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Sign up with GoogleRichard Dawkins demonstrates the evolution of the eye
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copacetic
King of the Hippies
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Looks like hopeful conjecture to me.
I don't think your eyes are evolved enough to see clearly.
Looks like hopeful conjecture to me.
The video makes it so simple even a toddler could understand it.
Understand the conjecture? Yes.
HapticSimian
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Denial of evolution shows one to be at best ignorant, and at worst a victim of indoctrination. I doubt be.plato would have to fortitude to actually investigate the issue honestly.
He should first watch the video.
Here is a nice, recent article, on eye evolution:
Metazoan opsin evolution reveals a simple route to animal vision
be.plato, I suspect you are a creationist (like I am). Nothing about any evolutionary process suggest that creationism is false (not YEC of course) and you don't have to support Intelligent Design to be a creationist (that would actually be silly really). So, even if all this research about eye evolution completely solves the puzzle of the emergence of eyes, it is not an argument against creationism. People tend to make that mistake a lot.
Metazoan opsin evolution reveals a simple route to animal vision
be.plato, I suspect you are a creationist (like I am). Nothing about any evolutionary process suggest that creationism is false (not YEC of course) and you don't have to support Intelligent Design to be a creationist (that would actually be silly really). So, even if all this research about eye evolution completely solves the puzzle of the emergence of eyes, it is not an argument against creationism. People tend to make that mistake a lot.
SaiyanZ
Executive Member
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The only thing is, that creationists use the eye as an argument for creation because of it's complexity. So when someone shows them otherwise, they feel like they're being attacked.
Arguing from complexity to creation is silly anyway.
One thing about eye evolution is the genetic machinery and circuitry needed for its development. One animal that I find fascinating is the Trichoplax adhaerens. Here you have an animal that looks like a flattened blob with only four cell types. There are no nerve cells, sensory cells, muscle cells, bone cells etc. It is an animal at the base of the eukaryotic evolutionary tree .
Several types of eyes exist and these include the camera-type eye, the compound eye, and the mirror eye. Ernst Mayr proposed that eyes evolved in all animal phyla 40 to 60 times independently (maybe even more).
A monophyletic program governing the development of the different eye types is proposed and the Pax6 gene is posited to be the master control gene. The Pax6 gene also plays a part in controlling the development of the nose, ears and parts of the brain.
What is needed for the developmental program of eyes?
A few core genes include:
Pax6 (eyeless [eye]) in Drosophila)
Six-type genes (E.g. Six3)
Sox-type genes (E.g. Sox2)
atonal ( E.g. Atoh7)
Retinoid receptors
Fox transcription factors (E.g. FoxN4)
Pitx
Fascinating experiments have been conducted by shuffling around the genetic program architecture of genes associated with eye development in various animals.
For example in Drosophila:
Ectopic eye structures are able to be induced on the antennae, legs, and wings of fruit flies. This is done by targeted expression of the eyeless gene (Pax6 Drosophila homologue) (Figure 2). The Pax6 gene from the mouse is able to do the same job as the Drosophila version (Figure 3). And in Xenopus embryos, ectopic eye structures in can also be induced by the Drosophila eyeless (Pax6) version (Figure 4).
What about the Trichoplax adhaerens genome? Any genes for eye development?
It seems quite a chunk of the circuitry needed for eye development is present. (From table 1)
PaxB (eyeless?)
Six genes
Sox gene
Atonal gene
Retinoid X Receptor
Fox transcription factors
Pitx
So, large chunks of the circuitry for eye development was present in Trichoplax way before the eye even emerged.
The same is true for the development of multicellularity.
Several types of eyes exist and these include the camera-type eye, the compound eye, and the mirror eye. Ernst Mayr proposed that eyes evolved in all animal phyla 40 to 60 times independently (maybe even more).
A monophyletic program governing the development of the different eye types is proposed and the Pax6 gene is posited to be the master control gene. The Pax6 gene also plays a part in controlling the development of the nose, ears and parts of the brain.
What is needed for the developmental program of eyes?
A few core genes include:
Pax6 (eyeless [eye]) in Drosophila)
Six-type genes (E.g. Six3)
Sox-type genes (E.g. Sox2)
atonal ( E.g. Atoh7)
Retinoid receptors
Fox transcription factors (E.g. FoxN4)
Pitx
Fascinating experiments have been conducted by shuffling around the genetic program architecture of genes associated with eye development in various animals.
For example in Drosophila:
Ectopic eye structures are able to be induced on the antennae, legs, and wings of fruit flies. This is done by targeted expression of the eyeless gene (Pax6 Drosophila homologue) (Figure 2). The Pax6 gene from the mouse is able to do the same job as the Drosophila version (Figure 3). And in Xenopus embryos, ectopic eye structures in can also be induced by the Drosophila eyeless (Pax6) version (Figure 4).
What about the Trichoplax adhaerens genome? Any genes for eye development?
It seems quite a chunk of the circuitry needed for eye development is present. (From table 1)
PaxB (eyeless?)
Six genes
Sox gene
Atonal gene
Retinoid X Receptor
Fox transcription factors
Pitx
So, large chunks of the circuitry for eye development was present in Trichoplax way before the eye even emerged.
The same is true for the development of multicellularity.
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Unhappy438
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HapticSimian
Honorary Master
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It is, but the people being told to argue like that aren't ever told it's silly. You'll full-well know about the disingenuous quote-mine of Darwin on the eye's evolution from The Origin of Species - no church propaganda ever quotes beyond this sentence: "To suppose that the eye with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest degree."
It's horse manure.
Scientists should just do the intellectually honest thing and inform everyone that evolution and evolutionary theory are not arguments against creationism per se. And, religious figures should stop to try and use the "complexity argument" as an argument for creationism or confuse "design" for "creation" or "teleology". They are three distinct concepts.
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Thanks, I'll take a look.
OrbitalDawn
Ulysses Everett McGill
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The responsibility of scientists is to explain the science, not ease the intellectual burden of dimwitted people. The science is what it is, and scientists can't reasonably be expected to put disclaimers in to soothe things over for every group of people who wants to make supernatural claims about it.