Reading for Wed.

I hope everyone got the article I chose for this week. If you didn't, just email me, and I will send it on to you. I also want to say that I am really, really sorry that it is so long. Just skim it, and that should be good enough. In case you haven't had a chance to look at it yet, it is titled Biogeochemical modeling of the rise of in Atmospheric Oxygen. Basically, what it sets out to do is explain the how Earth went from a weak oxygen producing state, to having oxygen as the third most abundant gas in the atmosphere. I chose this article because Raup suggests, on page 24, of the book that the abundance of oxygen was a product of photosynthesis, which allowed live on earth to diversify, and therefore produced more free oxygen. This article tries to explain some of the specifics on a couple theories of how that may have happened. One specific theory it suggests is that cyanobacteria may be one of the earliest photosynthesizers. Just take a quick look at the article. It is pretty cool, but very long and a bit dry too. 

In reference to the book, the chapter this week covers a brief history of earth. 

One thing I would be interested in discussing is Raup's debate on the possible multi-origination of life. An analysis he explains early in the chapter asks whether, if there had been up to ten different originations, any others would have survived. He concluded no, and also that if there had been more than ten the likelihood that more than one would have survived increases. What are your thoughts on this? 

Along the same vein, do you agree that things such as flight all evolved independently and then faded out, only to be included in a different organism's evolution? 

Raup points out a notion held by many scientists: that humanoid intelligence would have arisen much the same as it did here on another planet. But the record shows no such consistence or predictability. What do you think about this? 

Those are just a few ways the discussion could go on Wed. Let me know what you think!

-Janie