The worst thing about creationism

Posted on March 20, 2009 by Michael

Of all the things about creationism, perhaps the worst is simply its lack of beauty. It teaches – nay, encourages – people to be content with a small Universe. It teaches that it is okay, even good, to look up at that deep band of stars that comprise the Milky Way and to say, “Meh. What else is there?” This is what believers in special creation are taught. They believe, most arrogantly, that there is nothing greater out there than their concept of an ever-shrinking, ever-so-tiny god.

Reason, rationality, and science encourage one to sit outside on one of those warm summer nights, pure awe undaunted by the anonymous fears lurking in the dark. They say, Look! there’s so much to be known. Don’t ever be satisfied with the Universe you know. They teach, “Wow! What else is there?” They teach that it is not good but stupendously great to wonder – and it is even greater to tear that wonder asunder and leave it in shattered little pieces so to discover that, yes, there are still deeper wonders. That is the prize of knowledge. Creationism rejects this beauty.

Of course, none of this says whether one or the other is true. Reality dictates that (and reality has a strong bias toward the truths of science). What this does suggest, however, is that something so vile, empty, and ugly as creationism or petty, little humanoid gods has no place among the robust beauty of science and reason and rationality.

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Early Eyes in Evolution

Posted on November 25, 2008 by Michael

I’ve already blogged about eyes and evolution, so I won’t go on about further research. But I will post an interesting article from sciencedaily.com.

ScienceDaily (Nov. 23, 2008) — Researchers unravel how the very first eyes in evolution might have worked and how they guide the swimming of marine plankton towards light.

Larvae of marine invertebrates – worms, sponges, jellyfish – have the simplest eyes that exist. They consist of no more than two cells: a photoreceptor cell and a pigment cell. These minimal eyes, called eyespots, resemble the ‘proto-eyes’ suggested by Charles Darwin as the first eyes to appear in animal evolution. They cannot form images but allow the animal to sense the direction of light. This ability is crucial for phototaxis – the swimming towards light exhibited by many zooplankton larvae. Myriads of planktonic animals travel guided by light every day. Their movements drive the biggest transport of biomass on earth.

“For a long time nobody knew how the animals do phototaxis with their simple eyes and nervous system,” explains Detlev Arendt, whose team carried out the research at EMBL. “We assume that the first eyes in the animal kingdom evolved for exactly this purpose. Understanding phototaxis thus unravels the first steps of eye evolution.”

Studying the larvae of the marine ragworm Platynereis dumerilii, the scientists found that a nerve connects the photoreceptor cell of the eyespot and the cells that bring about the swimming motion of the larvae. The photoreceptor detects light and converts it into an electrical signal that travels down its neural projection, which makes a connection with a band of cells endowed with cilia. These cilia – thin, hair-like projections – beat to displace water and bring about movement.

Shining light selectively on one eyespot changes the beating of the adjacent cilia. The resulting local changes in water flow are sufficient to alter the direction of swimming, computer simulations of larval swimming show.

The second eyespot cell, the pigment cell, confers the directional sensitivity to light. It absorbs light and casts a shadow over the photoreceptor. The shape of this shadow varies according to the position of the light source and is communicated to the cilia through the signal of the photoreceptor.

“Platynereis can be considered a living fossil,” says Gáspár Jékely, former member of Arendt’s lab who now heads a group at the MPI for Developmental Biology, “it still lives in the same environment as its ancestors millions of years ago and has preserved many ancestral features. Studying the eyespots of its larva is probably the closest we can get to figuring out what eyes looked like when they first evolved.”

It is likely that the close coupling of light sensor to cilia marks an important, early landmark in the evolution of animal eyes. Many contemporary marine invertebrates still employ the strategy for phototaxis.

Can you feel the beauty?

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