Here's a breakdown of the evolutionary reasons:
* Survival of the fittest: More nipples means more piglets can be fed at once, increasing their chances of survival.
* Efficient milk production: The large number of mammary glands allows for a higher volume of milk production, ensuring that all piglets have adequate nourishment.
* Reproductive success: Pigs that can successfully raise larger litters are more likely to pass on their genes, leading to the evolution of more nipples.
It's important to remember that the number of nipples varies between breeds, with some having more than others. However, the general principle remains the same: more nipples equal a greater ability to care for a large litter.