Ruminant diets and the Miocene extinction of European great apes in Proceedings of the Royal Society B. From the abstract:
The successful evolutionary radiations of European hominoids and pliopithecoids came to an end during the Late Miocene. Using ruminant diets as environmental proxies, it becomes possible to detect variations in vegetation over time with the potential to explain fluctuations in primate diversity along a NW-SE European transect. Analysis shows that ruminants had diverse diets when primate diversity reached its peak, with more grazers in eastern Europe and more browsers farther west. After the drop in primate diversity, grazers accounted for a greater part of western and central European communities. Eastwards, the converse trend was evident with more browsing ruminants. These opposite trends indicate habitat loss and an increase in environmental uniformity that may have severely favoured the decline of primate diversity.
The article is open access.
Science Daily has a couple of interesting items.
First, Mining in Africa Is Spreading TB, Study Suggests looks at a study on the cultural and economic factors that are impacting the spread of tuberculosis in Africa:
Men travelling from afar to work in mines, such as from Botswana to South Africa, are at the greatest risk of getting tuberculosis. But their wives, children, and friends are also at high risk when miners travel back and forth to work, often many times a year.
This means that even if mining clinics successfully diagnose tuberculosis in miners and start treatment appropriately, the message is often not relayed back to doctors who work at the miners’ hometowns. The authors suggest that this disruption of treatment poses a major threat of developing a drug-resistant form of tuberculosis.
The team also found that on average 1 in 140 individuals have obtained a new L1 insertion from their parents. When all retrotransposon insertions, including L1 and others, are considered about 1 in 40 individuals have received a new insertion from their parents.
The current study counted insertions in the heritable germ cell line, that is in egg and sperm cells. “The real elephant in the room is the question of the incidence of somatic insertions, insertions in cells that aren’t eggs or sperm” says Kazazian. “We don’t yet know the incidence of those somatic insertions.”
Because the insertions detected in this study and others like it are present in some individuals and not others, there is the possibility of association with genetic disease.
Potassium channels are specialised pores in cell membranes. They have a signature region termed the ion selectivity filter, which is responsible for ensuring that only potassium, and not sodium, permeates the membrane.
Dr Gulbis, with Mr Oliver Clarke, Dr Brian Smith and Mr Alex Caputo from the institute’s Structural Biology division, in collaboration with Dr Jamie Vandenberg and Dr Adam Hill from the Victor Chang Cardiac Research Institute, has illuminated key aspects of the gating process.
Although previous studies have implicated a constriction in the ion conduction pathway in gating, this study describes a gate that is located in the ion selectivity filter.
Using the Australian Synchrotron, Dr Gulbis’s team determined that once the conformation of a regulatory domain — which is the part of the channel that sits inside the cell — changes, it allows the selectivity filter to act as an on/off switch.
PhysOrg.Com has a interesting item on Charles Darwin and spiders:
The first specimen was found in the Tijuca forest located in the heart of Rio de Janeiro and collected by Darwin when he visited during the voyage of the H.M.S. Beagle in 1832. After making the voyage back to London with Darwin for study, the specimen was somehow lost. More than a century and a half later, the GW researchers traveled to Rio to complete the research started by Darwin and found the specimen living in the botanical garden in Rio’s National Museum. Soon thereafter, the researchers were able to realize the importance of these newly collected specimens and understand the only spider name that can be attributed to Darwin. Now, taxonomists will be able to understand even more about this orb-weaving group of spiders and hope that it leads to additional species recognition.
The research article is available here
Also from PhysOrg.Com, Researchers Link Tooth Chipping in Fossils With Diets of Early Humans:
By taking a very simple measure of the size of a chip on a fossil tooth, the researchers were able to determine the bite force the animal used when the chip was made. The researchers also found that tooth size correlates with previous estimates of maximum possible bite force, allowing scientists to now determine the greatest force at which an animal could bite and decipher the range of foods that the animal could have possibly eaten.
This new method of detecting dietary habits and bite force is especially useful because it only requires a single tooth with a well-defined chip from the species. Previous methods of measuring bite force from fossils have been based on analyses of jaw mechanics and require a nearly complete skull. Now paleontologists can apply the new method to estimate bite forces for a whole range of fossil species for which it was previously impossible, including almost any toothed vertebrate that occasionally ate hard foods.
Finally, how about those surfing crocodiles:
Dr Hamish Campbell, from UQ’s School of Biological Sciences, together with colleagues from Australia Zoo and Queensland Parks and Wildlife Service, found, like a surfer catching a wave, the crocodiles ride ocean currents to cross large areas of open sea and populate many South Pacific islands.
“Although it spends most of its life in salt-water, it cannot be considered a marine reptile in the same class as a turtle, as it relies upon the terrestrial environment for food and water,” Dr Campbell said.
“Many anecdotal accounts exist of large crocodiles being sighted far out to sea, but this is the first study to show – using underwater acoustic tags and satellite tracking – that estuarine crocodiles ride surface currents during long distance travel, which would enable them to travel between one oceanic island and another.”
Hang eight, dudes! May you never be caught inside!
Update 1: My bad, the Darwin article is not open access.