Science from 1898 TO 1949

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Science from 1898 TO 1949

Post  Admin on Wed Nov 21, 2012 9:38 pm

1898 TO 1949
Bumpus’ Sparrows (1898). Herman Bumpus was a
zoologist at Brown University. During the winter of 1898,
by accident he carried out one of the only field experiments
in natural selection. One cold morning, finding
136 stunned house sparrows on the ground, he tried to nurse
them back to health. Of the total, 72 revived and 64 died.
He weighed and carefully measured all of them, and found
that those closest to the average survived best. This frequently
quoted research study is another evidence that the
animal or plant closest to the original species is the most
hardy. Sub-species variations will not be as hardy, and
evolution entirely across species (if the DNA code would
permit it) would therefore be too weakened to survive
(*R. Milner, Encyclopedia of Evolution, 1990, p. 61).
*Hugo deVries (1848-1935) was a Dutch botanist and
one of the three men who, in 1900, rediscovered Mendel’s
paper on the law of heredity.
One day while working with primroses, deVries
thought he had discovered a new species. This made
headlines. He actually had found a new variety (sub-species)
of the primrose, but deVries conjectured that perhaps
his “new species” had suddenly sprung into existence
as a “mutation.” He theorized that new species
“saltated” (leaped), that is, continually spring into existence.
His idea is called the saltation theory.

This was a new idea; and, during the first half of the
20th century, many evolutionary biologists, finding absolutely
no evidence supporting “natural selection,”
switched from natural selection (“Darwinism”) to mutations
(“neo-Darwinism”) as the mechanism by which
the theorized cross-species changes occurred.
Later in this book, we will discover that mutations cannot
produce evolution either, for they are always harmful.
In addition, decades of experimentation have revealed they
never produce new species.
In order to prove the mutation theory, deVries and other
researchers immediately began experimentation on fruit
flies; and it has continued ever since—but totally without
success in producing new species.
Brief History of Evolutionary Theory 35
Ironically, deVries’ saltation theory was based on
an observational error. In 1914 *Edward Jeffries discovered
that deVries’ primrose was just a new variety, not
a new species.

Decades later, it was discovered that most plant varieties
are produced by variations in gene factors, rarely by
mutations. Those caused by gene variations may be strong
(although not as strong as the average original), but those
varieties produced by mutations are always weak and
have a poor survival rate. See chapter 10, Mutations, for
much, much more on the mutation problem.
*Walter S. Sutton and *T. Boveri (1902) independently
discovered chromosomes and the linkage of genetic
characters. This was only two years after Mendel’s
research was rediscovered. Scientists were continually
learning new facts about the fixity of the species.
*Thomas Hunt Morgan (1886-1945) was an American
biologist who developed the theory of the gene. He
found that the genetic determinants were present in a
definite linear order in the chromosomes and could be
somewhat “mapped.” He was the first to work intensively
with the fruit fly, Drosophila (*Michael Pitman, Adam and
Evolution, 1984, p. 70). But research with fruit flies, and
other creatures, has proved a total failure in showing mutations
to be a mechanism for cross-species change (*Richard
B. Goldschmidt, “Evolution, as Viewed by One Geneticist,”
American Scientist, January 1952, p. 94).
*H.J. Muller (1990-1967). Upon learning of the 1927
discovery that X-rays, gamma rays, and various chemicals
could induce an extremely rapid increase of mutations
in the chromosomes of test animals and plants, Muller
pioneered in using X-rays to greatly increase the mutation
rate in fruit flies. But all he and the other researchers
found was that mutations were always harmful (*H.J.
Muller, Time, November 11, 1946, p. 38; *E.J. Gardner,
Principles of Genetics, 1964, p. 192; *Theodosius
36 The Evolution Cruncher
Dobzhansky, Genetics and the Origin of the Species,
1951, p. 73).


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