Abstract
Evolution refers to the change of properties of a living organism from one generation to the next over a period of time. Human has impacted both negatively and positively during the evolution period, a time when man was also undergoing evolution. Such positive changes include the preservation of some plants that were considered as weeds during the advent of agriculture, the use of stem cells, and genetic modification technologies to modify the properties of the organisms. Negative changes include the use of weapons of mass destruction, destruction of water towers thus spread of deserts as well as the extinction of some indigenous organisms. The way forward to all these is to do re-afforestation, use irrigation for crop production, and technology to produce high-quality plants for food besides diversification of eating habits.
Introduction
Evolution refers to change from the original status of a material: biological evolution, therefore, refers to the changes in the properties of the same living organism from one generation to the other (Futuyma, 1986). From the other quarters, however, it has been defined as the change in the allele within a pool of genes from one generation to the next over a period of time (Helena and Barnes, 1989).
Most of the evolutions that have been recorded have been accredited to the continued changes that the organisms seem to experience within their surroundings whereby they acquire new properties or organs that can make them survive while those that they no longer require are shed off or simply become extinct. Some evidence of evolution was postulated by Darwin in his theory of survival for the fittest where the giraffes developed long necks as a way of out-competing each other for the limited food reserve thus leading to the extinction of the short-necked giraffe species. There are however many lingering questions as to how the actual evolution really happened but with a common understanding that evolutions happened within the history of living organisms.
The behavior of Human Beings from the Stone Age to Modern Times
Human beings (Homo sapiens) have never been left behind in the evolution theory; it said that human beings at one point had a tail, just like the primates e. g the chimpanzee, gorilla, and bonobo but since their lifestyle made little use of this feature, it became vestigial and can only be noticed when doing the human skeleton anatomy. This evolution, marked by a sharp difference between these animals in terms of their behaviors, psychology, and even morphology, has taken place over millions of years. During the Stone Age, human beings, otherwise called man, were mainly hunters and gatherers who lived in temporary nomadic residences called band societies. Over the years and with the advent of agriculture, food became surplus and they developed rather permanent structures compared to the previous ones. This provided them with the opportunity to start domestication of animals, to use metal as well as trade amongst themselves. It resulted in the springing up of the modern complex society; complete with the military to guard the territories and the formed states competing for the diminishing resources causing conflict between some of the so formed states. Developments in the 18th and 19th centuries led to the advent of such transport systems like the railways and automobiles as well as the use of electricity and coal as energy sources. By the 20th century, otherwise termed as the information age, there was the innovation of such technologies like mobile telephony with people living in an increasingly globalized world where people are interconnected through the internet. This allowed for information to be shared more freely at an increased frequency. Technology has enabled man to inhabit all the continents and has subsequently adapted to the locally prevailing conditions. With the population increasing to unprecedented levels of up to over six billion in 2008, up from one billion in 1800 (Whitehouse, 2008), man has continued to explore chances of relocating some population to other planets and most notably, the moon.
The diets of man have also evolved with the changing lifestyle; from the days before the advent of fire when they ate raw food to the post-fire advent era. Man being omnivorous, they eat both animal and plant products. The exact types varied based on the locally available materials. Their eating habits have evolved such that in the 21st century, they not only eat more refined foods but also more diverse with stress being laid on the nutritional values.
Over the periods, man has transformed from the ancient days when the population didn’t undergo any formal education to the present day when there is not only a system for formal learning but also there is a standard language that people from different cultural backgrounds can use to communicate, referred to as the National Language. Also, it has moved from the days when people used to worship their ancestors under trees they considered sacred or on top of mountains while facing the sun to the present day where there are formal worship places (churches) with the pastors leading the prayers in a more civil and organized manner.
As much as the evolution story of man is welcomed, it has come with a baggage of its own kind: by starting to live in more permanent settlements, states complete with governments emerged and so the scramble for resources with each state using her military power became the order of the day. This resulted in wars between different governments; Increased population also meant more of the forest cover had to be cleared to give way for human settlement and this spelled doom to the environmentalists who forever have seen this as the cause of the current unpredictable weather with high drought frequencies and the once flourishing water sources drying up at alarmingly high rates. Change in the dietary trends has brought mixed fortunes to some people. In some cases, restrictions on what to consume have led to an upsurge in levels of deficiency diseases. What to or not to consume purely lay on the culture adopted within the locality. Interestingly, the number of obese has also risen to catastrophic levels leading to health complications and increased mortality among the populations. This is especially true within the developed countries.
Every country in today’s world is striving to develop and being at one level with technology. However, more industries would mean more pollution to the environment thus threatening the delicate ecosystem balance; moreover, the emissions from such industries have a direct relationship with the current big issue of global warming. The effect of the destruction of the forest cover could not be overemphasized since water is life. Lack of rainfall would just compound the already bad situations of food insecurity that is experienced across the globe.
