Curio Cabinet

Who would have ever thought that the prey would have something to thank the predators for? Researchers at Wageningen University & Research in the Netherlands have published a paper in Science Advances showing how predators drive the evolution of their prey. The experiment involved guppies, chosen for their quick reproduction cycles, living in an enclosed environment. Researchers selectively introduced and removed predators from the controlled environment and observed how the guppies adapted. As expected, the presence of predators influenced the natural selection within the guppy population, but to a surprising degree. Within just three generations, the guppies responded by changing both their rate of reproduction and their body size. More specifically, the female guppies began reproducing earlier in life and produced more offspring. Meanwhile, the males’ bodies changed to improve their agility with shorter tails and smaller reproductive organs. Overall, the guppies grew smaller with each generation. The experiment influenced the evolution of the guppies purely with predation pressure, meaning that there was no sexual selection taking place at all. In the wild, female guppies are more likely to breed with colorful males, but such features were not affected during the experiment. The researchers were therefore able to determine exactly which physical features evolved due to predation pressure, and which ones were the result of other factors. While we already knew that predation is a major driver of evolution, this experiment surprised researchers by showing just how quickly it can cause change. Those are some speedy guppies.

[Image description: A colorful guppy fish against green aquatic plants.] Credit & copyright: 5snake5, Wikimedia Commons. This file is made available under the Creative Commons CC0 1.0 Universal Public Domain Dedication.
 

Here’s a look at everything, near and far. Astronomers at the newly-operational Vera C. Rubin Observatory just released the first batch of images from the state-of-the-art facility, and it’s revealing new things about the solar system while giving a clearer view of the greater universe. Named after American astronomer Dr. Vera C. Rubin, the observatory was designed to push the boundaries of what is possible with ground-based telescopes. That’s fitting, considering that Rubin herself pushed the envelope of astrophysics during her lifetime. Her most significant achievement was finding unequivocal evidence for the existence of dark matter.
 
Located in Cerro Pachón in Chile, the Rubin Observatory is equipped with the largest camera ever built and is capable of capturing images at 3,200-megapixels. Its main purpose—for now—is to take a survey of the sky continuously for the next ten years. Its decade-long mission is off to a strong start with an initial batch of images featuring distant galaxies and Milky Way stars in unprecedented clarity. Its first ten hours of observation alone revealed 2,104 asteroids within the Solar System that have never been seen before (thankfully, none of them are on their way to crash into Earth anytime soon). When all is said and done, the observatory will gather around 500 petabytes worth of images, a veritable treasure trove of space imagery. It also has one other purpose. Its ability to observe dim and distant objects could prove useful in the search for the fabled “Planet Nine,” which (if it exists) orbits the sun every 10,000 to 20,000 years. It seems that the more you can see, the more there is to find out.

 
[Image description: A starry night sky with a line of dark trees in the foreground.] Credit & copyright: tommy haugsveen, Pexels

These humped heroes sure know how to beat the heat. As a heat dome scorches much of the U.S. this week, it’s a good time to learn about an animal who wouldn’t mind these temperatures at all. Camels are Earth’s largest desert-dwelling animals. While most desert animals evolved to be small so that they could escape the scorching heat by burrowing or seeking out slivers of shade, camels took a different approach. They evolved large, portable energy-conservation tanks in the form of humps.
 
Contrary to childhood legends, camels’ humps don’t actually contain water. Rather, they’re full of fat, from which their bodies draw energy throughout long treks in the heat. This allows them to eat and drink very little while on the move. In fact, camels can survive around a week without water and several months without food, even while walking up to 20 miles a day in scorching temperatures.
 
Camels are part of a group of animals called ungulates, most of which are hooved. Camels, however, have soft foot pads with two large, hard toenails. Though there are seven species in the family Camelidae, only three are commonly called camels: the dromedary camel, Bactrian camel, and wild Bactrian camel. Dromedaries have just one hump while bactrains have two, but that’s not the most important difference between them. Dromedaries are a completely domesticated species, while some bactrian camels still remain in the wild, living mostly in northwestern China and the Gobi Desert in southwest Mongolia. While bactrains are critically endangered, dromedaries are fairly common, making up about 94 percent of Earth’s camel population.
 
