Male and female reproductive systems allow human reproduction. Fertilisation occurs when a sperm and egg join to form an embryo. An embryo develops into an unborn baby in the uterus during pregnancy.

Declining female fertility is a health issue that has received broad global attention. Oocyte quality is the key limiting factor of female fertility, and factors affecting oocyte quality involve the ...

Human birth has a reputation for danger. The usual explanation is simple enough: walking upright narrowed the pelvis, while ...

The slow maturation of human children—often viewed as burdensome in modern parenting—is, in fact, a remarkable evolutionary achievement. Unlike other species, humans remain biologically immature and ...

Human biology evolved for a world of movement, nature, and short bursts of stress—not the constant pressure of modern life. Industrial environments overstimulate our stress systems and erode both ...