The idea of gender is something that is under continuing debate in our society. Yet in nature, it can never really be questioned. The majority of animals are either male or female in gender and until they learn to communicate with us they will likely not be able to advocate for other genders. However, there are a number of occurrences where the gender of an animal was not straight forward. Let’s take a closer look.
In humans, we have hermaphroditism where a person can appear to be one gender but have a discrepancy between the external and internal sexual and genital organs. This condition is extremely rare in humans but it does occur. Experts estimate that a specialist in sex definition is called into a medical center about once in every 2,000 births. In animals, there is an even rarer condition that can occur called bilateral gynandromorphism.
Bilateral gynandromorphism is when an animal is born with one half of the body being one gender and one half of the body being an entirely different gender. This has never occurred in humans. This condition can occur in spiders, birds, and other animals but has been recently found in butterflies to a larger degree. Since 2008 there have been five cases of this condition reported.
In species where the difference between a male and female body type is not significant, it may go undiscovered completely. The most striking example of recent times was that of the great mormon butterfly (Papilio memnon). One half of the butterfly was almost fully black while the other half had red, blue, and orange flecks. The insect had a clear split down its body too with different types of antennae and different shaped legs on each side. To the ordinary person, it looked like two different butterfly halves had been glued together. This condition affects almost one in 10,000 butterflies and so is clearly a very rare occurrence.
Scientists are not certain how it occurs but they believe that it happens when two sperm enter a single egg. One sperm will join with the cells of the egg and develop normally while the second sperm will develop in the fluid of the cell and both will emerge in the same embryo. The reason this happens is completely random and there is no way to plan for it or to avoid it. It recently occurred three times at one museum. This either suggests the museum had some strange probabilities or that it may be happening more often than we realize and the museum that stumbled across it once is now looking out for it. If that is the case then who knows how rare this condition really is.
The specimens captured in the museum have now been kept for future study and they may remove part of the mystery in the future. For now, though, we have to assume this strange occurrence is as rare as they suggest. The expert who came across the butterflies suggested that he was so lucky he should buy a lottery ticket. It is a good idea but instead, he should probably write a detailed paper on the species of butterfly these conditions were found in and how he spotted them. This framework could then be applied across the world to provide greater clarity on the numbers of this condition in butterflies and other animals.
While gender is a question of two options in animals, it is clear that even there, things are not so simple anymore. Many people believe that gender is simply a construct and examples like this go further to prove that point. While these things are looked at as conditions or accidents we really have no idea what they are and we may need to simply rethink how we divide the lines of gender.