[TML] Alien ecologies

[shadow at shadowgard.com]

On 20 Aug 2008 at 9:40, darby eckles wrote:

> So, what I am wondering is: is it possible to have purple
> photosynthetic plants?  Is it just a matter of the
> chlorophyl/whatever processing UV spectrum light or reflect purple
> based colors, or would it necessitate some completely different
> system of light usage?  

Chlorophyll is green because it most strongly reflects in that part 
of the spectrum (it actually *uses* mostly red light)

There are some purple "plants". Mostly algae.

And there are plants using chlorophyll that are purple (as long as 
the don't reflect the fairly narrow band of "red" light that 
chlorophyll uses, they can reflect the rrest.

If the local evolution came up with an "efficient enough"  
photosynthetoic pigment, and that reflected purple (a mix of red and 
blue wavelngths) then most plants there would be purple.

How likely that is is anybody's guess.

> Also, what minierals have a purple hue?  Amethyst?  Can that be broken down and used by living creatures?

There are probably others. But that's irrelevant. Using some purple 
mineral won't make animals or plants purple. 

For example, amethyst is purple because it contains a certain metal I 
forget which) in a certain chemical state. A state that ain't likely 
in living critters.

There are lots of ways of getting colors in orgamic compounds. And 
they are generally not related to the way you get similar colors in 
inorganic materials.
--
Leonard Erickson (aka shadow)
shadow at shadowgard dot com