>>19862604through gene mutation a green caterpillar is born to a brown caterpillar breed, bird sees its brown peers better, many of them get eaten, green one survives out of sheer coincidence, gets to procreate, brings forth even more green caterpillars. one day a caterpillar is born with a yellow line on the back because of gene mutation, gets eaten by birds even less than its plain green brothers and sisters, gets to procreate, even more green caterpillars with yellow lines are born, survive even better etc etc.
gene mutations in and of themselves are likely too a random occurence, those species with immutable genes were not able to adjust to changing environmental conditions. being too rigid gene wise is not selected for so it seems. disabilities are a unfortunate side effect of that dynamic.
