Climate change and evolution - 6 Minute English

Hello.

This is 6 Minute English from BBC Learning English.

I’m Rob.

And I’m Sam.

When we think about famous figures in the history of

science, the name of

Charles Darwin often comes up.

Darwin is most famous for his theory of evolution,

the idea that animals change and adapt in response

to their environment.

In the 1830s he visited the Galapagos,

a string of islands in the Pacific Ocean

famous because of the unique animals living there.

It was while in the Galapagos, observing small birds

called finches, that Darwin started forming his theory of

evolution.

But today, the animals of the Galapagos face

the same pressures as animals across the world

because of the effects of man-made climate change.

Warming sea waters and more frequent extreme

weather events are affecting animals

as much as humans, so, in this programme,

we’ll be asking ‘can animals evolve

to deal with climate change?’

But first I have a question for you, Sam, and it’s about

Charles Darwin’s trip to the Galapagos.

In 1831, Darwin set sail around the world,

collecting samples of flora and fauna,

the plants and animals, of the places he visited.

But what was the name of the ship he sailed in?

a) HMS Beagle b) HMS Victory

c) SS Great Britain

Hmm, maybe it was B. HMS Victory.

Are you sure?

No.

OK.

I’ll reveal the correct answer later in the programme.

Now, it may have been the Galapagos finches that started

Charles Darwin thinking about how animals adapt to

their environment but, as naturalist, Kiyoko Gotanda

explained to BBC World Service programme The Climate Question,

Darwin’s first impression of the small birds

wasn’t very good:

When Darwin got to the Galapagos Islands,

he actually wasn’t that interested in the finches

– they were kind of a drab colour and didn’t have a

very interesting song.

He sampled, though, the finches from different

islands, and so when he got back to England he was

looking at all the variation in beak shape and size,

and body size and shape, and he was recalling how

certain finches were found on certain islands

but not on other islands.

In contrast to more colourful birds like Galapagos parrots,

the finches Darwin observed were drab, dull and

boring-looking, with little colour.

Instead, what Darwin noticed were variations in the finches’

beak, the hard, pointed part of a bird’s mouth.

Finches born with a beak that could help them get

more food were more likely to survive and have babies.

Over time, as the birds passed on their successful genes,

they adapted to fit in with their environment

– what we know as evolution.

So, if animals can evolve to survive their environment,

can they also evolve to cope with the impact humans

are having on the climate?

Well, there’s already some evidence to show they can.

Studies on birds in the Brazilian Amazon and red deer

on the Isle of Rum, in Scotland, show warmer temperatures have

caused animals to evolve smaller bodies.

It’s easier to keep cool when you’re small!

American conservationist Thor Hanson records and measures anole lizards

in the Caribbean.

He wants to see how the effects of man-made

climate change, in this case hurricanes, is affecting the lizards.

Listen to what Thor found out as he speaks with presenters of

BBC World Service’s The Climate Question.

What you can see is that large toe pads and strong

front legs give some lizards a tighter grip.

When they do start to let go and their body starts flapping

in the air like a flag, smaller back legs reduce

the drag, and allow them to cling on and survive the hurricane.

So the survivors were those lizards with those

characteristics, and they passed those traits along

to their offspring.

Thor’s lizards developed stronger front legs and smaller back legs,

allowing them to cling on, hold on to something tightly,

when hurricanes pass through.

It’s this trait, a genetically-determined

characteristic, that allows the lizards to survive,

and is passed on to their babies.

Thor checked other areas of the Caribbean where

hurricanes were frequent and found the same traits

in lizards there, proof of evolution in action.

But whereas we often think of evolution happening

over hundreds, even thousands of years, the changes in the

Caribbean lizards happened in around forty years,

something that would have surprised Charles Darwin.

Which reminds me of your question, Rob.

Yes, I asked you for the name of the ship Darwin sailed

around the world in.

Darwin’s ship was called the HMS Beagle and,

appropriately enough, it was named after an animal!

A beagle is a type of dog.

OK, let’s recap the vocabulary from this programme about

evolution, the way living things adapt to their environment

and pass these adaptations on to their children.

Flora and fauna is another way of saying the plants and animals

of a place.

Drab means dull and colourless in appearance.

A bird’s beak is the hard, pointed part of its mouth.

To cling on means to hold on very tightly.

And finally, a trait is a genetically-determined

characteristic.

Once again, our six minutes are up!

Join us again soon for more interesting topics and useful

vocabulary here at 6 Minute English.

Goodbye for now!

Bye!