Books like Jerry A. Coyne's "Why Evolution is True" and the upcoming "The Greatest Show on Earth" by Richard Dawkins shouldn't have to exist. In a rational world, there would be no need for books that directly take on the claims of creationists and "intelligent design theorists", because the evidence for evolution, at least in broad outline, would be known to most people, both for the intellectual satisfaction it brings and because it would take a central stage in our culture. Unfortunately, we live in a world where people are still profoundly misinformed about the process that gave rise to us, and as long as that continues, I'll be thankful for books that lay out the case for evolution.
These books are for people who are on the fence about whether to accept the theory. There are many people who simply aren't sure about what the case for it is, whether the "controversy" is a genuine one, and so forth. These folk can be swayed by being shown the evidence; they aren't extremists by any means but have perhaps never taken the time to delve into the issue or maybe have only a vague acquaintance with the theory but aren't sure whether it's as strong as scientists claim it is. Of course, there are people who can't be swayed by evidence, because their reasons for rejecting evolution have nothing at all to do with evidence in the first place. Those people won't have their minds changed by these books. However, if you know someone who is on the fence, or if you yourself aren't sure about the veracity of evolution but feel you could be swayed if shown solid examples of the sorts of things that together clearly demonstrate it, then I implore you to read Coyne's book, because believe me, it's worth it. Dawkins' book is coming out in September of this year, and it can be pre-ordered from his website. It should also make for another sledge hammer of a read, with the wit and elegance that Dawkins is so renowned for
My sincerest apologies to anyone following this site. I know I haven't put anything up lately, but I'll be doing so very soon (probably this week, in fact). Stay tuned!
Callosobruchus is a genus of beetles known for their genitalia, which include some very unpleasant looking pieces of kit. The sexual organs of males are covered in spines, and these are used to cling onto females during copulation.
Spines on the phallus of C. maculatus. Image from National Geographic
The existence of homosexual behaviour is a much discussed issue in evolutionary biology. Recently, scientists uncovered the likely reason for it in flour beetles. It appears that males can actually gan a reproductive advantage by mounting other males. They dribble sperm onto the other male, who in turn goes off and mates with females. However, while doing so, he may be passing on the sperm of the male that mounted him.
Many animals are endothermic. That is, they generate internal heat rather than relying upon the energy acquired directly from the ambient environment. This isn't an absolute delineation among animals, since even many animals that are nominally "cold blooded" - like bees and sharks - can raise their internal temperature when they really need to (though they do so in ways that are different to the way we do it, and some of them heat only certain organs) and some nominally "warm blooded" animals can in fact change their internal temperature at times. But ambiguities aside, what benefit is there to constantly maintaining a warm body? Is it actually an adaptation in and of itself, or is it a side-consequence of something else? Maintaining constant warmth expends a lot of energy. While reptiles, for example, need to eat relatively infrequently, relying for their heat by exposing themselves to the sun (and moving out of it to avoid overheating), we wouldn't survive for very long if we stopped eating.
Thermal signatures of a monkey. Image from Linda Hermans-Killam / outreach@ipac.caltech.edu
Mars already has life. But it didn't originate on the planet; it originated on Earth, and hitched a ride on the landers that have been sent there over the past few decades. Scientists are now more acutely aware of the ruggedness of microbes, and they are worried that if Earth microbes are able to survive and multiply, then they might disrupt Martian indigenous life (if it exists). To this end, they are refining some already existing protocols to minimise the risk of contamination (one of these is actually a UN accord that aims to protect celestial bodies from harmful contamination).
Image of the planet Mars. From Federation of American Scientists
In amazing new developments, the initial draft of the genome of a 38,000 year old Neanderthal has been completed (check out this article from Ewen Callaway in New Scientist for some more details). Scientists will be able to compare the genomes of modern Homo sapiens and the extinct human species H. neanderthalensis to see what sorts of changes have accrued since the two shared a common ancestor and what sorts of regions have likely been involved in developmental processes since the divergence. Also, it will give us more clues as to whether the two species engaged in any intermixing. Currently, signs are that they didn't do this to any significant extent if at all, but the newly sequenced genome will allow us to investigate this with considerably more certainty. I should also point out that I also said something apparently contradictory: I alluded to the possibility of two species intermixing. According to the biological species concept, a species is the most inclusive set of all potentially interbreeding individuals, so by that criteria, Neanderthals and H.sapiens should count as members of the same species if they could intermix and produce offspring. But, like so many things in nature, species are rather fluid and there are different ways to define them. Since species formation is typically a gradual process, a continuity must exist from varieties to sub-species to species proper (however defined). It is possible that we did interbreed and that the offspring were less viable but still left some genes behind in the population. Whatever the story, this is certainly a wonderful development and it will address some important questions about human evolution.
Turtles have proven among the most elusive lineages to study from an evolutionary perspective. Their relatedness to other groups has always been rather unclear, but a recent discovery could prove vital for a more definitive resolution. The fossil also provides clues as to how the turtle shell evolved.
Odontochelys semitestacea. Image made by Arthur Weasley. From Scientific American