PolITiGenomics » evolution

Unnatural selection

dd — Fri, 27 Mar 2009 21:33:58 +0000

In a recent series of posts (Embryo screening should be mandatory, Allowing children to be born with severe disease is morally equivalent to child abuse, round 2, and Arguments against routine screening for severe disease genes; food for thought), Daniel MacArthur over at Genetic Future has discussed the issue of genetic screening of potential parents and embryos so that genetic diseases can be avoided in the population. Many of the arguments revolve around moral issues, with some discussion on the accuracy of such testing. In this argument, as for many of its ilk, the lines are drawn and scientists end up on one side and ethicists end up on the other. In this case, scientists are typically in favor of genetic screening and ethicists typically oppose it. That is why these arguments, from scientists, center on the “ethical” reasons supporting genetic screening. Unfortunately, the singular focus on ethical arguments forces all other concerns, e.g., scientific concerns, to the background. So, are there scientific reasons not to screen embryos for known disabling genetic markers? Well, quite possibly, but human hubris is not likely to give one of them much weight: what makes us think we can do a better job than nature in selecting traits that are suitable for survival? How can we be certain that some of these markers determined to be detrimental are not in linkage disequilibrium with traits that increase survivability for the overall population? In other words, will the elimination of these traits also eliminate other, favorable traits? Would the widespread practice of eugenics decrease the natural variation in our species such that our ability to survive environmental change is reduced? Contrarily, given the current state of science and our existing political structures, are Homo sapiens still even susceptible to natural selection? Finally, if we are unable to replicate even relatively simple biological processes, e.g., fixation of nitrogen at room temperature and the efficient conversion of sunlight to energy, how can we hope to properly navigate the human biological system? It seems to me that these are the sorts of questions that need to be answered before the ethical questions, which are important, should even be asked.

Very gradual change we can believe in

dd — Fri, 20 Feb 2009 22:16:13 +0000

A colleague pointed out the clever image to the right created by Mike Rosulek. Mike has set up a storefront on Zazzle to sell items with the image and a few different slogans, giving the proceeds to the National Center for Science Education. Sadly, the top “Latest News” item on the NCSE’s website is a story about anti-evolution legislation recently introduced in the Missouri House of Representatives. Previous attempts to pass such a bill have failed. Here’s hope that, in this case at least, past performance is the best predictor of future outcomes. One last time for the slow learners: intelligent design is not a scientific theory. If you want to teach it, teach it in a social studies class.

Darwin must die, long live Darwin

dd — Wed, 11 Feb 2009 20:32:47 +0000

A couple of days ago, Carl Safina had an essay in The New York Times entitled Darwinism Must Die So That Evolution May Live that discusses the cult of personality that has grown up around Darwin and how it is hurting the acceptance of the theory of evolution. Much of what he says about how little of what we now know about evolution actually originated with Darwin is correct, but the case for killing Darwin is, perhaps, a bit overstated. I don’t think people reject evolution because of some lack of trust of Darwin or the fact that Darwinism kind of sounds like Marxism. Rather, people who would rather not believe in something like evolution try to poke holes in the theory any way they can. Darwin provides a convenient target. The problem is not those people, but the many people who don’t really care enough to look into it themselves and are happy to accept there is some ambiguity because there is dissent; regardless of how unsubstantiated that dissent is. The bottom line is that even if all scientists stop using any term derived from Darwin’s name, those who wish to foment distrust still will. And people who don’t have strong feelings one way or another will continue to listen (or not) to both. This is really just a symptom of the tenuous relationship our society has had with science (and intellectualism) for many years.

Pristionchus pacificus

dd — Thu, 25 Sep 2008 15:29:32 +0000

Have you ever wanted to learn more about parasitic roundworms that feast on the bacteria, fungi and other small roundworms that grow on beetle carcasses after they have died? Well, today is your lucky day. We have just published a paper in Nature Genetics about the genome sequence of Pristionchus pacificus entitled The Pristionchus pacificus genome provides a unique perspective on nematode lifestyle and parasitism. At this point you may be asking yourself, “What does P. pacificus do while the beetle is alive?” Interestingly, it exists in a dormant, resting state while the beetle is still alive to conserve energy while food is scarce. For a less technical discussion of the findings of the journal article, see Worm genome offers clues to evolution of parasitism.

