// posted July 25, 2006 by Lou Schuler
I’ve written before about my fascination with how the human species changed the during the Neolithic period, starting around 10,000 B.C. That’s when humans invented farming, and started building permanent settlements. With settlements came war, and with war came bigger settlements, and with bigger settlements came the need for a more or less permanent class of warriors to defend them.
(I can’t prove this, of course, but I’d suspect that somewhere in that continuum exercise was invented, as a way to train soldiers who didn’t have other jobs involving physical labor.)
At the same time humans began farming, they started domesticating animals, selectively breeding the wildness out of them.
How, exactly, did that work?
According to this fascinating New York Times piece by Nicholas Wade, Russian scientists, way back in 1959, set out to see for themselves:
Belyaev decided to study the genetics of domestication, a problem to which Darwin gave deep…
Leave a Comment
Tags:
Tags: science
// posted July 21, 2006 by Lou Schuler
Scientists in Germany and the U.S. have set off on an ambitious project to recreate the Neanderthal genome:
Long a forlorn hope, the sequencing, or decoding, of Neanderthal DNA suddenly seems possible because of a combination of analytic work on ancient DNA by Svante Paabo, of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and a new method of DNA sequencing developed by a Connecticut company, 454 Life Sciences.
The initial genome to be decoded comes from 45,000-year-old Neanderthal bones found in Croatia, though bones from other sites may be analyzed later. Because the genome must be kept in constant repair and starts to break up immediately after the death of the cell, the material surviving in Neanderthal bones exists in tiny fragments 100 or so DNA units in length. As it happens, this is just the length that works best with the 454 machine, which is also able…
Leave a Comment
Tags:
Tags: science
// posted June 12, 2006 by Lou Schuler
I’ve written about the body-parts trade before, but this Associated Press story offers the most complete treatment of its economics that I’ve seen so far:
Like a gallon of gasoline, the price of a human leg is all about supply and demand. And it’s a seller’s market. “There’s a lot of money to be made on corpses,” said Joshua Slocum, executive director of the nonprofit Funeral Consumers Alliance.
Over the past two decades, the tissue industry has exploded into a billion-dollar business, creating a huge demand for ligaments, tendons, bones and other valuable body parts.
The money to be made is pretty sweet:
Money is being made hand (which goes for $350 to $850) over foot ($200 to $400 each), according to the new book Body Brokers, by Annie Cheney.
Executives are earning generous salaries, and the companies for which they work are generating huge revenues thanks to advances in modern medicine…
Leave a Comment
Tags:
Tags: science
// posted May 26, 2006 by Lou Schuler
If smoking tobacco causes cancer, then smoking marijuana should cause cancer, too? Right? But what seems logical doesn’t appear to be true:
The largest study of its kind has unexpectedly concluded that smoking marijuana, even regularly and heavily, does not lead to lung cancer.
The new findings “were against our expectations,” said Donald Tashkin of the University of California at Los Angeles, a pulmonologist who has studied marijuana for 30 years.
“We hypothesized that there would be a positive association between marijuana use and lung cancer, and that the association would be more positive with heavier use,” he said. “What we found instead was no association at all, and even a suggestion of some protective effect.”
Federal health and drug enforcement officials have widely used Tashkin’s previous work on marijuana to make the case that the drug is dangerous. Tashkin said that while he still believes marijuana is potentially harmful, its cancer-causing effects…
Leave a Comment
Tags:
Tags: science
// posted May 19, 2006 by Lou Schuler
New year, new theory about the bones of little people discovered on the Indonesian island of Flores.
In 2004, we learned of the discovery of the bones, and the startling hypothesis that the bones were remains of a previously undiscovered human species, called Homo floresiensis.
In 2005, we learned of a counter-hypothesis, suggesting that the bones were merely Homo sapiens who’d grown steadily smaller over many generations because they were on an island with limited resources.
