Evolution
Yeast cells' ability to convert sugar into alcohol, essential for the production of beer and wine, can be attributed to a series of gene duplications that allow for optimal conversion of different types of sugars (such as sucrose and maltose) into alcohol, according to a new study in Current Biology.
The duplications arose because the genes for sugar processing are situated close to the unstable margin of the chromosome. The phenomenon appears not to be limited to alcohol production in yeast, but forms an important principle in the evolution of living organisms.
Living beings evolve…
The scientific method which provides us with so many technological goodies does not resemble the science of 1600. Ever since Bacon, science has undergone a slow evolution.
Landmarks in the history of the scientific method are the invention of libraries, indexes, citations, controlled experiments, peer review, placebos, double blind experiments, randomization, and search among others. At the core of the scientific method is the structuring of information. In the next 50 years, as the technologies of information and knowledge accelerate, the nature of the scientific process will change even…
The Cyc knowledge base (KB) is a formalized representation of a vast quantity of fundamental human knowledge: facts, rules of thumb, and heuristics for reasoning about the objects and events of everyday life. The medium of representation is the formal language CycL, described below. The KB consists of terms--which constitute the vocabulary of CycL--and assertions which relate those terms. These assertions include both simple ground assertions and rules. Cyc is not a frame-based system: the Cyc team thinks of the KB instead as a sea of assertions, with each assertion being no more "about" one…
Since Darwin proposed universal common ancestry (UCA) More than 150 years ago, the theory, though well supported, has remained beyond the scope of formal testing. But the author of a new letter in Nature says that the famous theory that underpins modern evolutionary biology has finally passed the first large scale quantitative hurdle.
Darwin proposed that, "all the organic beings which have ever lived on this earth have descended from some one primordial form." Over the last century and a half, qualitative evidence for this theory has steadily grown, in the numerous, surprising transitional…
lchircus |
Sometimes I feel like there is a hook in my chest. It rips me from my current location and pulls me through time and space to places deep within my imagination. The sensation is physical and real, and always from my heart and lungs, not my head. Looking out the window of the airplane between St. Louis and Baltimore, my world spins and I suddenly find myself looking down on a vast Devonian sea.
Lying on my back on a mountain top in Maine, I find myself jerked past Alpha Centauri, cruising back in time as I move away from Earth. As the stars rush towards me, my breath catches in my chest. The…
In War of the Worlds, giant alien robots emerge out of the ground and begin vaporizing large numbers of actors. There’s a lot to like in those scenes, but there are three things I could not stand.Like those three legs they walked around on. Not their fragile-appearing spindly-ness,but their actual three-ness.
Please get Tom Cruise first, please get Tom Cruise first, please get ...
There should be more legs. Around six of them, in particular. “Look,” you might reply, “it’s an alien ship, and who knows what kinds of principles they’ve uncovered.”
Of course, that’s possible. But another…
Biologists studying a population of lizards on the Bahamas say that competition among the brown anole lizard (Anolis sagrei) is more important than predation by birds and snakes when it comes to survival of the fittest lizard.
The Dartmouth team's results, published in Nature, may also aid efforts to teach the public about evolution.
For the study, researchers covered multiple small islands in the Bahamas with bird-proof netting to keep predatory birds at bay. Other islands were left open to bird predators, and on still other islands, the researchers added predatory snakes to expose the…
After extracting ancient DNA from the 40,000-year-old bones of Neanderthals, scientists have obtained a draft sequence of the Neanderthal genome. The effort revealed evidence that shortly after early modern humans migrated out of Africa, some of them interbred with Neanderthals, leaving bits of Neanderthal DNA sequences scattered through the genomes of present-day non-Africans.
"We can now say that, in all probability, there was gene flow from Neanderthals to modern humans," said the paper's first author, Richard E. (Ed) Green of the University of California, Santa Cruz.
The results of the…
Scientists at the Georgia Institute of Technology have successfully altered the brain of one type of Cichlid fish to resemble that of another and discovered differences in the general patterning of the brain before neurogenesis occurs.
The findings, published in PNAS, challenge the popular theory known as “late equals large,” first proposed in the mid 1990s to explain the way brains evolve across species.
The brain begins as a blank slate. In early development, the anterior, or front, part of the brain is specified from the posterior, or back, part.
research team were able to alter the…
A new study of island lizards suggests that geographical isolation may not be as important to evolution as previously thought.
The new research, published in PLoS Genetics, shows that even those lizards that have been geographically isolated for many millions of years have not evolved into separate species as predicted by conventional evolutionary theory.
The findings reject allopatric speciation in a case study from a system thought to exemplify it, the researchers say, and suggest the potential importance of speciation due to differences in ecological conditions (ecological speciation).…