Genesis: The Scientific Quest for Life's Origin

For book club this month we chose a book titled Genesis: The scientific Quest for Life's Origin by Dr. Robert Hazen

The topic of the book is a discussion of the current theories of how life may have emerged from the non-living chemical rich primordial earth. The word for this transitional event is autogenesis.

I've read a lot about evolution, but I was really interested to learn more about the beginning of life, specifically its creation. What does it even mean to be alive? It's easy to clarify in terms of humans, and mammals, but when you get down to smaller, simpler things, the answer becomes fuzzy. How did the first life form on earth organize itself? And how do scientists even begin to answer that question a few billion years later?

These were all questions I had going into this book, and I have to say that for the most part my curiosity concerning them has been satisfied. That's not to say the book had complete and definitive answers to my questions, but rather that it addressed them, and gave the best possible answer (as it is understood by scientists today), or answers if there were more than one possibility. It was both an overview and a history of the subject, and for the most part an easy read. The only difficulty was when the author explained certain chemical reactions, and used names like isoprene and phenathrene etc. But they were necessary to document in that they supply the "proof" to the claims the scientists are making concerning the origins of life and ultimately ourselves.

I wrote in the previous blog about emergent systems. Well, this seems to be the prevailing theory on how life on Earth came about. Through an unique combination of chemicals and the right influx of energy, life was able to emerge. I find that utterly fascinating. It was also really interesting to me how large a role geologists are playing attempting to answers to the origin of life questions. By examining rocks and the chemical signatures entombed within them they are helping biologists and chemist find clues to how life evolved. If I ever go for my PhD, I think this is where I'd focus.

The book begins by exploring a few of the many ways that life can be defined. From philosophical, religious, and scientific views come all kinds of answers. But the one that was used as a “working definition” by the author came from Dr. Gerald Joyce a member of a NASA exobiology panel. He said; “Life is a self-sustained chemical system capable of undergoing Darwinian evolution”.  And that works for me. It’s not very romantic sounding, but it gets the job done.

The book also recounts the history of some of the earliest origin-of-life experiments, back in the 1950’s. Among them the most famous Urey-Miller experiments where an early Earth atmosphere was simulated using ammonia, methane and hydrogen. When they sparked the mixture (as a proxy for lightning strikes) they were able to produce many amino acids, which are the building blocks of life! Those experiments, while inaccurate (the composition of the early atmosphere has been refined in recent years) created a lot of interest and basically began modern hunt for the origin of life.

The book also discusses the possibility of life elsewhere in the universe, spending a lot of time to examine the evidences for and against life on Mars through the inspection of the famous Allen Hill’s meteorite, or ALH84001.

The book discusses the methods of teasing out information from rocks millions of years old, and explains in pretty extensive detail the current experiments that are being conducted and what they hope to tell us about the origin of organic life.

There were really interesting chapters on chemosynthetic life (i.e. life that gets its energy from chemical reactions rather than the sun) and discusses microbes living miles beneath the Earth’s crust in in tiny pockets of otherwise dense rock.

There was a chapter about the possible mechanisms that evolved RNA (the precursor to DNA) that led to more complex life.

There was a discussion about how clay particles might have been the template for DNA, and how minerals could have substituted for membranes before primitive cells knew how to make their own!

There was so much unique information that I feel bad not covering it all in this review, but to go into any more depth would require a lot more explaining on my part, and I think in that case you’d probably be best off just reading the book yourself.

Anyway, in closing, I give this book four out of 5 stars. It was well written, easy to read (for the most part), extremely interesting, and I think it covered the subject thoroughly and in depth enough to be educational without being too technical. It also provided a history of how we got to where we are now, and a window into the future research on this mind boggling subject.

ATTENTION: If you are super lazy or don't like reading, but want to learn more about this I found a talk on the book given by the author on YouTube! You can check it out HERE.