Lovebirds are unusual not just because of their shameless PDA, but because they choose one mate for life. While more than 90 ...

Successful reproduction presents a fundamental evolutionary paradox: the immune system must tolerate genetically foreign sperm and embryos while maintaining ...

Female mammals have long thought to be born with all the eggs they would ever have, but new research is challenging that consensus ...

Males of the species Drosophila melanogaster pack thousands of almost two-millimeter-long sperm cells into significantly smaller storage organs. A new study reveals how they move in an orderly manner ...

I'll save this sperm for later, thanks ...

Scientists at MIT have found compelling chemical evidence that Earth’s earliest animals were likely ancient sea sponges. Hidden inside rocks over 541 million years old are rare molecular “fingerprints ...

The world’s life-forms reproduce sexually in a bewildering variety of ways, even though scientists still aren’t sure why they bother.

Earth’s earliest animals may have held evolution back because they reproduced asexually, creating low-competition communities that changed very little over time. When environmental pressures pushed ...

For most animals, reproduction is the beginning of the next generation. For these species, it's the end of their own. Salmon exhaust themselves on epic migrations before dying shortly after spawning.