It's a commonly held belief: Sperm cells are like runners in an epic race, competing against each other for access to the coveted egg at the finish line. The egg, in turn, waits patiently for the ...

Well-documented reports spanning 25 years have yielded mounting evidence that sperm counts are tumbling in industrialized countries. (See my April 20, 2017 post Going, Going, Gone? Human Sperm Counts ...

Researchers at Newcastle University in England report they have coaxed the first human sperm cells from embryonic stem cells, in a remarkable demonstration of how quickly the field of stem-cell ...

Oh, brave new world, that has such embryos in it. In a dramatic scientific first, researchers have created synthetic human embryos without using sperm or an egg. No one knows if these embryonic ...

"Swipe right. Swipe left." On an evolutionary level, the finger flick of choice in the human mating game is often influenced by subconscious input from our most primal instincts. "Swipe right. Swipe ...

Katsuhiko Hayashi pulls a clear plastic dish from an incubator and slides it under a microscope. "You really want to see the actual cells, right?" Hayashi asks as he motions toward the microscope.