Show Me The Science Month Day 18



The transition from one-celled microbes to multicellularity was a huge step in the evolution of life on this planet, but as daunting as this evolutionary step seems, it didn't happen just once. Today's plants, fungi, animals, and various types of algae are all descendants of separate transitions to multicellular life.

All of these transitions from a single-cell lifestyle to multicellularity occurred in the very distant past, so how can we learn anything about them? It turns out that it is not hard to find living, modern examples that closely parallel the momentous evolutionary transitions that led to animals, plants, and fungi. Right now on earth there are primitive multicellular organisms that, in many ways, resemble the first multicellular creatures that existed a billion years ago. Researchers are using these organisms to understand what kinds of genetic changes are needed to turn a single-celled organism into a multicellular one.

Show Me The Science Month Day 17



Often when something new crops up in evolutionary history, it's usually the result of tinkering with functional, preexisting molecular tools.. In a paper published in Science, some NYU researchers find that the protein cues used by  fruit fly embryos to direct their migrating reproductive cells are processed by some very ancient cellular machinery. The scientists test their ideas with a very weird experiment: they use their newfound knowledge to direct the reproductive cells to migrate into the embryos' brains.

Show Me The Science Month Day 16



Black wolves look like creatures out of frightening fairy tales, but their black color actually came from pet dogs. Today's evolution paper is about a potentially beneficial mutation for black coat color picked up by wolves as the result of interbreeding with dogs. This story got some press, so it may sound familiar, but here we're going to focus on just how scientists could know where the black color gene came from. This research is a great example of the genetic sleuthing that's now possible with easy, affordable DNA sequencing.

Show Me The Science Month Day 15



What happens when a big chunk of your genome is accidentally copied? Bad things could obviously happen when when sudden and dramatic changes are made to your genome (which is why we wear sunblock on the beach and lead shields when getting X-rayed). Recent studies have found that accidental duplications in the genome (which can change the copy number of sets of genes) are involved in a growing list of diseases, including autism, psoriasis, and susceptibility to AIDS. And yet we also know that big DNA duplications aren't always harmful, because we can find ancient duplications in our genomes that harbor genes filling useful roles in our physiology.

How frequently do these large duplications arise, and what role have they played in human evolution? A group led by Evan Eichler, at the University of Washington, aided by the DNA sequencing powerhouse of the Genome Sequencing Center at Washington University (in St. Louis - not the same place as the University of Washington!), has studied these questions by looking for big, duplicated chunks in our closest relatives - the great apes. Their results show that big DNA duplications have probably played an important role in the evolution of our species.

Sunday Science Book Club, February 15 2009

Monkey Girl: Evolution, Education, Religion, and the Battle for America’s Soul
by Edward Humes
HarperCollins, 2007





It is rare for the world to see born on one day two towering individuals whose imprint on history is strong enough to be noted around the world 200 years later. Abraham Lincoln successfully saw the United States through a near-fatal convulsion, whose early symptoms had been palliated but not cured at the nation’s founding; the after-effects have reached all around the world. Charles Darwin, more than anyone else in the 19th century, put biology on its modern scientific footing, and his ideas play a critical role in the genome sciences at the very forefront of 21st century biology.

We celebrate their achievements this week, but both Lincoln and Darwin have left legacies of divisiveness, and in fact these legacies intertwine. The contours of the rift that initiated the Civil War still shape American politics, from Nixon’s influential Southern Strategy to the Red State-Blue State divide in the 111th Congress. Evolution is a poster child for culture war. It may not be a top issue on the national political agenda, but it is a culture war conflict that penetrates just as deeply and personally than any other, as Edward Humes vividly describes in Monkey Girl, the best book about the nation’s first court trial over Intelligent Design in public schools.