Same but different
Children look a bit like their parents, but not exactly. Find out why that matters, meet birds whose beaks fit their food, and play 'hungry birds' to see why the best-hidden moths survive.
Read
Living things have babies that look a bit like their parents. Lots of things are passed on from parents to their young.[1]
But the young are not all exactly the same. Some are a little bigger, or darker, or have a different beak.[1]
On the Galápagos Islands there are birds called finches. Finches that eat seeds have thick, strong beaks. Finches that eat insects have thin, pointed beaks. Each beak fits its food![1]
In England there is a moth called the peppered moth. Some are light and some are dark.[3]
Long ago, smoke from factories made the trees dark and dirty. Birds could easily see the light moths on the dark trees and ate them. The dark moths were hidden, so more of them lived and had babies.[3]
After a while, almost all the moths there were dark! Over a very, very long time, living things can change like this. Scientists call it evolution.[3][1]
Try it: Hungry birds: which moths survive?
You need
- Two big sheets of newspaper
- Moth shapes cut from white paper (10)
- Moth shapes cut from newspaper (10)
- A timer
Safety
Use safety scissors or ask an adult to cut the moths. Pick up the moths gently, one at a time; no grabbing or pushing.
What to do
- Lay one newspaper sheet on a table. This is the dirty, dark tree.
- Guess: which moths will the birds find more easily, the white ones or the newspaper ones?
- Your teacher scatters all 20 moths on the newspaper while the 'birds' look away.
- One child is the hungry bird. They have 10 seconds to pick up as many moths as they can, one at a time.
- Count the moths that are left. How many white? How many newspaper?
- Take turns being the bird and do it again.
What happens, and why?
The white moths are easy to see on the newspaper, so the 'bird' finds them first. The newspaper moths are hidden, so more of them survive. Long ago, birds found the light moths more easily on dark, sooty trees.[3]
Play: Hidden or easy to see?
Would a hungry bird spot it? Tap the right group.
Your best score is kept only on this device. Nothing is sent anywhere.
Quiz
Other ages: Ages 10–11 · Ages 15–16