The Coelacanth is a fish which lives off the coast of Southern Africa, 300 metres below the surface where light barely penetrates through.
In this twilight zone it lurks in caves during the day emerging at night to attack surface fish as they descend down and deep sea fish as they ascend to the surface. Coelacanths were believed to have fallen extinct 70 million years ago until a specimen was recognised in a South African fish market in 1938.
Its fins have a structure similar to the limbs of a tetrapod. Coelacanth are very rare and classified as endangered species. Lungfish, which share some characteristics with tetrapods, are not rare at all.
Found all over Africa, Asia and South America, they have the distinction of having both lungs and gills.
Tetrapods are all land living vertebrates from frogs, tortoises, birds, buffalos, lions and humans; and include animals that have returned to live in water including dolphins, whales and seals.
The importance of the Coelacanth and the lungfish is that scientists have wondered which one of the two is more closely related to tetrapods and by implication to humans. Consider the evidence.
The Coelacanth has a genome containing 2.8 billion units of DNA, about the same size of the human genome. The lungfish genome is much bigger at about 100 billion DNA units.
Because the Coelacanth has no known predator its genetic make up has evolved very slowly over millions of years. It is therefore often called a living fossil. It looks the same as it did 400 million years ago and behaves with the necessary arrogance.
The Coelacanth, as mentioned above, waylays fish going about their business. It does not extract a bribe, just eats them.
The lungfish is a freshwater hustler omnivore eating what comes its way; feeding on fish, insects, crustaceans, worms, amphibians and plant matter. Even though our behaviour, bar a few, is more closely related to lungfish, in DNA terms we are closer to Coelacanths. Scientists have found one Coelacanth gene that in animal species builds the placenta.
Even though Coelacanths have no placenta, they produce extremely big eggs, with a good blood supply, that hatch inside the mother’s body.
Further, when scientists took some DNA material from Coelacanth and injected it into mice, the DNA material encouraged mice genes to make a limb. So when you imagine the first fish that ventured from water to land, the Coelacanth is the closer relative.
The image might be one of a hesitant fish probing looking around and then ducking back into water or it might be one of a confident fish striding out of the water. Either way, thereafter it took humans thousands of years before footwear evolved to the present day where especially for women fashion dictates that they wear very high heels that would make a lungfish gasp at the Coelacanth’s relatives.
A shoe is meant to fit on the distal part of the lower limb, the foot. The foot consists of flexible structures of bones, joints, muscles, and soft tissues that let us stand upright and perform activities like walking, running, and jumping.
The foot divides into three sections; the forefoot containing the five toes and the five longer bones; the midfoot, which is a pyramid-like collection of bones that form the arches of the feet; and finally the hindfoot, which is the heel and ankle.
A shoe should protect and support these structures. But studies show that up to 90 per cent of women who regularly wear high heels report soreness, fatigue, numbness and bunions of the feet.
Long-term use can lead to knee osteoarthritis and higher risk of ankle sprains. It has been found that women who wear heels five days a week over two years can shrink their calf muscles by up to 13 per cent.
However, heels give the wearer a shorter stride, a supposedly more elegant gait and a superficial 'shaping' of the leg towards the slim. Given this, it is no surprise that women insist on wearing high heels.
Some realise the folly of their habits and pack their car boots and bags with an assortment of shoes for the different minutes of the day.
But studies have also shown that women who swap their heels for flats at the end of the day may also do more harm than good.
This is because, over time, walking in heels causes calf muscles to become shorter and weaker. Switching back and forth strains these shortened muscles are stretched causing further pain and discomfort.
And when it comes to the evening out scientists have also measured the effects of high heels on the typical salsa dance step.
They found that increasing heel height could cause an increase of impact forces in the forefoot and a reduction in the heel region. That is increased soreness and injury to the forefoot.
Almost inevitably in the long run the woman who wears high heels moves around a lot less.
High heels can lead to atrophy of muscles used for walking. Eventually such a woman beautiful as she is; the lower limbs are good only for swimming like a fish. At which point she will have no alternative but become a mermaid and return to sea. Swimming is good exercise.