I have a new favorite animal — but it is not limited to just one species.
Bilateral gynandromorphs are animals that exhibit “bilateral asymmetry” in their sexual phenotype. In layman’s terms: It is as if they have been split right down the middle, and exactly one half decided to become female, and the other half decided to be male.
Bilateral gynandromorphs have been found in all manner of life — butterflies, birds, bees, lobsters, crabs — even reptiles.
There are different theories as to how and why gynandromorphism occurs in nature, and in the end, it may not be limited to one reason.
In one theory, dividing cells split their sex chromosomes atypically during mitosis. An XY cell would normally duplicate its chromosomes to become XXYY, and from there, divide into two XY cells. In this situation, however, the cell would split into an X cell and an XYY cell.
The X cell would lead to female characteristics, and the XYY cell would lead to male sex characteristics, all merged within the same body.
Another theory states that gynandromorphs are two non-identical twins fused down the middle. A female egg cell usually discards half its chromosomes in a lump of DNA called “the polar body.” If, for whatever reason, the polar body is not discarded, it can be fertilized along with the egg during sex.
From these two different groups of cells, an organism can develop with two different genomes in one body — and two different sexes in one body.
The story of a gynandromorph’s mating life is remarkably familiar to anyone who has struggled with gender roles or sex-based social structures, or simply dating in general. Isolation is common. Mating can be confusing.
Female and male roles in animal mating rituals are often governed by a different set of guidelines. Because bilateral gynandromorphs have both one teste and one ovary, they have been observed behaving as both male or female, or neither.
I am so personally excited about bilateral gynandromorphs because they are not only remarkably beautiful, but they are examples of non-binary creatures found in the wild.
Of course, there are many other examples of non-binary beauty in nature. Similar to gynandromorphs are my other heroes, hermaphrodites, although hermaphrodites are a little different. Hermaphrodites simply have both male and female sex reproductive organs, while gynandromorphs combine maleness and femaleness all throughout their bodies.
Snails, as well as many other species, are naturally hermaphrodites — so, it is already incorrect to ever refer to a snail as “female” or a “male.” There simply is no such thing. (In people-world, intersex refers to folks who possess characteristics of both female and male sexes, but there are a wide variety of causes and manifestations.)
Of course, to compare non-binary animals to non-binary people is a little complicated, and I’m not going to pretend it isn’t. Non-binary in people-world is a gender expression. When I say that gynandromorphs are non-binary, I am referring to their sexual identification.
One refers to how human beings define their selves socially and culturally. The other refers to a biological assignment.
Of course, we can only identify an animal based on its sex — we cannot ask how an animal identifies itself, gender-wise, although, dear god, I wish we could.
But if we could miraculously be able to communicate with an animal for just one minute, and ask a gynandromorph whether it identifies as female or male…it would probably look at you very confused. To ask any person where gynandromorphs fall on the binary map would be difficult, challenging, and ultimately impossible.
My point is, to make an argument that someone ought to only identify as female or male because it’s “only natural” …is futile.
Gynandromorphs are not only non-binary inspirations. They are also scientifically useful. Studying gynandromorphs can help scientists understand how early cell development works for different species. In one study I found, bilaterals were studied to research how mutation-induced diseases could be confined to just one lateral body half.
Today, researchers continue to have many questions about bilateral gynandromorphs — what can they tell us about biology and genetics? Do they exist in species we have not discovered yet? Why is bilateral gynandromorphism more prevalent in certain animal species over others?
But there is only one thing that nobody can question — bilateral gynandromorphs’ tendency to display remarkable, indescribable beauty.