Genesis Alpha One

This achievement is far easier than the description suggests.

Instead of infesting your ship with 20 hazardous aliens or eggs, rather look for the benign and beneficial lichen called Leven.

Leven is Life, literally. Leven looks like the disease Zot, initially at least, but it heals you and your clones rather than cause sickness.

Leven is green and bumpy and has a pale green sphere at its centre, similar to a melon. By far its most distinguishing feature is a collection of green fireflies buzzing above it.

Leven can get onboard like all other spore clouds, through the Tractor Beam and Hangar. It also resides in resource boxes so it can appear in/near deposits, refineries and potentially even Greenhouses.

I suggest using the Alien Location - Leven artefact, if you have it, to locate a low danger planet and repeatedly send your clones on an expedition. You will find that Leven spore clouds come back often and spread quickly throughout your hangar and nearby modules. Repeat the process until you have at least 20 tiles covered by Leven. Leven can grow on floors and in service tunnels so check both when counting.

It is wise to farm more than 20 because aliens will attack and destroy Leven to make room for their eggs.

Once you have 20 or more Leven on board, initiate a genesis to unlock the achievement.

This achievement might work with the other two lichens, Guston and Protare. I cannot confirm if that is true because I unlocked it using Leven. Guston is red with red fireflies and Protare is grey with blue fireflies.