Posted on 03/11/2010 12:11:56 PM PST by decimon
(Santa Barbara, Calif.) –– By studying the hydra, a member of an ancient group of sea creatures that is still flourishing, scientists at UC Santa Barbara have made a discovery in understanding the origins of human vision. The finding is published in this week's issue of the Proceedings of the Royal Society B, a British journal of biology.
Hydra are simple animals that, along with jellyfish, belong to the phylum cnidaria. Cnidarians first emerged 600 million years ago.
"We determined which genetic 'gateway,' or ion channel, in the hydra is involved in light sensitivity," said senior author Todd H. Oakley, assistant professor in UCSB's Department of Ecology, Evolution and Marine Biology. "This is the same gateway that is used in human vision."
Oakley explained that there are many genes involved in vision, and that there is an ion channel gene responsible for starting the neural impulse of vision. This gene controls the entrance and exit of ions; i.e., it acts as a gateway.
The gene, called opsin, is present in vision among vertebrate animals, and is responsible for a different way of seeing than that of animals like flies. The vision of insects emerged later than the visual machinery found in hydra and vertebrate animals.
"This work picks up on earlier studies of the hydra in my lab, and continues to challenge the misunderstanding that evolution represents a ladder-like march of progress, with humans at the pinnacle," said Oakley. "Instead, it illustrates how all organisms –– humans included –– are a complex mix of ancient and new characteristics."
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David Plachetzki, who received his Ph.D. for work done in the Oakley lab, is the first author. Plachetzki is now a postdoctoral fellow at UC Davis. UCSB undergraduate Caitlin R. Fong is the second author of the paper.
Cnearsighted.
I don’t believe them.
Then don't.
>>”Instead, it illustrates how all organisms –– humans included –– are a complex mix of ancient and new characteristics.” <<
Is that statement very scientific. It appears to be a statement of fact about something that, at best, is an hypothesis.
Well I'll be a hydra's uncle! Keep telling humans that they're no different from the animals, and in a few generations they'll start to act like it.
Can a biologist explain this to me? The Hydra is a genus. Above that you have Family and Order and Class. Then you get to Phylum.
There seems to be an implication here that humans have this gene because cnidaria developed it 600 million years ago. Well, humans are in a different Phylum, so I don’t see how we got anything from the cnidaria. Meanwhile, flies are yet another phylum, and the article indicates that vision among such animals emerged later and separately. Why wouldn’t they say that about humans?
I fail to see why any connection is made between humans and hydra. If the gene is the same it would seem to argue more for an Intelligent Designer who re-used an idea that works rather than for a line of descent from two separate phyla.
Didn’t most - if not all - life on earth get trashed a mere 65 million years ago from an asteroid hit? Kinda like hitting the Reset button on all of this?
I agree. Somehow the Hydra would have to be representative of a common ancestor for this article to make sense.
I know the origins of human sight.
It is sad that so many people are blinded to the truth.
I'm just an uneducated rube, but I don't see how this hangs together as any sort of orderly descent.
Nature liked this gene so much that she transplanted it to other species.
More handwaving and just so stories, couched in ‘scientific’ jargon.....
Blind nature, of course, cannot do that. An Intelligent Designer can certainly do that. But what is being described here violates any sort of straight line of descent and therefore is an argument against Evolution.
Wow... I didn't know that these creatures are still around... 
It’s a scam. I once got an e-mail from those Cnidarians promising me riches in exchange for a small processing fee.
bookmark
But you saw right through that.
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