Epigenetics

If you haven't heard about this rapidly growing branch of biology, you will be intrigued. Nutshell: environmental factors such as diet can cause changes in gene expression that can be passed on to offspring.

In other words, you are what your grandmother ate. But, wait, wouldn't that imply what every good biologist knows is practically scientific heresy: the Lamarckian inheritance of acquired characteristics?

If agouti mice are any indication, the answer could be yes. The multicolored rodents make for a fascinating epigenetics story, which Randy Jirtle and Robert Waterland of Duke University told last summer in a Molecular and Cell Biology paper; many of the scientists interviewed for this article still laud and refer to that paper as one of the most exciting recent findings in the field. The Duke researchers showed that diet can dramatically alter heritable phenotypic change in agouti mice, not by changing DNA sequence but by changing the DNA methylation pattern of the mouse genome.3 "This is going to be just massive," Jirtle says, "because this is where environment interfaces with genomics."