Rare Earth: How Vital Minerals “Evolve”
David Coppedge
Something else that is special about planet Earth has been noted: its mineral content, compared to other planets. Robert Hazen, an origin-of-life researcher at the Carnegie Institute, states in an article posted by NASA’s Astrobiology Magazine that Earth’s mineral abundances may be unique in the cosmos. There were only a dozen or so minerals present at the birth of our solar system, he argues, but there are about 5,000 types today. Most of these, he says, can be “linked directly or indirectly to biological activity.”
That much Hazen and his team already knew. Now, they have taken the concept of “mineral evolution” further, determining the probability of mineral distributions:
they discovered that the probability that a mineral “species” (defined by its unique combination of chemical composition and crystal structure) exists at only one locality is about 22 percent, whereas the probability that it is found at 10 or fewer locations is about 65 percent. most mineral species are quite rare, in fact, found in 5 or fewer localities.
“minerals follow the same kind of frequency of distribution as words in a book,” hazen explained. “for example, the most-used words in a book are extremely common such as ‘and,’ ‘the,’ and ‘a.’ rare words define the diversity of a book’s vocabulary. the same is true for minerals on earth. rare minerals define our planet’s mineralogical diversity.” [emphasis added. )
Unique in the Cosmos.
This is why Hazen believes Earth’s mineral signature is “unique in the cosmos.” His idea resembles Stephen Jay Gould’s notion that re-playing the tape of life would produce a very different menagerie of creatures.
What must strike any astrobiologist with amazement, though, is how many elements and minerals vital to life exist near the surface of the earth. The abundant elements — carbon, hydrogen, nitrogen, oxygen — are not that surprising. But life as we know it requires other elements that are less common: potassium, phosphorus, magnesium, calcium, selenium, sulfur, and even chlorine. That’s why the typical astrobiological speculations about life on other planets, such as this evidence-free press release from Washington State University, are misleading. WSU planetary scientist Dirk Schulze-Makuch speculates about “what life could be like elsewhere in the universe” with thoughts about what might exist on Mars or Titan. Has he performed an elemental analysis of the minerals available on those worlds?
The unique availability of so many elements and minerals at the surface of the Earth could merit a design inference, when considered in addition to all the other factors that make it habitable, as discussed in The Privileged Planet. Astrobiology, despite its confidence in Darwinism, ends up making a pretty good case for intelligent design.
