Serially cloned mice hit a genetic “dead end” by generation 58, underscoring that sex evolved for variation, purging harmful ...

A study from Karolinska Institutet in Sweden, among others, presents the theory that egg-sperm fusion, a crucial feature of sexual reproduction in plants and animals, may have originated from an ...

Some female birds, reptiles and other animals can make a baby on their own. But for mammals like us, eggs and sperm need each other. Parthenogenesis could be the future for this California condor ...

Animals, from worms and sponges to jellyfish and whales, contain anywhere from a few thousand to tens of trillions of nearly genetically identical cells. Depending on the organism, these cells arrange ...

The evidence that environmental enrichment promotes reproduction by reducing stress is mostly implied rather than empirical.