Thursday, July 31, 2008

Do you "lub-dub" or "pitty-pat"?

Way back when, my goal was to become a scientist. Specifically biology.....research....genetics. I wanted to find a cure for leukemia. Lofty goals indeed, and long ago discarded for a different path, but I have remained fascinated by biology and the advancements that have occurred in the past decades. I've always admired the elegance of mathematics as well - okay, okay, so I'm a nerdy girl. Guilty as charged.

A few months ago I was listening to NPR, a discussion about animals and relative longevity. (http://www.npr.org/templates/story/story.php?storyID=12877984) We've always known that smaller animals generally have a shorter lifespan than larger ones, and that their heartbeats are much faster. So one might logically conclude that a small animal's heart just plain wears out sooner.

It turns out that this is true - but there's more to the story. There's a mathematical connection to this fact: All animals' hearts have a capacity for about 1.5 billion heartbeats in a lifetime. Wow! Interesting...and there's more.

Scientists at the Santa Fe Institute in New Mexico call it Quarter Power Scaling: larger animals have so many more cells to keep going that they have to be a lot more efficient. Their cells actually are slower and do more work than those of smaller creatures. So elephants, rhinos, and whales take a lot longer to use up their 1.5 billion beats than mice, moles, and butterflies. Prof. Geoffrey West, head of the Institute is now proposing that big cities and small villages have a similar relationship: the larger cities - by necessity - are more efficient.

Add this phenomenon to the fractal nature of .....errrr....nature. The closer we look, the more predictability and pattern we see.

1 comment:

Sarah C. O'Neill said...

That's very interesting indeed...well, I'd rather be a nerdy girl than a "duh, I dunno, I'm just a girl" girl.