Scientists are making inroads in understanding one of the central mysteries of human reproduction: Why do women’s eggs deteriorate as they age? The broad strokes have been well-known — the ticking of ...

The cellular biology of reproduction is often depicted as an epic journey, in which millions of intrepid sperm fight to be the first to claim the ultimate prize: the chance to fertilize the egg, which ...

The following outlines aspects of the female reproductive system, including the internal and external organs, the menstrual cycle, the egg, and reproductive hormones. The menstrual cycle is a monthly ...

During mammalian reproduction, millions of sperm undertake a journey that only one will finish. This journey to fertilization has been commonly viewed as a race: a sea of sperm competing to get to the ...

Genetic quality or genetic compatibility? What do female fruit flies prioritize when mating? Researchers show that both factors are important at different stages of the reproductive process and that ...

One of the immutable truths about being alive is that we age. This happens at every level, down to our cells. When they divide, our cells copy our DNA into each new cell. But as the weeks, months, and ...

Getting the job done. A female Asian water dragon (Physignathus cocincinus) produced a daughter (left) without the assistance of a male. Skip Brown/Smithsonian’s National Zoo An Asian water dragon ...