Have you heard of humming fish? Learn more on this Moment of Science.
Imagine you're a female cardinal and you're looking for a mate. Before you are three males. Which one should you choose?
After all, for the basic body plan to change, not only do you need a random genetic mutation that results in a sixth finger, but that mutation must also provide an evolutionary advantage when it comes to reproduction.
If you think dating is tough, just be glad you aren’t a garden snail. When you live life at a snail’s pace, you’d better be able to mate with the next snail you meet without worrying if it’s male or female. That’s why garden snails are hermaphrodites and can take on both the male and female roles in reproduction.