evolution

WTF Fun Fact 13711 – Whales Evolved from Wolves

When we received a fun fact submission suggesting that whales evolved from wolves, we were pretty skeptical. After all, we’ve taken evolutionary biology at the collegiate level—we’re smart people—and that just sounds silly.

Well, so much for that confidence! Researchers believe they really have found proof of this mind-boggling evolutionary relationship.

But whales’ journey from land to sea is one of evolution’s most astonishing tales. This transition didn’t happen overnight. It involved millions of years, with ancient wolf-like creatures at its inception. Today’s whales, creatures of the ocean’s vast expanses, share a lineage with terrestrial mammals. Their story of evolution is a testament to nature’s adaptability and the intricate pathways of evolutionary change.

From Land to Sea

The story starts around 50 million years ago. Imagine a time when the ancestors of whales roamed the earth on four legs. These ancient mammals, resembling wolves, embarked on a journey that would lead them to become the ocean’s giants. The first step in this transformation was a shift in habitat. Early ancestors, known as Pakicetus, lived near water bodies. They gradually ventured into the water for food, driven by survival needs and the abundance of aquatic prey.

As these mammals spent more time in water, natural selection favored traits beneficial for aquatic life. Over millions of years, their body shape began to change. Limbs transformed into flippers, tails became powerful propellers, and their snouts extended to better catch fish. This gradual morphing wasn’t just physical. Changes occurred internally, too, such as the development of a mechanism to drink seawater, filtering out the salt, and adjustments in reproductive behavior to give birth in water.

How Whales Evolved from Wolves

The transformation from land-dwelling to fully aquatic life forms was marked by significant evolutionary milestones. The development of echolocation allowed whales to navigate and hunt in the deep, dark waters of the oceans. Their lungs adapted to allow them to dive deep and stay underwater for extended periods. These adaptations were crucial for survival and exploiting new ecological niches.

One of the most pivotal moments in whale evolution was the emergence of two distinct groups: baleen and toothed whales. Baleen whales, like the blue whale, evolved a unique feeding mechanism using baleen plates to filter small fish and krill from the water. Toothed whales, including orcas and dolphins, pursued a different evolutionary path, focusing on hunting larger prey.

The Legacy of Land-Dwelling Ancestors

Despite their fully aquatic lifestyle, whales retain remnants of their land-dwelling past. Vestigial structures, such as hip bones, hint at their four-legged ancestors. Even their breathing reminds us of their terrestrial origins, as they must come to the surface to breathe air.

The journey from wolf-like creatures to the majestic whales of today is a profound example of evolutionary adaptation. It underscores the dynamic nature of life on Earth and the constant drive for survival that shapes all living beings. Whales’ evolution from land to sea is not just a story of change but a narrative of resilience, innovation, and the enduring bond between all creatures of our planet.

— WTF fun facts

Source: “Fossil find shows how a wolf turned into a whale” — The Independent

WTF Fun Fact 13206 – The Bombardier Beetle

You may have heard of the Bombardier beetle since they have a rather interesting ability. Or as National Geographic (cited below) puts it, “the infamous ability to synthesize and release rapid bursts of stinky, burning-hot liquid from their rear ends.”

Tell me more about the bombardier beetle!

There are actually over 500 species of bombardier beetle (and about 40 in the US alone). These creatures live in many different types of ecosystems. The boiling hot chemicals they can shoot out of their rears as a defense mechanism can reach temperatures up to 212 degrees Fahrenheit. And the beetle can shoot the spray multiple times in quick succession. The spray can also produce a loud popping noise as it is released, adding an extra deterrent.

The details are even more fascinating.

In the bombardier beetle, special cells produce hydroquinones and hydrogen peroxide which then collect in a reservoir. In order to spray, the beetle has to open a valve controlled by a muscle in order to release the chemicals into a separate “reaction chamber.” This chamber is lined with cells that catalyze the chemical reaction that makes the compounds hazardous to the beetle’s predators.

The catalases and peroxidases lining the chamber also aid in the reaction that generates enough heat to bring the mixture to the boiling point (though some of it becomes vapor). The pressure created by the gases closes the valve and expels the chemicals at high speed. Amazing, right?!

Should I be afraid of this creature?

People don’t need to be afraid of the bombardier beetle. They’re too small to hurt humans (about the size of a fingernail), and they don’t go around indiscriminately spraying. They use that function only as a defense mechanism against predators.

