Image source: yourgenome.org - Photo: 2019

The Slow Process That is Evolution

Viewpoint by Dr S.S. Sira*

TORONTO (IDN) – Evolution is a slow process. It is surprisingly orderly. Everything that is observed obeys laws that have been enunciated by science. Only in the last 100 years much progress has been made.

Physics of the structure and the properties of the atom have been worked out. The fundamental particles are the quarks. Quantum mechanics has been successfully applied to explain many phenomena, often counter intuitive to common experience.

It is worth our while to explore the course of events in general terms and examine on the way how things have evolved since creation began. Planet Earth is 4.5 billion years old. When it had cooled down life began.

Dr S.S. SiraAs an aside, in 2004 NASA sent a probe into the tail of a comet to analyse the structure and composition. It was quite a surprise to find glycine, one of the four essential amino acids found in all living organisms on earth. It is very likely that planet Earth was inoculated by organic compounds from outer space.

It is thought that the first life forms were the bacteria. ss

The basic unit is the cell, and each and every cell contains a copy of the genome. The genome can be compared to a computer which is equipped with all the software ever produced and the machinery to manufacture anything ever needed by the organism. It is potentially capable of producing any type of cell.

Each cell has a lifespan but to ensure its continued survival, specialized cells are able to procreate usually by a sexual process. So, the cell never dies in reality.

There is cooperation. For example, every human cell contains an organelle called mitochondrion. This is thought to be a bacterium that lives in the host cell in a symbiotic relationship. It supplies the energy needs of the cell and the cell in return provides all the necessities the bacterium needs to continue to survive within the cell. A very cosy relationship indeed. Each time the cell divides, the mitochondrion divides. In fact, it is believed that the entire body is simply a vehicle for the perpetuation and survival of the mitochondrion.

It is often asked how is it that if evolution has progressed, we still see bacteria, viruses and so on. It should be recognised that bacteria and viruses have evolved to perfection in their respective category. Each evolves at its own pace which is determined by environment and other factors. For example, Homo sapiens societies have evolved according to environment and geographic location, to name just two. Nevertheless, each species and sub-species has developed fully biologically.

Lucy, the skeleton of a female of the hominin species classed as Australopithecus afarensis, fell in the Olduvai Gorge in Tanzania some 3.5 billion years ago and is on the way to becoming a hominid – not quite human as yet.

Lucy skeleton reconstruction at the Cleveland Museum of Natural History - CC BY-SA 2.0In Eurasia 40,000 years ago Neanderthals, now definitely human, were living in caves as hunter gatherers. Agriculture started about 8000 years ago. In Mesopotamia, the region between the Tigris and the Euphrates rivers provided fertile ground for settlements.

Contemporary civilised societies include the Indus Valley (more correctly, Harrapan) civilisation, that of the Egyptians and the Hittites. In Central and South America were the Mayans and Aztecs civilisations respectively, which developed independently. There were various scripts: the Hittites had the cuneiform writing, the Egyptians the hieroglyphics as did the Mayans and the Aztecs. These scripts have been deciphered.

The Indus Valley script remains somewhat elusive but appears to be similar to the Hittite cuneiform script. Recent discoveries indicate that the script closely relates to Brahmi script. The language was Sanskrit.

It is to be noted that Indus Valley civilisation artefacts have been recovered from a vast area stretching from the Caspian Sea in the north, Baluchistan in the west, Afghanistan, Pakistan, Gujarat and parts of India up to Burma in the east.

Some historical facts relating to this region are pertinent.

In 500 BC, a Greek called Democritus visited southern India and learned that the smallest part of matter was the atom. He also discovered that the Indians were measuring distances to various celestial bodies and were adept with the use of the zero. In 350 BC, Alexander’s teacher Aristotle included this information.

The Greeks appear to have had long contacts with the Indians. Chandragupta 1 of the Gupta dynasty had filial relations with the Greeks. He is known as Sandrokotos. In 323 BC, Alexander the Great was chasing the Persians across Asia. In India he met his match in Porus and a defeated Alexander died on the way home. He had been given a safe passage after leaving behind princess Roxana as a hostage. There were other Greeks like Seleucus who followed Alexander and met a similar end.

