Native life Edit
Sex didn't appear on Arcandoil. To maintain a high genetic diversity, complex lifeforms rely on "genetic parasitoidism": cells of a genetically close organism are destroyed so that an egg can absorb and incorporate into its own the freed genetic information. Unlike sex, this mechanism is asymmetric: the aggressor transmits to the resulting child more of its genome than the victim. This has resulted in heavy intraspecific competition: almost any organism on Arcandoil is both a hunter of its own kind and ready to defend itself, and presents both offensive and defensive adaptations. For example, the Arcandoilan equivalent of the first tetrapods was a trilobite-lookalike with eyes all around its body to avoid or hunt its own peers.
Multicellular life on Arcandoil is primitively parasitoid: the host is killed and consumed for nutrients and for genetic variations.
Some species survive being impregnated, by having specialised galls feeding the voracious embryo until it leaves their body. This is the case of many social animals, and the dominant clade of flora, the Cecidiophora (which use a symbiotic flying "bug", whose larva grows in the gall alongside the plants, as carrier for their parasitic seeds). Other social animals manage to dodge the issue by laying eggs into freshly dead members, which they bury to protect from other scavengers.
Asexual species appeared frequently through the ages, as they can quickly colonize new environments and don't predate on themselves; they usually ends up disappearing during ecological crisis as genetic parasitoids do adapt faster to new conditions, but the strategy is temporarily efficient enough that it regularly redevelops.
The majority of parasitoid lifeforms tends toward r-strategy, as their self-predation comes with heavy losses. They are subject to contradictory selection pressures: the quicker they adapt, the sharper the edge they have over their fellows, but diverging too much from the rest of the species means having difficulty exploiting their genes. Groups toward the "slow-moving" end of the spectrum evolve slowly, and have complex genetic mechanism to make better use of exotic sets of genes: they are reproductive generalists, able to successfully parasite significantly varied hosts. Fast-evolving critters (among which the Charlaks themselves) outcompete those by virtue of adapting faster, but can have difficulty finding partners, bringing down their overall fitness to the level of their slower cousins.