World of Wonders

When we see things that aren’t, we miss the wonderful things that are.

It’s Not Easy Being a Spider

Two items I recently wrote for a children’s science and nature magazine:

Assassin bug vs. Spider!

When a leaf falls into a spider’s web, the spider can tell from the vibrations it hasn’t caught an insect. But when it feels fluttering insect wings, it knows dinner has arrived. It also knows to attack quickly, before its prey escapes. And when it feels vibrations from a weak insect, the spider moves in slowly. It knows its meal isn’t going anywhere.

Now, two scientists from Australia are studying how assassin bugs catch spiders using the spider’s own web. Anne Wignall and Phillip Taylor watched as an assassin bug used its legs to pluck the threads of a web. It didn’t vibrate the web like a leaf—then the spider wouldn’t come. And it didn’t vibrate it like an escaping insect—then the spider would attack too quickly. Instead, it shook the web as if it was a small, weak insect. The spider approached slowly, making it easy for the assassin bug to grab its prey.

Wolf spider vs. Sundew!

Different species of animals compete with each other—especially when they eat the same food. This usually happens with animals that are similar, like dolphins and tuna, or lizards and snakes. But now, a scientist from Florida has discovered an animal and a plant that compete for food. David Jennings studies wolf spiders and tiny plants called sundews. The sundew feeds itself by catching insects with its sticky spines. The wolf spider catches insects with its web.

Credit: Christopher V. Anderson, Univ. of South Florida

Jennings placed sundew plants in terrariums. Next, he put wolf spiders in with some of the sundews. Then he added insects. When a sundew had to share the food supply with spiders, the plant didn’t grow as well. And in the wild, he found that wolf spiders either built bigger webs when sundews were nearby—or they built their webs farther from their spiny competitors. It was as if they knew the sundew would “steal” some of their food!

Filed under: nature

How Does Understanding Evolution Make Us Better Citizens?

On his Discover blog today, Carl Zimmer asks “…how understanding evolution allows American citizens to formulate more informed decisions about societally important matters. How does a good understanding of evolution better prepare us to make decisions as citizens?” He invited readers to submit their views. Here’s the answer I posted in reply:

It is not so much our understanding of the fact of evolution that is so important to being an informed, responsible citizen. What’s critical is our understanding of how we know that evolution is a fact. Evolution instructs us how to understand. Evolution challenges us to ask: how do we know? Do we “know” God created the millions of species on Earth because that’s what religious doctrine declares? Or do we know that species evolved from common ancestors because of the century and a half of empirical evidence that proves the idea true, and because it makes sense of and explains all we see around us.

Do we know what we know through fear, irrationality, ideology, a lack of education, or fundamentalist beliefs? Or through rationality, reason and empiricism? In this way, evolution touches issues and ideas that are important to any informed citizen. How do we know anthropogenic global warming is real? How do we determine what causes AIDS, cancer or autism? How do we know flying saucers, time-traveling cellphone-users, homeopathic cures, and Iraqi weapons of mass destruction don’t exist? We know by looking at these questions in the same way Darwin looked at the world around him.

Filed under: evolution, science literacy

About me

CHRIS SASAKI
I am a Toronto-based writer, author and photographer who is inspired and fascinated by science. Science is our best way of understanding the natural world, but it is much more than that. Science is culture, and its pursuit ultimately leads to meaning, values and wonder.  My interests include evolution, Darwin, the Galapagos Islands, secular humanism, religion, skepticism, climate change, and science culture.  For many years, I wrote and produced astronomy programs for the McLaughlin Planetarium of the Royal Ontario Museum. I am author of many books for young readers (Sterling Publishing and Penguin Young Readers, N.Y.) and articles for children's magazines. I also write non-fiction related to the themes reflected in this blog. You can read some of my longer non-fiction and view my photographs at www.chrissasaki.com, and follow me at www.twitter.com/chrissasaki.

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