ANTpogo, I am going to address your comments on the paper but can't waste a lot of time trying to explain something over and over again.
You aren't explaining anything, merely asking questions that are
addressed in the paper itself.
They considered their findings "paradoxical."
Why?
Because, in
general, simple organisms have simple genomes. But, as we've been trying to point out to you (and as this paper itself warns), using that to make the assumption that simple organisms
should or
will always have simple genomes is misleading.
"Given that this organism contains apparently few tissue types....", etc,... So these scientists find it paradoxical because the organism does not have complex nerve function, pretty much exactly my point except for the part about addressing the larger question of mechanisms for evolution.
And, as I pointed out to you before (complete with quoting the entire relevant section of the paper), the scientists know
how the coral uses these genes as part of its simple neural net and few tissue types. For example, the all-trans-retinol dehydrogenase photoreceptor, not found in other invertebrates, is used in the coral's larval stage, and an early form of the Pax-6 gene found in vertebrate nervous systems expresses itself in
A. millepora's neurons.
Do you actually think that the paper says the coral has
all the genes for our complex nervous system, just laying about unused in its genome?
Note the reference to "human" and the use of the term "surprisingly similar." Did you read the paper and note where they did say the findings were "paradoxical" and "surprising" and "appears to turn upside down several preconceived ideas about the evolution of animal genomes."
We can't talk about a paper or data if you won't admit what it says.
They use human because they were looking for those genes in comparison to the specific human genome. But you are aware that just because a gene is found in humans that doesn't mean it's
exclusive to humans, right?
The paper actually lists every gene that both humans and
A. millepora have in common. Not a single one is exclusive to humans, with all of them being found in other vertebrates (and even some invertebrates, depending on the gene in question).
The three genes that the paper even calls out as being nervous-system related genes that have no invertebrate counterpart, the one encoding all-trans-retinol dehydrogenase (a photoreceptor), Churchill, and Tumorhead (both of which regulate the early neural development in vertebrates), are far from exclusive to humans, and can be found in mice and even frogs.
This is from the research group's website.
Again, that doesn't say what you seem to think it says. It says that the
A. millepora genome contains some genes that are also found in humans (and other vertebrates), but not in invertebrates that are closer phylogenetically to the coral. It attributes this not to invertebrates gaining these particular genes after the evolutionary diversion, but to invertebrates later losing them.
But these are only a few specific genes, and though they're the same genes used in basically the same way, vertebrates use them as part of a much more complicated nervous system than
A. millepora has, because of the massive volume of genes that vertebrates
did gain after the evolutionary split that construct the
rest of the nervous system that
A. millepora does
not have.