Evolution Observed in Just 30 Years?

Here are the details: On a tiny rocky islet (a “skerry”) off the coast of Sweden, lived a group of marine snails . . . until a toxic algal bloom killed the entire population. In 1992, one researcher reintroduced the same species of snail to the skerry—but she introduced a different ecotype than had been there before.

You see, this species appears in multiple ecotypes—“crab” and “wave” being the pertinent examples in this study. Crab snails, who live in a predator-dominated environment, are larger and have thicker shells with no patterning and a smaller shell opening. Wave snails, who have little predator pressure, are smaller and have a thinner, patterned shell and a larger shell opening.

The researcher introduced crab ecotype snails to the skerry, and scientists have documented the changes in the population over the last 30 years. Within just a few years, the snails began to adapt to the new, predator-free environment. One researcher shared:

Over the experiment’s 30 years, we were able to predict robustly what the snails will look like and which genetic regions will be implicated. The transformation was both rapid and dramatic.

Now, they’re calling this rapid evolution, claiming the snails are evolving right before their eyes. But what’s really going on? Well, the researchers give the answer:

However, the snails did not evolve these traits entirely from scratch. . . . “Some of the genetic diversity was already available in the starting Crab population but at low prevalence. This is because the species had experienced similar conditions in the recent past. The snails’ access to a large gene pool drove this rapid evolution.” (emphasis added)

In other words, the genetic diversity for these ecotypes already existed in the snails’ DNA. Nothing new is being created; nothing is coming “from scratch.” The snails were able, over generations, to adapt (which means a particular genetic trait survived best) to their new habitat because they had the genetic diversity to do so!

As the article goes on to explain, within a few generations the population’s shell shape adjusted (they call this “phenotypic plasticity”), individual gene variability led to further adaptation, and “chromosomal inversions” caused large genetic changes to regions of the DNA.

This snail study is just another example of natural selection and adaptation, not evolution. Marine snails remained marine snails—there was no change of kind or even species in this instance. There was simply variation of ecotype because of already existing genetic information.

God, in his wisdom, gave each of the kinds he made tremendous genetic variability so they could adapt and thrive in an ever-changing world. We observe this genetic variability and adaption. What we don’t observe is brand-new, functioning information coming from nowhere or one kind turning into another kind of creature.

God, in his wisdom, gave each of the kinds he made tremendous genetic variability so they could adapt and thrive in an ever-changing world.

Snails remain snails—and they always will!

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This item was discussed Monday on Answers News with cohosts Dr. Georgia Purdom, Patricia Engler, and Bryan Osborne. Answers News is our weekly news program filmed live before a studio audience here at the Creation Museum, broadcast on our Answers in Genesis YouTube channel, and posted to Answers TV. We also covered the following topics:

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Thanks for stopping by and thanks for praying,
Ken

This item was written with the assistance of AiG’s research team.