In terms of chronology, it is to be noted that Gautama Buddha (1258-1178 BC) and Mahavir (1244-1172 BC) of the Jains were contemporaries. These dates are at variance with commonly accepted dates for these two individuals. In any event they were both familiar with the ancient Indian scriptures commonly known as Vedanta. This of course means that the Vedanta, which includes the Upanishads, was already formulated and much discussed among scholars, placing it between 3000 BC and 5000 BC. 

There is a claim that the Rig Veda, part of the Vedanta, is nothing but physics in code. In fact, modern-day science and Vedanta converge on this. The Vedas maintain that in the beginning there was nothing and it was very cold, later warming up to create the universe that we now have. This was to continue to expand for a time then start contracting to a cold crunch and the cycle begins again. Modern science has similar ideas, except the Big Bang starts from nothing, heats up and expands, quickly at first and then more slowly.

The age of the universe counting from the Big Bang is about 15 billion years. Our Sun and all the visible universe are this age. How long it will go on for is unknown. It seems both time and space were created at the time of the Big Bang.

We are not the centre of the universe

Our Sun is in one of the arms (Sagittarius) of our galaxy, the Milky Way. Another nearest sun called Alpha Cenrauri is four light years away. That is to say, it will take four years travelling at the speed of light at 186,284 miles per second to reach Alpha Centauri. It will be recalled that it took three days for the Apollo astronauts to reach the Moon travelling at 27,000 miles per hour. Our neighbouring galaxy Andromeda is on a collision course with our Milky Way galaxy. A cosmic dance is in store.

It is worthwhile noting that Man is the only animal that has learnt how to communicate and leave a permanent record. This capacity is the only difference between any other living being and a human being.

So, how did life begin?

It is thought that life began in what are called thermal vents at the bottom of the oceans. Chemicals dissolved in water in microtubules in the vicinity of the vents are thought to be the precursors of living organisms which in turn evolved to become unicellular microorganisms.

Two classes of unicellular micro-organisms are known. They are the Bacteria and the Archaea. Both were the dominant forms of life. The Archaea are supposed to have evolved to produce the human form.

It was a giant step when the cell organism developed chlorophyll which could trap light (photon) to convert that to sugar and use the latter as fuel for the cell. An example is the unicellular Euglena. It is a unicellular micro-organism cell which could qualify as being animal and plant at the same time. It is a plant that swims. Similarly, the Paramecium could be the earliest animal but there are other candidates, for example the Amoeba.

Soon there developed a relationship where the plant would produce oxygen as a by-product which the animal cell could use: the animal cell would produce carbon dioxide as a by-product which the plant could use. Then there was no stopping! Life evolved. If there were no Sun, there would not be any life as we know it.

The next step was the living cell. Individual and groups of cells organised themselves.

As noted, some cells organised themselves into groups and later specialised to perform different functions. But the basic architecture of the cell was retained.

In the centre is the nucleus which contains all the information the cell needs to function. Outside, the cytoplasm serves as a store or place for manufacture of whatever the cell is supposed to do.

Let us consider a specialised cell: the neuron. Each neuron has a nucleus containing nucleic acid. This is the DNA that will instruct the cell to make a specific protein. Like other cells, neurons possess ribosomes, mitochondria, etc, and the biochemical mechanisms of neurons are similar to those used by all the cells of the body. Neurons need oxygen constantly and the mature neuron does not divide. This is the main difference between the general body cell and the neuron.

Two classes of cells make up the brain: neurons, which are designed to receive, integrate and transmit information, and the glia, cells which do things like maintaining the neurons. They regulate the levels of substances they are used by neurons. They also provide structural framework for neurons. There are approximately 80 billion neurons in the human brain. The chimpanzee has seven billion.

