Male Lactation - Evolution and Biology

Evolution and Biology

Many male mammals have been observed to lactate under unusual or pathogenic conditions such as extreme stress, feeding castrated animals with phytoestrogens or animals with pituitary tumors. Hence it was hypothesized that while most mammals could easily develop the ability to lactate this does not provide the males, or the species with any evolutionary advantage. While the males could in theory improve the chance to pass on their genes by improving the feeding their offspring by male lactation, most of them have developed other strategies such as mating with additional partners. Presently only very few species are known where male lactation occurs and it is not well understood what evolutionary factors control the development of this trait.