No one defies artificial life

dd — Thu, 11 Sep 2008 19:31:01 +0000

There is interesting story in Wired about an alternative approach to creating artificial life, Biologists on the Verge of Creating New Form of Life. While some are trying to create artificial bacteria, the Szostak lab‘s protocellular work is trying to create a form of life that does not currently exist, but may be similar to the earliest forms of life on Earth. Thus, they not only have to face the controversy of creating artificial life, but also the origin of life.

Junk DNA

dd — Wed, 10 Sep 2008 21:05:56 +0000

DNA that does not encode genes or is not in known regulatory regions has long been called “junk DNA”. This junk DNA makes up over 90% of the human genome. Last year, the ENCODE project reported that this notion of massive portions of the DNA not serving any function was likely wrong. Rather, their findings suggested that the human genome is a complex network of interacting elements containing very little unused sequence, not gene islands in an ocean of junk. Now, researchers at Yale have found that junk DNA may have triggered key evolutionary changes in the human thumb and foot.

Candidates on science

dd — Thu, 04 Sep 2008 15:59:28 +0000

Scientists and Engineers for America have posted Sen. Obama’s responses to questions they sent him regarding his stance on a variety of science-related issues. Sen. McCain has not responded, but SEA has an analysis of his positions. There is also a chart comparing the two candidates’ positions on scientific issues. Below is a summary of the candidates’ major differences on these issues.

Sen. Obama favors subsidies for alternative fuels and Sen. McCain does not
Sen. McCain is a stronger supporter of nuclear energy than Sen. Obama (although both include it as part of their energy plan)
Sen. McCain supports expanding offshore drilling while Sen. Obama only would allow its expansion as part of a compromise plan that includes incentives for energy alternatives
Sen. Obama wants universal healthcare coverage including allowing people to purchase the Congressional plan while Sen. McCain’s plan includes taxing healthcare benefits while providing offsetting tax credits
Sen. Obama favors sex education that includes information about contraception while Sen. McCain favors abstinence-only sex education
Sen. McCain thinks intelligent design should be taught in science class, Sen. Obama does not
Sen. Obama is in favor of net neutrality, Sen. McCain is not

Update: Sen. McCain has answered the questionnaire and SEA has updated the McCain page linked above accordingly.

Personal DNA testing

dd — Wed, 09 Jul 2008 13:38:08 +0000

Last night on NOVA scienceNOW there was a segment on the personal DNA tests currently being marketed to consumers (you can watch the segment on the website, unfortunately no ability to embed video on other sites). The host, Neil deGrasse Tyson, had his DNA tested by Navigenics and learned his “probability” as compared to the rest of the population for getting certain diseases; even deciding to learn the genotype associate with his APOE4 gene, the so-called Alzheimer’s gene (something James Watson decided not to do when his genome was sequenced). As all the scientists who do not work for one of these personal genomics companies said when interviewed, while these tests may provide some information about a person’s genome, we really don’t know what they are telling us about the person’s health, how the SNPs detected affect phenotype, how to use them to guide lifestyle, treatment, diet, etc.

Later in the program there was also an interesting segment on geneticist and rocker, Pardis Sabeti, who pioneered a statistical approach to determine if mutations in a population were random or enriched due to natural selection.

Speaking of Neil deGrasse Tyson, check out the tour of the Hayden Planetarium he gives to Stephen Colbert so Stephen can become an astrophysicist if the Colbert Report doesn’t pan out.

Lincoln and Darwin

dd — Wed, 02 Jul 2008 15:29:08 +0000

It turns out that Abraham Lincoln and Charles Darwin were born on the same day. No, they didn’t just share a birthday, they were actually born on the exact same day: February 12, 1809. In fact, there were even more parallels between their lives, e.g., both lost their mothers early in childhood and both suffered from depression. These and other similarities and differences are explored in recent books (e.g., Rebel Giants by historian David R. Contosta) and a Newsweek article out this week entitled “Who Was More Important: Lincoln or Darwin?” The Newsweek article focuses on how each of these men transformed the world into which they were born into the world in which we live today. It’s a fascinating read about true icons in politics, science, and history (although it is a bit odd that Newsweek feels the need to declare one more important than the other).

A gift for the platypus enthusiast

dd — Tue, 24 Jun 2008 17:40:12 +0000

If you are looking for the perfect gift for the platypus enthusiast in your life, consider a t-shirt with the following image.

It is even up to date with the latest research. You can get them at snorgtees.