Below are some more interesting news items in the world of science.
Cetacean evolution, continued
I wrote last week about the evolution of cetaceans (dolphins and whales); the entry was inspired by a post at Olduvai George with beautiful illustrations and descriptions of Pakicetus, a land mammal ancestral to cetaceans. He just posted the second in the series, this time focusing on Ambulocetus.
An environmental court in Australia has blocked a proposed coal mine since its environmental impact assessment “did not take into account the impact the mine would have on climate change, including emissions caused when the coal is burned later in foreign countries,” according to New Scientist’s Catherine Brahic. As I previously mentioned, Australia is not a signatory to the Kyoto Protocol.
Quirin Schiermeier writes on Nature’s news site about the increase in severity of monsoons in India. As published in this week’s Science, Indian scientists report on the worsening of several aspects of the monsoons and the probable link to global warming. (See also my previous post on global warming.)
A number of spearheads and a stone carved to resemble a snake have been found in a cave in Botswana, reports J. R. Minkel of Scientific American. They have been dated to around 70,000 years ago and represent the oldest evidence for ritual behavior, the precursor to modern religion; they are significantly older than previously known ritual artifacts (about 40,000 years old). Homo sapiens is believed to have evolved perhaps around 200,000 years ago.
Life ingredients from outer space?
New Scientist’s David Shiga writes about tiny carbon globules in meteorites that could potentially have played a role in the origin of life on Earth, providing protective pockets for nascent life as well as raw materials. Though previously it was unknown if the globules were originally present in the meteroite or were created by Earth organisms, isotopic analysis shows that they did not form on Earth, and indeed probably originated before the sun began shining.
Nature’s Kerri Smith reports on attempts to find ways to treat prion disease (a prion is an infectious protein particle thought to cause disease by having an abnormal structure, and causing normal copies of the protein to take on the abnormal structure as well). Prions are responsible for diseases such as bovine spongiform encephalopathy (known as mad cow disease). A treatment using RNA interference showed promising results in mice, though the technique won’t be directly applicable to humans.
The case of Mr. Litvinenko’s poisoning with polonium-210 (which I’ve discussed in several prior posts) continues to develop. New Scientist’s Debora MacKenzie reports that his autopsy would be very carefully conducted today by pathologists wearing radiation suits. They will take samples to identify other radioactive elements present that may help determine the source of the polonium-210. CNN reports that British investigators have now found traces of radiation at twelve sites, though the risk to the public is extremely low. Mr. Litvinenko’s widow has tested positive for polonium, as has Mario Scaramella, who met Mr. Litvinenko at the sushi bar shortly before he became ill. The U.S. Federal Bureau of Investigation (FBI) has been asked to assist in the investigation. (See my initial post for a brief overview on the phyiscs of polonium and radioactivity.)