Tag: evolution

Posted in Psychology & Medicine

Cuteness

Posted on by Jinavie

The word cute is used in many different contexts: a girl saying a guy is “cute” could mean that she finds him attractive, while a guy saying a girl is “cute” may imply that they find them lovable but not in an attractive way. But essentially, cuteness can be described using the concept of neoteny.

What is neoteny? This is a concept in evolution where adults of a species preserve traits of youth. The end result is a mature organism that appears to be immature. A good example of this is the axolotl, which preserves its juvenile aquatic form (e.g. gills and overall look) in adulthood, even when they are living amphibiously. 
It has been hypothesised that human beings originate from neotenised chimpanzees, as a baby chimp has striking resemblance to a human. 

Cuteness and neoteny have an extremely intricate relationship. It is common knowledge that the most powerful attractors of care from an adult is cuteness. Almost every infant organisms have “cute” appearances that make people instantly feel warm and fuzzy. Ergo, being cute (i.e. neoteny) is a survival advantage as the young are cared for more until they are mature. This simple concept has led to the lengthening of childhood in humans, as children require a long time under the care of adults while they absorb knowledge and learn how to function in society. This also solved the problem of babies being born with immature brains (as the head is already too large to fit through the birth canal) and still having a chance at survival.

It has been scientifically proven that people with cuter faces are seen in a more positive light, more likely to be hired and less likely to provoke aggression in violent people (the human brain is wired to inhibit aggressiveness when faced with cuteness, presumably an effort to reduce child abuse and improve survival). In short, cuteness invokes maternal or paternal love and causes a sudden want to protect the cute thing.

This leads to another advantage of cuteness: attractiveness. Although beauty and cuteness are almost diametrically opposed, many men (and women) find “cuteness” to be appealing in the opposite sex. This is likely related to the brain confusing parental love with romantic love. A youthful look is also associated with fertility, which greatly influences a man’s subconscious choice of a partner. However, it is also true that because of this effect a man may see a cute girl only as a “little sister” figure they need to protect, rather than a potential love interest.

So what makes for a cute person? As stated above, these are traits of neoteny, or in other words:

  • large eyes
  • small nose 
  • small jaw and teeth 
  • flattened and rounded face 
  • large brain/forehead (causing the eyes/nose/mouth to be lower on the face)
  • hairless face and body 
  • limbs shorter than torso length 
  • legs longer than arms
  • upright posture

These characteristics are commonly used in animations and cartoons to boost the audience’s affection towards the character. This is especially the case in Japan where the a cultural obsession with cuteness is clearly evident.

Posted in Psychology & Medicine

Superbug

Posted on by Jinavie

Frequently on the media, the word “superbug” is used as if it were the new Black Death or the coming apocalypse. What is a superbug and why is it so feared?
Superbug is the colloquial nickname for drug-resistant bacteria. For example, one of the most famous superbugs is MRSA (methicillin-resistant Staphylococcus aureus). This strain S. aureus, a common bacteria found on skin and inside the nose, is resistant to a powerful antibiotic called methicillin and thus very hard to treat. Unfortunately, MRSA is most commonly contracted in hospital settings as patients are vulnerable to infections (e.g. after surgery) and hospitals are perfect breeding grounds for superbugs.

The cause of a “normal” bacteria turning into a superbug is due to the incorrect use of antibiotics. When antibiotics are used, they wipe out a significant portion of the bacterial population but fail to kill all of them in the first attack. The surviving bacteria are the more adapted ones that are able to withstand the harsh environment for a little longer. If the patient stops taking the antibiotics and the bacteria remains, these “drug-resistant” bacteria multiply to create a second infection that is resistant to the drug that was used previously. In fact, this is a classic example of natural selection in motion, except that the environmental change is man-made.
This is the reason why doctors are reluctant to prescribe antibiotics for diseases such as the common cold or viral diseases, as the risk of developing superbugs is greater than the benefit (which is zero in viral diseases as they do nothing) of the treatment. It is also why a course of antibiotics must be finished even if the patient is feeling well, so that even the surviving bacteria are eventually killed.

