sexta-feira, 22 de junho de 2012

Como a evolução copiou a si mesma

How Evolution Copies Itself
 on 4 April 2012                                                                                 ENLARGE IMAGE                           
Sequenced. Decoding the DNA of 21 threespine stickleback fish (inset) showed the importance of regulatory changes in the evolutionary transition from a marine form, with bony plates (bottom), to a freshwater form (top).
Credit: (fish drawings)Felicity Jones/Stanford U.; (photo inset) Tim Howes/ Stanford U.
A tiny fish is helping to answer a big question about evolution. The threespine stickleback (Gasterosteus aculeatus) has long been abundant in the sea. But after glaciers melted 10,000 years ago, many wound up in new freshwater lakes and streams. In these unfamiliar environments, the fish lost their bony plates and spines and developed novel behaviors and physiology. A new study reveals that many of these relatively rapid changes were due not to mutations in specific genes, as some biologists had long assumed, but rather to changes in the activity of these genes. The finding should help focus more attention on the role of gene regulation in evolution, not just of fish but of all organisms, including humans.
For decades, evolutionary biologists have been fascinated by the repeated evolution of freshwater traits in marine sticklebacks. In these fish, evolution has duplicated itself thousands of times as marine ancestors moved into fresh water in many parts of the Northern Hemisphere, including Alaska, California, Europe, and Japan. All of these fish have undergone similar changes in their kidneys, body shape, eye size, and number of bony plates on their bodies. David Kingsley, an evolutionary biologist at Stanford University in Palo Alto, California, took advantage of this parallel evolution to look at how the genome causes these changes.
Porque tantas questiúnculas sobre direitos de autor? patentes?subsidios? amortizações? pirataria (não) oficializada? afinal, no mundo natural cópias/rascunhos fazem parte da evolução e sem isso não obteríamos diversidade nem sobreviveríamos e inclusive cópias restantes (restos) ficaram depois de extinções..como aconteceu a um certo ratinho que milhões de anos atrás evoluiu até nós, após a extinção dos dinossauros. Imaginem que os seres vivos tivessem que pagar por essas cópias? rascunhos???
A economia natural dá fortes lições à "economia"!

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