Evolution

"The placenta is this amazing, complex structure and it's unique to mammals, but we've had no idea what its evolutionary origins are," says Julie Baker, PhD, assistant professor of genetics at Stanford Univeristy and senior author of a study in Genome Research which discusses its evolution. The placenta is the mother's intricate lifeline to her unborn baby, delivering oxygen and nutrients critical to the baby's health. New evidence suggests the placenta of humans and other mammals evolved from the much simpler tissue that attached to the inside of eggshells and enabled the embryos of our…

In research published in Nature, researchers at Rockefeller University and the University of Tokyo state that insects have adopted a strategy to detect odors that is radically different from those of other organisms -- an unexpected and controversial finding that may dissolve a dominant ideology in the field. They state that insects use fast-acting ion channels to smell odors, a major break with current ideology, and that this means Darwin's tree of life will need to be redrawn. Since 1991, researchers assumed that all vertebrates and invertebrates smell odors by using a complicated…

Nice blog today on mutualisms by Olivia Judson who writes the Wild Side blog/column for the New York Times (I seem to be writing a lot about writers for the NY Times these days ... not sure what is going on with that). She even features one of my favorite organisms in the blog: The clam Calyptogena magnifica, which lives on deep-sea vents, depends on a bacterium to supply it with nutrients; the bacterium is transmitted through the clam’s eggs Last year we published a paper on the complete genome sequence of this symbiont (which I wrote about here when I was clearly in a whiny kind of mood…

The Human Genome Project revealed that only a small fraction of the 3 billion “letter” DNA code actually instructs cells to manufacture proteins, the workhorses of most life processes. This has raised the question of what the remaining part of the human genome does. How much of the rest performs other biological functions, and how much is merely residue of prior genetic events" Scientists from Cold Spring Harbor Laboratory (CSHL) and the University of Chicago now report that one of the steps in turning genetic information into proteins leaves genetic fingerprints, even on regions of the DNA…

In the first experiment of its kind conducted in nature, a University of British Columbia evolutionary biologist has come up with strong evidence for one of Charles Darwin’s cornerstone ideas – adaptation to the environment accelerates the creation of new species. “A single adaptive trait such as color could move a population towards the process of forming a new species, but adaptation in many traits may be required to actually complete the formation of an entirely new species,” says UBC post-doctoral fellow Patrik Nosil. “The more ways a population can adapt to its unique surroundings, the…

Higher organisms do not have a “cost of complexity” — or slowdown in the evolution of complex traits — according to a report by researchers at Yale and Washington University in Nature. Biologists have long puzzled over the relationship between evolution of complex traits and the randomness of mutations in genes. Some have proposed that a “cost of complexity” makes it more difficult to evolve a complicated trait by random mutations, because effects of beneficial mutations are diluted. “While a mutation in a single gene can have effects on multiple traits, even as diverse as the structures of…

Nathaniel Abraham got a job as a biology post-doc at Woods Hole and then chose to disclose that he wasn't necessarily hip to every little aspect of evolutionary biology - like the whole evolution part. You all know me pretty well. I am middle of the road about anything not to do with the science aspects and the culture hoopie is way off my radar. Clearly the guy got a Ph.D. with his religious beliefs so they were not an impediment to him academically and that's where I would let it lay. Only the true atheist crazies can find a way to complain about Francis Collins because of his religion. But…

Writing in PNAS, a group of researchers says they have determined the first pervasive 'rule' of evolution - that animals become increasingly more complex. Examining the last 550 million years of the fossil catalog, the team investigated the different evolutionary branches of the crustacean family tree. They were seeking examples along the tree where animals evolved that were simpler than their ancestors. Instead they found organisms with increasingly more complex structures and features, suggesting that there is some mechanism driving change in this direction. “If you start with the simplest…

I don't often see bacteriophage ecology and evolution papers in the open source literature, but there is a nice one in next month's American Naturalist (occasionally Am Nat selects papers for open access). The paper by Rick Heineman and colleagues addresses the question of optimal foraging, a body of theory that seeks to explain the food choices of organisms in terms of how they maximize energy intake over time. As a model organism, the authors use the bacteriophage T7, a parasite of Escherichia coli. Naturally, phages don't "eat" per se, nor do the make conscious "choices", but for the…

The news keeps coming in, and examples of how real science works (as opposed to make believe creationism or so-called intelligent design) are beginning to get so numerous that it is hard to imagine people capable of reading newspaper articles are still capable of denying evolution. Last month, for instance, a spectacular discovery was published in Nature magazine, a finding that has resolved a long-standing question about the evolution of bats. Darwin listed the problem as one of the great mysteries of evolution he was not able to address in “The Origin of Species”: how did bats originate…