Apr. 16, 2012
This discussion is to have a recurrent thread for science news, tidbits, quick facts, videos, photos, etc, that do not merit their own separate discussion. I think it's better to post here than in the Comments section where it may be more difficult to find material afterward. If you are interested in science news, tidbits, quick facts, please choose "Follow" so you will know every time something new is posted.
Apr. 16, 2012
William G. Eberhard and William T. Wcislo in American Scientist:
By focusing on evolutionary increases in brain size, biologists generally have overlooked nervous system organization in the smallest of animals. But when one looks closely at very small animals, an important question emerges: Where can a relatively large brain fit in a small body? The answers displayed by one animal after another deliver a new perspective on variation in nervous system design among animals. And this variation calls into question some basic assumptions regarding the uniformity of how central nervous systems function overall. In other words, much remains to be learned from the smallest of the small.
Posted by Abbas Raza at 11:08 AM | Permalink
It required some serious luck:
The atmosphere that we take for granted is a relatively recent thing. In particular, it took billions of years of organisms turning sunlight, carbon dioxide and water into carbohydrates -- an energy source that could be used even in the absence of sunlight -- which produced oxygen as a by-product. At first, this trace amount of oxygen was absorbed by the oceans or by the seabed rock. Once the oxygen began to make its way out of the oceans, it was absorbed by the land surface. Finally, the oxygen accumulated in the atmosphere, paving the way for life as we know it.
Some perspective on the scope of human history:
About 83 million years separated Apatosaurus from Tyrannosaurus and Allosaurus from Triceratops. The so-called Age of Mammals—which began when the non-avian dinosaurs were wiped out—has been going on for about 66 million years. Less time separates us from Tyrannosaurus rex than separated T. rex from Stegosaurus.
(Video: A mashup of Carl Sagan narrating the creation scene from Tree of Life)
Even a humble sea slug can be stylish, if you find the right slug in the right place. That's what photographer Ximena Olds did when she snapped a picture of an orange headshield sea slug amid the green seagrass in the U.S. Virgin Islands. Her contrasting-color picture took the top prize in this year's Underwater Photography Contest, hosted by the University of Miami's Rosenstiel School of Marine and Atmospheric Science. More than 700 images were submitted for the 2012 contest, showing scenes from 20 countries. Awards were given in several categories, including Macro, Wide Angle, and Fish or Marine Mammal Portrait. Another category was set aside for University of Miami students. Olds' photo was submitted in the Macro category but was singled out for the "Best Overall" prize.
Posted by Azra Raza at 05:07 AM | Permalink |
Christine Dell'Amore in National Geographic:
And, in a "big advancement," these artificial compounds can also be made to evolve in the lab, according to study co-author John Chaput of the Biodesign Institute at Arizona State University. (See "Evolution vs. Intelligent Design: 6 Bones of Contention.")
Nucleotides, the building blocks of DNA are composed of four bases—A, G, C, and T. Attached to the bases are sugars and phosphates. (Get a genetics overview.)
First, researchers made XNA building blocks to six different genetic systems by replacing the natural sugar component of DNA with one of six different polymers, synthetic chemical compounds.
The team—led by Vitor Pinheiro of the U.K.'s Medical Research Council Laboratory of Molecular Biology—then evolved enzymes, called polymerases, that can make XNA from DNA, and others that can change XNA back into DNA.
This copying and translating ability allowed for genetic sequences to be copied and passed down again and again—artificial heredity.
Last, the team determined that HNA, one of the six XNA polymers, could respond to selective pressure in a test tube.
Posted by Abbas Raza at 08:33 AM | Permalink
This is a great website!
Hours of browsing ahead...
Published on 4/17/2012 under Misc - by Gracie Murano -
Ain't a opening 404 message.
Apr. 20, 2012