This should be relevant read for everyone involved in the discussion on the Life Before Earth paper yesterday. (b_b, mk, symmetry, JakobVirgil)
Nice find. Points well taken about them cherry picking data. I don't know if anyone knows enough about the various genomes to develop a complete picture (besides, defining what they mean by 'complexity' is nebulous at best). But I strongly disagree with some of the methods that the author and the commentors use to tear down the paper. For example, "There's no such thing as a theoretical biologist" isn't an argument. Neither is "this guy is just a 'staff scientist' at NIH, whatever that means." Firstly, there is a such thing as a theoretical biologist (see D'Arcy Thompson, one of the greatest 20th c thinkers, whose work On Growth and Form should be required reading for biology students). Second, a lack of a central theory is exactly what keeps biologists in their "data are God" type of thinking. Oh my how we love giant data sets. Want to know everything about the brain and mind? How about build a brain map! (for example) Biologists have a real problem with their endless generation of huge amounts of data and general lack of insightful ways to interpret it. I don't think that this Moore's law paper is about hubris; I think it's about stirring the pot. If it's bad science, attack it with good science. Don't attack the scientists. Biology is a religion, in which 'data' are its deity (hell, they even have something called the 'central dogma'). If I were a betting man, I'd guess that life did originate on Earth, so don't take my interest in this paper as an endorsement of its thesis. I am, however, an enthusiast of people who use some extreme imagination to try to fill holes left by conventional wisdom.
I think the key is that no one knows enough about functional genomes to calculate increasing rates of complexity (as you point out). That is really where the criticism stops for me. I read the paper thoroughly last night and both authors make some great points about how punctuated equilibrium as a concept can't really explain how early life developed so quickly into complex multicellular life. I think you made the point yesterday that there could have been some analogous cambrian explosion that we are unaware of (and may always be unaware of). But evolution of simple replicating chemicals into a RNA world would have taken a tremendous amount of time and we already know that all the comets in Kupier belt are covered with glycine - a crucial amino acid. It is certainly plausible to suspect that life originated pre-Earth. I think the authors made the mistake of a) not going through a proper peer-review channel and b) not being a little more humble with their analysis. They in no way proved that life originated pre-Earth. However, the most insightful aspect of this paper was not discredited by PZ Meyers analysis at all (and I don't think he read the paper to find out) but they make a compelling argument that the universe may be experiencing a "civilization pulse" over the next 100 million - 1 billion years. I have thought for a while that one of the most compelling answers to Fermi's Paradox is the fact that at the very earliest the universe would have been able to produce an intelligent civilization 10-12 billion years into its evolution. The conditions of the early universe and the length of time it takes for a species like us to evolve would prevent one arising much earlier than that.
:) Thanks. It smelled like something someone in the field would swat down. arxiv is like a box of chocolates. I think http://plosone.org is a much better model. However, I recently reviewed an article for them, and I was shocked that the second 'reviewer' simply filled the check box questions available, and made no comments at all. IMO I was the only one that peer-reviewed that submission.