So, why domesticate camels? For people living near deserts, it makes perfect sense. Dromedary camels can comfortably carry up to 330 pounds over long distances, and even more during short trips. Humans can comfortably ride them, which makes them invaluable for crossing areas where roads are scarce. Camels can also be used for milk and even meat, making them one of the most versatile domesticated animals around. That’s not to say that all dromedaries live a sheltered life. Central Australia is home to a sizable population of feral dromedaries, whose ancestors were brought to Australia by 19th century European settlers. As an invasive species, they’ve caused some harm to local wildlife by eating native plants and drinking valuable water that native animals need to survive. A hunting program allows for a certain number of these feral camels to be killed each year, but their population remains fairly large. Some dromedaries are just determined to walk on the wild side.

 
[Image description: A dromedary camel walking on a road beside a wooden fence and green trees.] Credit & copyright: A1000, Wikimedia Commons. This file is made available under the Creative Commons CC0 1.0 Universal Public Domain Dedication.

You just can’t beat this heat. This year’s summer is getting off to a brutal start for much of the U.S. as a heat dome stretches over multiple states. Heat domes are defined by suffocating heat and humidity which have a synergistic effect and make it feel even hotter than it actually is. While heat domes can cause heat waves, the two meteorological phenomena are not the same. The source of a heat dome’s elevated temperatures and humidity is a lingering high-pressure system in the atmosphere that prevents heat on Earth’s surface from rising. The high pressure comes from the jet stream after it weakens and deviates beyond its normal course. Until the jet stream corrects itself, the heat dome will continue to persist, and the longer it lasts, the worse it gets. Because the high pressure also prevents cloud formation, the sun’s rays beat down on the ground, making the heat dome hotter over time. Temperatures can easily exceed 100 degrees Fahrenheit, and it can feel tens of degrees hotter. Sometimes, a heat dome will dissipate after just a few days, but they can last for weeks.
 
In 1995, a particularly devastating heat dome claimed over 700 lives in the Chicago area in less than a week. Even worse, a heat dome over the southern Plains back in 1980 claimed around 10,000 lives. Part of what makes a heat dome so dangerous isn’t just the heat itself, but the humidity, which makes it impossible for sweat to effectively wick excess heat away from our bodies. When a heat dome forms over a given area, it’s best to avoid venturing outside. The best policy is to stay in a climate-controlled area and drink plenty of water until the heat dome dissipates. Some problems are better avoided than faced head on.

 
[Image description: The sun shining above a treetop in a clear blue sky.] Credit & copyright: TheUltimateGrass, Wikimedia Commons. This file is made available under the Creative Commons CC0 1.0 Universal Public Domain Dedication.

Chromosomes are fundamental to creating life, but you can have too much of a good thing. Just one extra copy of chromosome 21 is responsible for causing Down syndrome, which itself causes many different health problems. Now, scientists at Mie University in Japan have developed a way to remove the extra chromosome using CRISPR technology. The chromosome responsible for down syndrome is called trisomy 21. When someone is born with this chromosome, they end up with 47 total chromosomes, rather than the usual 46. This results in a range of health effects, including congenital heart problems and cognitive issues.
 
Until recently, genetic disorders like Down syndrome were considered untreatable, but medical advancements have been changing things. Back in 2023, the FDA approved Casgevy and Lyfgenia, both of which are cell-based gene therapies to treat sickle cell disease (SCD) in patients over age 12. The treatments were developed using CRISPR-Cas9, which utilizes enzymes to accurately target parts of the DNA strand responsible for the disease. It’s the same technology used by the scientists at Mie University, who targeted trisomy 21 in a process called allele-specific editing, or, as one of the researchers described, “Trisomic rescue via allele-specific multiple chromosome cleavage using CRISPR-Cas9 in trisomy 21 cells.” The process was performed on lab-grown cells which quickly recovered and began functioning like any other cells. It’s unlikely that this new development will signal an immediate reversal of Down syndrome, as it will be a while before the treatment can undergo human trials. One particular hurdle is that the treatment can sometimes target healthy chromosomes. Still, it shows that CRISPR-Cas9 can be used to remove entire chromosomes and that cells affected by trisomy 21 can make a full recovery with treatment. That’s a lot of medical advancement in one crisp swoop.

 
[Image description: A diagram of a DNA strand with a key for each labeled part. The key from top to bottom reads: Adenine, Thymine, Cytosine, Guanine, and phosphate backbone.] Credit & copyright: Forluvoft, Wikimedia Commons. The copyright holder of this work has released it into the public domain. This applies worldwide.