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December 23, 2006
Cicadas
Just a thought to add to this:
Take the cicada. Some forms of this insect hide in the ground for 17 years before emerging into the forest, where they breed, lay eggs and die after six weeks. Scientists believe that the cicada has a predator that also emerges periodically.
“If the cicada came up every nine years and the predator came every six years, the cicada would be killed off after 18 years. If the cicada came up every seven years, it would take 42 years before it was killed. By emerging after 17 years, a prime number, it keeps out of step with the predator for longer. That’s the beauty of prime numbers,” Professor du Sautoy said.
The way that story is told, isn't it getting causality the wrong way around? Our assumption is, rather, that there were indeed cicadas that came up at 6, 7, 8 and 12 years, and did get eaten by the predators. Only those coming up on the 17 year cycle survived down the generations?
December 23, 2006 in Science | Permalink
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Comments
Those people who like maths and would like their children to have some exposure before adulthood should tune their TV's to channel Five for the "Royal Institution Christmas Lectures" - primes are covered in the second episode. I believe the BBC are running repeats of "Cash in the Attic" for those requiring public service television.
Posted by: Kit | Dec 23, 2006 10:40:08 AM
Quite correct TW - and I get the impression from the line of argument that the mathematician might not have understood this: but it may simply be an example of journalistic misreporting. It happens all the time.
Posted by: Bruce G Charlton | Dec 23, 2006 10:55:56 AM
I expect he does know. Attributing intention to processes of evolution is such a convenient shorthand that even textbooks use it, often with an apologetic paragaraph somewhere saying they know it's not like that really.
Posted by: Natalie Solent | Dec 23, 2006 2:32:10 PM
The newspapers are full of bacteria "learning" to cope with antibiotics. Some people don't understand that it's just a metaphor. They're probably the same people who believe that genes can literally be "selfish" or that liberals really believe in an invisible hand.
Posted by: dearieme | Dec 23, 2006 3:23:19 PM
What makes the author think the predator is going kill all the Cicada(i)?(s)? Each time they emerge?
Posted by: David Rotor | Dec 23, 2006 3:26:46 PM
"Those people who like maths and would like their children to have some exposure before adulthood should tune their TV's to channel Five for the "Royal Institution Christmas Lectures" ....I believe the BBC are running repeats of "Cash in the Attic" for those requiring public service television."
What!! The Christmas Lectures have always been on the Beeb, haven't they?!
Disgraceful!
Posted by: JuliaM | Dec 23, 2006 6:05:45 PM
The bloke is only a mathematician. Thank you for reaffirming my opinion that a free market economist (is there any other kind? What should we call those guys how claim to be economists but aren't free marketeers? Charlatans? Idiots?) is more likely to understand Darwinism than anyone else.
So why doesn't Dawkins understand economics?
Posted by: Chris harper | Dec 24, 2006 1:47:49 AM
