Looking for sources on the information argument

[Rumraket (Mikkel R.)]

@Giltil

There is no reason to think that there are functional gradients connecting different overall designs/solutions (in my illustration above, there is no reason to think there is a functional gradient connecting H or H’ with C).

I should add that I actually do agree that we don’t have reason to think ALL different adaptive solutions to any given challenge faced by an organism can be reached directly by natural selection, nor that any and all adaptations can be change gradually and adaptively into each other. And we even know of some such cases where distinct, unrelated, and non-optimal solutions to the exact same problem faced by different organisms have evolved.

I recall the example where bacteria and plants appear to have independently evolved entirely different enzymes that catalyze the exact same chemical reaction, and unsurprisingly the bacterial enzyme is catalytically superior to the plant enzyme(which makes sense given the vastly superior population sizes reachable by bacteria, and that bacteria have existed on earth for billions of years longer than plants):

Evolution of chalcone isomerase from a noncatalytic ancestor

Oh and another thing, apparently the function of this specific class of enzymes has evolved independently in bacteria in a completely different protein, which was already an enzyme. So apparently this function can be reached from wildly different positions in protein sequence space. From the OP paper: Discussion Our results indicate that CHI evolved from a catalytically inactive ancestor, thus demonstrating that emergence of catalysis and stereospecificity in noncatalytic scaffolds is a feasible evolutionary scenario. That said, a bacterial CHI29 has evolved independently in an enzymatic protein fold, exemplifying that plant CHI is an exception rather than the rule. The bacterial CHI referenced in 29 apparently evolved from a Ferredoxin-fold enzyme and stress-related protein. In that paper (29) we can read: 4. Conclusion The two-domain structure of the bacterial CHI is closely related to the ferredoxin-like fold of a chlorite dismutase and the stress-related protein SP1, despit…