New Evolution: 100 Proofs

Luca Galuzzi www.galuzzi.it

For indispensable reporting on the coronavirus crisis and more, subscribe to Mother Jones' newsletters.


Genes have long been considered the only way biological traits are passed down through generations of organisms. Now we know that non-genetic variations acquired during the lifespan of a plant or animal can be passed along to its offspring.

The phenomenon is known as epigenetic inheritance. We don’t yet know how prolific this mechanism is. But a new study in The Quarterly Review of Biology lists more than 100 well-documented cases of epigenetic inheritance between generations of organisms.

In other words, non-DNA inheritance happens a lot more than we thought. For example:

  • Fruit flies exposed to certain chemicals transmit changes—bristly outgrowths on their eyes—down at least 13 generations.
  • Exposing a pregnant rat to a chemical that alters reproductive hormones leads to generations of sick offspring.

In these and 97 other cases the changes in subsequent generations were not from changes in DNA but from epigenetics.

There are four known mechanisms for epigenetic inheritance. The best known involves on-off switches (sort of) that render genes active or inactive—without actually changing the DNA. The revelations of epigenetics are rewriting the study of evolution. And no, epigentics does not make creationism right.

The rewrite is a vindication of sorts for 18th-century naturalist Jean Baptiste Lamarck, whose writings predated Charles Darwin’s and who believed that evolution was driven in part by the inheritance of acquired traits.

His wonkiest supposition: Giraffe ancestors reached with their necks to munch leaves high in trees, stretching their necks to become slightly longer—a trait passed on to descendants.
 

More accurate: All the stuff we’re synthesizing and creating from plastics to nanomaterials is going to live in our bodies and take its toll down the generations for a long, long time.

Thank you!

We didn't know what to expect when we told you we needed to raise $400,000 before our fiscal year closed on June 30, and we're thrilled to report that our incredible community of readers contributed some $415,000 to help us keep charging as hard as we can during this crazy year.

You just sent an incredible message: that quality journalism doesn't have to answer to advertisers, billionaires, or hedge funds; that newsrooms can eke out an existence thanks primarily to the generosity of its readers. That's so powerful. Especially during what's been called a "media extinction event" when those looking to make a profit from the news pull back, the Mother Jones community steps in.

The months and years ahead won't be easy. Far from it. But there's no one we'd rather face the big challenges with than you, our committed and passionate readers, and our team of fearless reporters who show up every day.

Thank you!

We didn't know what to expect when we told you we needed to raise $400,000 before our fiscal year closed on June 30, and we're thrilled to report that our incredible community of readers contributed some $415,000 to help us keep charging as hard as we can during this crazy year.

You just sent an incredible message: that quality journalism doesn't have to answer to advertisers, billionaires, or hedge funds; that newsrooms can eke out an existence thanks primarily to the generosity of its readers. That's so powerful. Especially during what's been called a "media extinction event" when those looking to make a profit from the news pull back, the Mother Jones community steps in.

The months and years ahead won't be easy. Far from it. But there's no one we'd rather face the big challenges with than you, our committed and passionate readers, and our team of fearless reporters who show up every day.

We Recommend

Latest

Sign up for our newsletters

Subscribe and we'll send Mother Jones straight to your inbox.

Get our award-winning magazine

Save big on a full year of investigations, ideas, and insights.

Subscribe

Support our journalism

Help Mother Jones' reporters dig deep with a tax-deductible donation.

Donate

We have a new comment system! We are now using Coral, from Vox Media, for comments on all new articles. We'd love your feedback.