Scientists Think They Know How Whales Got So Big

iStock
iStock

It can be difficult to understand how enormous the blue whale—the largest animal to ever exist—really is. The mammal can measure up to 105 feet long, have a tongue that can weigh as much as an elephant, and have a massive, golf cart–sized heart powering a 200-ton frame. But while the blue whale might currently be the Andre the Giant of the sea, it wasn’t always so imposing.

For the majority of the 30 million years that baleen whales (the blue whale is one) have occupied the Earth, the mammals usually topped off at roughly 30 feet in length. It wasn’t until about 3 million years ago that the clade of whales experienced an evolutionary growth spurt, tripling in size. And scientists haven’t had any concrete idea why, Wired reports.

A study published in the journal Proceedings of the Royal Society B might help change that. Researchers examined fossil records and studied phylogenetic models (evolutionary relationships) among baleen whales, and found some evidence that climate change may have been the catalyst for turning the large animals into behemoths.

As the ice ages wore on and oceans were receiving nutrient-rich runoff, the whales encountered an increasing number of krill—the small, shrimp-like creatures that provided a food source—resulting from upwelling waters. The more they ate, the more they grew, and their bodies adapted over time. Their mouths grew larger and their fat stores increased, helping them to fuel longer migrations to additional food-enriched areas. Today blue whales eat up to four tons of krill every day.

If climate change set the ancestors of the blue whale on the path to its enormous size today, the study invites the question of what it might do to them in the future. Changes in ocean currents or temperature could alter the amount of available nutrients to whales, cutting off their food supply. With demand for whale oil in the 1900s having already dented their numbers, scientists are hoping that further shifts in their oceanic ecosystem won’t relegate them to history.

[h/t Wired]

This Wall Chart Shows Almost 130 Species of Shark—All Drawn to Scale

Pop Chart Lab
Pop Chart Lab

Shark Week may be over, but who says you can’t celebrate sharp-toothed predators year-round? Pop Chart Lab has released a new wall print featuring nearly 130 species of selachimorpha, a taxonomic superorder of fish that includes all sharks.

The shark chart
Pop Chart Lab

Called “The Spectacular Survey of Sharks,” the chart lists each shark by its family classification, order, and superorder. An evolutionary timeline is also included in the top corner to provide some context for how many millions of years old some of these creatures are. The sharks are drawn to scale, from the large but friendly whale shark down to the little ninja lanternsharka species that lives in the deep ocean, glows in the dark, and wasn’t discovered until 2015.

You’ll find the popular great white, of course, as well as rare and elusive species like the megamouth, which has been spotted fewer than 100 times. This is just a sampling, though. According to World Atlas, there are more than 440 known species of shark—plus some that probably haven't been discovered yet.

The wall chart, priced at $29 for an 18” x 24” print, can be pre-ordered on Pop Chart Lab’s website. Shipping begins on August 27.

Can You Really Suck the Poison Out of a Snakebite?

iStock
iStock

Should you find yourself in a snake-infested area and unlucky enough to get bitten, what’s the best course of action? You might have been taught the old cowboy trick of applying a tourniquet and using a blade to cut the bite wound in order to suck out the poison. It certainly looks dramatic, but does it really work? According to the World Health Organization, approximately 5.4 million people are bitten by snakes each year worldwide, about 81,000 to 138,000 of which are fatal. That’s a lot of deaths that could have been prevented if the remedy were really that simple.

Unfortunately the "cut and suck" method was discredited a few decades ago, when research proved it to be counterproductive. Venom spreads through the victim’s system so quickly, there’s no hope of sucking out a sufficient volume to make any difference. Cutting and sucking the wound only serves to increase the risk of infection and can cause further tissue damage. A tourniquet is also dangerous, as it cuts off the blood flow and leaves the venom concentrated in one area of the body. In worst-case scenarios, it could cost someone a limb.

Nowadays, it's recommended not to touch the wound and seek immediate medical assistance, while trying to remain calm (easier said than done). The Mayo Clinic suggests that the victim remove any tight clothing in the event they start to swell, and to avoid any caffeine or alcohol, which can increase your heart rate, and don't take any drugs or pain relievers. It's also smart to remember what the snake looks like so you can describe it once you receive the proper medical attention.

Venomous species tend to have cat-like elliptical pupils, while non-venomous snakes have round pupils. Another clue is the shape of the bite wound. Venomous snakes generally leave two deep puncture wounds, whereas non-venomous varieties tend to leave a horseshoe-shaped ring of shallow puncture marks. To be on the safe side, do a little research before you go out into the wilderness to see if there are any snake species you should be particularly cautious of in the area.

It’s also worth noting that up to 25 percent of bites from venomous snakes are actually "dry" bites, meaning they contain no venom at all. This is because snakes can control how much venom they release with each bite, so if you look too big to eat, they may well decide not to waste their precious load on you and save it for their next meal instead.

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