SciTech Talk: The secret to longevity and nature vs. nurture

HOW NAKED MOLE RATS LIVE LONG

Contrary to what many people might think, there are many things one can learn from rodents on how to live longer. More specifically, naked mole rats has made it to the radar for biological scientists as an interesting species to study on longevity. They can live up to 30 years — much more than a typical rodent — and have proven to be particularly healthy during their long life. While recent studies on these moles are preliminary, a serendipitous discovery by researchers at University of Rochester found the secret to a longer life.

The proteins in naked mole rats seem to be much “stronger” than in other species. The accidental discovery was made when the researchers were studying naked mole rat rRNA. It seemed that what usually results in two breaks in rRNA in a certain experiment, resulted in an unprecedented three instead. This extra break led to fewer errors during translation, the universal cellular process in which proteins are made. Errorless proteins made for particularly “high quality” cell machinery.

CROSSFOSTERED ZEBRAFINCHES

The Nurture proponents have scored yet another point in the epic battle of Nature vs. Nurture in the field of behavioral biology. Recently, researchers at the Max Planck Institute for Ornithology have discovered that the apple really can fall far from the tree, at least in zebra finches.

After conducting the experiment detailed below, researchers concluded that environmental influences can greatly outweigh the effects of inheritance. First, scientists mated a pair of zebra finches and then swapped half of the eggs in their nest with eggs from another zebra finch pair. In this set-up, half of the zebra finch hatchlings would be raised by their genetic parents, and the other half would be essentially raised by foster parents.

The researchers then studied the song behavior of the male children (since only the males sing in this particular species) once they had grown into adults. Song behavior in birds is incredibly critical to success as adults. Birds use song to court mates, communicate and defend territories, among other things.

In this experiment, researchers found not only did the adopted finches essentially imitate the song of their foster fathers, the neural circuits that underlie such behavior were also altered and directly correlated to the environmental factors that these adopted finches were exposed to.

In fact, except for the number of song syllables and the maximum frequency expressed by the adopted males’ singing, most of their song characteristics were quite unrelated to their inherited singing inclinations. This finding further underscores the entangled two-way relationship between physiology and behavior.

This kind of study has also been performed in humans, although in the form of “field observations,” if you will, rather than controlled studies (which would be considerably unethical as you can imagine.) Some researchers devote their lifetimes to studying the behavioral differences and similarities in twins separated at birth, which always yield fascinating results.