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 ...

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 ...