New Evolution: 100 Proofs

Luca Galuzzi www.galuzzi.it

Fight disinformation: Sign up for the free Mother Jones Daily newsletter and follow the news that matters.


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.

Fact:

Mother Jones was founded as a nonprofit in 1976 because we knew corporations and billionaires wouldn't fund the type of hard-hitting journalism we set out to do.

Today, reader support makes up about two-thirds of our budget, allows us to dig deep on stories that matter, and lets us keep our reporting free for everyone. If you value what you get from Mother Jones, please join us with a tax-deductible donation today so we can keep on doing the type of journalism 2022 demands.

payment methods

Fact:

Today, reader support makes up about two-thirds of our budget, allows us to dig deep on stories that matter, and lets us keep our reporting free for everyone. If you value what you get from Mother Jones, please join us with a tax-deductible donation today so we can keep on doing the type of journalism 2022 demands.

payment methods

We Recommend

Latest

Sign up for our free newsletter

Subscribe to the Mother Jones Daily to have our top stories delivered directly 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