Kamis, 06 Oktober 2011

The Last Universal Common Ancestor of All Life

Evolution of vacuolar proton pyrophosphatase domains and volutin granules: clues into the early evolutionary origin of the acidocalcisome. 2011. M. J, Seufferheld, et al. Biology Direct: 6:50.


My Greatest Adventure, DC Comics
New evidence suggests that the Last Universal Common Ancestor (LUCA) was a sophisticated organism after all, with a complex structure recognizable as a cell.
The study builds on several years of research into a once-overlooked feature of microbial cells, a region with a high concentration of polyphosphate, a type of energy currency in cells.

This site actually represents the first known universal organelle (acidocalcisome), once thought to be absent from bacteria and their distantly related microbial cousins.


By comparing the sequences of the V-H+PPase genes from hundreds of organisms representing the three domains of life, the team constructed a "family tree" that showed that the V-H+PPase enzyme and the acidocalcisome it serves are very ancient, dating back to the LUCA, before the three main branches of the tree of life appeared.

"There are many possible scenarios that could explain this, but the best, the most parsimonious, the most likely would be that you had already the enzyme even before diversification started on Earth," said study co-author Gustavo Caetano-Anollés.

"The protein was there to begin with and was then inherited into all emerging lineages." link

Died This Day: George Gaylord Simpson

Simpson (June 16, 1902 - October 6, 1984) is known for his contributions to evolutionary theory and to the understanding of intercontinental migrations of animal species in past geological times. Simpson specialized in early fossil mammals, leading expeditions on four continents and discovering in 1953 the 50-million-year old fossil skulls of dawn horses in Colorado.

Simpson helped develop the modern biological theory of evolution, drawing on paleontology, genetics, ecology, and natural selection to show that evolution occurs as a result of natural selection operating in response to shifting environmental conditions. He spent most of his career as a paleontologist at the American Museum of Natural History. image. From Today In Science History.

Selasa, 04 Oktober 2011

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