Tag: evolution

Mice Morphing at Warp Speed

  • Oliver Pergams used a tiny caliper to measure the mice, tracking changes in size over the years. (Photo by Gabriel Spitzer)

Evolution takes place over long stretches of time: millennia and epochs. But some new research shows that animals might be changing much
faster than nearly anyone thought. Gabriel Spitzer has more on those
changes, and how they seem to be linked to humans:

Transcript

Evolution takes place over long stretches of time: millennia and epochs. But some new research shows that animals might be changing much
faster than nearly anyone thought. Gabriel Spitzer has more on those
changes, and how they seem to be linked to humans:

Tall Trees Park is a little patch of green in Glenview, Illinois – a
northern suburb of Chicago. About a hundred years ago, a lot of this area
looked a lot like this. It was mostly farms and pasture and forest. And now
of course it’s a lot of strip malls and subdivisions and stuff. And the
population has grown seventyfold. The climate has changed, too. It’s
gotten a little warmer, a little wetter.

And all this has made life a lot different for the northern white-footed
mice who live here. It’s actually not just made life different for the
mice, it’s changed the mice themselves.

That gets back to a guy named Oliver Pergams. He’s an ecologist, and in
the mid-90s, he was looking at deer mice who live on the Channel Islands
off the coast of California. And he was taking these mice and comparing
them to museum samples of the same kind of mice from the same place, but
decades earlier.

“And I found something kind of strange – that the older specimens were
larger than the newer specimens, so they shrunk in size over a period of
about 30 or 40 years.”

That got him wondering if those relatively quick changes are happening in
other places. So years later, now on the faculty at the University of
Illinois at Chicago, he gathered up some of those White Footed Mice from
the Chicago suburbs. And he went to the Field Museum of Natural History…

(sound of a cabinet opening)
… where they have a hundred years of dead mouse specimens stored in
white metal cabinets.

“Here we have trays and trays of the northern white-footed mouse.”

With a tiny caliper, he’d measure their skulls, their feet, the distance
from their eyes to their noses.

“So this one here was collected by Aikley in 1903.”

And he compared mice from before and after 1950.

“Here are some skulls, this one was collected in 1989.”

Lo and behold, these mice had grown: by more than 10% on some measures.

This phenomenon goes way beyond Chicago. Pergams measured more than 1,300
rodents from four different continents – Alaskan lemmings, Mexican
gophers, Filipino rats. Some of them got bigger, some smaller. But across
the world, most of the animals have changed over time spans thought to be
mere evolutionary eyeblinks.

The next step is to figure out why.

“You can’t get in a time machine and go back and look to see what
actually happened. So the next best thing is to see if there’s
associations or correlations with big factors.”

He found the variations correlate with changes in climate and human
population density. The exact reasons aren’t clear – more people might
mean more yummy trash for the mice to eat, for example. That’s going to
take more research to figure out, and these critters might be overdue for
some extra attention.

“One of the questions is, well, why didn’t anybody notice this before?
And I think the answer is, they haven’t looked.”

Larry Heaney curates the Field Museum’s mammal collection. He says
Pergams’s research opens up new questions about how animals respond to
changes driven by humans.

“The implication is, these animals are changing very, very rapidly. So in
a sense, it’s good: they can change. But the other side of the coin is,
they’re having to change.”

Now, the question is, is this happening in other species, too? What about
birds or bugs or plants?

“There’s been this default attitude that if you go to one place and you
capture or you observe animals or plants, that essentially there’s going
to be the same animals or plants 50 years or 100 years later. I don’t
think that’s possible to assume at all. We have to include the fact of
this change in all of our decisions, from ecology to evolutionary biology
to conservation.”

Pergams’s findings show that even the most common creatures have more to
teach us – when we ask the right kinds of questions.

For The Environment Report, I’m Gabriel Spitzer.

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Humans Evolve – Fast!

A new study says modern humans are in the evolutionary fast lane. Scientists say world
population growth is leading to beneficial genetic mutations. Chuck Quirmbach has
more:

Transcript

A new study says modern humans are in the evolutionary fast lane. Scientists say world
population growth is leading to beneficial genetic mutations. Chuck Quirmbach has
more:


Some scientists contend modern culture and conveniences have basically halted human
evolution. But anthropologist John Hawks says that’s not so. He’s been analyzing data
from an international gene-cataloguing study. He says many genes have rapidly changed
within the last 5-thousand years. For example, Hawks says one positive development is
that humans have more genes that fight off some diseases:


“Things that resist malaria, things that resist smallpox, things that are resistant to new
diseases that have emerged in the last 10,000 years.”


