I question why doesn't some amoeba just maximize its fitness and so turn into effectively a bioweapon that eats all the mammals on the planet? It has some sort of intelligence that restrains it from wiping out its food source? I do wish for Genetic Science and all relevant fields to take that mystery very seriously and solve it securely before its confident to mass replicate novel species in the huge system. Species which have evolved somehow over ages to not be routinely in massive flux between champion species. The microbial world could liquidate swathes of the phylogenetic tree repeatedly, if all it needs is a chance mutation to create a new alpha species. What stops an experimental GMO containing such an over-competitive mutation, or a precursor to such?

There is so much yet not known or controllable in microbiology, it does worry me that the prevailing attitude is so confident with the little that is known and doable. Its alarmist and uncertain, but so is the foresight that significantly increasing ghgs through the whole atmosphere is too dangerous, or filling the sea with more plastic waste than there are fish left in it is not worth the price and risks. Hopefuly culture is on the verge of accepting these concerns have had rational basis. It needn't result in the end of modernity, but in the appreciation and protection of some older things.

> Why doesn't some amoeba just maximize its fitness and so turn into effectively a bioweapon that eats all the mammals on the planet?

Evolution takes a long time. It's not totally unfair to describe humans as that amoeba, now approaching the nightmare scenario of consuming almost everything on earth.

Part of the answer is that mammals are three to seven orders of magnitude larger than amoeba. That comes with some advantages! Immune systems are super complicated, and can leverage the resources of a vast cooperating superorganism of cells.

That sort of thing has happened before though. Oxygen was originally a pollutant that caused the extinction of most species on the planet. This is sometimes called the Oxygen Holocaust (more commonly, the Great Oxidation Event https://en.wikipedia.org/wiki/Great_Oxidation_Event).

Its not a great answer because despite superior size and having immune systems, microbial life is still routinely deadly, just not too often so deadly to cause extinctions. I have read microbiologists puzzles over for example, what mechanisms 'evolves' strains of flu viruses between periods of relative dormancy and deadly flare up.

That oxidation event represents one major collapse on an ancient scale, but did not owe to a species over-predating others, which Im considering here as a more pervasive risk for species 'dynamics' than pollution/poisoning.

I find no firm answer to these concerns. We dont know that species genetic information has not evolved to avoid over-competitiveness, configurations that could be broken by non-evolved modifications, mass reproductions and releases into the system. Its not a matter which can be settled by current insights, so its somewhat plausibly disguarded as fear and uncertainty. But it might even be the case that what genetics may naturally evolve are naturally confined to modest competitiveness by a property of the yet mysterious steps which enable life to evolve - because we don't even know in what circumstance life evolves. Plenty of theories but no one has ever observed life assembling and evolving from lifelessness, or even modelled a viable sequence illustrating it, and not from lacking of trying for the great achievement and accolades that would bring. Its such an amazing scientific subject, the developed science is amazing too but not nearly so much as its subject matter - biological complexity and remaining mysteries. Its worth treating with special care and humility of some kind.

The fact that we can’t explain the exact steps from stones to microorganisms is no reason to start showing “humility” to intelligent design - agnostic respect to that idea on an equal footing to all others is more than sufficient.

The prospect of intelligent creators is irrelevant here as if they are present they are unseen. What can be partially made out is the broad path of evolution which has actually somehow arrived by its own properties on intelligence in animals - and also appearances of intelligent/cooperative etc. relationships between species. Many different kinds of relationships over kinds of chemistry and activity are present, which themselves may evolve and may have evolved over and throughout species.

The presumptive outlook is that all of the simple and complex evolutionary processes are in sum and product - assuredly mundane, stochastic, resilient to any accidental discord which could be caused by humans bodging their evolved configurations and then non-competitively reproducing trillions of carriers and spreading and maintaining them across the globe with no means to ever recall the version. That's GM agriculture described 'on an equal footing' with the products of natural history.

One aspect is the speed of evolution - as one species evolves, its competitors evolve just as much, making it difficult to dominate too much. This is a limitation that GM does not share - it can make genetic leaps in a few years that would be vanishingly unlikely to occur naturally, or would take millions of years. Other species could not keep up.

To illustrate with the previous example, insects evolve resistance to the chemical countermeasures that plants evolve. But give those countermeasures a GM kick, and insects won't be able to keep up. I'm sure eventually they would evolve something, but there could still be a huge crash in their population before that happens.