Is Evolutionary Tunneling a Recognized Concept in Evolutionary Biology?

[Loren Booda]

Evolutionary "tunneling"

Consider a specific organism. It initially undergoes a genetic change which is nonbeneficial - even detrimental - to several generations. That intermediary state, however, eventually leads (synergistically with a secondary mutation) to an overall positive adaptation. Without the once defective genes, the progenitor organism in this case would not have achieved the eventual fitter progeny.

Is such "tunneling" considered in evolutionary biology?

 

[Moonbear]

Why do you call it "tunneling?"

Of course such a thing can happen, and is even postulated to be part of the process whereby proteins and their receptors have become functional. In other words, a receptor may exist without a ligand, and has no particular function in the unbound state...until a mutation occurs in some other protein that permits it to bind to the receptor, and a ligand-receptor complex can form. It is not expected that both simultaneously appear in an organism/species.

However, if the change is detrimental, HOW detrimental will factor into it. If it prevents the organisms from surviving, then it is unlikely to be retained long enough for the second mutation to ever happen or have an effect.