Evolution
About 10% of couples who want a baby have fertility problems and causes offered tend to break down around advocacy issues; environmentalists blame pollution while psychiatrists point to our stressful lifestyles, but evolutionary biologist Dr. Oren Hasson of Tel Aviv University's Department of Zoology has a different take than the others, though also based on his speciality.
The reproductive organs of men and women are currently involved in an evolutionary arms race, he says in a new study, and the fight isn't over yet.
"The rate of human infertility is higher than we should expect it to be…
Belemnoteuthis antiquus is technically not a squid, but a belemnite. Belemnites were the first cephalopods (as far as we know) to develop the ingeniously internalized shell that led to the radiation of nearly all modern cephalopods--octopus, squid, and cuttlefish. External shells like those of the ammonites provided predator protection, but they were heavy and hard to maneuver. Presumably, internalizing the shell led to improvements in swimming, freeing these proto-squid so they could compete effectively with fish. However, belemnites did not evolve directly into modern cephalopods--they went…
Should early 20th century researcher Paul Kammerer be credited as the founder of epigenetics? It would certainly be a dramatic change from current perceptions of his work.
Kammerer, a leading proponent of the Lamarckian theory of evolution, achieved global prominence in the 1920's by arguing that acquired traits could be passed down through generations and, in his most controversial experiment, forced land dweller midwife toads to live in water. Their offspring preferred to live and mate in water and by the third generation he noted that they began to develop black nuptial pads…
Birds have a wide variety of vibrant plumages and have evolved various chemical and physical mechanisms to produce these beautiful colors over millions of years. When did feathers first get iridescence, the quality of changing color depending on the angle of observation, such as the rainbow of colors seen in an oil slick? We may be closer to an answer.
A team of paleontologists and ornithologists has pushed the date back and discovered evidence of vivid iridescent colors in feather fossils more than 40 million years old. It's the first evidence of a preserved…
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Can even the human form grow tiring?This ORGY of a culture wepresuppose to be endlessly entertaining - perpetually self-gratifying -could it all be an elementary school yard game?Our brains areslowly connecting the dots - understanding that humans are not somespecial gift from the heavens brought to Earth to use the elements andother beings to fuel our desires and build our civilizations andreproduce until we collapse.The power of the sexual body to driveus to lust (for example), a deeply primal and psychologically embeddednatural drug that keeps us mating incessantly.A dopamine reward system…
The lowly appendix used to get no respect and was simply regarded as a useless evolutionary artifact but two years ago researchers at Duke University Medical Center proposed that it actually serves a critical function as a safe haven where good bacteria could hang out until they were needed to repopulate the gut, like after a nasty case of diarrhea.
Now a group writing in the Journal of Evolutionary Biology claim something even more aggressive; that Charles Darwin was wrong and the appendix is a whole lot more than an evolutionary remnant. Not only does it appear in nature much more…
Not only is Hamilton's Rule not a rule, it isn't even a strong suggestion. The relationship c rb (1), doesn't begin to qualify as a meaningful description of anything.
The first problem one encounters is that all the variables are highly subjective. It is also problematic in describing what a cost and benefit actually is in a quantifiable way. In a book describing the research of white-fronted bee-eaters, this helpful piece of information was provided:
"For example, imagine an individual with nine units worth of aid that it can dispense to relatives. Suppose that this…
Garter snakes like to eat newts. Newts don't like to be eaten, and to deter snakes from eating them, they have evolved a seriously lethal neurotoxin. This toxin, called tetrodotoxin (TTX), is chemically similar to that found in pufferfish, and a few milligrams is enough to take out a hefty adult human.
But some garter snakes really like newts, and instead of searching for other prey, several species of garter snakes have managed develop resistance to newt neurotoxins.
So how does neurotoxin resistance evolve? A group out of Utah State University, writing in PNAS has used the garter snake -…
It doesn't take a catastrophe to end entire lineages. (Well, for the dinosaurs it did.) But an analysis of 200 million years of history for marine clams found that vulnerability to extinction runs in evolutionary families, even when the losses result form ongoing, background rates of extinction.
"Biologists have long suspected that the evolutionary history of species and lineages play a big role in determining their vulnerability to extinction, with some branches of the tree of life being more extinction-prone than others," said Kaustuv Roy, a biology professor at the University of…
I’m reviewing a book by philosopher of science Peter Godfrey-Smith entitled “Darwinian Populations and Natural Selection.” (This is not the book review, forthcoming.) Godfrey-Smith makes an excellent argument at some point in the book (chapter 7, on the gene’s eye view) that genes are not at all the sort of things Richard Dawkins and some other biologists think they are. For instance, contrary to the standard view, genes are not “unities of heredity” (and therefore do not last as “individuals”) for the simple reason that crossing-overs (the molecular processes that shuffle bits and pieces of…