Canadian anomaly: frog with eyes in the mouth

Canadian anomaly: frog with eyes in the mouth
Canadian anomaly: frog with eyes in the mouth

This one-of-a-kind toad found alive in a garden by two little girls in Ontario, Canada According to scientists, it is most likely affected by a genetic phenomenon that biologists call macromutation.

Macromutation is a mutation that has a significant effect on the body, caused by a change in a regulatory gene that is responsible for the expression of a number of structural genes. While it is widely believed that the adaptation process is due to the accumulation of tiny genetic changes, biologists have suggested that macromutations may be responsible for some of the adaptations.

Macromutations are the only explanation for differences in the number of body segments in arthropods, according to Princeton University, since very few changes in genes are needed to cause such a huge physical change. Polydactyl cats are another example where a significant physical change - extra toes - can be the result of a slight change in the phenotype of an individual, like in flies with double or missing wings. However, in general, macromutations are believed to have little impact on the evolutionary process.

This photo was taken by Scott Gardner of The Hamilton Spectator, a local newspaper in Hamilton, Canada. She appeared in Richard Dawkins' 1996 book Climbing Mount Incredible with the following caption: "Macromutations happen. This ugly toad with eyes in its mouth was found surviving wild in a Canadian garden."

Later in Dawkins' book, a more detailed explanation of the photograph is given:

“According to photographer Scott Gardner of The Hamilton Spectator, the toad was found by two girls in their garden in Hamilton, Ontario. He says they put it on the kitchen table to take a photo of it. eyes. When she opened her mouth, it turned out that the eyes were located there."

It is assumed that the cause of the mutation was a parasitic infection with a trematode worm (Ribeiroia ondatrae). Trematode infestation has been reported to be associated with an increased number of mutations in amphibians' limbs, especially missing, malformed and extra hind legs.

A 2002 study led by Jeffrey Stopper of the US Sacred Heart University Department of Biology reported that "fluke cysts cause massive disruption and abnormal cell growth in the limbs of infected individuals."

There is no evidence yet that trematodes can cause eye misalignment, so for now, this little Canadian toad remains a bizarre mystery.

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