When most foreigners think of Africa, they think abstract print, grasslands and wild fauna, exotic dance styles, afrobeats, heat, and of course, crude oil. But what most people, including Africans themselves are unaware of, is that our riches surpass the multiple threads of cultural heritage that link us all together, and run deeper than the fossil fuels we extract from the ocean’s base.
Archeological and biological evidence has since proven that Africa was the birthplace of our species, Homo sapiens, and that the majority of human evolution at the beginning of our existence occurred across the expanse of African soil.
Each of us is a composition of a multitude of intricately woven networks, some easily seen, others not quite. We are far more complex than blood and bone, because even such fundamental elements of our being comprise of much smaller units known as cells.
The human body is a giant mass of billions of different cells, and these microscopic units are so incredible that some develop even further to perform specialized functions such as fighting against infections and diseases, determining a person’s sex, the smooth running of all body systems, and the creation of human life, among others.
If the cell is said to be the unit of all life, then the nucleus, a small egg-shaped structure inside the cell, is the command centre controlling all cellular activity. The nucleus is able to wield so much power over the cell because it enforces the written instructions found on even tinier string-like structures known as chromosomes found within it.
Chromosomes come in pairs, and humans have 23 of them (46 chromosomal units). Half of these chromosomes come from one parent, while the other half are derived from the other. This is where genes come in. Remember when I mentioned the nucleus enforced written instructions that controlled a cell’s activity? Well, these instructions are what make genes so special.
Genes are more commonly known as the basic units of heredity. They carry the information that determines what traits a person inherits from their parents, such as eye color and height. But, they are also segments of the ultimate instruction maker, the DNA (deoxyribonucleic acid). This is where things get really interesting.
The structure of a chromosome is quite complex, but basically, it is a form wound up so tight with the help of proteins called Histones and DNA itself that forms bands around the chromosome’s now solid structure. It is when these bands are unwound that the true structure of DNA is seen. DNA is helical in nature with rungs similar to those of ladder steps bonding both ends.
Genes, on the other hand, are portions of DNA that code for a protein. These proteins however are different from Histones which were mentioned earlier. When it is said that ‘DNA codes’, it means it gives out specific instructions for the formation of proteins – its most invaluable function.
Proteins are the building blocks for everything in the body. Bones, teeth, hair, and even muscles and blood are all made up of proteins. Some genes code for proteins, while others do not. Hence, why genes are only certain segments of DNA, as some segments of DNA do not code for anything.
Genetic diversity is the key to unlocking how African genes are so rich and why they are integral to research. The term ‘genetic diversity’ refers to the diversity within a species, for example, Homo sapiens. We vary more in our physical appearances, but less so internally. There are numerous constants to our genetic makeup (unique combination of inherited genes). But our differences are a result of our need to adapt. Different environmental conditions warrant a means for survival, so our bodies make the necessary changes internally, sometimes leading to external effects. These changes are then passed on to future generations.
The greater the genetic diversity within a species, the greater that species’ chances of long-term survival. Positive traits (such as resistance to diseases) can be inherited along with negative ones (such as inherited diseases) which can become widespread within a population when that population is left to reproduce only with its own members.
As stated earlier, the rise of the new humans-the Homo sapiens, evolved from their predecessors-the Homo neanderthalensis, in Africa. The ‘Out of Africa’ dispersal which happened over a hundred thousand years ago, was a massive demographic event that spread individuals and their genes outside Africa and throughout the world. As these smaller populations migrated to different ends of the earth, they experienced a ‘genetic bottleneck’ due to their reduced size which limited genetic diversity. They recycled the same genes among themselves with seldom changes to increase their chances of survival.
As a consequence of that dramatic effect, African populations today harbor more genetic diversity than any other population in the world, and the genetic diversity found in non-Africans represents only a subset of that found in Africa.
The African continent houses so many gene varieties that have evolved over time, some responsible for the resistance to several diseases accustomed to the region, unlike its counterparts abroad. The riches of the African genome remain largely a mystery and need to be studied for the populations’ complexity, variation in climate, diet, and exposure to infectious disease, which have resulted in high levels of genetic (gene related) and phenotypic (physical) variation in its populations. The answers to so many genomic questions and novel discoveries lie within these genomes if only inspected closer.