Found surviving in a garden by two little girls in Ontario, Canada, this one-of-a-kind toad was likely affected by a genetic phenomenon that biologists call a macromutation.
A macromutation is a mutation that has made a significant impact on an organism, caused by a change in a regulatory gene that’s responsible for the expression of an array of structural genes. While the process of adaptation is widely regarded to be driven by an accumulation of tiny genetic changes, biologists have suggested that macromutations
could be the cause of certain adaptations.
User Pipistrellus posted on Reddit an impressive photo of a frog with eyes in its mouth as a result of macro mutation. Macromutation is a mutation that has a significant effect on the body and causes major changes in it, for example, a mutation in a regulatory gene that controls the expression of an array of structural genes. There is speculation that the eyes in the frog’s mouth were the result of parasitic infestation with the trematode Ribeiroia ondatrae , a class of flatworms that are classified as digenetic flukes.
Trematode infections are usually associated with an increase in the number of limb mutations in amphibians, for example, the appearance of additional hind legs or, conversely, their lack or underdevelopment. In most cases, mutations induced by trematodes are harmful to the body, but sometimes it happens that parasites push their hosts towards physical development, sometimes unwittingly causing the process of new speciation, as often happens in insects.
A research report program has been conducted in this regard :
Natural historian David Attenborough also showcased this phenomenon in his “Fabulous Frogs” documentary for the BBC: