Do you ever wonder if you might be related to the people you are passing on the street? Due to common descent, we are all related. Bryan Sykes is a medical geneticist that investigates the interrelatedness of humans by examining their mitochondrial DNA, and shares the results with you in this book. Continue reading
Teachers operate on the assumption that students are “empty vessels” they can fill with new information. But many students begin classes with assumptions about the world that, although intuitive, are actually incorrect. For example, many students incorrectly believe that individuals can evolve or that all members of a species evolve together. Teachers assume that instruction and testing will make students understand that both of these assumptions are wrong and that only populations evolve. However, recent research suggests that simply providing students with factual information doesn’t make them drop their faulty assumptions. As it turns out, old misconceptions die hard.
Although I am now a practicing geneticist, I hated genetics when I was in school. My Genetics 101 course followed the same syllabus that colleges all around the country use, a historical outline that emphasizes discovery — the discovery of phenotypic variation (Mendel and his wrinkled peas), the discovery of DNA and its structure (Watson and Crick and Franklin), the discovery of genetic mutation (in Mendel’s case, a disruptive insertion within the rugosus gene). We’re presented a top-down view of genetics from phenotype (wrinkled versus smooth) to genotype (mutation in rugosus) that should compel us to ask “Why?” But before the bell ever rings on that first day, most students already know that the answer to this question. “Why?” lies somewhere in our DNA and we don’t want to discover it all over again. And, unfortunately, this historical top-down approach doesn’t increase our understanding of genes in the age of whole-genome sequencing. In response to this problem, PLoS Biology published the short article, “Why Do We Have to Learn This Stuff? A New Genetics for 21st Century Students.” In it, Dr. Rosemary Redfield describes the problems of current genetic courses and offers her own remedies. Continue reading
The retina is a paper-thin layer of tissue found at the back of the eye that allows us to see light. Without a retina (or the cells that make it up), we’re blind. Because mutations that cause the retina to break-down affect nearly 1 in 4,000 people world-wide, researchers eagerly study new ways to treat this condition. So far, they have identified over 50 genes that, when mutated, cause retinal degeneration and blindness. In fact, some of the earliest successes in gene therapy involved cases of retinal degeneration and blindness. Now researchers are trying something new: retinal transplants, or physically moving cells from healthy eyes to those that are unhealthy. In a recent study published by Pearson et al. (2012) in Nature (not open-access, sorry), researchers moved rod photoreceptor cells from healthy mice to those that suffered from night-blindness and — boom! — restored vision to the mice. They even have a cool video. Continue reading
The GOP presidential candidates have been in a race to announce either their acceptance or skepticism of scientific topics like evolution and global climate change. I’ve previously commented on both Michelle Bachmann’s and Rick Perry’s stance on evolution. Both Bachmann and Perry support teaching Intelligent Design Creationism in public schools, and so I’ve dumbed them IDiots. Well, now former Utah Governor and US Ambassador John Huntsman made his position known via Twitter — and you’re in for a surprise! Continue reading
The Washington Post Magazine published an interesting profile yesterday of biologist J. Craig Venter: “Rad Scientist: Maverick biologist J. Craig Venter is in a race to save the planet.” The profile discusses Venter’s company Synthetic Genomics, the J. Craig Venter Institute (JVCI), and his recent effort to create a new species of algae that can generate biofuels and process green-house gases. Venter’s work is truly ground-breaking and will one day change our lives — in fact, it already has (see below). The article by Susan Okie is terrific and is a must-read for anyone interested in genomics and the future of biotechnology. Continue reading
One common misconception about evolution is that the processes that produce phenotypic change between species (macroevolution) are different from those that produce phenotypic variation within species (microevolution). For example, creationists might accept microevolution, since this can easily be observed in a lab, but would argue that since macroevolution is difficult to observe over the span of one human lifetime, there is no evidence for it and that large-scale differences must be the result of some designer. In reality, however, there is no real distinction between microevolutionary and macroevolutionary changes: the same microevolutionary processes that result in variation within species give rise to macroevolutionary differences between species. And this afternoon, evolutionary biologists from the University of Maryland and Syracuse University published a study in the journal Proceedings of the National Academy of Sciences that nicely illustrates this link between microevolution and macroevolution. Their study, titled “Craniofacial divergence and ongoing adaptation via the hedgehog pathway“, highlights the genetic basis of within and between species variation in jaw shape in African cichlid fishes. Continue reading