Life Sciences
loom | November 5, 2005The insects scandalously embracing in this picture are decorated crickets (Grylllodes sigillatus), which can be found in the southwestern United States, among other places. The droplet on the male's tail is--for want of a better word--a gift. After producing this glob he sticks it onto the package of sperm he places on the female. After the crickets are finished with their encounter, the female will grab the gift and snack on it.
In an age when penguins can become role models for traditional family values, some people may be tempted to celebrate the decorated cricket as everything a gentleman…
emjohnson | November 1, 2005Reprinted from Wildlife Conservation Magazine
"Behind Enemy Lines"
November/December 2005
By Eric Michael Johnson
December 2002 -- After four days traveling upriver in a dugout canoe, Belgian primatologist Jef Dupain became the first researcher in five years to return to the war-torn Lomako Forest in the Democratic Republic of Congo (DR Congo). As he surveyed the overgrown field station that had once been his home, a boy soldier wielding an AK-47 stepped into view from a concealing tangle of vines. Fortunately the boy was only one of the rebel fighters who had escorted Dupain…
tlambert | October 14, 2005Extracts from "Agricultural production and malaria resurgence in Central America and India" by Georganne Chapin and Robert Wasserstrom published inNature Vol 293 17 September 1981 pages 181--185
Among the inhabitants of Asia, Latin America and tropical Africa
malaria, remains a major cause for alarm. Yet only a few years ago,
health officials in a dozen developing countries (capitalizing on the
discoveries of British parasitologist Ronald Ross half a century
earlier) pointed triumphantly at their efforts to eradicate entirely
this mosquito-borne scourge[1-5]. Following World Health…
loom | September 15, 2005A lot of people think of viruses and bacteria in our bodies as nothing more than pests. It's certainly true that a lot of them do an excellent job of making us ill. But some viruses and bacteria merged with our ancestors over the course of billions of years, and if you were to have them removed from your body today, you'd die faster than if you'd gotten a massive dose of Ebola.
In order to breathe, we depend on sausage-shaped blobs in our cells called mitochondria. When I say we, I mean not just humans or animals, but a vast group of species known as eukaryotes, which also includes plants,…
loom | September 13, 2005(Warning: this post contains some journalistic/blogging inside-baseball material.)
Back in the dark ages (otherwise known as the 1990s), writing about science felt a bit like putting messages in a bottle. I'd write an article, a few weeks or months later it would appear in a magazine, and a few weeks or months later I might get a response from a reader. In some cases, an expert might point out an error I made. In other cases, she or he might explain the real story which I had missed. The delay could make for some disconcerting experiences. The first time I met the late Stephen Jay Gould, to…
loom | August 31, 2005Clint, the chimpanzee in this picture, died several months ago at a relatively young age of 24. But part of him lives on. Scientists chose him--or rather, his DNA--as the subject of their first attempt to sequence a complete chimpanzee genome. In the new issue of Nature, they've unveiled their first complete draft, and already Clint's legacy has offered some awesome insights into our own evolution.
The editors of Nature have dedicated a sprawling space in the journal to this scientific milestone. The main paper is 18 pages long, not to mention the supplementary information kept on Nature's…
loom | August 27, 2005Sometimes a picture can tell you a lot about evolution. This particular picture has a story to tell about how two species--in this case a fly and an orchid--can influence each other's evolution. But the story it tells may not be the one you think.
Coevolution, as this process is now called, was one of Darwin's most important insights. Today scientists document coevolution in all sorts of species, from mushroom-farming ants to the microbes in our own gut. But Darwin found inspiration from the insects and flowers he could observe around his own farm in England.
Darwin's thoughts about…
loom | August 24, 2005Scientists have been making some remarkable discoveries about viruses recently that may change the way we think about life. One place to start understanding what it all means is by looking at this picture.
You can't help put see a bright triangle with its three corners sitting on top of the black circles. But the triangle exists only in your mind. The illusion is known as a Kanisza triangle, and psychologists have argued that it plays on your brain's short-cuts for recognizing objects. Your brain does not bother to interpret every point of light that hits your retina in order to tell what you…
dmunger | August 24, 2005Welcome to Tangled Bank—we're thrilled to finally have the opportunity to host. For CogDaily readers who may not be aware of Tangled Bank, it's a fortnightly "carnival" of the best science blog postings from the previous two weeks. There's always an incredible variety of posts from all areas of the scientific world, and this week is no exception. Even if you're normally only interested in psychology, we encourage you to take this opportunity to see what else is going on in the world of science. We think you'll be pleasantly surprised.
We've done something a bit unusual with Tangled Bank this…
loom | August 21, 2005New branches on the tree of life have just turned up in Africa. Some are cuter than others.
