2014-08-30
Explanation
The Joke
A woman asks a man: "Hey, wanna come increase your fitness with me?" The man declines, saying "Oh, no thanks. I hit the gym this morning." The caption at the bottom reads: "And so, the biologist's mating call went unheeded."
The Humor
The joke hinges on the double meaning of the word "fitness." In everyday language, "fitness" refers to physical exercise and health — which is how the man interprets the woman's question. But in evolutionary biology, "fitness" refers to reproductive fitness — an organism's ability to survive and reproduce, passing on its genes to the next generation.
The woman, being a biologist, is using "increase your fitness" as a euphemistic come-on, essentially asking him to reproduce with her. The man completely misses the innuendo because he only understands "fitness" in its colloquial sense. The caption confirms the biological framing by calling her proposition a "mating call."
References
- Biological/Darwinian fitness: In evolutionary biology, fitness is a measure of an organism's reproductive success — how effectively it passes its genes to the next generation. This is distinct from the common usage meaning physical health or exercise ability.