Old Weblog - April 2005
The greatest mass extinction recorded in Earth history did not occur as a result of one single cataclysmic event. A joint UK-Chinese team tell Nature magazine the disaster that befell the planet 250 million years ago must have happened in phases. Their conclusion is based on the abundance of "organic fossils" found in rocks at Meishan in southern China. These suggest there were at least two episodes to the mass die-off that saw up to 95% of lifeforms disappear.
Modern humans may have driven Neanderthals to extinction 30,000 years ago because Homo sapiens unlocked the secrets of free trade, say a group of US and Dutch economists. The theory could shed new light on the mysterious and sudden demise of the Neanderthals after over 260,000 years of healthy survival… Jason Shogren, an economist at the University of Wyoming in Laramie, US, says part of the answer may lie in humans’ superior trading habits. Trading would have allowed the division of labour, freeing up skilled individuals, such as hunters, to focus on the tasks they are best at. Others, perhaps making tools or clothes or gathering food, would give the hunters resources in return for meat.
At first, I thought this was an April Fool's joke, but apparently not. So, a bunch of economists reckon that our success over the Neanderthals may be down to free trade. Well, I suppose everyone has their own way of looking at the world. This would appear to be a totally untestable hypothesis (and not, as the article states, a theory)—although that doesn't necessarily mean it's wrong.
Experts are a step closer to answering whether an ancient skull from Africa belonged to a possible human ancestor or to a creature closer to apes. Fresh fossil finds from Chad in central Africa, as well as a new analysis of the skull, seem to confirm "Toumaï" was closer to us, Nature magazine reports. The Toumaï specimen was unearthed in Chad in 2002 to international acclaim. But rival researchers attacked claims by the discovery team that it was the oldest hominid, or human-like creature.
The Earth's most successful primates—humans—are on the brink of killing off nearly a quarter of their 625 cousin species, a report has said.
Ancient hominids from the Caucasus may have fed and cared for their elderly, a new fossil find has indicated. The 1.77 million-year-old specimen, which is described in Nature magazine, was completely toothless and well over 40; a grand old age at the time. This may suggest that the creature lived in a complex society which was capable of showing compassion.
Ten scientists each nominate evolution's most stunning innovation.
The Great Crested Grebe, promoted by Evelyn Waugh’s novel Scoop to be the avian patron of journalists everywhere, has many unusual and appropriate habits. This bird needs a daily diet of light and fluffy feathers, either eaten from its own back or from the backs of friends and colleagues. It likes permanent liquid surroundings, and staggers inelegantly on land, particularly when failing to differentiate a road from a river at night. It depends on fiercer birds to protect the exclusivity of its possessions from rivals, and sometimes rewards those guards with a small egg in exchange.
A surprisingly informative book review.
A huge cosmic explosion could have caused a mass extinction on Earth 450 million years ago, according to an analysis by scientists in the US. A gamma ray burst could have caused the Ordovician extinction, killing 60% of marine invertebrates at a time when life was largely confined to the sea. These cosmic blasts are the most powerful explosions in the Universe.
Gives a whole new meaning to the phrase death-ray.
A project spanning five continents is aiming to map the history of human migration via DNA. The Genographic Project will collect DNA samples from over 100,000 people worldwide to help piece together a picture of how the Earth was colonised.
See also: The Genographic Project (National Geographic)
The first dinosaur eggs found complete with shells in the body of the mother has solved the long-standing mystery of how dinosaurs laid their eggs. The evidence shows they laid a clutch in a series of sittings, like birds, rather than all at once like crocodiles and other living reptiles.
Ernst Mayr, Harvard University professor emeritus and biologist extraordinaire, died peacefully in Bedford, Massachusetts, on February 3. He was 100 years old and had been associated with the biology department at Harvard since he joined its faculty in 1953. An era in evolutionary thought, called variously the New Synthesis, neo-Darwinism or the Modern Synthesis, came to an end with his passing. The death of the last of the great evolutionary biologists of the 20th century concluded an intellectual movement in the study of evolution—a point of view whose most striking aspect was the extent to which all of the evolutionary history of life on Earth was perceived as a subdiscipline of biology. Whereas Thomas Kuhn, author of The Structure of Scientific Revolutions, might have called it a paradigm, Ludwik Fleck (author of Genesis and Development of a Scientific Fact, 1935) would have recognized the correlated demise of neo-Darwinism and the death of Professor Mayr as a paradigm lost.
Modern life has caught up with the cradle of evolution. Too many tourists, expanding population, over-fishing and pollution are endangering the flora and fauna.
A unique fly from the Canary Islands has helped shed light on one driving force behind the birth of new species, Nature magazine reports this week. The type of robber fly is found nowhere else, and scientists speculate that the rich biodiversity on the islands may actually have led to its emergence. The researchers think sharing an island with a myriad of other lifeforms may push one species to spawn another. This new theory adds fresh insight into how biodiversity arises.
A tiny tropical ant has developed a gruesome way to catch prey much bigger than itself. Scientists say it uses traps reinforced with fungus to ambush large insects, stretching them out like victims on a medieval torture rack as nest mates swarm in for the kill.
Charles Darwin was lactose intolerant, researchers deduce, adding a fresh twist to the mystery of what caused his 40-year-long illness. This would explain the bouts of vomiting, stomach pains, severe tiredness, skin problems and depression Darwin suffered, symptoms a new report says improved when he stopped eating milk and cream. His family also suffered in a similar way, suggesting a genetic component, researchers led by Professor Anthony Campbell from Cardiff University reports in the current issue of the Postgraduate Medical Journal.
There have been loads of explanations put forward for Darwin's mysterious illness. This one sounds pretty plausible.
A piece of jawbone that has lain in Torquay Museum, Devon, for nearly 80 years could be the oldest example of a modern human yet found in Europe. The Kent's Cavern specimen was thought to be about 31,000 years old, but re-dating shows it is actually between 37,000 and 40,000 years old. However, the early dates lead the team behind the research to wonder if the jawbone is actually from a Neanderthal.
The ivory-billed woodpecker, a spectacular bird long thought to be extinct, has been found alive in North America, Science magazine reports. The news has stunned ornithologists worldwide, with some comparing the discovery to finding the dodo.
Neh! It's great news that the ivory-billed woodpecker isn't quite extinct, but the discovery of a living dodo would be about a trillion times more remarkable.
TV naturalist Sir David Attenborough and former House of Commons Speaker Baroness Boothroyd have been awarded the Order of Merit by the Queen. The honour, founded in 1902 by Edward VII and a personal gift of the monarch, is awarded for exceptional distinction in the arts, sciences and other areas.
The more awards and honours for Sir David the better.
Over 360 new species have been discovered in Borneo over the last decade, highlighting the great need for conservation in the area, the WWF says.