Truncation selection is when a breeder selects for animals that exhibit a value for a trait that is above a certain threshold. What is it called when nature selects for a value of a trait that is above a certain threshold? I want to say natural truncation selection, but I don't see any mention of that. To clarify, what I mean is, what is it called when, as a result of natural selection, all perish but those with a value for a particular trait that exceeds a particular threshold.
The term truncation selection has been used a lot in theory papers because it is a simple model and because it is of interest to breeders. Truncation selection is most likely more common in a breeding setting than in nature and from wikipedia, truncation selection is defined as specific to breeding
In animal and plant breeding, truncation selection is a standard method in selective breeding in selecting animals to be bred for the next generation
However, as much as the definition fail to repeat
animal or plant instead of just
animal, IMO it fails to recognize that such notion could as well exist in nature. I would personally not be shock to read a paper talking about truncation selection in wild populations.
If you really want to avoid talking about truncation selection, then you can eventually picture the phenotypic trait as a liability factor (as it is done in sex determination literature, see Perrin and Beukeboom's book) and selection acting as a threshold on this factor. Note that the concept of threshold and threshold model is very common and everyone will understand what you mean.