Climate change plus human pressure caused large mammal extinctions in late Pleistocene
... the Australian continent, Barnosky cautioned, but little climate change was going on at the time of extinct...imate change is just the opposite - it affects the little guy first and then, through them, the big guys. Today, we see humans taking out the bigger animals a...Cigarette smoke causes breaks in DNA and defects to a cell's chromosomes, Pitt study finds
...changes in DNA sequence caused by cigarette smoke, little attention has been given to how smoke affects genomic stability of cells. In laboratory studies using human fibroblasts, common cells found in connective tissue, William S. Saunders, Ph.D., and colleagues discovered that exposure to even a small amou...'Dead zone' area shrinking, Texas A&M prof says
...ions in water - had broken up and appeared to pose little threat to marine life, while in other areas the hypoxia appeared to have moved further off shore. Hypoxia can result in fish kills and can adversely affect many types of marine life where it is present. The dead zone area encompassed more than 6,000...Scientists sequence genome of kind of organism central to biosphere's carbon cycle
... ability of diatoms to withstand long periods with little sunlight even to overwinter and then start growing really rapidly once they return to sunlight," she says. Three or four microns in width as many as 70 could fit in the width of a human hair Thalassiosira pseudonana is among the smallest diatom...Pack-MULEs are toting a new look at plant evolution
...ximum potential. So Jiang allowed herself to get a little sentimental. The first Pack-MULE she found in a piece of rice sequence was lugging around the gene that triggers cold responses in a plant. In 1998, MSU molecular geneticist Michael Thomashow and his associate found that increasing a plant's express...New research shows plants can shuffle and paste gene pieces to generate genetic diversity
... like viruses, they can make lots of copies but do little to help the host. There is mounting evidence, however, that TEs help organisms evolve by making it easier to generate the sort of genetic novelty that is necessary for them to cope with a changing world. Thus, instead of being beasts of burde...Gene clusters predict atherosclerosis severity, susceptibility
...were known to researchers, although there was very little overlap between genes identified in the severity and locations groups. The genes in the severity cluster tended to be involved in the inflammation process, while those related to susceptibility tend to mediate cellular responses that occur prior to t...Tracing genes, biologists show lizard migration is traced to Florida
...e small hatchlings of the Anolis carolinensis, the little green lizards native to the state. It has been noted, also, that some Florida populations of the introduced brown lizards have gotten larger than the usual brown lizard size. And the brown lizards have become prey to the Nile Monitor, a seven-foot-...Marijuana use could cause tubal pregnancies
...ging the embryo toward the uterus. Too much or too little of this "endocannabinoid tone" can result in pregnancy failure. In support of this hypothesis, abnormal muscular contraction that prevents human embryos from reaching the uterus is one known cause of ectopic pregnancy, Dey said. Polymorphisms (differ...New sequence involved in DNA replication timing may aid in cancer detection
...arly always duplicated late." Until recently, very little was known about how cells control replication timing. Studies in budding yeast ( Saccharomyces cerevisiae ) have suggested that, by default, replication origins fire early in S phase, but they can be forced to fire later by flanking and internal DNA ...New fossil sheds light on old mystery
...anystropheus' 12, which might have made its neck a little more flexible. "These two species are not very closely related, which demonstrates that this strange, long neck evolved twice within the group of protorosaurs," Dr. Rieppel said. Dinocephalosaurus' neck measures 1.7 meters, while its trunk is less ...A long-necked sea predator from China described in Science
...difficult to add muscles to a fossil when there is little or no evidence for muscles in the fossil record, and even tougher when the fossil has no living counterpart, Rieppel said their ideas are based on the preserved bone structures, biomechanics and the complexities of hunting in water, a dense medium th......ation has taken place in recent decades. However, little is known about these rare carnivores, and previous proposals to list them as a federally threatened species have been rejected due to a lack of data that documents declines caused by human related threats. ...Certain genes boost fish oils' protection against breast cancer
...s efficiently out of the body and GST that works a little slower. The researchers looked at the genetic makeup of study participants and grouped them according to which polymorphisms they had. They found that postmenopausal women who had low-activity versions of genes associated with GSTs (known as GSTM1, G...UAF scientists discover new marine habitat in Alaska
...scoveries also send an important message about how little we know about the sea." The discovery came ...und the sieve right away. But then I noticed these little pink tumbleweeds everywhere. I thought I was looking at a rhodolith bed, but rhodolith beds had neve...Study reveals why eyes in some paintings seem to follow viewers
...t that changes in viewing direction had remarkably little effect on the observers' perceptions," Todd said. The only difference they found is that, when viewed from an angle, the torso looked "squashed" in other words, it looked thinner to viewers. But the far points and near points, and the overall relief...Green, leafy spinach may soon power cellphones and laptops
... current. "An important caveat is that we got very little current out, mostly because we had just a thin layer of the complexes in our devices," Baldo said. "Most of the optical excitation passed straight through without being absorbed. Of the light that was absorbed, we estimate that we converted around 12...Scientists explore genome of methane-breathing microbe
...bionts are very important ecologically but we know little about how they work since they live inside of animals and cannot be grown in pure cultures on their own,"says Eisen. "Since the symbionts are closely related evolutionarily and biologically to Methylococcus capsulatus, we can now use the information ...Amyloid fibers sprout one step at a time
...et despite the importance of this process, we know little about the underlying mechanism by which amyloid forms and grows." For example, said Weissman, evidence is accumulating that it is not the plaque itself that is toxic, but rather the smaller and more amorphous oligomers that typically accompany plaqu...22nd amino acid synthesized and added to genetic code of e. coli bacteria
... experiments has shown us is that it is probably a little easier than we might have thought it would be to change the genetic code in an organism like E. coli," Krzycki said. "It gives us some new insight into how the genetic code evolved, that's the take-home message." Chan called the project itself "a gre...