Encyclopedia of Evolution.pdf - Online Reading Center

English) were a resounding success, and Harvard offered him
a professorship in 1848. Agassiz saw in the United States
a land of opportunity for intellectual growth as well as for
the financial possibilities that drew most immigrants, and he
accepted the Harvard professorship. Agassiz played a major
role in building Harvard’s famous Museum of Comparative
Zoology.
Agassiz’s reaction to the thunderbolt of Charles Darwin’s
Origin of Species (see origin of species [book]) was
to defend the eternal separateness of species even more vigorously.
He also, but less vigorously, opposed Lyellian uniformitarianism.
In 1860, just after the release of Darwin’s
Origin of Species, Agassiz’s younger colleague at Harvard, the
botanist Asa Gray, debated him publicly about evolution (see
Gray, Asa). Agassiz’s defense of the fixity of species spilled
over into his social convictions. He was offended by having
to be close to African Americans. He considered non-European
races to have been separately created by God. Agassiz
defended slavery and opposed interracial marriage as being an
unnatural mixing of what God had intended to keep separate.
Today, Agassiz might be classified as a creationist (see
creationism), but he would not be accepted by the creationists
as one of their associates, because (1) he was a Unitarian,
rather than what would today be called a fundamentalist,
and (2) he believed in a dozen separate creations of humans,
rejecting the biblical story of Adam and Eve. Interestingly, it
was his opponent, the evolutionist Asa Gray, who was the
orthodox Christian and who accepted Africans as his fellow
humans.
It is impossible to tell whether his continued opposition,
in his later years, to evolution was due to stubbornness or
sincerity. During a voyage he actually visited the Galápagos
Islands and saw the same evidence that Charles Darwin had
seen, but he refused to admit their evolutionary implications.
Nevertheless his studies of zoology and of the Ice Ages have
contributed substantially to the modern scientific understanding
of the evolutionary history of the Earth. He died on
December 12, 1873.
Further Reading
Lurie, Edward. Louis Agassiz: A Life in Science. Baltimore, Md.:
Johns Hopkins University Press, 1988.
age of Earth Most mythologies contain a nearly instantaneous
creation of the Earth by one or more gods, followed
shortly thereafter by the creation of humankind. The modern
evolutionary insight that humankind has existed only briefly
in the long history of the Earth is a product of only the last
two centuries and is an insight most people even today do
not appreciate. The 5,000 years of human history is only onetwentieth
of the approximately 100,000 years that Homo
sapiens has existed as a species in fully modern form, and
only one-millionth of the 4.6 billion years that the Earth has
existed. According to science writer John McPhee, if a person
stretches out his or her arms to represent the age of the Earth,
all of civilization corresponds to a day’s growth of fingernail.
The predominant source of Earth history that was available
to scholars in the Western world until just a few centuries
age of Earth
ago was the Bible. By adding up the genealogies of the Old
Testament, Bible scholars calculated that the Earth was about
6,000 years old. Some Bible scholars, early in the age of science,
got caught up with a desire for precision, without having
any more information from which to work. The most famous
example of this is James Ussher, Archbishop of Armagh and
Anglican Primate of All Ireland. He published Annals of the
Old Testament, Deduced from the First Origin of the World in
1650, in which he identified 4004 b.c.e. as the year of creation.
Theologian John Lightfoot, about the same time, added
that the creation occurred at noon on October 23, 4004 b.c.e.
Earlier scholars had concluded that the Supreme Being’s plan
for the history of the world fit into precise millennia. This is an
assumption shared by many modern people, who expected
Earth-shattering events to occur in the year 2000 (called
“Y2K” in modern jargon). Ussher knew that King Herod, a
Jewish king who ruled Israel under Roman occupation, died in
4 b.c.e. yet, according to the Bible, was alive when Jesus was
born. Therefore, Ussher concluded that the Western calendar is
off by four years, and he chose 4004 b.c.e. rather than 4000
b.c.e. as the year of creation. Biblical scholars disagreed as to
whether there may have been “pre-Adamite” humans that
existed, possibly for long periods of time, before the creation
described in the first chapter of Genesis. Even from a study of
the Bible, such precision as exhibited by Archbishop Ussher
was not accepted by all scholars. Evolutionary scientist Stephen
Jay Gould (see Gould, Stephen Jay) has written more extensively
on the topic of how Ussher and other biblical scholars
calculated the age of the Earth and its major historical events.
If the Earth was only 6,000 years old, then it must be
virtually unchanged since the moment of creation, with the
exception of the Noachian Deluge (the Flood described in
the Old Testament), according to these biblical scholars. As
scientific investigation of the Earth began, many observations
did not fit with the concept of a recently created Earth.
Most famously, geologist James Hutton (see Hutton, James)
observed the sedimentary layers of rock at Siccar Point in
Scotland and realized that vast stretches of time were necessary
for their formation (see unconformity). Geologist
Charles Lyell (see Lyell, Charles) expanded Hutton’s view
into a geological model of uniformitarianism in which the
Earth was, as far as scientific inquiry could determine, eternal.
As Hutton wrote in a 1788 treatise, “The result, therefore,
of our present enquiry is, that we find no vestige of a
beginning,—no prospect of an end.”
As the documentation of fossils continued (see fossils
and fossilization), it became apparent that there was a
time early in the history of the Earth when complex life-forms
did not yet exist (see Precambrian time). Although this
implied that there must have been a beginning, this beginning
might have been many billions of years in the past. Geologists
were able to determine the relative order in which the
different assemblages of species had existed on the Earth (see
Smith, William). The present sequence of geological time
scale was largely established by geologists during the 19th
century, although they had no way to calculate the absolute
periods of time in which these organisms had lived.