Impact of Human on Evolution
In a perfect situation, natural factors are supposed to influence the nature of the environment. However, this is hard to achieve since man has a stake in determining the state of the environment due to his supremacy. Many people have directed all their blames about the environmental changes to the advent of new technologies and the continued expansion of human knowledge, forgetting that man started to influence the environment as early as the stone age era when they used fire to clear their farms and also not only to communicate but also to clear vegetation cover in the areas they wanted to settle in (PhysOrg, 2005). This, without realizing it, signaled a chain of other events that would influence the future evolutionary processes of humans. The impact of humans on evolution can either be deliberate or unintentional whereby other factors drive the whole process only for the result to cause some sort of evolution. This can be demonstrated by a case in point when the affection human had for certain flowers which led him to start their cultivation. This could not have been the case since these flowers could have been extinct since they could be considered as weeds when the people embraced the agricultural settings. But due to their beauty, humans not only tolerated them but also took good care of them. This was purely driven by the man’s inborn attraction to flowers and not a deliberate move to preserve the flower species. In some instances, however, the movie has been deliberately just to alter the evolution process like in the case of stem cell technology due to ‘the better understanding of such a complicated progression’ (Farber, 2007). “Human stem cells are unique cells that can transform into all the parts needed to create a living being. There are different types of stem cells. Brain stem cells in a human fetus, for example, morph into the neurons and all other cells needed to make a mind” (Britt, 2005).
The stem cell technology has the advantage of producing organisms that resemble the parent (cell source), thereby retaining all the desirable and undesirable features of the donor organism.
Another instance of human impact on evolution is the production of genetically modified food that conforms to the desires of mankind. In such a situation, they take a gene that is responsible for some desirable quality of a particular organism and introduce it to the other. This way, it is as good as saying that the same property shall have been transferred to the target organism. As much as this technology is plausible, the jury is still out especially in cases where it’s used to control pests and diseases yet over a period they develop resistance and the comparative effect of the newly introduced genes on the final consumer of the products. On the brighter side, however, there is a great potential using this technology especially on improved yield output and improved quality, only if these concerns are properly addressed.
It is an open secret that there is a population surge over the years with the same amount of land as was there in the 19th century. What this means is that the forest cover has to be cleared to create room for the extra population; water catchments are destroyed in the process. Destruction of these sites means the spread of desertification thereby driving the indigenous trees into extinction and instead a new species that is well adapted to the created microclimate shall emerge. The fires used to clear the same end up killing even the soil microorganisms that are responsible for the decomposition of the organic matter thereby positively contributing to soil fertility. What this portends is widespread soil infertility. New plant varieties that can do well under this condition shall come up to replace the indigenous ones. If this continues unchecked, it could completely transform the local environment and even the use. The rundown water towers across the globe mean water shortage and even unpredictable rainfall patterns. This limits food production activities and or reducing yields.
Human activity has not spared parasites and other disease-causing microorganisms: for long periods man has tried to come up with a cure for such diseases as malaria. Once they get the same and after a while, these drugs become ineffective since malaria-causing pathogen shall have evolved from the previous strain such that the previously developed one has to be improved on. This meant the introduction of a combination of treatments or going back to the laboratories to get a new set of cures. This could not be true if the status quo were left and thus the evolution was induced by mankind in his quest to cure himself.
Way Forward
Some if not all human activities have been meant for the well-being of mankind with little regard to the side effects on the environment. Interestingly, if mankind becomes extinct, all other components of the environment would be ‘delighted’ because of assured prosperity. Since this seems not very possible, man needs to take corrective measures to check on the deteriorating condition of the planet. Towards this end, there should be the massive restoration of the depleted forest cover by re-afforestation while at the same time protecting the endangered indigenous plant species. The trees would play their role as water catchment towers while the falling leaves of the plant materials would undergo natural decomposition processes thereby improving the soil fertility.
Since there has been an upward increase in population over the years, there has also been an equivalent increase in food requirement by the populace, yet the rainfall levels have ever been diminishing and since there are no alternatives on the issue, new food production techniques like using irrigation as well as the planting of drought-resistant crops should be embraced. People should also diversify their diets to avoid over-reliance on particular foods. There should be a concerted effort to make people comprehend the demerits of land subdivision into smaller parcels in light of food production.
Emissions from automobiles and industries have spelled doom to the environment. It is blamed for global warming and the continued depletion of the ozone layer. A depleted ozone layer would mean more UV radiation reaching the earth and this has the potential of causing cancer of the skin. Moreover, it leads to pollution of the air that we breathe and may lead to the falling of acid rain. In this regard, more pressure should be put to regulate the number of industries in a locality, and the automobiles that are worn out should be removed from the roads to reduce the exhaust fume emissions.
One of the reasons for the much pressure that the world finds itself in is due to the unprecedented high population growth. Even though a high population means cheaper labor and the accompanying increases in economic growth, its negative impact on the ecosystem very much outweigh the positives. Therefore, different countries should invent motivational packages for parents who keep the number of their offspring as low as possible while at the same time setting an upper limit to the number of people that a family can have: failure of which a fine charged.
Researchers should use their research work to develop plants that are more resistant to the local pests and diseases, drought, and of high yield. This would help improve food security for the high population. However, before releasing any new technology to the people, tests must be done with the same to check on the possible side effects they might have on the local person who shall adopt the same technology. Also, they should launch a campaign strategy so as educate the people on how the so said technology is used in the simplest terms possible.
References
Britt, R. R. (2005). “Human Affection Altered Evolution of Flowers”
Curtis, H. and Barnes, N. S. (1989). Biology, 5th ed. Worth Publishers, p.974
Whitehouse, D. (1999). “World’s Population reaches Six Billion”. BBC News.
Farber, B. (2007). Human Impact on Evolution. Evolution Literature; paper no.1.
Moran, L. (1993). What is Evolution?
Futuyma, D.J. 1986. Evolutionary Biology. 2nd ed. Sinauer Associates, Sunderland, Massachusetts. PhysOrg. “Study: Ancient humans ‘altered’ climate”