Humans do not have tails, but do we have “what it takes” for a tail? Hens don’t have teeth, but they have the genes for it. With atavism, it is as if our genomes serve as archives of our evolutionary ...

What do the earliest stages of a pregnancy look like? Embryonic development has been extensively studied, but most of our knowledge of the earliest stages of a growing baby come from stationary ...

Seals give birth only when conditions are right. After mating, a female seal can delay implantation of the embryo in the ...

Over the past year or two, we have been exploring what we termed the origins—or the embryology—of human development. We examined the three pillars of development: Feelings (Affects), Language, and ...

The earliest days after fertilization, once a sperm cell meets an egg, are shrouded in scientific mystery. The process of how a humble single cell becomes an organism fascinates scientists across ...

"Volume I ,with 423 illustrations." "Volume II, with 658 illustrations." Volume 1: xviii, 548 pages; volume 2: viii, 1032 pages, 1 leaf of folded plates. Beckwith, J ...

Researchers have used stem cells to develop new human embryolike structures that model the earliest stages of fetal development so realistically that they even secrete hormones that can turn a lab ...

Nearly half the embryos studied underwent developmental arrest because of genetic mishaps in early development—a revealing insight that suggests more IVF babies could come to term with changes in the ...

A lot happens in the first month of human embryo development as a single cell morphs into multitudes. Yet despite its significance, this period is basically a “black box” to researchers, says stem ...

Scientists can now create realistic human embryo models in the lab, leading some to suggest that we rethink how we legally define an embryo. When you purchase through links on our site, we may earn an ...