Are we too easily fooled by our ability to write huge numbers? Numbers that represent how far light travels in a year (light years) trick us into assuming we can take command of whatever those numbers represent. As a result, we assume we can travel to other stars or “colonize the galaxy.” We worry about attracting alien invaders, or we feel unique because life has not been found anywhere else. Seems to me we are not embracing, with our imagination or with our intellect, how huge “everywhere else” is.
The September 2016 issue of Scientific American ran an article by Paul Davies, director of BEYOND at Arizona State University and author of the book “The Erie Silence: Renewing Our Search for Alien Intelligence.” Davies reminds us that our early assumptions were that Earth’s complex life was unique in the universe. Now it seems more important for us to know that we are not unique—just a natural and beautifully gifted example of precious life throughout the universe.
At least, now we know that Earth is not unique—just one of many planets orbiting tolerable suns in the “Goldilocks” (liquid water) zone. However, many details of planetary existence had to be just right (or the planet had to be very lucky) for Earth to host life of any sort. Even more unlikely is the evolution of very complex life, like us. The process requires a lot of time with good luck. Ward and Brownlee’s book Rare Earth: Why Complex Life is Uncommon in the Universe is a good read on that topic.
True—as Davies says in his SA article—we “…do not know the process that transformed a mishmash of chemicals into a living cell…”. But we are coming close. Davies doesn’t mention the work of Nick Lane and others who are analyzing the energy potential of alkaline hydrothermal vents, the most likely candidates for the location of life’s origin on Earth. I have been discussing the details of their hypothesis in the last few blogs here. As we watch for further developments, an overview of Lane’s work gives me hope that he is on the right track.
“Energy flux promotes self-organization of matter,” says Lane in his book The Vital Question, “…sustained and predictable physical structure can be produced by energy flux.” This flux, he suggests, is what the alkaline hydrothermal vents provided in order to put together a living cell capable of evolving into complex beings. By “complex beings” he means beings put together with a large and talented variety of eukaryotic cells—cells with a nucleus and an energy engine called a mitochondria.
Other ingredients for creating life provided by the undersea alkaline vents are a “…continuous supply of reactive carbon….”, catalysts, and excretion of wastes. A protective compartment and hereditary material, the last two requirements to “make a cell,” were provided by the “endosymbiosis of two prokaryotes.” A simple organism like a bacterium and an independent mitochondria-like form of simple life got together in symbiosis to form our eukaryotes (our cells with a nucleus). Those complex cells proceeded to bond, specialize, and take off to conquer Earth’s biosphere.
Lane makes a credible case for the alkaline vents as the source of Earth’s life by describing the vents’ gentle porous environments and their chemical potential. They nurtured the symbiotic partnership that also included the sharing of many genes. As a result, energy was harnessed to make the molecule ATP. Adenosine triphosphate was the key needed to power more complex options–larger biological structures that could invent new types of cells and evolve into more and more complex critters.
True, Lane admits, “..the origin of the eukaryotic cell was a singular event on Earth. One type of cell may be all that survives on any one planet, simply because it works so well. Nothing else can out-compete it–but ATP-powered cells could have evolved elsewhere, given a bit of luck.
Thanks to energy gurus like Mike Lane, we now know that what we enjoy as life is most likely not unique, but devising its complexity took some doing. Because this is a very big universe, life of any kind could be very far away and/or difficult for us to find anywhere else. We may never find anything but its simplest forms similar to our bacteria or archaea. Meanwhile, we need to respect and do better at nurturing our complex life here as the wonder it is.
Author of The Archives of Varok
The View Beyond Earth (Book 1.)
The Webs of Varok (Book 2.)
Nautilus Silver Award 2013 YA
ForeWord IBPA finalist 2012 adult SF
The Alien Effect (Book 3.)
An Alien’s Quest (Book 4. coming in 2016)
Excerpts, Synopses, Reviews, On Writing, Characters and More-
Reviews of significant books- www.goodreads.com/Cary_Neeper
How the Hen House Turns- www.ladailypost.com
Complexity, Bio, Bibliography and Links- caryneeper.com
Astrobiology- astronaut.wpengine.com search:Who’s Out There