MadSci Network: General Biology

Re: What elements would comprise a metallic (living) p

Date: Thu Nov 1 14:49:18 2001
Posted By: Aydin Orstan, Staff, Office of Food Additive Safety, Food and Drug Administration
Area of science: General Biology
ID: 1003787739.Gb

Dear Christopher,
I am guessing that you mean an organism constructed entirely or mostly out 
of the familiar malleable metals, such iron, aluminum, copper. I don't 
think such a creature could originate and evolve on its own. Earth-based 
organisms heavily rely on polymers (long-chain molecules). For example, 
DNA and proteins (including enzymes, our skins, muscles, the collagen in 
our bones, etc.) are all polymers. One reason why metals don't appear to 
be suitable as the main building blocks of life is that they don't readily 
form polymers. Universal abundance may also be a problem. Hydrogen, 
oxygen, nitrogen, carbon and sulfur are five of the 10 most abundant 
elements in the universe. It may not be a coincidence that they are also 
among the 10 most abundant elements that make up the organisms. In 
contrast, there is only one malleable metal, iron, in the list of 10 most 
abundant elements in the universe. Probably one can come up with other 
reasons as to why an entirely metallic organism is not feasible. 

However, it may be possible for a carbon-based organism (similar to those 
on earth) to evolve a metallic outer layer as a protective shield. This 
could happen if the organism lived in an environment where a suitable 
metal was abundant and if such a shield would increase the chances of 
survival of the organism. If the organism already used that metal in some 
of its metabolic reactions, from those metabolic reactions additional 
steps could theoretically evolve to deposit the metal in the form of a 
shell. The overall process would be similar to the way snails build their 
shells from calcium carbonate. 

Was this an idea for a Halloween costume?

Current Queue | Current Queue for General Biology | General Biology archives

Try the links in the MadSci Library for more information on General Biology.

MadSci Home | Information | Search | Random Knowledge Generator | MadSci Archives | Mad Library | MAD Labs | MAD FAQs | Ask a ? | Join Us! | Help Support MadSci

MadSci Network,
© 1995-2001. All rights reserved.