Zerg Genetics

[Visions of Khas]

So the Larvae are purported to contain the genetic information for all other Zerg breeds and sub-species within their extensive genome. However, we have seen evidence suggesting this is not the case, or at least not the entire story. Case in point, several templates were "lost" during the internecine that followed Kerrigan's de-infestation. The most notable was the Corruptor's utter dissolution, but also included Lurkers, Brood Lords, even Hydralisks. How can this be?

One theory I have is that Talen Ayers was not far off the mark when he spoke of "singing organelles" when conducting research at Blackstone. It's clear that at least some genetic information can be relayed by means of the Zerg Hivemind. With the fracturing of the Swarm came dissonance in that communications network, and possibly corruption or cessation of genetic information transfer as Queens went rogue and isolated themselves and their broods.

Any other ideas?

[Gradius]

I'll chalk it up to a cerebrate benefit. When the swarm stopped using cerebrates, the larvae themselves had to be streamlined, and code had to be transferred through the hive mind instead of being carried in individual larvae. Perhaps even to prevent any one queen from becoming too powerful.

[Nissa]

It's entirely possible that the swarm simply decided not to use older strains any longer, and that they weren't so much lost as abandoned.

Unless there was a dialgue bit somewhere that specifically says they were lost, and I don't remember it.

[Visions of Khas]

Perhaps even to prevent any one queen from becoming too powerful.

It does seem as though Broodmothers' broods each carry only a fraction of the overall genetic knowledge available to the Swarm: Zagara and Naktul had only the most basic breeds available to her; Nafash had specialized strains; and Khaleesi lorded over a fleet of Leviathens. However, this doesn't seem to have any bearing on the "strength" of an individual Broodmother, since Zagara seemed able to hold Char by herself, and Naktul represented the remainder of the renegade Broodmothers towards the end of the campaign.

I suppose this works to encourage Broodmothers to either vie for domination, or cooperate, in order to wield the full might of the Swarm. But apparently this strategy backfired where the Corruptor is concerned. Well, at least until LotV.

[Turalyon]

I assume "lost" as meaning that they "lost access" to it. I know gameplay is not meant to be a valid answer but I guess it's the same reason why the Zerg have to grow certain structures/mutate their Hive in order to "access" the genetic code of other strains even though the larvae ostensibly contains them already from the get-go. The Overmind or the cerebrates were probably prerequisites for (easier) access to these strains and since they're gone, well...

[The_Blade]

My theory:

Zerg breeding is just like chemistry. Particular patterns of resources/hormones show the needed traits/appearance after passing through a Larva. Neither Cerebrates nor Queens know about these recipes as they are first created/born. They are then tutored into blending the necessary resources and hormones to breed each of the particular known strains. Buildings help create easier recipes by launching a single package with all the juicy cocktail into Larvae through creep. However, a being with enough skill may choose to insert new packages. Gameplay might be blamed for most of this progression mechanics on campaigns; but I believe there should be more to it. In particular, the Hivemind protects itself from repetition/weakness and finds new ways to be efficient.

(disclaimer: the following information might be biased by someone else's opinion)
The Overmind created Cerebrates as a division of it's consciousness to learn again about the universe. Without them, It might fall into repetition and develop weaknesses through prejudice, arrogance or laziness. Unlike Humans, the Overmind can tap into its subconscious mind; but it also exists as a conscious being. Cerebrates, on the other hand, are more similar to humans and can't tap back into their subconscious mind (which is the Overmind's). Therefore, the Overmind's hivemind might not be a democracy, but every Cerebrate contributed with its own opinion. Daggoth's Hunter Killers are still my favorite Zerg strain after the Torrasque.

Advantage: Cerebrates could restore the backup database of the Zerg strains and evolution history of both the Overmind and other Cerebrates if any perished.
Disadvantage: Overmind dependency.
(end of disclaimer)

Now, The Queen of Blades's hivemind works without the central hub. Each Brood Mother is able to do as it pleases, under a hierarchy of fear/power as limitation.

Advantage: Hostilities within the Swarm create a dynamic collective. Faster adaptations and mutations.
Disadvantage: All knowledge is lost upon brain death scenario. Kerrigan may regrow a new body, but there's nothing that suggests all Brood Mothers can.

The Abathur dilemma:

We really don't know the source of Abathur. For all we know he serves the Swarm, but Kerrigan is a brainless fool. I would not be surprised if he works for Amon.

So far, he is the best Zerg weaver, at the time. The Primal Zerg Swarm is still being molded by his architecture. There's evidence Kerrigan can wield a decent Zerg strain, but falls short from Abathur. Abathur is then outranked by the first Overmind, IMO.

Old and lost strains:

I'd say most lost strains and lost elite groups could be linked to the death of the first Overmind. Let's call this event the "First Zerg Extinction". Kerrigan would not be able to hold a Defiler from eating her face even if she wanted.

The "Second Zerg Extinction" happened after Kerrigan was deinfested. At this time either Abathur poped into the timeline or withdrew into the heart of the strongest Leviathan. The remaining Brood Mothers slaughtered each other (the knowledge!) and created resistance groups against Terrans, Protoss and even Zerg. Corruptors and Nydus Worms might have been lost, but we are still not sure.

[Visions of Khas]

I'd say most lost strains and lost elite groups could be linked to the death of the first Overmind. Let's call this event the "First Zerg Extinction". Kerrigan would not be able to hold a Defiler from eating her face even if she wanted.

Well it seems the Defiler strain was finally "tamed" by introducing Primal DNA into the Viper, and realized its full potential by the time of LotV. I kind of like the thought that only the Overmind could properly leash and harness the Defilers.

But essentially the consensus so far is that Larvae do NOT store all strains within their DNA?

[Nissa]

But essentially the consensus so far is that Larvae do NOT store all strains within their DNA?

Guess so. Or it may be that the larvae only store the beginnings of certain strains, like the current set of most used Zerg types by a given cerebrate.

Where did the larvae thing come from, by the way?

[Visions of Khas]

Where did the larvae thing come from, by the way?

Which part? Where they store all Zerg DNA? Or what inspired my question? Or where did Zerg Larvae come from?

[Nissa]

Which part? Where they store all Zerg DNA? Or what inspired my question? Or where did Zerg Larvae come from?

Where they store all DNA, of course.