Hawks says there have also been changes related to what some groups can eat and drink,
for example, many northern Europeans can now drink milk their whole lives. The study
of genetic change is published in the Proceedings of the National Academy of Sciences.


For the Environment Report, I’m Chuck Quirmbach.

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Teachers Criticized for Evolution Lessons

  • Some teachers are struggling with teaching evolution because some disagree on religious grounds. (Photo by Elliot Jordan)

Science teachers in high schools and middle schools are on the front lines of the culture wars. Conservative Christians and others are confronting them about teaching evolution in the classroom. At the same time, teachers are learning about the growing body of evidence that supports the theory of evolution. The Great Lakes Radio Consortium’s Julie Grant reports:

Transcript

Science teachers in high schools and middle schools are on the front lines of the culture wars. Conservative Christians and others are confronting them about teaching evolution in the classroom. At the same time, teachers are learning about the growing body of evidence that supports the theory of evolution. The Great Lakes Radio Consortium’s Julie Grant reports:


Some science teachers got a chance to attend a major science conference recently. Researchers from around the world were in Akron, Ohio to present findings and learn about advances in evolutionary biology. The conference was organized by people studying the dramatic transition whales made when they moved from the land to the water.


It’s only been a few years since Ohio even allowed the concept of evolution into the state’s high school academic standards. Those standards are the basis for the state graduation test that students must pass to get a diploma.


Even though it’s part of the state curriculum, many science teachers get the brunt of complaints from students and parents who oppose teaching evolutionary theory.


THOMAS: “I did have a student come to me and literally say, ‘I cannot sit in this classroom and listen to what you’re talking about.’ And I said, ‘Why not?’ And she said, ‘Well, I’m a Christian, I can’t listen to this.’ I said, ‘Well, I’m a Christian too, so where’s the problem?’”


GRABERT: “Well, I’ve had a number whose fathers are ministers come in and tell me how I need to teach the class, and I have to talk about creationism and I just share with them what we have to teach and how the curriculum is.”


STONE: “There’s a point when you just sort of have to tell the kids, This is what you need to know to pass the test to get out of high school. So, sit down, listen, learn the facts you need to know. I’m not saying you have to believe what I say, but this is what the state says you need to know to get out of high school.”


These are teachers from rural, suburban, and city school districts but they are all dealing with this issue. They try to stay up to date on new scientific evidence to defend their classroom lessons. That’s part of the reason they’re at this science conference.


(Sound of lecture)


This day’s activities are geared toward schoolteachers. The world’s top researchers on whale evolution are explaining their latest findings. Ann Sowd teaches honors biology at Hoover High School in North Canton, Ohio.


“It’s important to be at workshops like this so that you can, as a high school teacher, be really accurate with your teachings and understand what the evidence for evolution is and why it’s really- what we do know about how organisms change over time. Because the worst thing that can happen is you’re inaccurate and then someone comes with the opposing argument and you don’t know what you’re talking about.”


The teachers are hearing from scientists from all kinds of disciplines from anatomy, to functional morphology, to geo-chemistry. The scientists are showing how their discoveries and analyses fit together and provide a picture of the evolution of the whale as it moved from land back to the ocean.


But one leading researcher says the schoolteachers need more than just new scientific research to defend their lessons in the classroom. Howard University anatomist Daryl Domning says students who question evolutionary evidence are often looking for answers that lie beyond the realm of science. But Domning says teachers often respond with the latest research and recent fossil discoveries.


“And then they’re amazed that it doesn’t convince them. Because even though they’re raising questions about scientific evidence, they’re really not passionate about the scientific evidence. They’re passionate about ‘what is the meaning of my existence?’ and until you get down to that level and surface those concerns and show that hey, evolution doesn’t mean there’s no meaning to your existence, on the contrary, it can mean all these things, it means there’s more meaning then you thought there was maybe, only then is there a way of breaking through this pattern of talking past each other, which is what we’ve been doing for thirty years here.”


Domning says teachers can help students and parents understand that accepting the evidence of evolutionary theory doesn’t have to undermine religious faith.
He encourages teachers to tell students they can believe both at the same time, to point them to places where they can get more information, and to quickly get back to the science lesson.


For the GLRC, I’m Julie Grant.

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