That would depend entirely on the situation and the organism in question but it would still be – and I repeat - without purpose or ultimate reason.
So you would be shocked(!!!) after years of participating on these threads, to hear that biologists do not posit any particular direction to evolution.
You would be shocked to hear that specified complexity makes no sense to a biologist because biologists do not theorise that specifications precede selection.
But you apparently think selection just eleminates individuals at random. (yes or no)
Have to go watch Pompeii get obliterated. Back later.