6 3 5, 0 0 0, 0 0 0 years ago . . . .

...sponges (which are animals) existed.

Or so infers a group led by Gordon Love (UC Riverside), as published in the Feb. 5th edition of Nature. You can read about it here, and here. The short version is that signature steroid compounds characteristic of the cell membranes of desmosponges have been isolated from pre-Cambrian strata found while doing petroleum industry-funded research in Oman.


Gotta love all those carbon-based compounds funding the investigation of other carbon-based compounds by carbon-based life forms....even if this is a silicon-based blog.

If this finding turns out to be robust, this pushes the inception of the Metazoa back another 75 million years, at a minimum, and that would (gasp!) extend the 'Cambrian Explosion' by a similar amount, effectively atomizing what was a bad creationist argument in the first place.

(I will now cross my fingers and hope against hope: is there any argument so wretched, so hopelessly contrary to the available evidence, that it will not be repeated in the pews?)


Returning to the science, this finding would also be consistent with recently-published molecular work that estimates a divergence time for sponges around 650 million years ago. I admit that I'm still a bit skeptical: I'd like to see morphology instead of behavioral traces, but it will be interesting to see how this looks in five years.