The common bed bug (Cimex lectularius) is not only creepy,
but provides three lessons in why Charles Darwin was right. Bed bugs can go through a couple of
generations per year, so we are able to see them evolve in out lifetime. And they aren’t through evolving yet.
These three lessons are in vestigial traits, genetic
mutation and modification of an existing body part to do a function that it
wasn’t originally intended for.
Vestigial Wings
Place a bed bug under a microscope and you’ll see along their
sides tiny pads that appear like a little like stunted mosquito wings. Well, that’s because they are wings. However, after millions of generations of not
flying, the wings atrophied and eventually shrunk. These pads are located exactly where wings
would be in other insects such as mosquitoes.
According to Creationism, all species appeared in their
current form less than 10,000 years ago.
Creationists tend to state that either vestigial organs do not exist or
vestigial organs have functions yet undiscovered. But Creationism cannot explain why bedbugs needed to lose their wings.
But evolution can.
The common ancestor bed bugs, bat bugs and swallow bugs fed on
cave-dwelling critters such as bats, according to Virginia Tech entomologist
Dini M. Miller, PhD. But when people
started dwelling in caves, a new food source was ready to be exploited. Flying takes up a lot of energy. By hitching lifts on human goods, clothes and
bodies, bed bugs could save energy.
Genetic Resistance to
Pesticides
With the sequencing of the bed bug genome, scientists
discovered just why bed bugs are resistant to so many pesticides -- they evolved
genes to neutralize the pesticides. Many
pesticides like pyrethrins kill by harming nerve cells and paralyzing the
insect. Bed bugs are genetically
different from bedbugs fifty years ago.
In an effort to find out why bed bugs are so hard to kill,
researchers from Ohio
State University US military’s
entomologist that began the colony, Harold Harlan. The Harlan breeding colony has never been
exposed to insecticides. The genes of
these bedbugs were compared to bedbugs from a Columbus , Ohio
And the genes were slightly different. The Columbus
bed bugs could produce vast amounts of enzymes which help to break down toxins
and flush them from the body. The Harlan
bed bugs did produce this enzyme, but in much lower quantities. As a result, they are much easier to kill
than modern bedbugs.
Female Bed Bugs and
Traumatic Insemination
Remember that creatures adapt in order to help the
individual survive to pass along its genes and not necessarily adapts for the
benefit of the entire species. This can
lead to survival struggles between members of the same species – and takes the
battle of the sexes to a whole new level.
Female bed bugs lack sexual organs. So how do they get pregnant? The male bed bug wields a hypodermic-like Sexual
intormittent organ that pierces the female and pumps sperm directly into a
groove in her abdomen. This process is
called, appropriately enough, traumatic insemination. Females can die from their wounds.
A lot more would die if the female bed bug had not evolved a
pseudo-sexual organ called the spermalege.
Thought to be modified from part of the female’s immune system, a spermalege
is merely spongy tissue filled with blood-like liquid called hemolymph. The male bed bug’s organ can only penetrate
through parts of a female’s abdomen – not the entire abdomen.
Over the millennia, these injection sites filled with large
tissue in order to quickly eliminate any pathogens introduced from the puncture
wound. There is also a theory that the
female bed bug’s immune system chooses which sperm lives and kills the rest.
Conclusion
Creationists state that all species alive today were created
in one week about 10,000 years ago.
However, the bed bug has gone through genetic changes in just 50 or 60
years. Bed bugs also have useless wing
pads and females have parts of their immune system to act as a sexual
organ. The Creator either has a perverse
sense of humor or there was no creation in a week. Creatures are never done adapting to survive
and reproduce in ever changing circumstances.
References
“Why Evolution is True.” Jerry A. Coyne
National Public Radio.
“Bedbug Genome Reveals Pesticide Resistance.” Jon Hamilton.
January 19, 2011 . http://www.npr.org/2011/01/19/133057071/bed-bug-genome-reveals-pesticide-resistance
“Costly traumatic insemination and a female
counter-adaptation in bed bugs.” Edward H Morrow and Göran Arnqvist. Proceedings
of the Royal Society B: Biological
Science. November 23, 2003 . 270(1531):
2377–2381.
http://rspb.royalsocietypublishing.org/content/270/1531/2371.full.pdf
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