Hello there.

My name is Mr. Wilshire, and in this lesson, we're going to be looking at Charles Darwin and finches.

The outcome for this lesson is I can model how different shaped beaks are adapted to suit different food sources.

There are also some key words to consider as we progress through the lesson.

The first is Charles Darwin.

Next, observations.

Now, species, then finch.

And finally, adapted.

Don't worry if you're not too sure what some of these words mean as the definitions will appear on the screen for you to read.

You can pause the video now and you can have a recap as to what they mean, but don't worry as they will be used throughout the lesson.

Pause the video now and have a recap.

The first part of this lesson is called Charles Darwin's observations.

Charles Darwin was an English naturalist.

He was born in 1809.

You can see there a photograph taken of Charles Darwin.

A naturalist is a scientist who studies things in nature such as animals, plants and how they live.

You may have heard of Charles Darwin before.

His name does crop up in quite a lot of different cartoons and documentaries about animals.

So let's stop and think.

What did Charles Darwin study? Was it the English language, the natural world, materials and their properties, or earth and space? The correct answer here is the natural world.

Charles Darwin studied the natural world.

As part of his studies, Darwin spent years travelling the world and observing animals in different habitats.

There you can see a picture of the world map.

Pinpointed on the world map is South America.

In December 1831, he set sail to South America on a Royal Navy ship, the HMS Beagle.

He went there to investigate the plant and animal species living there.

It took around a month for the HMS Beagle to reach South America.

In those days, ships would take a very long time to get anywhere.

You imagine going on a holiday to anywhere in America from England, and it took a month to get there.

The HMS Beagle did have lots of sails and lots of mass.

Looked like a very complicated ship to be able to sail.

The journey was very long and for Darwin, he suffered some terrible sea sickness on the way, and he wrote a letter to his cousin.

"I hate every wave of the ocean, with a fervour, which you who have only ever seen the green waters of the shore, can never understand." You can imagine for someone in those times it would've been very expensive to travel anywhere.

So a lot of people living in the United Kingdom would only ever really see their city or their village or the town that they lived in wouldn't really be able to travel around too much.

Being able to travel on a ship in this way would've been quite rare and very, very exciting.

And of course, if those of you who weren't very used to travelling, it would've been a very bumpy ride.

Let's pause and think.

To which continent did Darwin travel in 1831 to study the local wildlife? Was it Africa, Europe, North America or South America? The correct answer here is South America.

Darwin travelled in 1831 to South America to study the local wildlife.

Now, Darwin explored many different countries and varied habitats in South America.

He made many observations of animals living in deserts, rainforests, and oceans, and he found many species that had never been described before.

Here are just some of the animals that Charles Darwin observed in South America.

Can you imagine if the only life you've ever known is living in the United Kingdom and you've suddenly seen some of these animals, that's going to look very strange to you indeed? And in fact, a lot of the things that Charles Darwin was able to bring home to show people, a lot of people really didn't believe that those animals even existed.

In September 1835, Darwin arrived at the Galapagos Islands where he would make his most famous of observations.

You can see there a picture of the world map where the United Kingdom in the very top right.

So you can see how far away these countries really are from each other.

Now, the Galapagos Islands are a set of small volcanic islands around 966 kilometres off the west coast of Ecuador, South America.

Here, you can see the Galapagos Islands.

So it would've taken a very long time to get to South America, let's alone then be able to get to islands on the complete other side of the continent from the United Kingdom.

Let's stop and think again.

On which set of islands did Darwin make his most well-known observations of animals? Was it the Falkland Islands, the Shetland Islands, or the Galapagos Islands? The answer here is the Galapagos Islands.

The set of islands that Darwin made his most well-known observations of animals was the Galapagos Islands.

Now, Darwin observed that there were many different species on these islands that were similar to those living on the mainland in South America, but there were some variations.

Here, you can see an image of the Galapagos Islands and you can see how spread out they are.

He also noticed that some species had slightly different characteristics on each of the different islands.

So I wonder what that means, the different characteristics.

Well, really, it's going to be the different ways that those animals lived.

Or maybe there were certain things about them that were different to others to enable them to live on a set of islands like this.

Let's find out more.

For example, he observed that tortoises on one of the islands has some subtle-shaped shells, and on another island they were dome-shaped.

Here, you can see an image of the saddle-shaped shell tortoise.

Here, you can see a dome-shaped shell, which is very strange.

The two animals, exactly the same, living in close proximity to each other on different islands, yet one looks very, very different to the other.

Now, Darwin also observed variation in finches, a species of bird across the different islands.

