Tag Archives: factslaps

The Woke Sea

Oysters can change their gender multiple times in their lifespans.

Within 12 hours of their birth, oysters begin pulling calcium out of the water to create their signature shells. For the first few weeks of their lives, these newborn bivalves zoom around in a current until they eventually settle on some hard substrate, whether it’s a rock, pier, or another oyster. This place of protection is where the oysters will spend the rest of their lives (which can be as long as 20 years). Eventually, usually a year after birth, it’ll be time for the oysters to breed, and that’s where things get interesting. 

Although born male, oysters have the impressive ability to switch their sex, seemingly at will. Every season, females can release up to 100 million eggs, and the amount of sperm released is so high it’s essentially incalculable. Once the egg and sperm are released, the oysters rely on pure chance for fertilization to take place, as the egg and sperm meet in the open water. Because any resulting larvae are extremely vulnerable to predators (especially filter feeders), oysters have evolutionarily compensated by being one of the most virile and sexually flexible species in the world — meaning that their ability to change sex likely evolved as a matter of survival. This impressive fecundity means that natural oyster reefs can grow to tremendous size; as little as 10 square feet of reef can house up to 500 oysters. Scientists theorize that water temperature could play a role in triggering whatever causes an oyster to change its sex, but many aspects of the process remain a mystery. 

Factslap: One tree predates dinosaurs


There is no tree on Earth like the Ginkgo biloba. It’s the sole survivor of its genus, family (Ginkoaceae), order (Ginkgoales), class (Ginkgoopsida), and even its phylum (Ginkgophyta). In other words, it has no living relatives. Ancestors of the ginkgos now filling our parks and city streets lived on Earth 270 million years ago; for those keeping track, that means the ginkgo predates the Triassic period (aka the beginning of the dinosaurs) by a cool 18 million years. The gingko is the oldest living tree species in the world — it’s been nicknamed a “living fossil.”

However, the ginkgo tree’s historic run almost came to an end before it was saved by an unlikely ecological hero: humans. Ginkgos began declining from certain areas of the world, including North America and Europe, as the Earth started to cool 66 million years ago. By the time the last ice age ended and kicked off the Holocene epoch, the Ginkgo biloba only thrived in what is modern China, where people began planting and eating their seeds. Ginkgos then found their way to Japan and were eventually discovered in the late 17th century by German scientist Engelbert Kaempfer, who reintroduced the tree to the West. 

For decades, scientists believed Ginkgo biloba was effectively extinct in the wild, only surviving through human cultivation, but small colonies of wild ginkgo have since been spotted in southwestern China. Today, the ginkgo’s beauty and hardiness make it a natural candidate for city parks and streets, and the tree can be found scattered throughout the U.S. So when you next enjoy the shade of a looming ginkgo, remember that those beautiful leaves once provided refuge for dinosaurs.

Did The Earth Just Move For You Too?

Factslap: The Earth shakes every 26 seconds, and scientists aren’t sure why.

Like a lot of strange happenings, it was first noticed in the 1960s: A small seismic pulse, large enough to register on seismological instruments but small enough to go otherwise unnoticed, occurring every 26 seconds. Jack Oliver, a researcher at the Lamont-Doherty Geological Observatory, first documented the “microseism” and sussed out that it was emanating from somewhere “in the southern or equatorial Atlantic Ocean.” Not until 2005 was it determined that the pulse’s true origin was in the Gulf of Guinea, just off Africa’s western coast, but to this day scientists still don’t know something just as important: why it’s happening in the first place.

There are theories, of course, ranging from volcanic activity to waves, but still no consensus. There does happen to be a volcano on the island of São Tomé in the Gulf of Guinea near the pulse’s origin point, not to mention another microseism linked to the volcano Mount Aso in Japan, which has made that particular explanation more popular in recent years. Though there’s no way of knowing when (or even if) we’ll learn the why of this phenomenon, one thing’s for sure: better a microseism than a macroseism.