Real Science and Other Adventures

Helicopters and convergent evolution

Nature comes up with brilliant ways to solve all sorts of problems. There’s pretty good evidence that this happens by a process called evolution. Some solutions are so good that they’re used again and again by different organisms. This is known as convergent evolution.

Seed dispersal is an adaptation that helps plants spread out, and find places to grow where there’s less competition from their neighbours.

Here are two examples of plants that send their seeds away to a new home in helicopters. These are seed pods that spin as they fall from the tree. The spinning slows down their fall, and if there’s a breeze it can catch the seed and take it away to grow in a new location.

The helicopters I played with growing up in Queensland were from a hiptage bush. This plant is originally from Southeast Asia.

hiptage-jpg

These seed pods make beautiful little helicopters. With three blades they spin quickly as they fall.

 

If you live in North America or Europe you might have seen or played with a different type of helicopter seed – from a maple tree (in Europe it’s called sycamore tree).

Here’s one spinning.

These two plants aren’t related (and the helicopters look quite different – one blade or three) but they’ve both come up with the same solution to a problem.

Plants worked out how to use aerodynamics a long time ago. More than once.

MORE READING

Scientists have worked out the science behind how the maple seed spinshttp://www.livescience.com/3672-secret-flight-helicopter-seeds.html

Ichthyosaurs and dolphins – another example of convergent evolution. http://phenomena.nationalgeographic.com/2015/02/06/why-an-ichthyosaur-looks-like-a-dolphin/

Inventing the eye – an amazing technological feat and yet another example of convergent evolution. https://cosmosmagazine.com/biology/all-eyes-on-the-prize

This is a very nice activity on convergent evolution – written for teachers. http://nationalgeographic.org/activity/examining-convergent-evolution/

Hiptage image: Creative Commons license by Siddarth Jude Machado. Creative Commons license. From http://indiabiodiversity.org/observation/show/378471?species%3DHiptage%20benghalensis%20(L.)%20Kurz

Cross-posted (modified) from Fireside Science

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