Are connections genes in a genome ever deleted or just disabled? When a new node is added, the previous connection is disabled and not removed.



Is there any situation in which a connection gene is removed? For example, in the above diagram connection gene with innovation number 2 is not present. It could be because some other genome used that innovation number for a different connection that isn't present in this genome. But are there cases where a connection gene has to be removed?
The original paper never goes further than disabling the link, but I have seen implementations on github that did have a probability of deleting the link.

python-neat is such an eaxample.