I wonder if you can see any differences here between the finches in these pictures from the Galapagos Islands.

Take a moment now, sir.

Have a study and then have a discussion.

Restart the video when you've done that.

Hopefully, you've had a good chance to discuss the two different images there.

Is there anything different or anything similar about these two birds? Hmm, let's find out more.

Darwin observed that different finch species had differently shaped beaks on different islands.

Pause the video now and have a look.

What is it that's different about the beaks on these different birds here? Have a discussion and restart the video when you've done that.

Were you able to spot some of the differences and similarities in these different beaks? Let's find out more.

Well, you can see that some finches have got short, wide beaks and some were thinner and a little longer.

I wonder why though.

Pause the video again and discuss why were the beaks so different? Is there a particular reason that they needed to be different? Pause the video and discuss.

Restart when you've done that.

So I wonder why.

Why do you think this could be? Well, Darwin wondered if the difference in beak shape might be related to the food that was available to the finches on the different Galapagos Islands.

Again, these are the same species of bird, so they should look very similar.

But as you saw in that last diagram, they really weren't.

He suggested that thin, pointed beaks would be better for snatching up tiny insects.

While broad and blunt beaks would be more suited to cracking seeds and nuts.

So the different food sources that the birds like to eat would dictate the type of beak that they would end up having.

So let's stop and think.

Complete this sentence.

Darwin observed that finches on different islands were identical to each other, similar but with some differences between them, or completely different to each other in every way.

The answer here is B.

Darwin observed that finches on different islands were similar, but with some differences between them.

So this brings us on to task A.

Follow the instructions on the worksheet here.

You need to test out some different models of birds beaks with different sources of food.

Here's some instructions to help you do that.

Number one, spread out the food sources inside a tray.

Number two, use each beak to find out how much of the food that you can gather up and put in your stomach in 30 seconds.

Number three, measure the mass of each food gathered by each beak and record your findings in the table provided.

Number four, repeat for different food sources.

You can use this table here to record your findings as you work your way through the experiment.

Best of luck.

Restart the video when you've done that.

Here are some answers that Lucas has collected.

So your answers may be a little bit different.

You can see that the type of beak he was using was a clothes peg, some tongs, pipette and a spoon.

The clothes peg was able to get not many different types of insects or anything else at all.

The tongs were very good at collecting insects and so was the spoon.

The pipette was good at collecting nectar, but that was just about it.

The spoon seems the best there to be able to collect, well, anything.

I wonder how your results were similar and I wonder how they were different.

Hopefully, it's given you a good idea for the different food sources that they would be able to collect.

So you can see why having different tools to use would be a good idea.

The second part of our lesson is called animal adaptations.

Here's the image of the four different finches with their different beaks again.

Darwin observed that the beak shape of finches was best suited for the food sources available on the different Galapagos Islands.

Fruit eating finches had parrot-like beaks, very good for breaking open nuts and seeds, whereas finches that mostly ate insects had narrow, pincer-like beaks.

So that would enable them to pick up the different insects with their beak before eating them and even fit in their beak inside a small hole.

And the nectar-sipping finches had long, narrow, tubular beaks, little bit like the pipette, able to use their beak a little bit like a straw.

So let's stop and think.

What did Darwin observe about the differently shaped bird beaks on the different Galapagos Islands? Have a read of these different statements and decide which one best answers the statement.

The answer here is C.

They were all best suited to the types of food available on each island.

So the different food on the different island would certainly dictate the type of beak that these birds would end up having.

But they don't just grow a beak like that overnight, do they? This is something that has happened to over a long period of time.

Darwin noticed that the finches on the Galapagos Islands were not only different from each other but also different to the ones that living on the mainland in South America.

His observations of these different birds led him to wonder how these new species developed.

Darwin theorised that many, many years ago, finches had travelled from the mainland of South America to the Galapagos Island.

There you can see some finches out in the wild.

Over time, these finches adapted to become better able to gather food on the islands that they had settled on.

On islands with mainly tiny insects to eat, finches with very small beaks would've been able to easily gather lots of food.

Here, you can see a finch eating some seeds.

As these birds flourished and reproduced their physical characteristics including their thin beaks, would've been passed down through generations to their ancestors.

Over time, the results and the finch being well adapted to the food source on its island.

So as I said before, this is something that would've taken place over a very long period of time.

As the finches got used to the different types of food and the different island, their beaks would slowly adapt.

On islands where mostly larger seeds were available, the birds with larger beaks would've survived well and passed their large beak trait onto future generations.

Over many generations, this results in the finches on these islands having a much larger beak, which is well adapted to the environment that they live in.

