The strange structure of the elephant's body can actually prevent cancer? | Nature Trumpet

Welcome to the Nature Trumpet. In the past half month, we have collected the following natural news and research worth reading:

1) Adopted and then abandoned by enemies, the miserable life of the little red-tailed hawk

2) Why don’t elephants get cancer? The secret lies in their testicles

3) El Niño is coming, and marine iguanas are facing famine

4) Batman is out to chase away the moths in the greenhouse

5) Why do biting flies flock to blue traps?

6) When under pressure, rattlesnakes need friends too

Taffy the Red-tailed Hawk

Recently, a red-tailed hawk has touched the hearts of many people - it was first adopted by its natural enemy, the bald eagle, but unfortunately died.

At first, wildlife photographer Doug Gillard accidentally captured a magical event: a little red-tailed hawk was captured by a female bald eagle and was about to become a dinner; however, when the bald eagle returned to the nest, it suddenly changed its mind and adopted the little red-tailed hawk .

A Red-tailed Hawk (Buteo jamaicensis) being captured by a Bald Eagle | Doug Gillard

This is very unusual - bald eagles and red-tailed hawks have always been enemies . This bald eagle was raising a nest of children, and perhaps it was the maternal instinct that made it suddenly decide to raise the little red-tailed hawk. Bird watching enthusiasts named the little red-tailed hawk "Tuffy". Under the camera record, the bald eagle mother took care of Tuffy as carefully as feeding her own children.

A loving family (left: Lola, the bald eagle’s biological child; middle: Taffy; right: the bald eagle’s “stepmother”) | Doug Gillard

However, the good times didn’t last long. One month later, when Taffy was begging for food from her stepmother in the nest, her stepmother suddenly started to attack her and threw her out of the nest again and again . A few days later, someone found Taffy lying motionless on a nearby tree, with his eyes closed and listless, while her stepmother was feeding the squirrels she had just caught to her own children. People tried to rescue Taffy, but it was too late. Taffy, who had not eaten for several days, had already died.

Taffy just left the nest | Doug Gillard

Scientists believe that it may be because of the way Taffy flew recently that the "stepmother" realized that it was a red-tailed hawk and not her child at all , so she attacked it. The direct cause of Taffy's death was hunger - after being kicked out by the bald eagle "stepmother", Taffy lost the protection of his parents and had no food, so death was almost inevitable.

Testicles and cancer prevention

Elephants are less likely to get cancer, and the secret may lie in their testicles.

Elephant | Byrdyak / Wikimedia Commons

Theoretically, animals with larger bodies have more cells that are likely to become cancerous . However, as the largest mammal on land, elephants are no more likely to get cancer than other animals. Scientists have found that this is because they have 20 copies of the gene encoding the p53 protein on a single chromosome (humans only have one ) - p53 can regulate gene repair. If a cell is severely damaged and may cause cancer, p53 will kill the cell to prevent it from continuing to proliferate.

But what does this have to do with testicles?

Many animals, including humans, have their testicles outside the body to facilitate heat dissipation and cooling - sperm is very sensitive to temperature, and DNA is more easily damaged at high temperatures, which is not conducive to the production of healthy sperm. But strangely, elephants' testicles grow inside the body, which is not convenient for heat dissipation, and sperm are always in a higher temperature environment .

A sample of a pig's testicles, also outside the body | Wagner Souza e Silva / Wikimedia Commons

Scientists speculate that the 20 copies of the p53 gene in elephants are just right for the testicles in the body - more p53 can regulate gene repair, reduce DNA damage, and keep sperm healthy even at high temperatures . By chance, these 20 copies of the p53 gene not only protect sperm, but also play a natural anti-cancer role.

Galapagos Marine Iguana

This year's El Niño phenomenon will not only bring high temperatures, but will also bring a severe famine to marine iguanas.

El Nino is a phenomenon of persistent and significant warming of sea surface temperatures in the eastern and central Pacific Ocean near the equator . This year's El Nino is one of the most severe in recent decades . For the marine iguanas of the Galapagos Islands, they will have to lose their food - seaweed.

Marine iguana eating seaweed | Derek Keats / Wikimedia Commons

Marine iguanas can live up to 60 years and can dive to a depth of 12 meters and stay underwater for an hour in search of food. In the past, when El Nino occurred, a large number of algae died and the marine iguanas had to starve . During the 1983 El Nino, the number of marine iguanas in the Galapagos Islands dropped by 60%; in 1998, the same disaster struck and the number of marine iguanas on some islands dropped by 90%.

Researchers X-ray marine iguanas to study their length changes | BBC Earth

The IUCN said that this El Niño is so severe that the number of marine iguanas may drop by another 90% , and some subpopulations may even disappear completely.

El Niño also affects the size of marine iguanas. Scientists have found that in order to survive El Niño, marine iguanas shrink by an average of 5 cm in length - being shorter consumes less energy and requires less food, thus having a higher chance of surviving famine.

