extinction

It’s one of those situations where everything we knew about the tiger’s (thylacine wolf’s) extinction is true, but some new information rounds out the picture. From “Tasmanian Tiger’s Jaw Was Too Small to Attack Sheep, Study Shows” (ScienceDaily, Aug. 31, 2011), we learn: Australia’s iconic thylacine, or Tasmanian tiger, was hunted to death in the early Twentieth century for allegedly killing sheep; however, a new study published in the Zoological Society of London’s Journal of Zoology has found that the tiger had such weak jaws that its prey was probably no larger than a possum. “Our research has shown that its rather feeble jaw restricted it to catching smaller, more agile prey,” said lead author Marie Attard, of the University Read More ›

In “Alternative Evolution” of Dinosaurs Foresaw Contemporary Paleo Finds” (Scientific American August 10, 2011), Brian Switek surveys the great changes that have taken place in how dinosaurs are viewed, many of which may have been foreseen by Dougal Dixon, who thought he was writing a fantasy about how dinosaurs would have evolved, had they survived. Except that they happened way back then. Read More ›

In “Stick insects survive one million years without sex” (BBC Nature, 19 July 2011),  Ella Davies reports. Timema genevievae is a female-only species of stick insect “All the evidence points to Timema tahoe and Timema genevievae having persisted for over one million years without sex,” Dr Schwander told BBC Nature. “Our research adds to the growing amount of evidence that asexuality does not always result in the rapid extinction of a lineage,” she said. After the shocking ant revelations, we’re all skeptics here.

Parents strongly cautioned: ant sex discussed

At The Scientist (July 18, 2011), Tia Ghose explains, “Asexual Ants Have Sex”, which will take some explaining, but here goes:

Some populations of ants long thought to be asexual get a dose of genetic diversity by having sex.

On paper, asexuality seems like a winning strategy. Sexless creatures pass on all their genes—as opposed to just half—and “you don’t have to spend huge amounts of energy going around and finding a mate and going through courtship and exposing yourself to disease,” Tsutsui said.

[ … ]

But the fungus-farming ant is one of the few species that appeared to adopt a purely asexual lifestyle: researchers had never seen a male in the wild, and ants in the lab produced clonal offspring.

But hang on, Read More ›

Recently, Brandon Keim, presenting “11 Animal Wonders of Evolution” (June 28, 2011) at Wired says no,

After all, their lineages haven’t survived ice ages and warm spells and every natural upheaval just to be visualized in amber by some upstart hairless ape. A better term is “evolutionarily distinct.” They’re simply, impressively unique.

One could say that of the Kha-Nyou  Read More ›

In “A Home Before the End of the World” (Design Observer Group, 06.09.11), Adelheid Fischer reminds us,

To date, only about two million species of plants and animals have been identified and described. An estimated 10 million species still await discovery, description and naming. But this taxonomic handshake is just the beginning and tells us little about how organisms actually make their day-to-day living in the world — and therefore how they might also be of use to us.Our ignorance is truly staggering. According to some estimates, 95 percent of organisms in the soil alone are unknown to science. Read More ›

Recently, New Scientist defended cryptobiologists, people who search for creatures presumed to never exist or no longer exist: Read More ›

This ScienceDaily piece, (June 3, 2011) “Mass Extinction Victim Survives: Snail Long Thought Extinct Isn’t” looks at a recent local extinction of snail species (limpets) of which, it turns out, there was a survivor:

… a major mass extinction took place in North America in the first half of the 20th century, when 47 species of mollusk disappeared after the watershed in which they lived was dammed. Read More ›

At MSNBC (5/25/20), Charles Q. Choi tells us “Bizarre shrimp-like predators grew larger and survived longer than thought”:

The creatures, known as anomalocaridids, were giant predators (ranging from 2 to possibly 6 feet in length) with soft-jointed bodies and toothy maws with spiny limbs in front to snag worms and other prey.

[ … ]

Past research showed they dominated the seas during the early and middle Cambrian period 542 million to 501 million years ago, a span of time known for the “Cambrian Explosion” that saw the appearance of all the major animal groups and the establishment of complex ecosystems. Read More ›

In “Calculations may have overestimated extinction rates” (New Scientist, 18 May 2011), Debora MacKenzie advises that a mathematical error undetected for decades may affect estimates of extinction rates (the “sixth great extinction,” said to be due to human dominance): Read More ›