Day: May 11, 2009

Proterozoic Metazoans?

Complex life pushed back in time (ABC News in Science).

The Vindyan sedimentary basins in central India have been contentious for quite some time, with claims of animal body and trace fossils going back into the Meso-Proterozoic (1.6-1.0 Gya.) That claim has been given a shot-in-the-arm by new work reported in the Proceedings of the National Academy of Sciences which describes fossils found in the Vindyan from 1.65 Gya (late Paleoproterozoic) akin to those usually found in the Cambrian and Ediacaran.

So what’s going on? Is complex life really so old? Did it experience a global setback and took a billion years to recover?

There’s merit to that idea. A current puzzle of astrobiology, that I’ve blogged on time and time again, is the Fermi Paradox – in sum, if Life is similar in age to the Galaxy then why isn’t the Galaxy full of obvious signs of Life? As in alien space-junk in our Solar System, or stars shrouded in Dyson Swarms or whatever…

But what if there’s a faulty assumption? What if Life only gets so old, then gets knocked back to microbes? Perhaps we’re now in an epoch of recently removed restrictions on Life – like frequent gamma-ray bursts – and soon, in cosmic terms, the Galaxy will be colonized. Or perhaps what we’re seeing in the fossils is a reminder that the Galaxy may still be a dangerous place.

Giant trilobites had (complex?) social lives

Giant trilobites had complex social lives (ABC News in Science).

Trilobites ganged together to molt, just like modern day horseshoe crabs – themselves relicts of a bygone age. Such “social” behaviour is surprisingly old, as molting groups have been found dating back 520 million years, making me wonder why Arthropods never did develop intelligence as we know it in larger animals. Possibly it’s because they usually don’t reach huge sizes, though multi-metre long Eurypterids (“Sea Scorpions”) are known. On land they seem to be limited by their circulatory systems and the weakness of their chitin-based exoskeletons. Perhaps on a different world that might not be the liability it is here on Earth… imagine a low-gee moon with a dense atmosphere.

Maybe we will know one day.

New Nanocrystals Show Potential for Cheap Lasers, New Lighting : University of Rochester News

New Nanocrystals Show Potential for Cheap Lasers, New Lighting : University of Rochester News.

Lasers are one of the backbones of interstellar travel via large reflective sails. If they can be made sufficiently powerful and sufficiently efficient that is… and sufficiently cheap. This research might address the latter point.

As the saying goes: “No Bucks, No Buck Rogers”