Tag: origin

Posted in Psychology & Medicine

Laughter

Posted on by Jinavie

We laugh when we are happy. Laughter provides us with happiness and is the best medicine available to us, relieving the pain and stress of life. In fact, when we laugh we secrete a neurotransmitter called endorphin, which as the name suggests (endo(inside) + morphine), has the same properties as morphine.

What makes us laugh? The best theory to date is that laughter is an instinctive response to the passing of danger (also called the relief theory). For example, if our ancestor came across a predator but it passed by without noticing him, he would have laughed in response to the relief he felt. Others would see from his laugh that the danger had passed and laugh also (possibly explaining why laughter is contagious).

This theory also explains why humour makes us laugh. When you throw a joke, you are essentially giving the other person a “cognitive riddle” with a logical inconsistency. This inconsistency causes the recipient’s subconscious to become confused: “Why is it funny? Why can’t I understand it?”. As jokes are fundamentally a “surprise” to the other person’s mind, they try to solve it and figure it out whether it is a danger or not. If they get the joke, the inconsistency is solved and the person feels relief (as it has been revealed that the confusion brought on by the inconsistency was not dangerous). Once the confusion passes, the person laughs in response. But if the person does not get the joke, the “danger” has not passed and the person does not laugh. This is the basis of one of the laws of comedians: “if the audience is confused, they do not laugh”.

Laughter is beneficial for your health. Frequent laughter lowers the blood pressure, boosts the immune system, relieves pain and lowers the levels of stress hormones such as cortisol. Laughter is especially good for your mental health, therefore having a five-minute laughter yoga session every day where you just laugh as hard as you can will help you lead a happier life. However, ironically laughter can kill you too. Cases of “death from laughter” have been recorded since ancient Greek times to the modern day. The cause has not been identified but it is known that intense laughter can cause cataplexy, which is a paralysis induced by extreme emotions. It is possible that intense laughter overloads the nervous system and causes a heart attack.

Whatever it is, anything is toxic in excess.

Posted in Science & Nature

Mitochondrial Eve

Posted on by Jinavie

We were all born from our parents. Our parents were all born from our grandparents. Everyone has a family tree and a root. If so, is it possible to find the beginning of mankind – our true “root”?

Our cells have an organelle (a part of the cell) called mitochondria. Mitochondria act as the cell’s engine and allow the cell to generate energy through respiration. An interesting fact about them is that they are not originally “ours”. About 1.5 billion years ago, there was an event where a prokaryote (cells without a nucleus, like a bacteria) invaded (or was eaten by) a eukaryote (cells with nuclei, like our cells). The prokaryote and the cell began a symbiosis and the prokaryote became a part of the cell.

Due to the external origin of mitochondria, they have a different genome to us. This is called mitochondrial DNA, shortened to mtDNA, which allows mitochondria to divide and synthesise proteins without the help of the host cell. It used to be a completely independent organism, but it has lost some of its functions to the cell.

mtDNA is inherited in a different way to normal DNA. Normally we receive half of our mother’s and half of our father’s genes, but we only inherit our mother’s mtDNA. This is because sperm keeps mitochondria in the tail which is lost during fertilisation, meaning our father’s mitochondria cannot be inherited. The only way to gain mitochondria is from those in the cytoplasm (the material that fills cells) of our mother’s egg. This is known as maternal inheritance.

Using this information, scientists compared a large sample of people’s mtDNA to turn back the clock. Knowing that a child and its mother share the same mtDNA and the mother and grandmother share the same mtDNA, we can analyse mtDNA to find the origin of mankind, or our first common female ancestor – also called Mitochondrial Eve.

Mitochondrial Eve is estimated to have lived 200,000 years ago in Africa, thus she is also known as African Eve. Her mtDNA is an ancient heirloom passed along generation after generation to us, as evidence of evolution. Every living person on the face of the Earth is a descendant of her. So in some ways, it could be said that we truly are one big family.

Posted in History & Literature

Buttons

Posted on by Jinavie

There is an extremely simple way to tell if a shirt or jacket is designed for a man or a woman – buttons. A male garment traditionally has buttons on the right side while female garments have them on the left side.

The reason for the male garment is that having the button on the right side is easier to button up when dressing oneself (given that he is right-handed). So why is this not the case for female garments? This is because during Victorian times, women were usually dressed by a maid or servant so it would be easier for them to button up a dress if it was on the left side. This theory is very plausible as zippers were not available then and dresses were mostly buttoned from the back. Even when women’s clothing started having buttons in the front, tailors were already accustomed to the traditional convention.

Alternate theories are quite interesting too. It is hypothesised that buttons on male clothing were modelled after a knight’s armour that would be latched on so that a right-handed opponent could not jam their pike through a seam. Contrary to the military origin of the male buttons, female buttons may be placed in such a way to allow the lady to easily expose her left breast – which is closer to her heart – to nurse her baby.

(Source: http://j-jm-m.deviantart.com/art/Button-66176952)