
James K. Adams, Professor of Biology,
Dalton State College

Kim Davis, Mike Strangeland, and Andrew Warren,
Butterflies of America
In the realm of genetic anomalies found in living organisms perhaps none is more visually striking than
bilateral gynandromorphism,
a condition where an animal or insect contains both male and female
characteristics, evenly split, right down the middle. While cases have
been reported in
lobsters,
crabs and even in
birds,
it seems butterflies and moths lucked out with the visual splendor of
having both male and female wings as a result of the anomaly. For those
interested in the science, here’s a bit from Elise over at
IFLScience:
In insects the mechanism is fairly well understood. A fly
with XX chromosomes will be a female. However, an embryo that loses a Y
chromosome still develops into what looks like an adult male, although
it will be sterile. It’s thought that bilateral gynandromorphism occurs
when two sperm enter an egg. One of those sperm fuses with the nucleus
of the egg and a female insect develops. The other sperm develops
without another set of chromosomes within the same egg. Both a male and a
female insect develop within the same body.
Above are some great examples of bilateral gynandromorphism, but follow the links above and below for many more. (via
Live Science,
The Endless Airshow,
Butterflies of America,
IFLScience)