In Madagascar, our primate family was enlarged by two adorable species of mouse lemurs. Meanwhile, other scientists made an uglier discovery in the small country of Djibouti, in the Horn of Africa. They found a surprising diversity of bacteria that cause tuberculosis. When most people think about the joys of biodiversity, they probably don't think about the hidden expanses of parasites waiting to be discovered. But in cases such as this one, they can have a fascinating story to tell--one that may…
loom | August 14, 2005Mole rats are a pretty ugly, obscure bunch of creatures. They live underground in Africa, where they use their giant teeth to gnaw at roots. Those of you who know anything about mole rats most likely know about naked mole rats, which have evolved a remarkable society that is more insect than mammalian, complete with a queen mole rat ruling over her colony. But according to a paper in press at the Journal of Human Evolution, mole rats are important for another reason. Their evolution and our own show some striking parallels that may shed light on how our ancestors diverged from other apes.
The…
stcynic | July 26, 2005Back in June of 2004, I wrote an essay about the varying degrees of credibility among creationists (with people like Kurt Wise and Art Chadwick at the top and people like Kent Hovind and Karl Priest at the bottom) that included a snarky little tidbit about William Gibbons. Gibbons describes himself as holding a "Ph.D., in Creation Science Apologetics summa cum laude, Emmanuel College of Christian Studies, Springdale, Arkansas." I made a snippy comment or two about that and said:
But Gibbons' bio gets even better. Under "special achievements", he actually lists "Conducted four expeditions to…
loom | July 8, 2005
I've been fascinated by this picture since I first saw it over the weekend. It's a hint of how we may be visualizing life in years to come.
As Darwin was trying to figure out how new species could evolve from old species, he began to think of evolution as a tree. He scribbled some simple branches in a notebook, and then published a more elaborate one in The Origin of Species. Darwin didn't actually put any animals or plants on the branches of these trees; he was just thinking about the process itself. Today, though, evolutionary trees are a common sight in scientific journals, whether…
loom | June 21, 2005Back in 1986 a biologist named Cindy Lee Van Doverwas poking around the innards of shrimp from the bottom of the sea. They came from a hydrothermal vent in the Atlantic, where boiling, mineral-rich water came spewing up from cracks in the Earths crust and supported rich ecosystems of tube-worms, microbes, crabs, and other creatures. The animals that lived around these vents were generally blind, which wasnt surprising considering that no sunlight could reach them. But Van Dover noticed that they had two flaps of tissue running along their backs that connected to nerves. Closer inspection…
loom | June 16, 2005In October 2004 Australian and Indonesian announced they had discovered a three-foot tall species of hominid, Homo floresiensis, that was still alive no earlier than18,000 years ago. As Ive detailed in previous posts, this claim has inspired a lot of debate, much which revolves around whether the fossils, found on the Indonesian island of Flores do in fact represent a new species, or whether they were human pygmies. This week a new study was published in the journal Biology Letters (link to come) that puts this debate in the proper evolutionary frame. The paper is not about hominids, however…
tfk | May 22, 2005Reposted from the old TfK.
Burt Humberg has a long and detailed analysis of Creationist Fears, Creationist Behaviors at the Panda's Thumb:
Creationists Are in Fear
To understand why creationists fear evolution, it is necessary to consider three things. First, many creationists believe that the Bible must be taken literally, though this literalism is typically ad hoc. (They interpret literally when literalism serves their purposes and they interpret metaphorically or symbolically when it does not.) Second, one must consider the concept of salvation, specifically Christian salvation. (No other…
loom | April 28, 2005From time to time, scientists discover that a species that was once thought to have become extinct is actually surviving in some remote place. If the species is a salamander or a lemur, it gets a quick headline and then promptly goes back to its obscure, tenuous existence. But here's one rediscovered creature that I suspect will get some major press: the Ivory-billed woodpecker is back. Science is publishing a paper in which scientists report several sightings and a video of the magnificent bird, which hadn't been seen since in the United States since 1944. Here is a report from the AP.
The…
loom | April 12, 2005I have a weakness common to many bloggers--I like to check my site meter to see who's coming to my blog, and from where. Often I wind up discovering intriguing sites run by people whose interests run along the same lines as mine, such as evolutionary biology. Today, however I was surprised to see a lot of traffic coming from Answers in Genesis, a creationist web site.
First off, greetings to all visitors who come through the link. I hope you find some interesting things here.
I decided to investigate the source of the link, and the results were interesting. It turns out that today Answers in…
loom | February 25, 2005Earlier this month I wrote two posts about the evolution of the eye, a classic example of complexity in nature. (Parts one and two.) I'd like to write now about another case study in complexity that has fascinated me for some time now, and one that has sparked a fascinating debate that has been playing out for over fifteen years. The subject is language, and how it evolved.
In 1990, Steven Pinker (now at Harvard) and Paul Bloom (now at Yale) published a paper called "Natural Selection and Natural Language." They laid out a powerful argument for language as being an adaptation produced by…
loom | February 16, 2005In my last post, I went back in time, from the well-adapted eyes we are born with, to the ancient photoreceptors used by microbes billions of years ago. Now I'm going to reverse direction, moving forward through time, from animals that had fully functioning eyes to their descendants, which today can't see a thing.
This may seem like a ridiculous mismatch to my previous post. We start out with the rise of eyes, a complex story with all sorts of twists and turns, with gene stealing, gene borrowing, gene copying; and then we turn to a simple tale of loss, of degeneration, of a few genes mutating…