Anemones Raise a Tentacle in Support of Evolution

Editor's note: This post was selected for publication in the anthology Open Lab 2007: The Best Science Writing on Blog.

Pachycerianthus fimbriatus from the Puget Sound raises each tentacle in support of evolution. Photo from seaotter.com.

The Anemone genome paper, that I previously had posted on, was a landmark paper in comparative phylogenomics. It provided a 'backbone' (yes, pun intended) for comparison from a supposedly more primitive state to a more derived state (i.e. arthropods, nematodes, mammals). The findings of the paper were very interesting, yet somehow they are being highly misinterpreted by certain factions, namely intelligent design "theorists". At the creationist blog, uncommon descent, there is blatant misinformation being spread about the findings. After reading the post and its comments, it is obvious that the poster and certainly the commenters have not bothered to read the paper. To really understand a scientific article one must move beyond the press releases and read the work as it stands.

As someone who has and currently is studying anemones, I would like to respond to some of the ID claims both from the original post and some of the more 'interesting' comments. I will proceed on a point by point basis:

The Waratah anemone of Australia (Actinia tenebrosa)from the Sydney Aquarium.

1) The title: Where did sea anemones get human genes? The questions is inversely phrased. It should read Where did humans get anemone genes. Or more importantly, why did humans conserve genes from the last common ancestor between an anemone and a bilaterian.

2)

Just how the heck is the Darwinian paradigm going to explain this? Advanced genetic programs installed before there was any chance of natural selection acting on them. Yikes! Another finding in the real world not predicted by, or even possible within, the Darwiniam paradigm. Another surprise for Darwinists.
Sooner or later they’ve GOT to start questioning underlying assumptions. (Naive, ain’t I?)

Yes, but for a different reason. Underlying assumptions are always tested in science. That is perhaps the penultimate reason for testing a null hypothesis. The authors of this study's underlying assumptions were certainly not that anemone's shared more in common genetically than with humans. This was an interesting surprise. Though more research is needed, the authors hypothesized that the similarity may, in part, be due to conservation of introns in human. Whereas in fly and nematode have lost not only introns, but whole genes and the links between genes. This is seen when comparing the base-pair alignments.

With regard to "advanced genetic programs installed before there was any chance of natural selection acting on them", I'm not sure what you mean by advanced. The authors described the origins of eumetazoan genes, ancient genes (i.e. predating the anemone) comprise 80% of all eumetazoan genes. Natural selection did act on the other 20% of genes to give us the fantastic animal diversity that we see today, from the cnidaria to the chordata and everything in between (including the Lophophorata Christopher!). So most of the genetic programs were evolving over millions of year prior to the last common ancestor to the cnidaria and bilateria.

Metridium senile from the New Jersey Scuba Diver

3)

Inrons[sic] again. Funny how these sections of “junk DNA” keep turning up, conserved over hundred of millions of years, with no physical expression of them for natural selection to work on.

The term 'junk DNA' is a historical term and a known misnomer to biologists. It is more readily defined as regions of the genome which no function has been identified as of yet. There are several reasons for its presence including that it is an evolutionary remnant from a time when one or several mutations rendered a coding region, insertions of transposable elements, or an unknown regulatory function. There conservation is a result of the lack of selection acting upon them. In fact in the quote above you are arguing for common descent. When genes get turned off that doesn't necessarily mean they go away. The net selective pressure purports greater exertion on physiology or morphology that is being acted on in the present, rather than reducing the genome size, which is not necessarily acted upon by external factors, i.e. no selection from the abiotic environment or biological interactions.

4)

I need not add (but will anyway, for anyone who needs it spelled out) that Darwinism has NO explanation for where these complex genes came from. How can you have a program to build complex multicellular creatures before there are any such creatures for natural selection to work on? How can you select mutations and build gene programs before there is expression of the genes? Hmmmm?

Evolutionary biologists do indeed have an explanation for the rise of complex genes, its called evolution, which coincidentally has been explaining biological phenomena for about 100 years prior to the advent of ID. The adaptations necessary to go from a single-celled organism to multicellular ones have occurred independently several times throughout evolutionary history. This is evidenced by statistically rigorous phylogenetic methods comparing single-celled protists with other multicellular eukaryotes. Hopefully someone can chime in with a reference for this. I have seen the data before but can't remember any studies and its late here... Additionally, mutations aren't selected for. An organism is not thinking that it needs a mutation so it can outrun its predator. Natural selection and indeed evolution, are reactive not proactive. We have seen evidence of rapid evolution in populations of species. For instance, snail shell thickening over 100 years with the introduction of an invasive crab is just one of many that come to mind. Snails with thicker shells survive more attacks by crabs and live longer to reproduce more often giving rise to progeny with the ability to synthesize thicker shells.

Corynactis viridis aff. off the shore of Devon from the BBC.

The following are some of the more intriguing comments:
1)

"I’m still new here, but I can’t help but ask…do people actually read the articles before declaring they falsify evolution?"

To which was replied in the next comment:

"I don’t think you fully get it. Those of us at UD (for the most part) have been following the NDEvo/creo and now NDEvo/ID debates for a long time. We are well versed in NDE and have long been making predictions of these sorts of things. Dembski and others have been doing the theoretical work which was dismissed by NDE proponents.

So when we see stories such as this, they are just more emprical findings confirming predictions of ID. We see these sorts of stories all the time. Some of them, when contested, are read thoroughly and discussed in detail. Others are just “Ok, so Darwinism is surprised again, what else is new?”

Neo-Darwinism is already falsified (in myriad ways…stick around and pay attention); new findings are fun, because they show just how “onto something” ID really is."

Was the original commenters question answered? No, therefore I will answer the question to the best of my ability. No. It is clear that the people contributing to this forum did not indeed read the actual article. Else they might have been surprised themselves to learn about the genetic evidence for the common descent of all animal phyla from the eumetazoan ancestor.

2)OK there really isn't anything else worth my effort there, I'm just wasting my time.

Pereclimenes sp. all nestled in and cozy with an anemone, ready to settle down for the night. So am I off to nestle into the cozy tentacles of my sheets and pillows (my wife would kill me if I woke her up). Good night! Sleep tight! Don't let the nematocysts bite!Photo from Acquario Marino Mediterraneo