By Ella Davies
The sperm is the smallest cell in human biology, but also one of the most complex. The egg meanwhile is the largest cell and similarly intricate. Looking further out into the natural world, the diversity of these sex cells, or gametes, is truly remarkable.
Most species have two gametes, which we term male and female.
“Gametes have two fundamental jobs: to carry resources to nurture the resulting offspring, and to find gametes of the same species and fuse with them. To be good at both is a challenge, because the two jobs create opposing drives across a size-number trade-off,” explains Matthew Gage from the University of East Anglia, UK.
“One optimum is to produce gametes that maximise offspring survival, and so evolution makes large, nutritive gametes, which we call eggs produced by females.