Evolution

Pegasus - A Load Of Horse Feathers? Evolution proceeds by producing variants of a life-form which may, or may not, thrive in their current environment.  An interesting question arises: "In an alternate history of Earth, could horses have evolved feathers?" Image source: Wikimedia, public domain. It is entirely probable that the phrase 'horse feathers', meaning 'nonsense', originated with the Pegasus myth.  Legend has it that when Pegasus was made into a constellation, a single feather floated down to Earth near the city of Tarsus.  Well, you can tell that story to the marines…

http://www.redorbit.com/news/science/15854/sparks_of_life_darwinism_and_... Advocates of Intelligent Design creationism like to play Stump the Scientist by asking evolutionary biologists "what would disprove evolution?" Scientists often have trouble answering this question, leaving some people with the impression that evolutionary theory is no more scientific than Intelligent Design (ID). This challenge is based on the idea of falsifiability, which was formalized by the philosopher Karl Popper as the test to separate science from non-science. Scientists generally dismiss ID on the grounds…

When administered in lethal levels, antibiotics trigger a fatal chain reaction within  bacteria that shreds the cell's DNA. But, when the level of antibiotic is less than lethal the same reaction causes DNA mutations that are not only survivable, but actually protect the bacteria from numerous antibiotics beyond the one it was exposed to, says a new study recently published in Molecular Cell. The findings underscore the potentially serious consequences to public health of administering antibiotics in low or incomplete doses. "We know free radicals damage DNA, and when that happens, DNA…

There is a presumption among many people that extraterrestrial life is a foregone conclusion and that it is only awaiting our discovery.  The Drake equation is usually highlighted as many astronomers suggest that with the billions of worlds available, that life is all but inevitable1. Equally there is a sense that life couldn't possibly be unique to a single planet, so there is a strong belief that there must be other planets on which life flourishes.  However, we need to consider what the basis for these assumptions actually is. In the physical sciences, it is clear that the Earth…

In an article published this week in Science, Monash University biochemists say they have discovered the process by which bacteria developed into more complex cells and that this crucial evolutionary step happened much earlier than previously thought. The team found that the cellular machinery needed to create mitochondria was constructed from parts pre-existing in the bacterium. These parts did other jobs for the bacterium, and were cobbled together by evolution to do something new and more exciting. "Our research has crystallized with work from other researchers around the world to show how…

Go check out Carnival of Evolution # 20 at Skeptic Wonder. This month's issue includes a metagenomic analysis of the carnival submissions. (I get a fairly long phylogenetic branch of my own!) Go check it out! Read the feed:

As addressed in other posts, there is a significant difference between "selfishness" and "self-interest".  However, it seems that there is still a general insistence on perpetuating the selfishness perspective. Recent articles have pointed out some of the altruistic actions that are performed by chimpanzees, however there are also articles that point out competitive or "selfish" behaviors that are used to rationalize and even extrapolate human behaviors. One of the first misconceptions is the assumption that the failure to share automatically constitutes selfish behavior.  It doesn…

The traditional view in biology is that ecology shapes evolution. The environment defines a template and the process of evolution by natural selection shapes organisms to fit that template. Some  recent research suggest, however, that evolutionary processes reciprocate by influencing ecology in turn. Now a team of biologists presents new evidence that ecology and evolution are indeed reciprocally interacting processes, presenting a fundamental shift in our understanding of the relationship between evolution and ecology. Study results appear this week in the online early edition of the…

What kinds of genetic changes are required to evolve significant changes in body shape and size? The availability of affordable, state-of-the-art DNA sequencing and array technology has made it possible to study evolution at a level of molecular detail inaccessible just a decade ago. Researchers are uncovering the details of molecular evolution, and answering some interesting questions along the way, such as the relative importance of changing genes themselves versus changing how those genes are regulated. Recall how genetically similar we are to chimps, and yet how morphologically different…

Researchers from George Washington University and the Institute of Vertebrate Paleontology and Paleoanthropology have discovered a new species of Jurassic theropod dinosaur called Haplocheirus sollers in Xinjiang, China. The team says the discovery illustrates how one family of dinosaurs called Alvarezsauridae came to look like birds independent of birds. The new finding extends the fossil record of the bizarre group of bird-like dinosaurs with a large claw on the hand and very short, powerful arms – back 63 million years, further distancing them from birds on the evolutionary tree.…