Continuing our narrative following anaerobic populations, we last left our friends at the following point:

• Vent 1 with anae1 (including anae1#101 genetic offspring) and anae 5 (anae1#564 but it has a mutation in a gene that determines the color of the outer membrane layer of the organism. It is now visible to small fish who like the taste of anae)
• Vent 2 with anae2 and anae6 (anae2#101 with a mutation in the other enzyme, similar to anae 3, but at a different point in the gene)
• Vent 3 with anae 3 and anae4 (anae3#101 engulfing another microorganism and using the energy it produces to reproduce more efficiently. Because of integration of the genomes, this characteristic is passed on).

This of course is simplified, as I explained earlier. 

Let's start with vent 1.

Simply put, anae5 and anae1 individuals replicate at the same rate, but anae5 is depleted at, let's say, twice the rate due to being visible to predators. So anae5 not only dies, but is eaten; but anae1 only dies. Any further mutatinos in anae5 offspring that increases the depletion rate of anae5 would lead to inevitable demise. But let's say that anae5#123 (random member, now anae7#1) has an altered amino acid in a membrane protein that allows it to attach to another anae with that protein. If it has the opportunity to replicate, it can attach to its offspring and its offspring's offspring. If it is eaten or lacks resources to replicate, it is but a fleeting mutation.

But let's take the best case scenario for diversity in our populations.

Anae7 are too large to be ingested by the same predators as anae5 and more likely to survive. Over several generations, further mutations in the amino acid sequences of membrane proteins may allow nutrient exchange between joined anae cells (anae8 population). Those with all anae8 will be better equipped to survive and anae7 may eventually disappear. (This also has implications with sharing genetic information, which I will address in a later post).

I'm completely ignoring time frame, and this could vary greatly depending on the local environment, stresses, and how often a new mutation doesn't get passed on due to a lack of replication (natural selection of alleles). 

We'll visit vent 2 next time.