Who’s Out There?— Earth’s Long Experiment–a book review
Complexity: The Evolution of Earth’s Biodiversity and the Future of Humanity by William C. Burger, New York, Prometheus books, 2016.
This blog is more than a book review. The author speaks directly to those of us who are interested in exobiology and the origins of life on Earth. On page 225 he gives us a well-supported argument that there is a ”…serious flaw in discussions regarding the possibilities of life elsewhere in our solar system.”
He reminds us that it took billions of years of competition and revision for Earth’s simplest life forms to learn how to exist in extreme environments–like those on Enceladus, Europa or Titan. But first he guides us through a briefing on the complexity inherent in the existence of beetles, bacteria, cells, sex, new species, Earth’s geography and its biodiversity.
Burger reminds us that the origins of simple life on Earth have apparently left no trace. Such origins were probably gobbled up by their more creative offspring capable of “…Protein synthesis within a protective vesicle” or by other early life forms using RNA. Perhaps there were “…instructions within the cell, while DNA…carried information across generations.”
The most ubiquitous and successful, but perhaps not the earliest species here on Earth, are the bacteria. The earliest life forms could have been simpler “quasi-cellular”– entities that exchanged genes, perhaps with the aide of viruses, then evolved protected by the deep sea alkaline vents. Organic chemistry, it is now thought, “…can exhibit inherent
self-organizing properties.” Proteins spontaneously fold into complex shapes. Cooperation between organic molecules is known to occur–given various energy sources in a stable environment and “…millions of years for trial and error.”
Bacteria now build DNA one way, and Archaea and us Eukaryotes build it in a different way, while “…having Bacteria-like operational genes and Archaea-like informational genes…” Life doesn’t reinvent itself now on Earth. Everything about us humans develops from a single egg cell, triggered by our Dad’s sperm.
Another fun part of this wonderful book Complexity is the author’s collection of tales that paint a clear picture of how evolution probably worked on Earth. Preparations for all of our features had to be made, one experiment at a time over millions of years, while various genetic experiments sorted themselves out, until something worked, was
preserved, then built on to another clever device.
On page 192 we learn that some of our ancestors were probably fish living in small streams with annoying fallen logs and aquatic vegetation. Luckily they had fins with a “lobe-like base,” giving them freedom of motion. As genetic trial and error moved on through the millions of years, the lobes elongated to become arms, which articulated
to add elbows, then digits for traction. Lousy water favored those with rudimentary lungs to aide their gills. Then a rib cage supported “…a more dynamic life on land, as their hind-quarters developed a second air of legs. Things were good to eat out there, so four lateral fins eventually became land-going legs. Hence most land vertebrates are tetrapods.
Burger’s stories begin with a delightful reminder of how Earth lucked-out–first being “…whacked by the proto-Moon…” which gave us a 23 degree tilt and a wobble to spread rain and variable annual seasons so we could grow goodies to eat. He reminds us exobiologists that Earth’s size is just about right. Agility in animals would suffer in stronger gravity, and weaker gravity couldn’t hold a “sufficiently dense atmosphere.” Earth’s daily spins are also just right–to help keep temperatures mild both day and night without gale-force winds.
As we follow the new exoplanets discovered by TESS and learn about their relationship to their suns, we need to keep Earth’s good luck in mind. Perhaps we shouldn’t expect too much out there.
—
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-
http://ArchivesofVarok.com
Reviews of significant books- http://www.goodreads.com/Cary_Neeper
How the Hen House Turns- http://www.ladailypost.com
Complexity, Bio, Bibliography and Links- http://caryneeper.com
Astrobiology- https://astronaut.com search:Who’s Out There