To show the potential risk of superbugs, the case of VRSA can be taken into consideration. When MRSA was first discovered, doctors found it very difficult to treat but luckily they had a secret weapon – vancomycin, one of the most powerful antibiotics known to mankind. However, they soon found that S. aureus and natural selection easily overcame this through a new strain called VRSA – vancomycin-resistant S. aureus. Here was a bacteria that could overcome the greatest weapon man had against bacteria, all because people were taking more antibiotics than needed and not taking the full course prescribed.

Thus, one of the growing problems of modern medicine is the development of new drugs so that we can make a comeback in the arms race against bacteria.

Posted in Science & Nature

Animal Hypnotism

Posted on by Jinavie

Animals can be hypnotised just like humans. Strictly speaking, it is not hypnotism per se but more of a trance or putting the animal to “sleep”. An animal in trance is in a state of complete relaxation and is immobile, staying still as if it is sleeping as its heart rate and breathing slows. After a certain amount of time, the animal wakes up and acts as if nothing happened.

For example, flipping a rabbit on its back causes it to stay still. It merely twitches its nose but its limbs are completely stiffened. An alligator shows the same response when flipped.
A pheasant can be put into trance if its stomach is rubbed and an iguana falls asleep when stroked on the head as the heat sensing organs are activated and they feel relaxed.
When stroked on its most sensitive part, the nose, a shark freezes from the intense sensation (considering a shark dies if it stops swimming, this must be quite a pleasurable feeling for the shark).
If you turn a lizard on its back and rub its stomach, its diaphragm and respiratory organs are compressed and oxygen supply is limited. This causes the lizard to “turn off”, falling into a trance.

These strange responses are most likely a survival instinct. For example, if a rubber hose with a knot on the end is held in front of a mouse, it will stay absolutely still. This is because it mistakes it for a snake and is frozen from fear. Also, predators such as snakes focus their vision around movement sensing and thus are blind to immobile objects. Similarly, rabbits and alligators mentioned above are playing dead to avoid danger.

Unfortunately, this instinct produces the opposite effects sometimes. Chickens are a good example.
When you press a chicken’s head against the ground and draw straight lines in front of it, it suddenly goes quiet as if possessed. Even after taking off the hand, it stays still. This technique was devised to make the process of cutting off the chicken’s head an easier task. Also, a chicken can be put into trance by gently tucking its head under its wing and then swinging the whole chicken side to side about 10 times. A turkey can be put to sleep the same way.

Posted in Science & Nature

From Cell To Birth: Growth

Posted on by Jinavie

After implantation, the embryo quickly grows from a ball of cells into what will be a fully-formed baby. However, it first needs a way to feed: the placenta.
It is an organ that actively takes nutrients and oxygen from the mother’s blood, exchanging it for the embryo’s waste products. It is extremely effective in keeping the fetus alive and protects it from infections or the mother’s immune system.
The blood is carried by the umbilical cord, which plugs into the belly button. This cord is the lifeline throughout term, and disrupting the blood supply will lead to permanent brain damage or even death.

In the first 10 weeks, the blastocyst develops into a very primitive disk-like object that shares no resemblance to a person. It keeps growing and differentiating at a rapid rate (almost doubling in size per week) until it forms an embryo that is more familiar, roughly about week 6. Interestingly, a human embryo looks almost identical to embryos of rabbits, chickens, turtles and fish, showing how all animals shared a common ancestor in the course of evolution. At this stage, the embryo has features such as gills, a tail and a fish-like appearance.

After 10 weeks, the embryo has grown to about 5~8cm (almost 10~20 times the size at week 6), and is now called a fetus. It begins to properly grow organs, and resembles a miniature baby with primitive features.
It continues to grow for the next 30 weeks, continuously relying on the mother for nutrition and life support.

Many different factors contribute to premature birth and IUGR (intrauterine growth restriction), which leads to the birth of a small baby. This may result in less developed organs (especially the lungs) and may affect the health of the newborn throughout its life. There are also many poisons known to harm the development of the embryo/fetus, such as alcohol, nicotine, cocaine, heroin and much more. These should be avoided from a few weeks before conception onwards (even after birth while breastfeeding).

