A number of interesting stories pertaining to evolution and/or anthropology are floating around the internet. Before I get to that, though, I urge you to check out this round up of the year in anthropology writing at Neuroanthropology.
Also, am evolutionary biologist who has never read On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life is going to read it and blog about it chapter by chapter. If you would like to join him, an online copy can be found here and a free pdf can be found here.
“We’ve caught evolution in the act,” said Craig Pikaard, Ph.D., WUSTL professor of biology in Arts & Sciences. “We’ve known for decades that RNA Polymerases I, II and III are found in all eukaryotes, but it’s only over the past several years that we’ve been aware that plants have two more nuclear polymerases, Pol IV and Pol V. Now it is clear that these enzymes evolved from Pol II over the past several hundred-million years. This is a new snapshot into the evolution of RNA polymerases, which are the enzymes responsible for decoding the information stored in the chromosomes.”
Analyzing purified Pol IV and Pol V by a sophisticated technique known as tandem mass spectrometry, the Pikaard lab and a team of collaborators at Pacific Northwest National Laboratory, led by Ljiljana Paa-Toli, discovered 12 subunits in both Pol IV and Pol V that correspond one-for-one to the 12 subunits of Pol II. Some of the Pol IV and Pol V subunits are encoded by the same genes as the corresponding Pol II subunits, but others come from duplicated Pol II subunit genes that have changed over time. Overall, four subunits of Pol IV are distinct from their Pol II counterparts, six subunits of Pol IV are different from their Pol II counterparts, and four subunits differ between Pol IV and Pol V. Yet, all of the Pol IV and Pol V subunits are “apples that haven’t fallen far from the Pol II tree.”
The paper the article was based on can be found here.
African Thicket Rat Malaria Linked To Virulent Human Form:
The results place the malarial parasites found in African thicket rats, P. chabaudi, P. berghei,, and P. yoelii,, as a sister group of human and chimpanzee P. falciparum, and P. reichenowi,. This is interesting and surprising because the parasite found in African thicket rats–the only malarial parasite to be discovered first in mosquitoes and only later in a vertebrate host–is the most common laboratory model for human malarial research. The ,P. falciparum,-rodent group is most closely related to malarial parasites that infect humans and primates in Asia and other primates in Africa. The other clades defined by this new evolutionary tree follow previously determined evolutionary trees for malaria-causing parasites, published earlier this year by Perkins and colleagues at the University of Vermont. These other phylogenies were based on both mitochondrial and nuclear DNA.
Now researchers from Rockefeller University have revived two groups of long-dead primate retroviruses to study whether defensive proteins that have rapidly evolved in humans and other primate species could kill them. They found that one protein, called TRIM5α, was disappointingly useless. But by scrutinizing the remnants of the extinct viruses found in the reference genomes of chimpanzees and rhesus monkeys, investigators discovered unmistakable signs that a different protein — APOBEC3 — was likely the exterminator. The research was published in PLoS Pathogens.
Researchers speculated that if trophy heads were spoils of war, they likely would have come from people who lived somewhere beyond the Nazca area. To test this notion, scientists took samples of tooth enamel from 16 trophy heads in the Field collection and 13 mummified bodies buried in the Nazca region. The results clearly show that donors of the trophy heads were from the same place as the people who kept the trophies, Williams said. This conclusion was based on research using modern technology to look for subtle differences in three elements found in the samples. Those elements – strontium, oxygen and carbon – each display a slightly different atomic structure that varies by geographic location.
The original paper can be found here (and if someone can send me a copy I would appreciate it).
Coming full circle (kind of) Wilkins discusses Darwin worship, and demonisation
Filed under: Interesting Science News |