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Meet the Protein That Plugs a Sperm Into an Egg During Fertilization

The successful union of egg and sperm in fertilization depends on a sperm cell’s ability to get through an egg’s thick protective coating and latch itself to its membrane. A study published in the journal Andrology yesterday gives us our first look at the protein responsible for the tie-down. » 8/27/15 5:50pm Thursday 5:50pm

Here’s Why We’re Not Overrun With Adorable Baby Giant Pandas

The Smithsonian’s National Zoo has been part of an international effort to breed highly endangered giant pandas in captivity ever since Richard Nixon visited China in 1972. But in 43 years, they’ve had only two solid successes–cubs Tai Shan and Bao Bao. They hope the new twins born this weekend will make it four. » 8/25/15 12:32pm 8/25/15 12:32pm

We're Only Beginning To Understand Why Humans Have a Skewed Sex Ratio

The ratio of newborn boys to girls slightly and consistently leans toward males: around 106 boys are born for every 100 girls. If that seems odd to you, it should: the way sperm form suggests that the ratio of X-sperm to Y-sperm should be exactly 50:50–and scientists are only now beginning to understand why the skew… » 8/20/15 12:20pm 8/20/15 12:20pm

A New Option for Crocodile Birth Control 

When they live in zoos, Mugger crocodiles happily mate and lay eggs. Maybe a little too happily: when they produce two clutches of 25 to 30 eggs each year, a zoo is quickly going be swamped by little croc babies. And rampant habitat loss means that there are fewer places to return them to the wild. What zoos need is… » 8/18/15 5:45pm 8/18/15 5:45pm

Why the Cervix Is More Amazing Than You Realized

Technically, the cervix is the bottom chunk of the uterus, a circular plug-like mass of tissue dividing the uterine space from the vagina. But where most of the uterine wall is made of smooth muscle, up to 90% of the cervix is built of stiff and unyielding connective tissue. At least, it’s stiff most of the time. » 8/14/15 5:44pm 8/14/15 5:44pm

Older Ovaries, Not Older Eggs, May Reduce Fertility With Aging

Women who are over 40 have a notoriously hard time getting pregnant by in-vitro fertilization (IVF), and it’s long been assumed that their problem stems from “old eggs”. But a preprint now available online at the Journal of Endocrinology suggests that the real problem might be the aging of the cells that surround the… » 8/13/15 1:58pm 8/13/15 1:58pm

The Unusual Mating Habits of This Octopus Totally Blow Biologists' Minds

We all know the sad story of octopus sex, right? They live alone until it’s time to find a mate, they have sex a few times, then the males die. Females live a little longer to lay eggs, but die soon after they hatch. Turns out that the (still officially unnamed) Larger Pacific Striped Octopus breaks all the rules. » 8/12/15 4:39pm 8/12/15 4:39pm

GPS Has Revealed How the Oldest Multicellular Organisms Had Sex

The global positioning system (GPS) can keep you from getting lost, manage air traffic, and track the migration of endangered species. And in a new study published today by Nature, it’s helped paleontologists understand how an organism that’s been extinct for about 540 million years reproduced.
» 8/03/15 12:29pm 8/03/15 12:29pm

Here's How a 13-Foot Wide Egg Mass Fits Inside a 5-Foot Squid

On July 9th of this year, divers off the coast of Turkey ran across an enormous lump of gelatinous goo which turned out to be one of the largest squid egg masses ever found. That inspired science writer and squid expert Danna Staaf to make this video explaining how all that goo fit inside a much smaller mother squid. » 7/31/15 2:09pm 7/31/15 2:09pm

What Should Parents Do With Their Spare IVF Embryos?

When in vitro fertilization was developed in the 1970s, critics of the technique imagined a world a la Aldous Huxley, filled with assembly-line designer babies. It didn’t turn out like that. Instead, the procedure simply gave infertile couples another route to start a family. But it also created a problem that critics » 6/22/15 7:28pm 6/22/15 7:28pm

A Brief History Of Vaginal Cutting During Childbirth

During childbirth, the vagina has to stretch to accommodate a head the size of a grapefruit. This, you may imagine, takes time. So if something goes wrong during labor and delivery has to happen fast, doctors or midwives might speed things along by artificially widening the vaginal opening. With scissors. » 6/12/15 4:41pm 6/12/15 4:41pm

Scientists Hope Tiny Asexual Animals Can Teach Us Why Sex Works

Sex is how most animals reproduce, so you might wonder why some scientists are using a tiny asexual animal to study it. In an article published last winter at Quanta, Emily Singer explains that the way bdelloid rotifers manage their genes has scientists asking what the term “sex” really means. » 5/29/15 11:41am 5/29/15 11:41am

2015's Top New Species Include Two Animals with Cool Breeding Habits


Let’s hear it for newly-discovered species with interesting sex lives! A pufferfish that builds complex circular spawning nests and a frog that gives birth directly to live tadpoles have been picked as two of the the International Institute for Species Exploration’s “top 10” new species of 2015.
» 5/21/15 10:17am 5/21/15 10:17am