Some animals can produce offspring from an unfertilized egg in an asexual reproduction process known as parthogenesis. When this is the standard process for a species it's said to be 'obligate' and ...

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 ...

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 ...