The study again bashes ID arguments

Sep 15, 2009 21:01 GMT  ·  By
The complex DNA inside mitochondria also appeared as a result of constant evolution
   The complex DNA inside mitochondria also appeared as a result of constant evolution

Intelligent Design proponents will need a lot of tinkering with logic and reason to get past the new finds made by an international team of researchers, including scientists from the Monash University. The new paper makes a hole right in the middle of ID arguments, which hold that molecular machines inside living cells are “irreducibly complex,” and therefore highly unlikely to have appeared naturally. The new investigations, published in the latest issue of the journal Proceedings of the National Academy of Sciences (PNAS), prove that evolution is, indeed, the path through which these components appeared.

“Our cells, and the cells of all organisms, are composed of molecular machines. These machines are built of component parts, each of which contributes a partial function or structural element to the machine. How such sophisticated, multi-component machines could evolve has been somewhat mysterious, and highly controversial,” Monash University Professor Trevor Lithgow says. He adds that the PNAS paper provides a “blueprint” for a general understanding of how these complex components appeared inside living cells.

“Our research shows that these machines, although complete and complex, were a result of evolution. Simple 'core' machines were established in the first eukaryotes by drawing on pre-existing proteins that had previously provided distinct, simplistic functions,” the expert continues. The focus of the new investigation was the TIM complex, which is in charge of transporting proteins into mitochondria (the power plant of the cell). The latter has always been widely used by ID proponents, as a fine example of an irreducibly complex structure. They no longer have this argument.

“Our cells literally are chimeras of a 'host' cell and these intracellular bacteria. Yet bacteria don't have TIM complexes – to understand where the TIM complex came from we simply applied scientific reasoning and looked at a modern-day bacterium akin to the organism that gave rise to mitochondria,” Lithgow adds. In their experiments on the Caulobacter crescentus bacteria, the team found bacterial proteins that were related to the components of the TIM complex.

“Our work describes a perfect example of Jacob's proposition, and shows that Darwin's theory of evolution beautifully explains how molecular machines came to be,” he concludes. Experts from the University of Melbourne and the Yale University have also contributed to the research, which has been funded by the Australian Research Council (ARC), ScienceDaily reports.