How the Common Bedbug Proves that Evolution is True

The common bedbug (Cimex lectularius) is not only creepy, but provides three lessons in why Charles Darwin was right. Bedbugs 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 bedbug 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 bedbugs, 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, bedbugs could save energy.

Genetic Resistance to Pesticides

With the sequencing of the bedbug genome, scientists discovered just why bedbugs 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. Bedbugs are genetically different from bedbugs fifty years ago.

In an effort to find out why bedbugs are so hard to kill, researchers from Ohio State University located a colony of bedbugs known as the Harlan colony, after the 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 apartment.

And the genes were slightly different. The Columbus bedbugs could produce vast amounts of enzymes which help to break down toxins and flush them from the body. The Harlan bedbugs did produce this enzyme, but in much lower quantities. As a result, they are much easier to kill than modern bedbugs.

Bedbug Reproduction

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 bedbugs lack sexual organs. So how do they get pregnant? The male bedbug 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 bedbug 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 bedbug'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 bedbug'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 bedbug has gone through genetic changes in just 50 or 60 years. Bedbugs 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. Penguin; 2009.

Purdue University. "De-Bugging the Bed Bug: Sucking it Up in 2008." Dini M. Miller. 2008. http://aapco.ceris.purdue.edu/doc/min2008/attach/03mar08/attach32.pdf

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 GÆ'¶ran 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