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