In today’s fast-paced world, quickly adapting to your environment is a game-changer. But genetic determinism cannot fully explain the rapid adaption seen in many species, which has left evolution in a dark age.
That is until the enlightening work of Michael Skinner’s laboratory at Washington State University. Their observations on transgenerational epigenetic inheritance have been turning classical evolutionary theory upside down ever since they provided a much needed explanation for why genetics alone cannot explain molecular inheritance.
Since then there’s been a lot of controversy about who’s taking who along for the ride. Some folk have stuck to genetic determinism, swearing that sequence alone drives epigenetic marks. Now Skinner’s second paradigm shift puts the nail in the coffin and synthesizes Darwinian and Lamarckian evolutionary theory by showing that alterations to DNA methylation resulting from environmental factors promote the generation of CNVs across generations.
Here’s what the pioneering team found in the sperm of rats with MeDIP-CHIP after exposing them to vinclozolin and comparing them with matched controls:
- The first generation had not only altered DNAm but also a minimal amount of CNVs that were within the range of natural biological variation.
- In the third generation, the CNVs occurred with a whopping 13 times higher frequency than in the first generation.
- These CNVs cluster into distinct regions that contain both gains and losses and the epimutations were mainly in CpG deserts and not promoters.
- Surprisingly, none of the CNVs and epimuations overlapped and very few were close together, suggesting that these are intergenic regulatory regions or that genetic mutations result in the removal of epimutations.
Living by his motto, “If you are not doing something controversial, you are not doing something important”, Skinner shares that the next steps are to “repeat this with other types of genetic mutations being examined, and with different environmental toxicants.”
This leaves Skinner concluding that “There’s not a type of genetic mutation known that’s not potentially influenced by environmental epigenetic effects.”
Go get your evolutionary paradigm shift on at Epigenetics, August 2015