[Paleopsych] The Week: The Father of Natural Selection

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The Father of Natural Selection
http://www.theweekmagazine.com/article.aspx?id=1228

[This is a nice, brief summation. I think Darwin became an agnostic, as he 
confessed to his diaries if not to his confidents.]

The work of Charles Darwin, the British naturalist whose ideas form
the basis of modern evolutionary theory, is under attack by religious
conservatives. What did Darwin actually say?

12/2/2005

How did Darwin become a biologist?

Born in 1809, the son of a physician in Shrewsbury, England, Darwin was a 
bookish youngster but a poor student. He attended the University of 
Edinburgh to study medicine, but dropped out because he couldn't stand the 
sight of blood. He did like studying living things, though, and indulged 
his interest by hiking, collecting beetles, and attending botany lectures. 
When Darwin was 21, he learned that Robert FitzRoy, captain of the HMS 
Beagle, was looking for a hardy companion on a trip to chart the South 
American coast. Although FitzRoy thought Darwin had a "lack of energy and 
determination," he took him on. The Beagle set sail on Dec. 27, 1831.

How did he spend the voyage?

As the Beagle made various landfalls, Darwin disembarked to observe, 
sketch, and collect plants, animals, and fossils. He sometimes traveled as 
much as 400 miles over mountains, through jungles, and up and down rivers, 
before meeting up with the ship. By the time the Beagle returned to 
England on Oct. 2, 1836, Darwin had accumulated an 800-page diary; 1,700 
pages of zoology and geology notes; 4,000 skins, bones, and other dried 
specimens; and another 1,500 pickled plants and animals.

What did he do with all this stuff?

Exhausted from the journey, Darwin holed up in London with his
collection to prepare his journal for publication. But as he did so,
he began thinking about some of the inconsistencies and anomalies he
had observed. He was particularly intrigued by the 12 previously
unknown kinds of finches he had discovered. Darwin realized they were
separate species, distinguished mainly by the shapes of their beaks.
Each was suited to a particular task--crushing seeds, eating insects,
poking into flowers for nectar, and so on. How, Darwin wondered, had
such similar birds wound up with different beaks? And why were the
birds' beaks so well-suited to the food supply on islands where they
were found? Darwin could think of no good answers until 1838, when he
came upon a book by Thomas Malthus, An Essay on the Principle of
Population.

How did this book affect him?

It was like a strike of lightning. Malthus, a minister and professor,
argued that human populations would always grow beyond their ability
to feed themselves unless they were checked by disease, catastrophe,
or some other restraint. The idea sparked a recognition in Darwin that
all living things, including plants, animals, and human beings, were
constantly struggling to survive in a world of limited resources and
myriad dangers. Those species that thrived, he reasoned, had adapted
to circumstances by some sort of biological mechanism. That is, they
had evolved.

Was evolution Darwin's idea?

Far from it. By Darwin's time, most respected scientists believed that
living things tended to improve as the need to do so arose. But they
had the details wrong. The most famous mistake was made by the French
naturalist Jean-Baptiste Lamarck (1744-1829). Lamarck proposed that
individuals developed specific characteristics by exercising them,
while losing others through disuse. He thought, for example, that
giraffes got their long necks by stretching for leaves that were out
of reach, then passed their elongated necks onto their offspring.
Darwin rejected this approach completely. Acquired characteristics, he
argued, are not inherited. Rather, random chance had favored
individuals or species with traits that allowed them to flourish in
their environments. Successful organisms reproduced, and came to
dominate their environments, while less successful organisms perished
and disappeared. In 1859, after two decades of thought, analysis, and
research, Darwin published his conclusions in a book, On the Origin of
Species by Means of Natural Selection, or The Preservation of Favoured
Races in the Struggle for Life.

Why did he wait so long to publish?

An introverted, nervous man, Darwin hated attention. He knew that his
findings would arouse the wrath of millions who believed in the
biblical creation story. Publishing his theories, he once told a
friend, would be "like confessing a murder." Darwin decided to publish
Origin of Species only when he discovered that a competitor, Alfred
Russel Wallace, was about to go public with his own version of
evolutionary theory.

What was the public reaction?

It was immediate and explosive. Origin of Species' entire first print
run of 1,250 copies sold out, necessitating a second printing of 3,000
copies just six weeks later. Eminent scientists, philosophers, and
liberal theologians recognized it as a groundbreaking work. The
botanist Hewett Watson wrote Darwin, "You are the greatest
revolutionist in natural history, if not of all centuries." But
others, including many intellectuals, were appalled at the notion that
man had evolved from lower life forms.

What did his critics say?

The astronomer Sir John Herschel openly derided Origin of Species as
nonsensical, calling it "the law of higgledy-piggledy." The geologist
William Whewell, master of Trinity College, Cambridge, refused to
allow it into the college library on the grounds that it would
threaten the moral fiber of England. In June 1860, the first great
public debate about Darwin took place at the annual meeting of the
British Association for the Advancement of Science. In a spontaneous
exchange, Samuel "Soapy Sam" Wilberforce, the bishop of Oxford,
clashed with biologist Thomas Huxley, one of Darwin's strongest
defenders. Wilberforce asked Huxley if he was descended from apes on
his grandmother's or his grandfather's side of the family. Huxley
replied that if given the choice between being descended from apes, or
from "a man highly endowed by nature" who used those gifts "for the
mere purpose of introducing ridicule into a grave scientific
discussion, I unhesitatingly affirm my preference for the ape." The
gale of laughter that followed Huxley's remark heralded a storm over
Darwin's ideas that continues, 145 years later.