Human-driven speciation: A peek into how we may alter the morphology of African elephants
September 9, 2021
Shweta Rana, Devanshi Parekh, Down to Earth

Evolution is the fundamental concept that has given birth to a rich diversity of life forms by speciation. The genetic contiguity between all the organisms existing or extinct on this earth creates a unique and impressive mosaic on the mural of life.

Planet Earth was formed approximately 4.5 billion years ago and millions of species evolved in this long journey. Members belonging to genus Homo appeared around 2.5 million years ago. We humans are probably the last entrants but responsible for ousting many of our fellow life forms.

Nature works on the law of survival of the fittest, a term coined by Herbert Spencer, an English philosopher. The tendency to survive by adaptation is the driving force behind the evolution of all life forms.

This natural phenomenon corroborates with the most compelling finding by Charles Darwin; ‘It is not the strongest of the species that survives, nor the most intelligent, but the one most responsive to change’.

A slow and continuous process of evolution nurturing in the womb of mother nature is losing its rhythm because of ongoing human activities. Unintentional and / or deliberate harm to the environment disrupts the ecological balance and impacts many life forms.

Many studies have established that human activities can drive evolution and increase speciation rates. The organisms detect these changes and acquire adaptations suited for their survival. The ones that fail to adapt, perish in the process.

We chose African elephants to present our narrative. African elephants are recognised by their long tusks, massive body size, huge ears and their versatile trunks. These characteristics have been popularised through media.

Anthropocene Morphology

Anthropogenic activities such as global warming, poaching, mining, deforestation and noise pollution could impact the morphology of African elephants.

It is known that increased emissions of human-caused greenhouse gases are warming up the earth. An increase in global temperature by 1.5 degrees Celisus in comparison to pre-industrialisation times has resulted in thermal expansion of oceans and melting of ice caps, making the sea levels rise.

The global sea levels are rising at a rate of about one-eighth of an inch per year. This will leave coastal areas vulnerable to flooding and eventually being taken over by the ocean waters.

A major population of African elephants, more than 10,000, are found in coastal countries. Elephants are good swimmers and can swim for around 500 km if necessary.

Their trunk plays an imperative role in this situation and acts as a snorkel, facilitating the elephants’ breathing despite their face half-submerged in the water. Increased sea levels and flooding can force elephants to swim longer distances for survival or live in submerged habitats, which eventually may result in an increase in their trunk size.

The wrinkles, which are a fine mesh of cracky lines on the skin, have major role in the animals’ thermoregulation. They retain mud and water and help these giant mammals stay cool and hydrated.

Interestingly, unlike other mammals, the distribution of thin sparse hair on the surface of the African elephant’s skin helps in releasing heat from their body. So hotter climates may make them more wrinkly and hairier.

The poaching of elephants for ivory has led to an unnatural decrease in the size of the elephant population. The number of elephants has decreased in Zambia’s Sioma Ngwezi National Park to 48 in 2019, from 900 in 2004.

Poaching is forcing elephants to evolve to lose their tusks. The Gorongosa National Park in Mozambique witnessed, large-scale poaching and hunting of elephants for ivory and meat during the Mozambique Civil War.

After the end of the civil war in 1992, some elephants were born tuskless and did not develop them later too. Studies from the Ruaha National Park in Tanzania also showed increased tusklessness after extensive poaching in the 1970s and 80s, providing a biological advantage to the elephants.

Tusklessness will leave elephants with compromised defense (and unattractive). It will have a larger ecological impact in the habitats facing seasonal droughts. Elephants dig deeper with their tusks in the ground to find water and create shallow water pools which also quench the thirst of many other big and small animals around.

Elephants show post-traumatic stress disorder symptoms. Acts of poaching and killing (by local farmers to protect crops) have caused symptoms in elephants as abnormal startle responses, depression, unpredictable asocial behavior and hyper aggression which hamper with their reproduction. These cruel events, if continued, may lead to the formation of a depressed progeny or infertility, eventually decreasing their population drastically.

Mining for fuels and minerals in the forest leads to deforestation and noise pollution. The highest hearing capacity of elephants is 12,000 Hz while that for humans is 20,000 Hz.

The habitat fragmentation and high frequency sounds of mining can force the elephants to move away from their habitat. It can cause the members in their population to get lost and separated. This isolation may lead to some associated alterations in their morphology and physiology

Do we realise our actions will form a more wrinkly, hairier, tuskless, larger trunked, infertile and depressed population of African elephants? I am sure most of us don’t. So, what should be done? Aren’t the answers simple and known to us?

Implementation of the cap and trade system can control carbon emissions and other atmospheric pollutions. Carbon dioxide converted to coal and buried back into earth can rewind the emissions clock. Fostering a change in the consumer behavior towards the elephant’s tusks for ivory can be helpful in controlling the poaching problem.

Contribution from global, national and individual levels to reduce the deleterious impact of human activities on the environment is need of the hour. Moving away from fossil fuels and switching to renewable energy resources and sustainable infrastructure, transportation and agriculture can provide effective solutions to these issues.

Let’s be aware of our ecological footprints and adopt the 7 R principle in our lives — Rethink, Refuse, Reduce, Repurpose, Reuse, Recycle, Rot.

“One of the first conditions of happiness is that the link between man and nature shall not be broken”. Leo Tolstoy

Important: The readers must know that evolution is a multidirectional and complex process. We have presented a simplistic linear explanation of how continued anthropogenic activities can impact the evolutionary processes and alter the morphology of life forms around us. Our effort is to draw the attention of our readers to something very important but unknown to many of us

Shweta Rana, is Associate Professor of Biology and Environmental Studies at FLAME University and Devanshi Parekh is an Undergraduate Student of Environmental Studies at FLAME University