RDF TV - Saddles and Domes: Evolution of the Giant Tortoises

Richard Dawkins, Josh Timonen

Download: iPhone | 720p HD

Richard Dawkins explains how and why the Giant Tortoises of Galapagos evolved on each of the different islands. He shows how the different shell shapes evolved to help the tortoises adapt to environments on the different islands.

"In May 2007 Josh and I were among those who went to Galapagos with a large group from the Center for Inquiry. As we walked with the guided parties over the islands, Josh took every opportunity to film the wildlife. Occasionally he would turn the camera on me, and I would ad lib a few words about whatever animals we were looking at. These 'vignettes' were unscripted and unrehearsed, and there was no time for any "Take 2" repetitions, because the guided walk was moving on."

Richard

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Camera & Music by
JOSH TIMONEN

Presented by
THE RICHARD DAWKINS FOUNDATION
FOR REASON AND SCIENCE

Posted: Friday, September 18, 2009 | Permalink

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1. Comment #416980 by user225937 on September 19, 2009 at 2:48 am

Beautiful video with a memorable point.

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2. Comment #416982 by Steve Zara on September 19, 2009 at 3:06 am

Wonderful photography, especially of the aquatic tortoises. Some scenes would make great posters.

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3. Comment #416984 by SaintStephen on September 19, 2009 at 3:16 am

That saddle-shaped shell, and the long-necked tortoise inside, are things that now seem utterly convincing with regard to the truth of evolution, even at first glance.

It's just such an amazing, amazing concept. Lately I've been imagining it this way. We have this long string of "gain/amplitude control knobs" -- our DNA in other words, and let's assume for the sake of simplicity that each "knob" controls the scaled-size of one of the bones in our skeleton. Turn one knob and the femur enlarges, turn another and the pelvis shrinks, for instance. Mutation randomly turns these knobs left and right, causing "morphed" representations of the same basic skeleton bauplan. If a particular "morphed skeleton" is effective at living and reproducing, it hangs around, and less successful versions die off.

Now let this crazy, random morphing process continue for hundreds of millions of years on a planet that naturally imposes fairly rigid requirements on these skeletons in terms of survival and reproduction, but can change these requirements also, every millenia or so. The result? A wide variety of weird skeletons, but all of them intimately related.

I have to believe that a well-coded, extremely graphical and interactive video game demonstrating Richard's "Bio-Morph" land, or Dennett's "Library of Babel" would convert many a skeptic. Evolution almost seems too obvious when viewed from these angles.

EDIT: Turtles sticking their necks out of their protective shells. Hmmm... a lesson in there, somewhere.

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4. Comment #417051 by God fearing Atheist on September 19, 2009 at 11:45 am

3. Comment #416984 by SaintStephen
I've been imagining it this way. We have this long string of "gain/amplitude control knobs" ...

That is only one tiny bit of it. Spider venom evolved to paralyze nervous system of insects ... ... ... ...

I have to believe that a well-coded, ... demonstrating Richard's "Bio-Morph" land, ... would convert many a skeptic.

Having written a similar system, I keep having the same thought, but keep stalling because it will always get the objection - "But you programmed it to do that". If someone doesn't want to believe in "emergent properties" they can always fall back on that excuse - and IDiots are very set in their beliefs. In another way its like micro and macro evolution. An IDiot will accept a moth can change colour ("because it was always capable of changing colour") but will not accept it descendants can't change into something that is not a moth. How the hell do you get them to see the continuum?

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5. Comment #417122 by SaintStephen on September 19, 2009 at 5:27 pm

4. Comment #417051 by God fearing Atheist on September 19, 2009 at 11:45 am

Very good points. Oh well, at least I would have fun playing with the morph game all day long. I played with somebody's version of Biomorph Land a few days back... they used stick figures and everything kept 'evolving' into snowflakes and lichens. Boring -- I only played with it for 3 hours or so...

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6. Comment #417134 by God fearing Atheist on September 19, 2009 at 6:10 pm

5. Comment #417122 by SaintStephen

I had a little "screen saver" where I had three types of "critters" red, green and blue pixels, that could see the 5 by 5 pixels around them, and move one pixel in any direction. Red "ate" green, green "ate" blue and blue "ate" red (rock, paper, scissors type game). They evolved genes to move in a certain direction when they "saw" a given pattern in (5*5-1)*3 = 72 bits of information, which started at generation 0 as totally random After 20,000 generations they began hunting each other down, and/or evading as opposed to randomly bumping into each other and eating or being eaten.

I'm tempted to try and find the program in my huge pile of abandoned 3 1/2" disks or re-write it. If I thought it would be any use I would. I would then put it on the web open-source, but I can hear the moans now "but you wrote it to do that ..."

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7. Comment #417144 by SaintStephen on September 19, 2009 at 6:42 pm

6. Comment #417134 by God fearing Atheist on September 19, 2009 at 6:10 pm

That sounds exactly like what Daniel Dennett described in Darwin's Dangerous Idea! I have to say, out of all the images and ideas put forth to me thus far, this had a massive, massive impact. As I'm sure you're aware, Dennett said a team of programmers actually succeeded in creating 'digital life', where creatures evolved, reproduced, and ate each other (and even shit?).

Dennett said the final implementation would have required an enormous pixelated screen the size of a football field, and therefore no actual viewing by humans would be possible except from a hovering helicopter, say, but then all the "creatures" would merely look like amorphous blobs or "nebulae" in space, so to speak.

Amazing, amazing stuff. This is what convinced me that life must have began in a Darwinian sense.

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8. Comment #417161 by God fearing Atheist on September 19, 2009 at 7:56 pm

7. Comment #417144 by SaintStephen

Its all fascinating stuff.

I wrote that program in about 1996. Even then there was a vast literature on genetic algorithms, genetic programming and "artificial life". One of my colleagues went on to do a PhD in genetic algorithms for engineering design - there was a whole section of a computer science dept. dedicated to it - they were attempting to solve difficult problems with real engineering applications. At the time I read 10 or 20 papers on it. One of the "artificial life" papers described an emulation of "single cell" critters evolving into "multi-cellular" using the spare cycles on a super-computer. After months "infecting the core of the machine" "multi-cellular life" emerged.

By this time I bet if you stacked every academic paper about GA,GP & AL end to end it would stretch kilometers. Yet more evidence for evolution, with the tiny careat that a human designer has to write the initial program to boot up the system.

Any yet we still have IDiots ... D'oh!

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11. Comment #417559 by Alternative Carpark on September 21, 2009 at 6:43 am

Had the pleasure of a giant tortoise ride while on holiday in the Seychelles in 1986. It is amazing how big, and how strong, they are.

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12. Comment #423049 by bluebird on October 11, 2009 at 11:30 am