inferior genetic variation within
the human species (see eugenics).
Even before widespread evolutionary thought, a few scholars
insisted upon the essential equality of all races. German
anatomist Friedrich Tiedemann measured the brain sizes from
skulls of whites, blacks, and orangutans. Many scholars considered
blacks intermediate between whites and baboons, perhaps
even more nearly resembling the latter than the former. Tiedemann
found that, while there were slight differences in average
brain size among races, the range in brain sizes among individuals
within each race was an order of magnitude greater than the
average differences among the races, which is to say that there
is no significant difference in brain size or intelligence among
the races. He found that all human races had larger brains than
orangutans. Tiedemann claimed that the supposed inferiority of
blacks was based upon two scientifically unacceptable procedures.
First, some researchers had chosen small black skulls to
compare to large white skulls, rather than choosing a large and
representative sample from each group. Second, the black people
whom scientists had studied were often slaves or former slaves,
whose characteristics were the result of abuse and deprivation
rather than natural inferiority. Today, scientists are careful to
choose samples that are large, representative, and unbiased (see
scientific method). Tiedemann published his results in 1836
in English to praise the British government for abolishing slavery.
The Descent of Man (see Darwin, Charles) not only
presented evolution as an explanation for the origin of
human races but also presented a new reason for them. Darwin
claimed that some racial differences reflected natural
selection, most notably the darker skins of races that live
in climates with bright sunshine. He suggested, however, that
most racial differences were arbitrary, as each race, in its own
separate line of evolution, made different choices of what
constituted physical beauty (see sexual selection). Such
arbitrariness of racial diversification strongly implied that no
race was superior in its evolutionary adaptation to any other.
The development of molecular techniques, allowing comparisons
of protein structure and of DNA (see DNA [evidence
for evolution]), created a revolution in thinking about the
races of Homo sapiens. First, geneticists found that the protein
and DNA diversity within the human species was much less than
within most animal species. This result implied the recent origin
of the entire human species. Even when the relatively small
amount of human DNA variation is considered, roughly 85
percent of that variation is within races; all differences between
races occur in the remaining 15 percent. Further study of human
genetics suggested that the human species had gone through a
genetic bottleneck, in which population size and genetic variation
was severely reduced and during which the human species
came close to extinction (see founder effect; population
genetics). Geneticists have suggested a date of about 70,000
years ago for this event. All of this evidence suggests that all
human racial diversity has evolved in less than 0.1 million years,
a miniscule length of evolutionary time. Scientists continue some
interesting studies of human racial differences (for example, why
some races are more prone to diabetes or heart disease than others).
Although there are few overall genetic differences among
the races, recent studies suggest that they differ by about 25 percent
in terms of the expression of those genes.
The fact that Homo sapiens has been the only surviving
hominin species for the last 20,000 years considerably simplifies
evolutionary ethics and animal rights. No one has any
idea how a human legal system might deal with Neandertals or
Heidelberg people. With the possible exception of cetaceans, no
other animal challenges the mental superiority of humans (see
intelligence, evolution of). This was not the case prior to
20,000 years before the present. H. sapiens and their evolutionary
ancestors may have actively killed off other hominin species
that they encountered. The belief of early H. sapiens that
they were superior created a situation in which they eliminated,
directly or indirectly, all challenges to this belief.
Further Reading
Balter, Michael. “Are humans still evolving?” Science 309 (2005):
234–237.
Gould, Stephen Jay. “The geometer of race.” Chap. 26 in I Have
Landed: The End of a Beginning in Natural History. New York:
Harmony Books, 2002.
———. “The great physiologist of Heidelberg.” Chap. 27 in I Have
Landed: The End of a Beginning in Natural History. New York:
Harmony Books, 2002.
Grine, F. E., et al. “Late Pleistocene human skull from Hofmeyr,
South Africa, and modern human origins.” Science 315 (2007):
226–229.
Lewis-Williams, David. The Mind in the Cave. London: Thames and
Hudson, 2002.
Tattersall, Ian. Becoming Human: Evolution and Human Uniqueness.
New York: Harvest Books, 1999.
Vanhaeren, Marian, et al. “Middle paleolithic shell beads in Israel
and Algeria.” Science 312 (2006): 1785–1788. Summary by Balter,
Michael. “First jewelry? Old shell beads suggest early use of
symbols.” Science 312 (2006): 1731.
Hooker, Joseph Dalton (1817–1911) British Botanist Sir
Joseph Dalton Hooker was a botanist who was one of the
closest confidantes of Charles Darwin (see Darwin, Charles)
especially as Darwin prepared for the inevitable controversy
connected with publishing a theory of evolution. Born on June
30, 1817, Joseph Hooker was the son of the prominent botanist
Sir William Hooker. He began attending his father’s botany
lectures at the University of Glasgow when he was seven
years old. He was especially interested in tales of travel and the
plants of distant lands, which would grow into the governing
passion of his career.
Like many other biologists at the time, Joseph Hooker
was a physician, obtaining his medical degree from the University
of Glasgow in 1839. Like Charles Darwin and T. H. Huxley
(see Huxley, Thomas Henry), Joseph Hooker began his
naturalist’s career by taking a long ship voyage. Unlike Dar-