Third year Psychology and Biology student, James Hodson, shares a round up the most interesting things he has learned during his degree.
1. Antifreeze Frogs
There is a frog called the North American wood frog, which can survive being frozen and defrosted. It can survive having 65% of water in its body being frozen,
Special molecules in its blood known as nucleating proteins cause water in the blood to freeze first. This sucks in water from the cells in the frog, dehydrating them. These cells are stuffed full of sugar by the frog which support them and prevent damage, allowing them to freeze and thaw at will!
2. We do not see with our eyes
This sounds confusing at first, but bear with me! Essentially, we look and gather visual information with our eyes, but our brain constructs this into an image and lets us see. The light enters our eyes through the cornea and falls onto our retina its detected by rod and cone cells. The information from these cells is combined in the brain into images. Before this point it’s just individual bits of information about where there are certain lines or points of light.
3. Cheetahs have nearly gone extinct twice
It quite impressive really, on 2 occasions 100,000 years ago and more recently about 10-12,000 years ago at the end of the last ice age cheetah populations have plummeted.
Cheetahs have managed to recover both times from small populations. 12,000 years ago, it is suggested there could have been as few as 6 litters from which cheetahs recovered! This has however come at a cost. Cheetahs currently have very low genetic diversity, which means they are much more prone to disease.
4. Moth Pheromones
Female silk moths produce a pheromone with a great name – Bombykol, to attract male moths. Male moths can detect this from up to 11km away, using sense organs in antennae on their forehead.
5. Birds and Alligators breathe in the same way
When human’s breath air flows into and out of our lungs the same, the flow is bi-directional. However, scientists have discovered that in birds, and more recently in alligators too the airflow is one direction. The air moves around in a loop-like system before exiting the way it came in.
6. We mirror people we like
Psychologists have shown that we love to be included. This can lead to us copying the majorities behaviours consciously, even if we think it is silly. But it also happens unconsciously, especially with people we like. This can take the form of subconsciously copying their movements e.g. crossing our legs after they do.
It can even go as far as blinking in time with them. This is so fast that scientists suggest it must be unconscious, because if it were conscious there would be more of a delay.
7. Marathon Migrations
Some species of birds migrate depending on food availability and temperature. One particular species, the bar-tailed godwit, travels monumental distances.
For example, it flies non-stop from Alaska to New Zealand (~7,200 miles) at a minimum average speed of 33 mph over 8 days. This is the equivalent of sprinting 275 marathons back-to-back.
8. Masquerading Caterpillars
There are some caterpillars, who look and act just like a twig. They select branches with more twigs to improve this disguise.
This is not just so they are not spotted however! It is so if a predator notices them, they mistake them as a twig, and ignore them!
This masquerade is seen across the animal kingdom, with birds pretending to be tree stumps, praying mantises pretending to be leaves, and seahorses pretending to be seaweed! Praying mantises, like the ghost mantis, are noticed by prey and mistaken for leaves and harmless. This make it much easier for them to catch their prey.
9. SM, the Fearless Woman
There is a Women named SM by the scientific community to keep her anonymous who cannot feel fear at all. This is because she has Urbach-Wiethe disease, which causes damage to parts of her brain called the amygdala, which are typically associated with fear. She can feel other emotions like happiness or sadness perfectly normally, but simply does not feel fear at all.
10. Sunless Hydrothermal Vents
Hydrothermal vents often occur in volcanic regions and are cracks in the seafloor which superheated fluid flows out of. This fluid contains lots of minerals and metals from the bedrock, and this allows hydrothermal vents to support all kinds of life without sunlight.
This is possible through chemosynthesis which involves bacteria turning chemicals from the fluid into organic material or energy, which can then be used by other organisms.