Now, in 2006, comes a third hypothesis:
Not all scientists agree that the 18,000-year-old “little people” fossils found on the Indonesian island of Flores should be designated an extinct human-related species. …
In today’s issue of the journal Science, researchers led by Robert D. Martin of the Field Museum in Chicago present evidence they say supports their main argument, that the skull in question is not that of a newfound extinct species, but of a modern…
Leave a Comment
Tags:
Tags: science
// posted May 18, 2006 by Lou Schuler
When humans and chimps split off into separate species, the divorce was messy, with occasional bouts of make-up sex messing up the DNA forever:
“For the first time we’re able to see the details written out in the DNA,” said Eric Lander, founding director of the Broad Institute. “What they tell us at the least is that the human-chimp speciation was very unusual.”
The researchers hypothesize that an ancestral ape species split into two isolated populations about 10 million years ago, then got back together after a few thousand millennia. At that time the two groups, though somewhat genetically different, would have mated to form a third, hybrid population. That population could have interbred with one or both of its parent populations. Then, at some point after 6.3 million years ago, two distinct lines arose.
Some experts in human evolution are skeptical of that precise scenario, but nevertheless impressed with the study.
“It’s…
Leave a Comment
Tags:
Tags: science
// posted April 6, 2006 by Lou Schuler
Two recent science stories caught me by surprise. The first is a fish tale:
Scientists have discovered fossils of a 375 million-year-old fish, a large scaly creature not seen before, that they say is a long-sought “missing link” in the evolution of some fishes from water to a life walking on four limbs on land. …
Several well-preserved skeletons of the fossil fish were uncovered in sediments of former stream beds in the Canadian Arctic, 600 miles from the North Pole, it is being reported on Thursday in the journal Nature. The skeletons have the fins and scales and other attributes of a giant fish, four to nine feet long.
But on closer examination, scientists found telling anatomical traits of a transitional creature, a fish that is still a fish but exhibiting changes that anticipate the emergence of land animals — a predecessor thus of amphibians, reptiles and dinosaurs, mammals and eventually…
Leave a Comment
Tags:
Tags: science
// posted February 26, 2006 by Lou Schuler
Just about a year ago, I wrote about scientific speculation regarding the possibility that humans and neanderthals did the paleo polka.
Since then, carbon dating has been recalibrated, and scientists now think that modern humans and our muscular cousins probably spent less time together than previously assumed:
The old radiocarbon calculation is now known to be off by as much as several thousand years, the new research shows. That means that modern Homo sapiens barged into Europe 46,000 years ago, 3,000 years earlier than once estimated. But the radiocarbon dating under the new calculation also shows that their takeover of the continent was more rapid, their coexistence with the native Neanderthals much briefer.
The revised dates reveal an overlap between the species not of 10,000 or more years, as previously thought, but of only 2,000 to 4,000 in many places, perhaps 6,000 in others. The shorter overlap suggests that modern…
Leave a Comment
Tags:
Tags: science
// posted February 6, 2006 by Lou Schuler
As a follow-up to this morning’s post about Super Bowl ads, John Williams sent this:
The idea was to do brain imaging of Super Bowl ads, and to do it the very same night the ads were shown for the first time. …
The participating subjects were interviewed after the experiment, to test whether the brain data collected in the scanner matched what the subjects thought they liked or disliked. …
Who won the Super Bowl ads competition? If a good indicator of a successful ad is activity in brain areas concerned with reward and empathy, two winners seem to be the “I am going to Disney” ad and the Bud “office” ad.
In contrast, two big floppers seem to be the Bud “secret fridge” ad and the Aleve ad. What is quite surprising, is the strong disconnect that can be seen between what people say and what their brain…
Leave a Comment
Tags:
Tags: science
// posted January 25, 2006 by Lou Schuler
If you’ve ever wondered why men are naturally ornery and combative, this explains it:
When times are tough, women tend naturally to abort a higher percentage of male fetuses. Researchers call it culling, but they don’t know why it occurs.
This much is known: During times of social or economic stress, a woman’s liver tends produces more of a hormone called cortisol that proves so damaging to male fetuses they actually kick out in response to it.
Female fetuses, more vital on the whole, seem relatively unaffected by the cortisol. One theory states that damage to male fetuses is a side effect of this hormonal stress response.
But in a new study, researchers provide evidence for the other theory, that the body is purposely culling the males by pumping out cortisol in an effort to get rid of a child-to-be that is less likely to survive the presumably difficult situation outside…
Leave a Comment
Tags:
Tags: science
← Older posts Newer posts →
