Heterochiral biosphere: a two-handed world

Original post:

Imagine a world in which both left- and right-handed chirality appeared and evolved into a variety of complex organisms comparable to post-Cambrian Explosion Earth (both plant and animals).

As on Earth, chirality would apply to amino acids, sugars, enzymes, and potentially other essential biochemicals. A biochemical with the correct chirality will taste or smell a particular way to an organism with matching chirality, and be digestible/usable by their body, while a biochemical with opposite chirality will lack flavour or smell differently, and their body may be unable to digest it.

Is it plausible for both forms of chirality to not only arise but thrive, without one driving the other to extinction very early on?

For clarification:

As stated in the comments below, assume the following:

• In primordial conditions the likelihood of a given biochemical molecule developing left- or right-handedness is 50/50.

• The conditions that give rise to such a molecule are, at least in the immediate area at the time of its formation, stable and/or repeatable enough that opposite-handed molecules will also form.

• If nearly identical conditions can be found elsewhere, the same processes there may give rise to opposite-handed molecules as well.

So in reading the question above, emphasis should be placed on the second half:

Is it plausible for both forms of chirality to not only arise but thrive, without one driving the other to extinction very early on?

"Early on" should be understood as any point prior to the emergence of multicellular life.

posted about 8 years ago

rek‭

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