Chickens, Eggs, and Molecular Evolution

Which came first, the chicken or the egg? How about neither?

According to a recent study by scientists, modern life may have evolved in a series of energetically favorable reactions, as opposed to the RNA World or Metabolism-first hypotheses.

The scientists, biology researchers at George Mason University, believe that their explanation of the beginning of life is more likely than other hypotheses because it does not require the assembly of extremely complex organic molecules (like RNA) by sheer chance.

In molecular biology, nucleic acids like DNA and RNA are the "egg." Nucleic acids allow for the synthesis of enzymes that drive metabolism (the "chicken").

In their paper, the scientists compare the evolution of complex life to the flow of water down a hill.

"Imagine a large pond of water sitting on top of a hill," the scientists wrote. "We know that there are any number of other states—any in which the water is lower than it is at the top—which have lower energy and are therefore states toward which the system will tend to evolve over time."

They go on to liken the evolution of complex biochemical pathways to the formation of channels through which the water can flow to the bottom of the hill. Eventually, a complex system of waterways forms to carry the water, analogous to the formation of complex biochemical interactions in modern lifeforms.

If the biologists' theory gains traction, it could prove one of the biggest paradigm shifts in the field since the Miller-Urey experiment.



Source: http://www.americanscientist.org/issues/feature/2009/3/the-origin-of-life/1

Bioethics of Abortion not Adequately Covered in Tiller Murder

WICHITA, Kan. -- Dr. George Tiller, one of three doctors in the United States willing to carry out third-trimester abortions, was murdered two weeks ago at church near his Kansas home.

And all that's on the news is a rekindling of the same old abortion debate. Pro's and con's are debated by shouting pundits for a few weeks, then his death fades from the news and it's back to business as usual.

Tiller's murder should have been much more than an awakening of the same dead-end debate. It should have been an opportunity for the mass media to educate people about what exactly an abortion is, what a third trimester abortion entails and the distinction between second- and third-trimester abortions.

Whenever the abortion debate comes up, I always think back to a quote I heard from my biology adviser, a well-known embryologist at UNC-Chapel Hill, Dr. Albert Harris. A News and Observer reporter asked Harris "at what point do you believe that life begins?"

"I say that life doesn't begin, it continues, and it becomes more complicated," Harris responded. "And at some point, it becomes something that it's definitely murder to kill."

This quote really gets to the heart of the problem with the mass media's blunt approach to abortion. Too often, abortion is debated without considering even the most precursory biological and bioethical concepts; concepts like the fact that life never does really begin in a fetus, per se. Rather, it continues as a result of conception and eventually results in the birth of a human being.

The distinction between a second- and third-trimester abortion is not a small one. I consider myself 100% pro-choice, but I have qualms about the idea of a third-trimester abortion. My notion is that by the third trimester, a fetus has grown complicated enough that to kill it constitutes a kind of murder.

The media did not adequately cover the bioethical implications of a third-trimester abortion versus a second-trimester abortion. As such, they failed to give the public adequate information upon which to base an opinion.