Bombardier beetles usually keep to wooded areas and fields and don’t roam around places with lots of humans. They typically have dark abdomens and reddish legs, antennae, and heads, in case you want to keep an eye out.

How on Earth did this beetle feature evolve?

Funny you should ask. Some creationists like to use the bombardier beetle’s two-chamber system as an example of their theory of irreducible complexity. They insist that since the beetle’s defense mechanism wouldn’t operate without two complex parts, they could not have evolved via small modifications and are therefore a product of “intelligent design.”

Most of the creationist rhetoric masquerading as science gives an incomplete or sloppy description of the beetle’s inner workings.

In fact, a step-by-step evolution of the beetle is pretty straightforward (even if it does seem weird to us). The beetle likely developed its ability to secrete chemicals as a defense mechanism that was released via the epidermis to make it distasteful to predators. While the steps in between are all hypothetical since we didn’t see the creature evolve, the development of the beetle we know now is easily broken down into tiny evolutionary steps we’ve seen in other species.

You’ve got to wonder why a creationist would assume God created this beetle specifically to shoot chemicals out its rear end. — WTF fun facts

Source: “Bombardier beetles” — National Geographic

WTF Fun Fact 13194 – Goosebumps Muscle

Did you know you have a goosebumps muscle? We get goosebumps when tiny muscles in our skin’s hair follicles called arrector pili pull our hair upright. Goosebumps evolved when humans had enough body hair for this “hair-raising” action to keep them warm. We still get goosebumps, but they no longer serve a purpose in humans.

How do the goosebumps muscles work?

The arrector pili muscle is a small muscle located at the base of each hair follicle. When this muscle contracts, it causes the hair follicle to stand upright, resulting in the characteristic “goosebumps” or “gooseflesh” that many people experience in response to cold temperatures, emotional arousal, or certain stimuli.

The contraction of the arrector pili muscle can also cause the hair follicle to become more sensitive to the surrounding environment, which may help to protect the skin from cold temperatures or other environmental factors. This contraction is also mediated by the sympathetic nervous system, which is activated in response to certain stimuli such as cold, fear, anger, or pleasure.

Why do we get goosebumps?

Goosebumps occur as a response to a variety of stimuli. The most common trigger is a change in temperature, such as feeling cold. Goosebumps also occur in response to emotional stimuli such as fear, awe, or pleasure. This is because the contraction of the arrector pili muscle is mediated by the sympathetic nervous system. That is activated in response to these stimuli.

Another reason why we get goosebumps is an evolutionary one. When our ancestors had more hair on their bodies, the contraction of arrector pili muscles would make the hair stand up. This created a thicker layer of insulation to help them stay warm in cold temperatures. This response is still present in humans, even though most of us have less body hair.

Goosebumps can also occur when listening to music. This is because the emotional response to music can activate the sympathetic nervous system, which triggers the contraction of the arrector pili muscle.

Overall, goosebumps are a physiological response to a variety of stimuli that can be triggered by both environmental and emotional factors. — WTF fun facts

Source: “What Goosebumps Are For” — National Institutes of Health

WTF Fun Fact 13073 – Teens Tune Out

Got teenagers? Do you feel like they listen to you? If not, it’s likely because our brains rewire themselves to tune out our parents in our teen years. In fact, Stanford University research shows that teens tune out their mothers’ voices around the age of 13.

How teens tune out

More specifically, according to Stanford (cited below), “Around age 13, kids’ brains no longer find their moms’ voices uniquely rewarding, and they tune into unfamiliar voices more.”

Of course, this doesn’t give a person a free pass not to listen to their mom. But it does seem to be an evolutionary mechanism. Our brains are preparing to separate us from our parents in the long run – something we all have to do in order to become successful adults.

Clinical associate professor of psychiatry and behavioral sciences Daniel Abrams, Ph.D. told Stanford News: “Just as an infant knows to tune into her mother’s voice, an adolescent knows to tune into novel voices. As a teen, you don’t know you’re doing this. You’re just being you: You’ve got your friends and new companions and you want to spend time with them. Your mind is increasingly sensitive to and attracted to these unfamiliar voices.”

Rewarding signals

All of these changes have to do with the reward centers of the brain. The brain prioritizes stimuli (like certain voices) that activate the reward centers. Unfamiliar voices start to stimulate the brain more around age 13. So while they are still capable of listening to their moms, teens simply don’t get the same level of stimulation and comfort from her familiar voice as they did as children.