By about 38 weeks, the lungs (the last organs to fully mature) are ready and the fetus is upside down. It is ready to leave the womb, and thus sends a signal to the mother, known as labour. This is when the arduous process of childbirth begins.

(Full series here: https://jineralknowledge.com/tag/arkrepro/?order=asc)

Posted in Science & Nature

Locust

Posted on by Jinavie

Locusts are a well-known symbol of destruction. The path of a locust swarm is bound to be left bare with nothing in sight. The most amazing feature of this insect is its reproductive abilities, which can be considered explosive. Furthermore, increased tactile stimulation of a locust’s hindleg causes it to release a neurotransmitter called serotonin, which causes mutual attraction, change of colour and increased consumption of food, thus priming them for reproduction. This allows them to reproduce even faster as the population grows, letting it easily reach numbers of billions in a short time. A large population then causes the locusts to swarm and migrate, and some species can cover distances of up to 500km. These swarms have been known to cover over 1000 square kilometres of land, and any food source in its path is instantly eaten up and used as fuel for reproduction. Because of this, locusts have become an icon of horror and destruction since ancient times as it can destroy crop fields within a matter of hours. This symbol is employed by the bible also, for example as the eighth plague of Egypt.

In some ways, a locust swarm can be seen as natural selection at its best. Explosive reproduction and voracious appetite is the basics of survival, skills that allow a species to beat the fierce competition of “the survival of the fittest”. Although humans curse locusts for destroying crop, they are not the only species that breed thoughtlessly and consume all resources in their path.

Posted in Science & Nature

Peppered Moth

Posted on by Jinavie

The peppered moth are a species of night-flying moth that have been studied extensively for over 200 years by biologists. They are known to be prime examples of the power of natural selection.

In England, there are two variants of this moth: one that has a peppery white appearance and another that is much darker, almost black. Originally, the white variant was much more common, as they could easily camouflage themselves on trees covered in light-coloured lichen.

However, during the Industrial Revolution, the heavy pollution killed the sensitive lichen causing trees to expose their dark bark. This caused the white moth to be extremely visible, making them easy prey for birds and other predators. The change in environment resulted in black moths, that used to be disadvantaged, to have a better chance of survival, causing the black moth population to become superior.

As people became more aware of air pollution and England began cleaning up its environment, lichen returned to the tree and the table turned once more – the dark moths were now better targets and were heavily preyed on. Instead, the white moth retook the majority position, thus showing how the environment affects which traits survive in a population.

Posted in Psychology & Medicine

Habit

Posted on by Jinavie

A habit is the automation of behaviour after many repeats. For example, if one fries an egg every morning, eventually frying egg becomes routine and can be done without even thinking. This is the most primitive form of learning.

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“Automation” suggests that a habit comes from the subconscious mind. Because of this reason, people often do not know they have certain habits, as they do not think about the behaviours that are already habits.
In psychology, habits are defined as “the reduction of sensitivity following repeated stimulation”.

The system of habituation played a crucial role in the evolution of life. Habits saved an organism time by using the subconscious mind to behave more efficiently and more quickly.
For instance, an animal that is faced by a predator usually flees before it can think about the situation. This is the result of practical experience that the animal had gained throughout its life, knowing that running is the best way to avoid being eaten. And because of the repeated behaviour, it has become habituated, subconsciously fleeing when the same scenario comes along. This way, the animal maximises its chance of survival.

However, in modern society this primitive system often causes harm rather than doing good. This is seen in cases of procrastinating students, impulsive consumers and businessmen who smoke every lunchtime (addictions are strengthened by habits). These phenomenon tend to be caused by stress brought on by life and the person’s desire to relieve that stress or resolve their discomfort. This is why having hobbies and interests to relieve stress regularly is a good way to prevent bad habits from forming.

Bad habits form quickly, but good habits seem to take longer. But this only appears so because of the short-term rewards. Bad habits tend to bring satisfaction and stress relief almost instantly, but the advantages of good habits only become apparent slowly (but also steadily). So, what is a way to develop good habits easier? Giving yourself a small reward (such as chocolate) after a desired behaviour is effective in reinforcing such behaviour, leading to habituation.
According to a research, the average time that takes for a habit to fully form is 66 days.