Nature and biodiversity globally is declining dangerouslydue to mounting anthropogenic pressures in terms of human greed and thrust formore energy, security, food and economic development. These activities havehampered the ecosystem functioning and created ecological imbalances to such anextent that biological life is in a struggling mode. Interestingly, May 22 willbe celebrated as world biodiversity day worldwide under the auspices of theUnited Nations (UNO) to increase the understanding and awareness about theextinction threats and conservation of biological diversity on this planet. Infact loss of nature will have major implications for human societies andcultures.
For those of the readers who don’t know it yet, let me tell you that earth has already entered into a sixth mass extinction event after having witnessed five mass extinctions during the course of its age at 4.6 billion years. This extinction is also called as Holocene or anthropocene extinction, because it is man driven. Scientists assume we are in the middle of this extinction and it is estimated to wipe out maximum of life from biosphere. A recent report from the Intergovernmental Science- Policy Platform on Biodiversity and Ecosystem Services at Paris (4 May, 2019) finds that around one million animal and plant species are threatened with extinction, first of its kind in the human history and species extinction rates are accelerating at an unprecedented rates worldwide. It is pertinent to mention that 8 million is the total estimated number of animal and plant species on Earth (including 5.5 million insect species) as per the recent scientific estimation.
Actually extinction is a natural phenomenon, and it occursat a natural background rate of about one to five species per year. We’relosing biological species at 1,000 to 10,000 times the background rate, withliterally dozens going extinct every day. As per the current IUCN estimates onred list of threatened species, one in four species are at risk of extinctionthanks to human pressures in terms of so called economic development andprosperity. The major driving forces behind it are human overpopulation andover consumption of natural resources. Further, habitat destruction,overhunting, toxic pollution, invasion by alien species and climate change allbased on anthropogenic activities are also responsible for this progressive andforthcoming loss or extinction of life. These undergoing events have resultedin the significantly faster extinction rate of biological species and loss ofbiological diversity. A recent research has also shown that nearly half of the177 mammalian species surveyed lost more than 80% of their distribution between1900 and 2015.
The fifth mass extinction popularly remembered and studiedas K-T (Cretaceous-Tertiary) extinction event happened 65 million years ago andwiped away around 75% of life including the massive dinosaurs. However,evolutionary it paved way for the emergence of larger mammals including humanbeings with their increased diversity all over the world. Pertinently, thefirst mass extinction called as Ordovician mass extinction happened about 440million years ago during the Ordovician Period of the Paleozoic Era on theGeological time scale. Overall, scientific evidences have accumulated thatclimate change, microbial infections, volcanic eruptions and meteor strikeshave been the possible causes behind the past extinction events.
One school of scientific thought has been stressing thatparasites, pathogens and predators are also the cause behind the extinction ofhost species due to severe host mortalities and debility, however, obeying thenatural ecosystem laws, the aim of a parasite or predator has never been toextinct its host populations or species. Under natural conditions, theextinction of species is caused by the events like population bottlenecks (eliminationof unhealthy populations), populations which are ecologically constrained dueto low genetic diversity or least biological fitness or minimal survivalchances due to diminished potential to demonstrate struggle for existence, orsurvival of the fittest. Biologically, the mass extinction events shape theevolution of species because a few lucky ones are enough fit to survive theseextinctions, propagate, flourish and dominate, and new ones evolve albeit undernatural control.
The climate change is a crucial factor that drives the massspecies destruction and extinction worldwide. There is enough of the evidenceand research showing that climate change and plastic pollution is altering thebiodiversity and it will have devastating effects on health, food security andeconomy. The North West temperate Himalayan region bordering the valley ofKashmir has been recognised as the high impact region of the possible effectsof changing climatic trends. The Himalayan fauna and flora including the insects,mammals and migratory species of birds will be the worst sufferers of theconsequences of climate change. Pertinently the impact of global warming onHimalayas has attracted the attention of scientists worldwide keeping in viewthe vast stretches of glaciers and its other ecological features which havedirect and indirect bearing on the animal life and economy.
Last but not least, we are in a deep environmental crisisand issues challenging the very essence of life. From now onwards future willpurely depend on what we do and plan for nature, but above all nature will takeits own course of action-at least we have to believe that natural selectionoperates with all accuracy, perfection and reason. It is a key mechanism ofevolution, which has happened, is happening, and will happen for the bettermentand continuity of life. Let us only hope for timely actions, priorityinitiatives and concrete policies by man to secure life in every form.
The writer teaches Zoology at Islamia College of Science andCommerce, Srinagar.