I’ve been rereading Jared Diamond’s The Third Chimpanzee – humans. He spends a lot of time on various aspects of sex, one of which is extramarital sex. According to various human studies, somewhere between one and 30 percent of children are conceived as a result of extramarital sex, but the data are dubious because interviewees …
There was an article in the New York Times recently about the evolution of birds, a field of knowledge that still has lots of mysteries. There are thousands of bird fossils, many of which have still to be fully examined and classified. But we are learning. One of the more interesting is Caihong juji, an …
Richard Dawkins is a British evolutionary biologist and author. He is an emeritus fellow of New College, Oxford. An atheist, he is well known for his criticism of creationism and intelligent design. Dawkins first came to prominence with his 1976 book The Selfish Gene, which popularized the gene-centered view of evolution. He has written a …
I received a comment from a subscriber the other day who asked me to publish a short article in my blog. The piece (if you want to read it) said, in a few short paragraphs, that birds are well adapted for flight with feathers, a light skeleton, and high metabolism, so birds must have been …
The Cretaceous, a geological period that lasted from about 145 to 66 million years ago, is the third and final portion of the Mesozoic Era, as well as the longest. In the early Cretaceous, the continents were in very different positions than they are today. There was a major landmass, a supercontinent called Pangaea. By …
Parthenogenesis means birth without fertilization. In other words, a female gives birth to offspring without having been impregnated by a male. This phenomenon occurs normally in some plants and a number of invertebrates like nematodes, some scorpions and mites, aphids, some bees, and parasitic wasps. It also happens among all vertebrates except mammals – yes, …
A recent study speculates that migratory birds have lighter colored feathers because they reduce the risk of overheating (Kaspar Delhey, James Dale, Mihai Valcu, and Bart Kempenaers. Migratory birds are lighter coloured. Current Biology, 2021). They say “We found across nearly all species of birds, migratory species tend to be lighter colored than non-migratory species. …
I have often mentioned that bird fossils are hard to come by, as compared to other vertebrates and hard-shelled invertebrates. It’s mainly because they are lightweight and thin-skinned. The earliest birds or birdlike creatures were reptile-like and were heavier boned than later bird forms and they left a decent fossil record, but later versions, as …
According to a recent study*, there are about 50 billion living birds in the world, six times as many as there are people. It was not easy to come up with that figure but the diagram below gives a graphic representation of how the researchers did it. It’s not easy to understand, but basically, using …
Why are there only 10,000 species of birds when there are 25,000 species of fish and 350,000 species of beetles out of at least 900,000 species of insects. A 1959 paper by G.E. Hutchinson entitled Homage to Santa Rosalia or Why are There So Many Kinds of Animals? provides some ideas. Birds have only been …
