Answer 1:
Good question!
One hypothesis for the
origin of life was that life began as a
self-replicating form of zeolite clay. I don't
think this is the favored hypothesis, but I don't
think anybody has disapproved it. As for
what minerals life likes, life on Earth uses
carbon as its main structural element and water as
its solvent. There is no other element with
bonding properties like carbon, so life as we
imagine it could not exist without carbon. There
are some carbon minerals, but not that many -
carbon generally likes to form light, volatile
chemicals like hydrocarbons than solid crystals.
Because water is life's solvent, it is also
difficult to imagine life as we understand it with
conditions favorable to water being in a mineral
form - it has to be liquid. Aside from that,
life generally uses what elements are available.
This means the common stuff - nitrogen, oxygen,
phosphorous, sulfur. I notice a preference for
nonmetals, although life does use metals too in
smaller amounts, particularly calcium (another
very common element). Heavy, rare elements,
particularly those that act chemically similar to
more common elements (lead, arsenic) tend to be
poisonous - they interact with life's chemistry
but not quite like the elements they are supposed
to (in this case carbon and nitrogen). I have no
doubt that if you made a planet composed of lead
and arsenic containing minerals but otherwise
suitable for life, any life that evolved on that
planet would find a use for these poisons and
would come to be unable to live without them. A
good example of this in Earth's history is oxygen:
oxygen is a deadly poison, until it became common
enough in its elemental form to be used, and now
most living things on Earth cannot live without
it. |
Answer 3:
I'm not sure about the role of minerals in
creating or evolving life,since early life seems
to be water-borne rather than occur in
solids.(It's hard for even one-celled organisms to
spread through a solid!)But some organisms are
amazing creators of minerals. For example,calcium
carbonate is chalk: a very weak, brittle material.
But abalone sea shells are 98% calcium carbonate,
and yet they're extremely hard. What's the other
2%? Somehow the abalone is able to make a mineral
which is much harder than its building blocks, and
it uses that mineral for its own protection in a
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