In most ways, this is a good thing. It’s a sign that their brain is maturing and getting ready to engage with the world independently from their parents. This allows them to become “socially adept outside their families” – something required for any adult.

How things change over time

Under the age of 12, kids can identify their mom’s voice with great precision, and it tends to activate reward centers and emotion-processing regions of the brain. But if you’re a mom, take heart. Your voice is what sets your child’s brain up for their social and emotional future.

According to co-author Percy Mistry, Ph.D., “The mother’s voice is the sound source that teaches young kids all about the social-emotional world and language development.”

But things change as we grow up. And the switch towards privileging unfamiliar voices between ages 13 and 14 happens at the same time in all genders. — WTF fun facts

Source: “The teen brain tunes in less to Mom’s voice, more to unfamiliar voices, study finds” — Stanford University

WTF Fun Fact 12974 – The Sex Lives of Constipated Scorpions

The Ig Nobel Prizes have been awarded to 10 unusual (or unusually unuseful) scientific research projects each year since 1991. While it’s all in good fun, we couldn’t help but do a double-take this year at one of the winners – a team that published a study on the sex lives of constipated scorpions.

Constipated scorpions have it rough

Solimary García-Hernández and Glauco Machado of the University of São Paulo in Brazil won the 2022 Ig Nobel in biology for trying to discern whether being constipated affects a scorpion’s sex life. (To be fair, we can’t help but think being constipated is kind of a bummer for any creature.)

According to an Associated Press story on the prizes, “Scorpions can detach a body part to escape a predator — a process called autotomy. But when they lose their tails, they also lose the last portion of the digestive tract, which leads to constipation — and, eventually, death, they wrote in the journal Integrated Zoology.”

“The long-term decrease in the locomotor performance of autotomized males may impair mate searching,” they wrote.

Ok, maybe constipated humans don’t have it so bad after all.

Why even study this?

So, this particular study came about in an interesting way. The paper’s lead author Solimary García-Hernández had long been studying the scorpion species Ananteris balzani.

This species has an interesting characteristic – they shed their tails to help them escape a predator.

According to Smithsonian Magazine (cited below): “It was a big surprise in 2015 when she, while working as part of a larger research team, found that Ananteris scorpions are capable of shedding their tails. “Autotomy”—the process of dropping a body part to escape a predator—was until then known to have evolved in only a handful of animal lineages like starfish, spiders and certain lizards.”

Ok, so we totally understand wanting to look more closely into that interesting fact, especially since it turns out that when lizards shed their tails, it can impact their ability to walk but doesn’t kill them. However, scorpions are different.

When Ananteris scorpions shed their tails, their digestive tract backs up with feces, and they get swollen and die within around 8 months.

That’s weird since animals don’t typically adapt in a way that’s fatal to them unless it somehow helps their species. In this case, the extra months likely give them more time to reproduce. And that’s where studying their sex lives comes in.

The sex lives of constipated scorpions

García-Hernández decided to monitor the post-tail life of these scorpions to see how tail loss impacted their ability to reproduce.

“The team then set up a series of matings between stump-tailed and intact scorpions. García-Hernández predicted that autotomized male scorpions would be less successful at mating than their fully endowed counterparts, since the tail plays an important role in their complicated mating ritual.”

Male scorpions use their tails both to show off to mates and during intercourse, so not having a tail should make mating difficult. However, it turns out they just used their stump and were just fine.

It was a different story for females, however.

According to Smithsonian, “when the team explored the reproductive costs paid by stump-tailed females, the story was different. They found that tailless females, while able to mate successfully, went on to have 20 percent fewer offspring than intact females.

The reason for this difference? The five-month scorpion pregnancy provides a lot of time for females to get more and more constipated, says García-Hernández. She hypothesizes that the buildup of feces caused by the loss of the anus is either toxic to the embryos or that the feces simply crowds out the developing scorplings. This latter hypothesis is supported by the fact that a severely constipated scorpion can weigh 30 percent more than it did before it lost its tail. By comparison, that’s equivalent to a 150 pound person gaining 45 pounds of poop weight.” — WTF fun facts

Source: “For Constipated Scorpions, Females Suffer Reproductively. Males, Not So Much.” — Smithsonian Magazine