Evolution

When aliens come to Earth to investigate life here, they don’t simply beam up a specimen and start probing. (And they’re also, by the way, not disproportionately interested in the anus.) Only a novice prober would do a simple beam-and-probe, and would surely get a quick rap on a proboscis from the instructor. The problem with abducting an animal of interest, all by itself, is that you can’t understand an animal without an appreciation of the environment the animal inhabits. These alien probers, you see, have a motto, and it roughly translates as: “My eye is not a squirt gun even though it…

A series of articles in the January 26 issue of PNAS illustrates recent progress in applying evolutionary theory to a range of questions in medicine and public health, and may lead to medical students soon being tested on evolution in medical entrance and licensing exams. So what does evolution – a theory that deals with changes over many generations – have to do with preventing and treating disease in our lifetime? A lot, some scientists say. "There are many ways you can use evolution to improve medical care and medical research," said psychiatrist Randolph Nesse of the University of…

Using high resolution genome sequencing, an international team of researchers has tracked a particularly virulent strain of MRSA as it traveled between South America, Europe and Southeast Asia. The findings shed light on how these deadly bacteria are able to spread from patient to patient in a single hospital and, on a larger scale of geography and time, between countries and entire continents. The results appear in a recent issue of Science. "MRSA is responsible for over 18,000 fatalities in the United States each year according to CDC estimates, a number virtually identical to the current…

In my library at home, I have three books that catch the eye because of their unusual heft. One is my old copy of the Handbook of Chemistry and Physics, and another is Stephen J. Gould’s massive treatise on evolution. Now, a third tome has made it a trio of thick, heavy books: Divine Action and Natural Selection, edited by Joseph Seckbach and Richard Gordon (World Scientific Publishing, 2009). If I had to pick one of the three to take to the beach on holiday, this would be the one.      Why? Well, it’s interesting reading for a scientist, and perhaps even for a thoughtful…

According to a new study in the American Naturalist that compared the skull shapes of domestic dogs with those of different species across the order Carnivora, domestic dogs have followed their own evolutionary path, twisting Darwin's directive "survival of the fittest" to their own needs -- and have proved him right in the process. The study found that the skull shapes of domestic dogs varied as much as those of the whole order. It also showed that the extremes of diversity were farther apart in domestic dogs than in the rest of the order. This means, for instance, that a Collie has a skull…

A new paper published in Zoologica Scripta argues that the distributions of the major primate groups are correlated with Mesozoic tectonic features and that their respective ranges are congruent with each evolving locally from a widespread ancestor on Pangea about 185 million years ago. The new theory incorporates spatial patterns of primate diversity and distribution as historical evidence for primate evolution, while previous models of primate evolution had been limited to interpretations of the fossil record and molecular clocks, says author Michael Heads, a Research Associate of the…

As described in my profile, I don't want to blog about my own field of research. However, in anticipation of questions about my research, I'm going to write this introductory post. So far, all my published work addresses how species concepts apply to bacteria. If you are interested in learning more about this issue, I recommend the following: 1) An essay proposing one approach to defining bacterial species.2) An essay panning the idea of universal species concepts.3) A detailed review of the problems with applying species concepts to prokaryotes (same first author as #2). For the heck of it…

 Air flows in one direction as it loops through the lungs of alligators, just as it does in birds, and this breathing method may have helped the dinosaurs' ancestors dominate Earth after the planet's worst mass extinction 251 million years ago, according to scientists from the University of Utah. Until about 20 million years after the extinction – called  the Permian-Triassic extinction – mammal-like reptiles known as synapsids were the largest land animals on Earth. The extinction killed 70 percent of land life and 96 percent of sea life. As the planet recovered during the next 20…

While people typically blame incompetency when airport security screeners fail to keep dangerous weapons off airplanes or when doctors miss developing cancer tumors, the real culprit may be evolution, according to researchers at Harvard Medical School. Their new study published in Current Biology suggests that people simply haven't evolved superior skills for finding things that are rare. "We know that if you don't find it often, you often don't find it," said Jeremy Wolfe of Harvard Medical School. "Rare stuff gets missed." That means that if you look for 20 guns in a stack of 40 bags, you'…

Writing in the Proceedings of the National Academy of Sciences, researchers say the subtle but ongoing pressures of human evolution could explain the seeming rise of disorders such as autism, autoimmune diseases, and reproductive cancers. They suggest that certain adaptations that once benefited humans may now be helping such ailments persist in spite of – or perhaps because of – advancements in modern culture and medicine. The team first presented their research at the Arthur M. Sackler Colloquium, co-sponsored by the National Academy of Science and the Institute of Medicine. Colloquium…