Yeast study yields insights into longstanding evolution debate

From Phys.Org:

In the past two decades, researchers have shown that biological traits in both species and individual cells can be shaped by the environment and inherited even without gene mutations, an outcome that contradicts one of the classical interpretations of Darwinian theory. But exactly how these epigenetic, or non-genetic, traits are inherited has been unclear. Now, in a study published Oct. 27 in the journal Cell Reports, Yale scientists show how  contribute in real time to the evolution of a gene network in yeast. Specifically, through multiple generations yeast cells were found to pass on changes in gene activity induced by researchers. The finding helps shed light on a longstanding question in ; scientists have long debated whether organisms can pass on traits acquired during a lifetime.

“Do  have to be the sole facilitator of gene network evolution or can epigenetic mechanisms also lead to stable and heritable gene expression states maintained generation after generation?” asked Yale’s Murat Acar, associate professor of molecular, cellular & , a faculty member at the Yale Systems Biology Institute, and senior author of the paper. During much of the last half of the 20th century, biology students were taught that mutations of  that helped species adapt to the environment were passed on through generations, eventually leading to tremendous diversity of life. However, this theory had a problem: advantageous mutations are rare, and it would take many generations for physiological changes caused by the mutation to take root in a population of any given species.

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