The beached conch surprised researchers – with rocket speed – Sydsvenskan

Kirsten Johansson, a professor of marine ecology at the University of Gothenburg, says this gives hope.

– It still gives some hope in the era we live in now. “We are changing the environment at an alarming rate,” she says, referring to climate change and environmental destruction.

Many species are affected when their surrounding environment changes. For some species, the solution may be to move.

– But this doesn't always work. Their ability to adapt raises hope.

When an unusually strong algal bloom hit the West Coast in 1988 and wiped out beach snails that lived in the surf on young seals, she seized the opportunity to start an experiment.

I replaced the broken shells with another set of beach shells that were transferred to the mug. The migration distance was only a few hundred meters within the same archipelago, but it was such a turbulent environmental change that I thought it would be difficult for the newly relocated snails to survive.

They were designed to survive surrounded by hungry crabs: they were equipped with a large and powerful shell and at the same time they were very cautious, constantly ready to be attacked by crabs.

Now they came instead to an environment where the challenge was dealing with powerful ocean waves. Their ancestors, who died in algae blooms, were adapted to this life – they were small, thin-shelled, and had to act boldly to constantly find places to get stuck in the waves.

Fully grown and transferred snails died after transfer. But before that, the female snail had time to release offspring that were half a millimeter in size. Some of these tiny snails survived and were able to reproduce, thanks to ready-made dormant genes.

– The sorting initially killed many of the young, but a few of them survived, and gradually their number became more and more, says Kirsten Johansson.

After about 30 generations, adaptation to the new environment has reached such a point that the crab snails now resemble their ancestors down to the smallest detail.

Kirsten Johansson points out that a prerequisite for such adaptation is the presence of genetic diversity. Some large crab shells carry the genes needed to become a small-sized crab.

– When you move it, these genes will become very, very useful. Their offspring gain an advantage and survive.

She stresses that this demonstrates the importance of genetic diversity so that a species can adapt in a changing world.

This is why, for example, the Swedish wolf tribe becomes weak if the number of wolves is small and all the wolves are related to each other. It reduces the likelihood that they will have to carry with them the range of different facilities needed if the environment changes.

“You can think of Baltic cod or any other species that would normally have very large numbers of individuals, but when we pushed them back and there weren't as many of them anymore, you reduce their chances of surviving environmental changes.” says Kirsten Johansson.

A snail study published in the scientific journal Advancement of scienceIt is the first of its kind.

In the United States, similar rapid adaptations to a new environment have been highlighted in studies of fish. In one case, it was a volcanic eruption that reshaped the environment. The fish came from the sea and adapted to life in a newly formed lake. In the second study on fish, the researchers followed how fish species adapted when the river water in which they lived became severely polluted.

That this happens at all is not surprising, because Darwin's ideas are here from beginning to end: natural selection is what changes living things. What's surprising is that it can go so fast, Kirsten Johansson says.