About 9% of men of reproductive age in the United States experience fertility problems. One of the many causes of male ...

Biologists have long puzzled over how organs develop into their final shapes, and the nearly transparent bodies of young sea ...

Getting it over the finish line was a labor of love—and now, more than five years after her death, the lab of former Sloan ...

Why humans have a philtrum, the groove above your lip, explained by an evolutionary biologist — from embryonic face-building ...

The genes and pathways behind the formation of the first human cell lineages during embryogenesis could have clinical implications for regenerative medicine, pregnancy loss, and infertility. 1. Egg ...

Gender is one of the most defining features of our identity. Most people think it is fixed. If you have two X chromosomes, you are female; if you have an X and a Y chromosome, you are male. This idea ...

Eating large amounts of ultra-processed food (UPF) is linked not only to reduced fertility in men, but also to slower growth in early embryos, and smaller yolk sacs, which are essential for early ...

Eating large amounts of ultra-processed food (UPF) is linked not only to reduced fertility in men, but also to slower growth in early embryos, and smaller yolk sacs, which are essential for early ...

In reptiles, sex isn’t decided only by DNA; it also depends on temperature. Just a few degrees can determine whether an egg hatches as male or female. This process, called temperature‑dependent sex ...

With such a small risk of illness, does this type of embryo selection border on eugenics? By Kwame Anthony Appiah Kwame Anthony Appiah has been The New York Times Magazine’s Ethicist columnist since ...

Cell division is an essential process for all life on earth, yet the exact mechanisms by which cells divide during early embryonic development have remained elusive – particularly for egg-laying ...