Over 200 year ago, the man who would change our understanding of biology and human history, Charles Darwin, was born.
This magnificent English scientist demonstrated that all species of life have descended over time from common ancestors in a joint publication with Alfred Russel Wallace.
Darwin’s work laid the foundation of the modern evolutionary synthesis which established natural selection as the basic mechanism of evolution.
In honour of Charles Darwin, I reproduce here a text I wrote two years ago , to demonstrate how natural selection works, even at social level.
It was titled: ‘On evolution by natural selection.’
Let me demonstrate how evolution by natural selection works by giving a few examples. Readers may further do research on the topic.
First, I will use biological systems and then show some of the social forms of the process.
Every time you are infected by a microorganism, say a bacteria or virus, your body fights them and when you use medication (in most cases antibiotic) you can eliminate the microorganism. However, part of the DNA of that organism will end up in your genome and may be transmitted to your children.
Imagine this happening over several generations. So, the fight against bacteria by your body on its own or by using antibiotic has been going on for thousands of years. That’s why close to half of human DNA is what biologists call retrotransposons, which are basically descendants of microorganisms that infected our ancestors and were transmitted to us.
This knowledge has in fact opened a new concept in biology known as microbiome (the microbes on our bodies). In fact, some of our organelles like mitochondria, were originally bacteria that had been engulfed by primitive cells. For this reason, they share 99% homology with bacteria in genome structure and arrangement (if you know the shape of Escherichia coli, you know its looks like mitochondria). The entire cells of our bodies are more than 50% bacterial cells.
Now back to the selection: as you treat the bacteria with antibiotic, majority will die but there’s always a chance that a few individuals may survive by developing the ability to degrade the antibiotic especially when its concentration is not maintained throughout the period of treatment. The result is that by the next infection, that antibiotic will not work in treating that disease as the bacteria will resist that “selection pressure”. The fittest bacteria will survive and evolve and they will always be genetically different from their ancestors.
This has been demonstrated in several laboratory experiments. In fact, the popular cutting edge technology of CRISPR is a process of evolution and so are the different techniques of genetic transformation and molecular breeding.
Selection pressure represents the driving force of evolution. It may be antibiotic, change in environment, increase in temperature, exposure to new environment, new knowledge, natural disaster, innovation, war, volcanic eruption or the Big Bang.
Any organism that survives a specific pressure is said to be selected and it survives until a new selection pressure emerges to put it out of circulation or not.
The thing about the selection pressure is that it is aimless. When fire breaks out and consumes every living thing in a forest, the fire has no intention of preserving the one or two bacterial species (or rats) that would survive because they develop thermostable skin or enzymes that allow them to overcome the fire.
As the surviving species reproduce, they pass that ability to their descendants. Fire burns and species survive.
If today in Zaria, your emir announces that what is most attractive in women (or men) is having large ears and the idea picks up (a selection pressure in the form of new knowledge), within the next few generations, everyone in Zaria will have big ears because those with small ears will have low reproductive success and therefore less children. Those with big ears will have more children who will inherit the famous “funkaso” ears and all zazzagawa will end up with big ears.
Now for social selection and evolution:
Until recently, the Igala ethnic group in Nigeria, tended to dominate the fuel dispensing business. I wager that this is because when the business of opening petrol stations first started in Nigeria, the first few individuals to engage in it were Igalas. With time, these individuals would naturally introduce more members of their ethnic group in to the trade (in DNA terms this is replication), thus establishing a selection pressure that ensures its survival among the Igalas.
The prominent Igala that are finding new ways of doing things today, will replace those in the fuel business tomorrow.
We see similar examples in other trades like Bureau de change, dominated by ethnic Fulanis from Yanleman in Kaugama Local Government of Jigawa State; the banking industry dominated by the Yorubas; spare parts, electronics and general sales dominated by Igbos etc.
Social evolutionary trait (like genetic trait) always starts with one or two members of a group until it becomes widely accepted or acquired by the whole group. It can then move on to other groups.
If you study clothing for example, you’ll notice that each social group tends to have its specific mode of dressing and the styles are handed down from generation to generation.
Sometimes modes of dressing undergo “mutation” (changes) and when these mutations accumulate to a certain level, they evolve into entirely new kinds of dresses. Study the evolution of “babbar riga” or “tazarce” for example, and you’ll see the innovation and prudence that have emerged to improve them by reducing the amount of material used in sewing.
This is analogous to truncated genes, the original form of which humans and chimpanzees inherited from their last common ancestor. For example, chimpanzees have the gene for synthesis of vitamin C but humans have the truncated version of the same gene. Your children today are inheriting the truncated version of the “babbar riga” our ancestors wore 100 years ago.
A selection pressure that promotes the survival of a view (religious, political or otherwise) may ensure that members of the same or closely related group of human species predominantly hold a certain view. This is essential for survival and acceptability.
In northern Nigeria for example, up until the 1990’s, the predominant religious belief was Sufi Islam. Back then, we used to sing “Dan izala mugun bawa”. And whenever someone did “qabalu” while praying, they were frowned at as “yan qabalu”. Today, if you don’t do “qabalu”, you are frowned at, as “dan shia”, even by the now overpowered remnants of sufi muslims.
Following Iranian revolution and oil boom in the Middle East, selection pressure(s) that saw the emergence of fierce competition between Saudi Arabia and Iran introduced evolutionary changes in religious beliefs (gene pool) in northern Nigeria such that today, the Saudi Arabia version of Sunni Islam is the predominant belief in the region.
God forbid, if Shekau was to succeed and subdue the entire region, in a few generations, everyone will be like him. Similar analogy may be drawn from the coming of Christianity in the coastal region of modern Nigeria in the years following colonial invasion and the new age evangelism of today.
That’s how evolution works.
Ibrahim, PhD, a Molecular Biologist & Science, Technology and Innovation Practitioner, writes from Abuja. (biorazi@gmail.com)
