I've often suspected (hoped) real scientists studying evolution could not
possibly be as dogmatic as the usual materialistic Darwin-defender on the
internet. Note the excerpt from the following article:
("That the rapid evolution is positively, not negatively driven is
important," said Wu. "Positive selection indicates that the DNA changes
are doing something better for the organism as opposed to something
worse or nothing at all, which would be the case if the changes were
just random mutations." )
If some genes can mutate non-randomly, why not others? The mechanism for the
"positive pressure" for sex genes to mutate (non randomly) is at present
unknown. Until that mechanism IS known, I argue that anyone who wants to
believe "God does it" is entitled. When all of nature is completely
understood, I will gracefully acknowledge materialism. Until then,
materialism should not be rammed down anyone's throats, including school
children, as "scientific truth".
Bertvan
The article can be read at:
http://www.uchospitals.edu/news/malegenes.html
Genes pertaining to "maleness" evolve more rapidly than their non-sexual
counterparts
Researchers at the University of Chicago report in the January 20 issue
of Nature that genes pertaining to male reproduction-those involved in
sperm production, transfer and morphology-evolve much faster than their
non-sexual counterparts.
Chimpanzee
Gorilla
Researchers Chung-I Wu
and Gerald Wyckoff
Chung-I Wu, Ph.D., professor and chairman of the department of ecology &
evolution at the University of Chicago, together with Gerald Wyckoff, a
graduate student and Wen Wang, Ph.D., a postdoctoral fellow, argue that
sexual pressure underlies this phenomenon.
"The pressure on a male to find a mate and fertilize her eggs is
constant, and the stakes of success or failure are enormous," said Wu.
"Presumably, genes governing male reproduction are under continuous
pressure to evolve ways to outcompete other males when it comes to
fathering offspring."
In previous research, Wu and colleagues found that genes related to
sperm production in fruit flies, mice and rats evolved faster than other
genes. In the January 20 Nature paper, Wu and his co-authors describe
the accelerated evolution of male reproductive genes in man and other
primates.
"That the rapid evolution is positively, not negatively driven is
important," said Wu. "Positive selection indicates that the DNA changes
are doing something better for the organism as opposed to something
worse or nothing at all, which would be the case if the changes were
just random mutations."
The title of the paper, "Rapid Evolution of Male Reproductive Genes in
the Descent of Man," makes reference to Charles Darwin's book Descent of
Man. "I chose this title because Darwin talks about how the drive to
mate is perhaps the strongest driving force behind evolution," Wu
explained. As Darwin wrote, the advantages of "conquering other males in
battle or courtship, and thus leaving a numerous progeny are in the long
run greater than those derived from rather more perfect adaptation to
the conditions of life."
Wu and colleagues examined a set of three homologous genes that may
directly alter the morphology of sperm in humans, chimpanzees, gorillas
and orangutans. When they compared the genes in different humans, they
found that the genes were virtually identical, as would be expected in a
comparison of genes from individuals of the same species.
Next, the researchers compared the genes in humans and chimps and were
surprised to find that they looked very different from one another. A
well established theory in genetic evolution states that even after
millions of years of evolution, homologous genes in closely related
species, such as humans and chimps, are barely distinguishable from one
another. That the human and chimp sperm genes were so radically
different suggests exceedingly rapid evolution.
"The genes in humans and chimps are evolving at the same rapid rate,"
added Wu. When he compared the genes in humans and gorillas, which are
more distantly related, he noticed that the rate of evolution of
maleness genes was still accelerated, but at a much slower rate in
gorillas.
The researchers also surveyed 50 genes from humans and old world
monkeys, of which 18 pertained to male reproduction and the rest did
not. They found that 11 of the 18 male genes evolved much faster than
the average rate of evolution of the non-sexual genes.
Wu thinks that the rapid rate of evolution of male genes is indicative
of the sexual behavior of the species. Chimps exhibit very promiscuous
behavior. A female may mate with numerous males during her receptive
phase. The competition to attract a mate, as well as internal sperm
competition, puts intense pressure on chimp male genes to evolve
rapidly.
Conversely, gorillas employ a harem system where one high-ranking male
has access to several females who mate only with him. In this case, the
male can be relatively sure that he is the genetic father of any
offspring produced by his harem. This takes some of the pressure off
sperm-producing genes to mutate rapidly because they don't compete
directly with other sperm in the female, said Wu.
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