Archive for the 'Organisms'

My wife tells me I ought to feature a fish that’s actually called the Sarcastic Fringehead on the blog — it’s a natural. I wonder if she was being sarcastic, but she looked so innocent when she told me.

The coelacanth genome has been sequenced, which is good news all around…except that I found a few of the comments in the article announcing it disconcerting. They keep calling it a “living fossil” — and you know what I think of that term — and they keep referring to it as evolving slowly The slowly evolving coelacanth The morphological resemblance of the modern coelacanth to its fossil ancestors has resulted in it being nicknamed ‘the living fossil’. This invites the question of whether the genome of the coelacanth is as slowly evolving as its outward appearance suggests. Earlier work showed that a few gene families, such as Hox and protocadherins, have comparatively slower protein-coding evolution in coelacanth than in other vertebrate lineages. Honestly, that’s just weird. How can you say its outward appearance suggests it is slowly evolving? The two modern species are remnants of a diverse group — it looks different than forms found in the fossil record. And then for a real WTF? moment, there’s this from Nature’s News section. It is impossible to say for sure, but the slow rate of coelacanth evolution could be due to a lack of natural-selection pressure, Lindblad-Toh says. Modern coelacanths, like their ancestors, “live far down in the ocean, where life is pretty stable”, she says. “We can hypothesize that there has been very little reason to change.” And it is possible that the slow genetic change explains why the fish show such a striking resemblance to their fossilized ancestors. Snorble-garble-ptang-ptang-CLUNK. Reset. Does not compute. Must recalibrate brain. None of that makes sense. The modern fish do not show a “striking resemblance” to their fossilize ancestors — they retain skeletal elements that link them to a clade thought to be extinct. This assumption that Actinistian infraclass has been unchanging undermines their conclusions — the modern...
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But after this week I just don’t care. PZ can feed me to the squids if he wants to. I just don’t care. Read more

It’s a big image, so it’s going below the fold. Read more

At least, that’s what I keep telling myself as yet another snowstorm bears down on us. (source)