Neurons have many branches. In fact, most of the brain consists of neuronal branches, which are the dendrites and the axons. As they emerge from the cell, dendrites divide many times. There is usually only one axon which divides into many branches at its terminus.

The neuron receives input via the dendrites. The axon carries the neuron output. The functional contacts between neurons are called synapses. These operate chemically. Most drugs that affect states of behaviour such as cocaine do so by modifying synaptic activity. Mental disorders like schizophrenia for example appear to be due to impaired synaptic mechanisms. Gautama Buddha (1258-1178 BC) and Mahavir (1244-1172 BC) of the Jains were contemporaries.

Memory and Mind

What about abstract ideas in the brain: where do they take place and how? What is memory? What is mind?

Memory is long-term and recent. There are areas where long-term memory resides in the cortex. The neurons here up actually undergo a permanent change so that when the neuron is stimulated the information can be recalled at any time. On the other hand, a telephone number may only reside in the recent memory area where it is almost forgotten as it has been used. In both cases, identical chemicals are used by the neuron.

What we term as mind can be viewed as made up of many parts which may include feelings, emotions, anxieties, and so on. Each of these attributes is located at different sites in the brain and each one is interconnected.

If, for example, the animal is experiencing an emotional situation, the area of brain dealing with emotions is accessed, and the neuron is stimulated which, in turn, may stimulate other areas of the brain to make the animal aware of the situation and take appropriate action such as fleeing from imminent danger. Previous similar episodes are accessed from the long-term memory area and the action may be modified to suit the occasion. 

More subtle thoughts such as thinking about creation may involve numerous individual sites where feelings, emotions, previous memory, etc. reside. All thoughts may be temporarily pooled, and an average taken. The final thought is usually the result of this average where one side of the average may be higher, for example a 60-40 split will favour the 60 and the appropriate thought associated with the 60 will be taken as the final course of action which, in turn, may just be a thought.

Sleep is controlled by neurons in an area called the reticular formation of the brain. Sleep rests the brain and provides time for restoring neural processes. Brain activity is reduced during sleep and there appear to be several phases of activity.

Deep sleep is different from rapid eye movement (REM) when the brain is highly active. It is during this phase that dreaming occurs. Typically, deep sleep is for 90 minutes and REM for 20 minutes. There may be four or five periods during the night. Most dreams are unpleasant, and most dreams are visual in sighted people but primarily auditory in blind people.

Consciousness is more complicated and defies definition. The phrase “being conscious” is being used ambiguously. When a person is asleep, he/she is not unconscious; a person in a coma is unconscious. The person who is asleep can be aroused but not the one in coma. When asleep or dreaming we are mentally and neurally active. When a person is comatose his/her brain activity is depressed and cannot be awakened.

Being conscious can have many meanings. We carry out many activities unconsciously. Being aware is perhaps a better term.

We can classify states of consciousness. Wakefulness is when the animal can respond to sensory stimuli, which can detect objects. The next level of consciousness is where the animal can demonstrate procedural memories. Animals can be trained.

The next level would be extended consciousness. There is recognition of past events and anticipation of future events. There is also the sense of self. Humans go beyond this and possess language, and also creativity.

* Dr. S. S. Sira, a retired surgeon based in Toronto, has deep interest in languages, literature, scientific and spiritual studies, and global affairs. Born in 1937 in Nairobi, he graduated from the University of Birmingham Medical School in 1963, was a surgeon for the Ministry of Health in Kenya, Lecturer at the University of Birmingham and Registrar at the United Birmingham Hospitals. He was also a Fellow of the Royal Colleges of Surgeons of England and Edinburgh and a Fellow of the Royal College of Surgeons of Canada. Between 1971 and 2017, he had a private surgical practice in Toronto. [IDN-InDepthNews – 14 August 2019]

Image source: yourgenome.org

IDN is flagship agency of the International Press Syndicate.

facebook.com/IDN.GoingDeeper – twitter.com/InDepthNews

Related Posts

Begin typing your search term above and press enter to search. Press ESC to cancel.

Back To Top