So the finches who were able to open up the nuts and seeds with their large beaks would've been thriving much more than the finches who were only able to pick up the insects or sip the nectar in this case.

Those other finches would've died off eventually making way for the different finches that you see today.

We don't see this generational kind of evolution in humans as much because humans do live a lot longer.

These birds live very short lives, so their evolution over time is going to be a much shorter time period than that of other animals.

This enabled Darwin to be able to observe this.

So let's stop and think.

What did Darwin's observations leaded to wonder and form theories about? Was it how new species develop? How animals choose a habitat? Or how species interact with each other? Discuss these different statements and choose the one that you think best fits.

The answer here is how new species develop.

Which of these statements is correct? Read these different statements now and decide which is correct.

The correct answer here is over many generations animal can adapt to their environments by passing on helpful physical characteristics.

Darwin uses observations from his voyage to help form theories about how living things adapt to their surroundings.

His ideas would go on to change the way people think about living things and their adaptations revolutionising our understanding of changes in the natural world.

Here, you can see a statue commemorating Darwin and the HMS Beagle.

The voyage that they went on changed the way that lots of people saw how animals developed over time.

It's a very fascinating thing to have studied.

It takes many years and multiple generations for a species to adapt to its surroundings.

Sudden changes to environments can threaten the animals living in those habitats as they may not be able to adapt quickly enough to survive.

If a species no longer has access to its usual food source, it may become extinct.

This is similar to what I said earlier.

Remember, the finches on one of the islands would've been thriving more 'cause of their ability to open seeds and nuts, whereas a nectar-sipping finches wouldn't have been able to survive as long maybe.

They would've thrived better on a different island where there were more flowers.

So think about our model of different bird beaks here.

Aisha is having a think.

Which birds would struggle to survive if their main food source was wiped out? And which birds would then migrate to a different island with a different food source and still survive? If their food source suddenly got wiped out, how would they be able to survive? Pause and think.

So I wonder if the island where there were lots of fruits also had lots of different nuts and seeds for them to be able to open up.

It would really depend on the types of plants that were growing on that island to see whether those different finches would survive.

Let's stop and think.

Darwin's ideas about how living things adapt to suit their environments would eventually change people's ideas.

True or false? The answer here is true.

He did do that and it did change people's ideas.

So can we justify our answer? The answer here is his ideas helped people to understand how and why animals and plants changed over time.

So here is task B, use your findings from the bird beak modelling activity to answer the questions.

One, which birds are adapted to feed on multiple food sources? Two, which birds are only adapted to eating one type of food? Three, how do you think each bird would be affected if extreme heat and drought cause all the insects and worms on the island to die? Four, how do you think each bird would be affected if flooding on their island caused all the flowers to die resulting in no nectar available or seeds? Have a think about these different questions.

Pause the video now.

Good luck with your task.

See you in a moment.

How did you get on? Let's go through some of these answers.

They may be similar to the answers that you gave.

The first question there.

The birds with a clothes peg, the tongs and the spoon shaped beaks could feed on multiple different food sources.

We saw that from our results before.

Two, the bird with pipette shaped beak could only eat one type of food, the nectar.

Question three, the birds with the pipettes and spoon shaped beaks would probably be fine as they can still eat nectar easily.

The birds with a beak shaped like tongs may struggle a bit more, as they were much better at eating insects and worms than they were at eating seeds and they couldn't eat nectar at all.

The birds with clothes peg shaped beaks would definitely find it difficult to survive if they managed to eat very little or none of the other food sources.

And question four, most of the birds would be fine as they were able to eat the other food sources.

The birds with beaks shaped like pipettes though would find it difficult to survive as they were only able to eat nectar.

Here you can see Alex, and don't forget, your answers may be different because some of your results may have differed slightly to the ones that you've seen here.

So let's summarise our lesson.

Charles Darwin was an English scientist who studied nature.

In 1831, he set sail to study the plants and animals living on the coast of South America.

While he was there, he noticed that the beak shape of the finches were best suited to the food sources found on different islands.

Darwin's observations led him to wonder how different species developed.

His ideas would eventually change people's thinking about how living things adapt to suit their environments.

How fascinating.

I wonder if you are ever out and about exploring whether you keep an eye on the different species of animals that you find there.

Maybe if you were able to go away on a holiday, you could keep a little record yourself and have a look at the different species of animals.

You could focus on birds, or maybe you might even want to focus on mini beasts.

Who knows? You could be the Charles Darwin of the future.

Thank you very much for listening.

My name's been Mr. Wilshire.