It’s too easy to assume that life is inevitable, given a watery planet and a friendly warm sun. It took a while—millions of years (not billions apparently) for life to happen on Earth. Recently, we’ve learned that it happened only once here, producing simple (!?) archaea and bacteria. Then two critters got together (Energy-producing mitochondria took up
residence in a welcoming bacteria), and the stage was set for the ongoing development of us complex critters. Of course, that took only a few billion years, and is still going on—like it or not.
But wait! Back up and consider how fancy life’s roadmap is. DNA—the stuff that builds, designs and runs us living beings—“is capable of complex behavior.” So says David Soloveichik at the University of Texas in Austin. (See Science December 2017) He and colleagues at CIT built a DNA compiler that takes molecule-building instructions and writes them into DNA sequences that craft circuits and machines “…to rival those found in nature.” They have made a molecular clock solely of DNA.
As if molecular DNA isn’t complex by itself, now we are confronted by the discovery of giant viruses that have such massive genomes they seem to “…blur the Definition of Life.” (Quanta Magazine.org 20180315 by Johane Capelaverez). Other “klosneuviruses” have more than 1000, some 2500, genes capable of synthesizing proteins. Debate centers on how such
huge viruses evolved . Thirty percent or more of those genes are unique, but some are “related” to genes found in all other life forms: archaea, bacteria and eukaryotes. Did they grow large from early viruses or start large and shrink to produce the common virus? Little is known about viral evolution.
Which brings us to how fast life took off in the Cambrian, after nucleated cells appeared, powered by their symbiotic partner the mitochondria. When one considers how complex DNA itself is, its no wonder that life took so long to get started on Earth. Once energized,
however, life was able to use atmospheric oxygen and explore designing critters with every imaginable design during the Cambrian.
Hammerlund and Pahlman of Lund University Sweden point out in Quanta Magazine 3/9/18 that cellular energy produced by cells increased “nearly twentyfold.” Life-forms quickly learned to take advantage of this sudden source of oxygen, along with DNA’s remarkable talents and “ecological interactions,” like the invention of the talented stem cell and hypoxia-inducible factor proteins (HIFs) that could use the oxygen creatively.
Life is amazing. We need to appreciate who we are. We’re very lucky to be around at all. Most likely, we’re not alone, but we’re probably quite rare.
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. Released Nov.21, 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.com search:Who’s Out There