The existence of functional, non-protein-coding DNA is all too frequently portrayed as a great surprise uncovered by genome sequencing projects, both in large media outlets and in scientific publications that should have better quality control in place. Eric Lander, writing a Human Genome Project 10th anniversary retrospective in Nature, explains the real surprise about non-coding DNA that was revealed by big omics projects.
Some regions of our genomes are under permanent lockdown because they are hazardous to our health - or at least the health of our future offspring. These secured regions include large swaths of parasite-infested DNA - DNA that contains transposable elements, virus-like genetic parasites that have the ability to hop around the genome and cause harmful mutations. Because out of control transposable elements are a major danger, cells (ours and those of most other organisms) have an elaborate maximum-security system for shutting these bad boys down. Just how this lockdown system works is an active area of research, and a recent paper revealed how plant cells enforce security and prevent prison breaks by these DNA parasites.
... Not that the Texas school board creationists were coherent before, but what else do they have left? After the defeat of language in the state standards to teach the "strengths and weaknesses" of evolution in Texas public schools, the creationist school board members have rallied under the motto "Somebody's got to stand up to experts!" Thus, in defiance of the logical thinking and coherent grammar embraced so fondly by those nefarious experts, the Texas school board on Friday passed a number of incoherent amendments to their state science standards.
Creationists have put us into a bizarre, alternate universe, at least when it comes to curriculum design. Their latest attempt to undermine science education involves inserting the code words 'strengths and weaknesses' into the public school science standards. The idea is that, whenever something religious fundamentalists find controversial crops up in science class, teachers have to teach the "strengths and weaknesses" of that particular topic. Fortunately, this creationist code has just been kept out of the Texas state science standards, but you can bet the code is going to crop up again at some point.It's worth taking a moment to think about how whacked this whole debate over strengths and weaknesses has become.
30 Days of Evolution Blogging - The Finish LineShow Me The Science Month Day 30 Installment 30
"Are you confused by all the talk about DNA and genes? We can help," claims the University of Utah. There is now no excuse for not knowing what stem cells do, what messenger RNA is, why SNPs are important, or about any other hot topic in the news about the latest biomedical research. University scientists are getting into the online communication game, although in many cases they are doing it awkwardly. What else do you expect from a bunch of pointy-headed, tweed-wearing, absent minded nerds?
There is a conversation about evolution that I’m apparently doomed to replay over and over with various family members, friends and acquaintances. I tell a friend that the evidence for evolution is overwhelming - everywhere in biology you find the signature of evolution; in every little bizzare, unexpected nook of biology you find unmistakeable evidence that all life is related, descended from common ancestors that lived long ago and took forms that were very different from what we observe in today’s organisms. We swim in a deluge of evidence, and I’m baffled that anyone can disregard the pervasive stamp of evolution in nature.Whoever I’m having this conversation with is equally baffled. How can I look around at the unparalleled complexity of nature, at the amazing adaptations possessed by millions of species, and think that this all came about through an unintelligent process?
Two guest writers on Olivia Judson's blog offer an interesting idea for spending stimulus money on research:Instead of simply funding more grants, we suggest using some of the windfall to provide an opportunity for fresh college graduates to pursue two years of research in the nation’s service while the job market is bottoming out. Call it “Research for America.” Our proposal would put young Americans to work and support science — without setting off a later bust cycle in research support, as previous funding booms have done.
Bell curves are everywhere. Pick 100 random people and measure them: measure their height, their weight, their blood pressure, their time to run a mile, or to sprint 50 yards, and their IQ, and you find that most of us fall in the middle of the spectrum, while there are always some people on either extreme. Why?The puzzle grows deeper when you think about genetics. If a trait like height is controlled largely by genes, how is it that height falls into a bell-curve pattern? Bell-curves seem completely at odds with what we learn about the discrete genetics of Mendel's round and wrinkled peas in high school biology.It turns out that the solution to this puzzle is fairly simple (although the details get messy). In fact, Darwin's cousin hit on the right answer (long before he or anyone else knew about Mendel's genetics), with what he called the "Supreme Law of Unreason": a bell curve is exactly what you expect when you toss together "a large sample of chaotic elements." In other words, genetics is like one big game of The Price Is Right.
Show Me The Science Month Day 25 Installment 25In nature, there is a sucker born every day. We humans may think that we're clever, but evolution has produced con games that would put Bernie Madoff to shame. One common natural swindle is mimicry, when one species tries to pass itself off as another. Orchids and cuckoos are classic examples of nature's swindlers, but mimicry isn't limited to plants and animals. A recent study has looked at how a fungus outsmarts a termite by dressing up as a termite egg.
Show Me The Science Month Day 24 Installment 24How do new genes arise? One common way is through gene duplication - the creation of a second copy of a gene when the DNA replication or repair machinery goes awry, followed by the the evolution of a new function for one copy. How genes are accidentally duplicated is reasonably well understood, but once a gene is duplicated, but how does the new copy acquire a new function? A pair of researchers in New York have looked at the role of a class of reproductive proteins in the mating behavior of different species of flies. One thing you can learn from this paper is that biologists will go to any length to learn about evolution - nobody watches fly sex for fun. Except for fly number three: (which was apparently put in by Photoshop):But there are more lessons here. Mating behavior is in fact an excellent place to look for lessons about evolution, since reproduction is subject to strong evolutionary pressures.
While you're sipping that morning cup and looking for excuses to put off work, here's what's interesting in science around the web today (well, ok, not just today - I haven't done one of these in about a month):Your tax money pays for the research, so shouldn't you be able to read that research without paying an arm and a leg? Biologist Michael Eisen defends the National Institute Health policy that scientists put copies of their manuscripts in a freely accessible, public repository, as Congress plans to revisit that policy at the behest of for-profit publishers. Eisen argues the policy doesn't hurt publishers, and thus there's no reason to scrap it:
Show Me The Science Month Day 23 Installment 23Thanks to your parents, you have two copies of each chromosome, which means that you have maternal and paternal copies of every gene. In most cases, having two copies of a gene is no problem, but in some cases, two is too much, and your cells have to shut one copy down. How does a cell do it?Shutting down one copy of a gene (or an entire section of a chromosome) is called genomic imprinting. (This is not the same thing as the newly hatched duckling that latches on to the first thing it sees, obviously). Genomic imprinting is a critical process used by placental and marsupial mammals to control the dosage of many genes, but how did this process evolve?The answer, in part, has been discovered by an analysis of the platypus genome. Genomic imprinting appears to have evolved from a defense mechanism used by cells to knock down parasitic DNA.
