3/22/2008

Science News - March 22nd, 2008


Skulls Of Modern Humans And Ancient Neanderthals Evolved Differently Because Of Chance, Not Natural Selection
New research led by UC Davis anthropologist Tim Weaver adds to the evidence that chance, rather than natural selection, best explains why the skulls of modern humans and ancient Neanderthals evolved differently. The findings may alter how anthropologists think about human evolution.





Deadly Genetic Disease Prevented Before Birth In Zebrafish
By injecting a customized "genetic patch" into early stage fish embryos, researchers at Washington University School of Medicine in St. Louis were able to correct a genetic mutation so the embryos developed normally.



The research could lead to the prevention of up to one-fifth of birth defects in humans caused by genetic mutations, according to the authors.







Researchers Unmask Proteins In Telomerase, A Substance That Enables Cancer
One of the more intriguing workhorses of the cell, a protein conglomerate called telomerase, has in its short history been implicated in some critical areas of medicine including cancer, aging and keeping stem cells healthy. With such a resume, telomerase has been the subject of avid interest by basic scientists and pharmaceutical companies alike, so you'd think at the very least people would know what it is.







Upright Walking Began 6 Million Years Ago, Thigh Bone Comparison Suggests
A shape comparison of the most complete fossil femur (thigh bone) of one of the earliest known pre-humans, or hominins, with the femora of living apes, modern humans and other fossils, indicates the earliest form of bipedalism occurred at least six million years ago and persisted for at least four million years. William Jungers, Ph.D., of Stony Brook University, and Brian Richmond, Ph.D., of George Washington University, say their finding indicates that the fossil belongs to very early human ancestors, and that upright walking is one of the first human characteristics to appear in our lineage, right after the split between human and chimpanzee lineages. Their findings are published in the March 21 issue of the journal Science.











Rethinking Early Evolution: Earth's Earliest Animal Ecosystem Was Complex And Included Sexual Reproduction
Two paleontologists studying ancient fossils they excavated in the South Australian outback argue that Earth's ecosystem has been complex for hundreds of millions of years -- at least since around 565 million years ago, which is included in a period in Earth's history called the Neoproterozoic era.




Until now, the dominant paradigm in the field of paleobiology has been that the earliest multicellular animals were simple, and that strategies organisms use today to survive, reproduce and grow in numbers have arisen over time due to several factors. These factors include evolutionary and ecological pressures that both predators and competition for food and other resources have imposed on the ecosystem.
But in describing the ecology and reproductive strategies of Funisia dorothea, a tubular organism preserved as a fossil, the researchers found that the organism had multiple means of growing and propagating -- similar to strategies used by most invertebrate organisms for propagation today.

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