… Wouter Bleeker, an Ottawa-based researcher with the Geological Survey of Canada, is one of eight members of an international team whose theory of “mineral evolution” – the idea that many of the Earth’s rocks are dynamic “species” which emerged and transformed over time, largely in concert with living things – is generating a major buzz in the global scientific community since its publication last week in a U.S. journal.
“The key message,” Bleeker told Canwest News Service, “is how closely intertwined the mineral world is with life and biology.” He said human teeth – with their key ingredient of apatite – are vivid reminders that the “seemingly static, inorganic” physical Earth should be viewed more like a “living organism” underpinning the biosphere.
Makes sense. As the world’s chemical components and physical processes (and biochemical reactions at the surface) change, so would the availability of minerals and subsequently the mineral composition of sediment and rocks. Earth scientists and laypeople usually think of geology and mineralogy influencing life on earth from the very beginning, but not of life guiding the generation of minerals and rocks. Even when I was out in the Nevadan desert a few weeks ago, I looked for plants that grow on soils generated by certain rocks to help me differentiate strata. Little did I think of those plants and that how they change affects a mineral’s composition. So, what stands out most is the following (emphasis mine):
… Among the best known examples of how living things transform the Earth’s rock layers is limestone, which is accumulated from the dissolved shells of tiny marine creatures. But the new study provides the first comprehensive analysis of the multitude of rock-life interactions and documents how mineral evolution unfolded rapidly as life took hold early in the planet’s history.
“Biochemical processes may thus be responsible, either directly or indirectly, for most of the Earth’s 4,300 known mineral species,” the study states.
… “For at least 2.5 billion years, and possibly since the emergence of life, Earth’s mineralogy has evolved in parallel with biology,” Hazen added. “One implication of this finding is that remote observations of the mineralogy of other moons and planets may provide crucial evidence for biological influences beyond Earth.”
This is so cool! The next time I’m out in the field, I will have to pay attention to the plants out there instead of accusing them of getting between me and the outcrop.