The Wild Experiment That Showed Evolution in Real Time

[SidDithers]

https://www.theatlantic.com/science/archive/2019/01/unprecedentedly-thorough-evolution-experiment/581521/

By placing wild mice in large outdoor enclosures, an ambitious team of scientists has illustrated the full process of natural selection in a single study.

In the fall of 2010, Rowan Barrett was stuck. He needed a piece of land, one with plenty of mice, and after days of futile searching, he found himself at a motel bar in Valentine, Nebraska, doing what people do at bars: telling a total stranger about his problems.

A young evolutionary biologist, Barrett had come to Nebraska’s Sand Hills with a grand plan. He would build large outdoor enclosures in areas with light or dark soil, and fill them with captured mice. Over time, he would see how these rodents adapted to the different landscapes—a deliberate, real-world test of natural selection, on a scale that biologists rarely attempt.

But first, he had to find the right spots: flat terrain with the right color soil, an abundance of mice, and a willing owner. The last of these was proving especially elusive, Barrett bemoaned. Local farmers weren’t keen on giving up valuable agricultural land to some random out-of-towner. After knocking on door after door, he had come up empty. Hence: the bar.

Barrett’s drinking companion—Bill Ward, or Wild Bill to his friends—thought the idea was bizarre, but also fun. “He told me, ‘I’ve got this alfalfa field. You’re welcome to come by tomorrow. I’m okay with you building this thing,’” Barrett said to me. “I just about fell out of my chair.”

Very cool experiment. Barret created large enclosures with either dark or light soil colours. Then released dna tagged mice into each enclosure and let them live. 3 months later they collected the survivors.

As time passed, many of the mice fell prey to owls, but after three months, the team returned and recaptured the ones that were left. Sure enough, they found that, compared with the average founding rodents, the average survivors were noticeably lighter in the light-sand enclosures, and darker in the dark-soil ones. Through the deaths of the most conspicuous individuals, the survivors from two initially identical populations had shifted in different directions thanks to their different environments. “It’s intuitive that if you match your background, you’re more likely to survive,” Hoekstra says. “But that’s been a just-so story for years.” This experiment showed that it matters—a lot.

Sid

[Aussie105]

1. Charles Darwin

first noticed that when he visited the Galapagos Islands. Finches, descended from mainland finches, on the different islands had different shaped beaks and behaviours to help them gather food.

It helped him formulate his Theory of Evolution.

So not a 'just-so story', and also, not new.

But a nice story nevertheless.

[rampartc]

2. how many mouse generations in 3 months?

what difference does color make to nocturnal echolocating predators?

[edhopper]

10. Which preditors are those?

Bats? Owls use eye sight.

And this is about the mice that survived, that would then go on to have similar colored offspring.

It shows natural selection at work.

[MineralMan]

12. Bats don't eat mice. And they're the only

echo-locating predators in that area. I think you're perhaps not familiar with the animal kingdom.

[paleotn]

16. You may be thinking of owls...

They actually hunt primarily by sight and their vision is still acute in very low light levels.

The experiment doesn't work as well for snakes, who can "see" in infrared. The warmth of a mouse stands out regardless of the color of the background.

[2naSalit]

21. Well, in agreement with the other responses above re bats...

I'l add that there are many predators out there from snakes and owls to hawks, coyotes, foxes and I know I'm forgetting a few. Most of those would rely partly on sight to hunt for prey.

[Botany]

3. neat study

more likely natural selection over a short period go time

[Glamrock]

4. Man that is really cool

Mother Nature never fails to amaze.

[genxlib]

5. That's cool

But this is my favorite story of evolution playing out in real time.

[world wide wally]

6. Here's one you can do at home.

Spring is coming, so take notice of how tall your dandelions are (if you are uckck enough to have some). As you mow the lawn throughout the summer, watch how each new generation grows shorter. What they are doing is adapting to the lawn mower blade in an effort to live longer and reproduce.
Plants aren't as stupid as you might think.

[Kurt V.]

8. no shortage of dandelions in my yard. thanks for info.

[MineralMan]

11. Yes. I've noticed that every spring here in Minnesota.

The shorter plants escape my weekly mowing and live to reseed themselves. I've been watching that for 14 years now in my front lawn. Last spring, there were no more tall dandelions at all in my lawn. All were short and had short flower stalks. Many, many generations of dandelions over the years. The ones that survived my mower and reseeded the yard are the survivors.

Notably, elsewhere in my yard, where I do not mow, there are many dandelions with tall flower stalks, still.

[Dorn]

14. My biology teacher in 1972 had my class do this dandelion experiment

[MineralMan]

15. Cool biology teacher!

[Kurt V.]

7. k&r. gotta hand it to wild bill for going along.

[bronxiteforever]

9. Kick and recommend. Thanks for posting

[Dorn]

13. Cool Yet why are there so many regressive and hateful people in government ?

What are the conditions that encourage and allow the creation and election of so many people who are nasty and brutish ?

[dalton99a]

17. Great article

[paleotn]

18. The engine that drives life on earth.

The engine is always running, even if we rarely notice it in our infinitesimally short lifetimes.

[jcgoldie]

19. If they need to expand this experiment...

I have a shed loaded with mice and they dont even need to bring their own... plenty of owls to boot... if they would please just take the "survivors" with them when they finish for evidence or whatever...

[Farmer-Rick]

20. Very interesting read.

They had to throw all the snakes out of the enclosures and the mice kept finding new ways to get into each other's enclosures. To stop the mice from leaving the metal paneled enclosures they had to pour concrete and knock down snow ramps.

And they found the gene (or sequence of genes) that changed the fur color.

I was wondering about the snakes.

[packman]

22. I remember a study done with moths in Industrial England

way back in the late 1800's ( Not sure of date). A scientist noticed that light colored moths were easy prey against the darkened, soot covered trees and eventually only dark winged moths were left to survive. They blended into the background and escaped predication.