Drone pest control

The moths, pests in the greenhouse, recently encountered a terrifying natural enemy - the "Batman" drone.

The researcher was inspired by mosquitoes. One night, the researcher was unable to sleep because of the buzzing of mosquitoes in the bedroom, so he made a drone to hunt mosquitoes. Then he suddenly thought: Why not use drones to hunt pests in the greenhouse ?

The company that made the "Batman" drone is called PATS, which means the sound of slapping a mosquito to death in Dutch | PATS

The researchers have tailored a combination of measures for moths. First, there are infrared cameras in the greenhouse that can automatically distinguish moths from other flying insects based on the frequency and size of their wingbeats, ensuring that species that are beneficial to crops (such as pollinating bumblebees) are not affected. Once a moth flies into the camera's detection range, a drone will be dispatched to chase the moth, making sounds similar to the moth's natural enemy bats, and then chopping them up with propellers .

Different moths may have different natural enemies, such as bats - the researchers also thought of this. They carefully selected the predators corresponding to each moth species and found the sounds that each moth fears the most (moths: Thank you for listening to me).

After Batman hunts down the moth, he returns to the wireless charging station | PATS

After hearing the sound of the "Batman" drone, the flying behavior of the moths changed immediately. Most moths fell to the ground , completely forgetting about mating or destroying plants. Some moths were even frightened and motionless and never flew again. This powerful tool for pest control can greatly reduce the use of pesticides , not only reducing pesticide residues on crops, but also protecting other beneficial insects.

Flies are attracted to blue

Flies such as tsetse flies and horse flies bite humans and animals. They feed on blood and spread diseases between humans and animals. It is not easy to eliminate them, but fortunately they will be fooled by blue traps , and this strange weakness is also used in fly control. But why do they fly to blue traps?

A blue trap used to catch tsetse flies | Rob Merkus / Wikimedia Commons

Scientists previously speculated that the blue surface might look like a cool place to flies , and they wanted to fly over to rest. But this is just speculation, as flies' vision is too different from that of humans - humans only have photoreceptors for red, blue and green light, while the compound eyes of flies such as tsetse flies and deer flies have five types of photoreceptors.

The eyes of a deer fly are actually pretty | USGS Bee Inventory and Monitoring Lab

Until recently, scientists finally found the answer. They used AI to simulate the visual receptor information of flies and found that flies actually regarded blue as the animal they wanted to bite .

This may sound strange, as the animals that flies bite are basically not blue. But according to the simulation, flies can use the relative strength of blue and green photoreceptor signals to judge whether it is an animal or a plant in front of them - if the green signal is more obvious, it means it is likely to be a leaf; otherwise, it is an animal. Therefore, when they see the blue trap, they will naturally fly over, thinking that they can have a good meal.

Experiments also show that this explanation is very convincing - flies caught in blue traps are generally in a hungry state.

Rattlesnakes need friends

When we are stressed, we need comfort from friends - the same goes for rattlesnakes.

The researchers captured 25 South Pacific rattlesnakes (Crotalus helleri), attached electrodes to them to monitor their heart rate, and then placed them in a dark and closed barrel, repeatedly hitting the barrel wall to cause them stress. The results showed that the heart rate of the stressed snakes increased, but if they were with their own kind, their heart rate would quickly return to normal , as if their companions shared their stress; if they were alone or with a rope, their heart rate would recover very slowly.

I'm a little stressed | Chelsea Martin

Being with people of the same species can reduce stress, a phenomenon known as social buffering . Social buffering is very common in mammals, and the stress-reducing effect is also related to the cause of stress, the relationship with peers, and the mental state of peers. This study is the first to discover social buffering in reptiles.

The researchers also compared mountain snakes with lowland snakes. Although mountain snakes overwinter in groups, while lowland snakes mostly overwinter alone, the social buffering effect was the same between the two types of snakes. In short, regardless of whether the snakes normally hang out with friends, they feel more relieved when they are stressed by the presence of friends .

However, if you see a snake, run away instead of asking if it has friends | Raveendrasharma Giritharasharma / Wikimedia Commons

References

[1] https://phys.org/news/2023-07-bay-area-birdwatchers-tuffy-kidnapped.html

[2]https://www.sciencedirect.com/science/article/pii/S0169534723001350

[3]https://phys.org/news/2023-07-el-nino-vulnerable-galapagos-iguana.html

[4]https://phys.org/news/2023-07-exterminating-greenhouse-pests-bat-inspired-drones.html

[5]https://royalsocietypublishing.org/doi/10.1098/rspb.2023.0463

[6]https://www.frontiersin.org/articles/10.3389/fetho.2023.1181774/full

Author: Cat Tun

Editor: Mai Mai

This article comes from GuokrNature (ID: GuokrNature)