What Is Biodiversity and Where Is It?

Biodiversity or biological diversity refers to the difference between all biological sectors on the Earth. It refers not only to the total number of life forms in an area but also to the difference between those life forms across the planet. Biodiversity is responsible for genetic diversity in a single population and the variations between ecosystems worldwide. The importance of biodiversity is that the more the biodiversity in species, individuals, and ecosystems, the more stable are those populations. For example, greater genetic diversity within a single population is the reason that the population can better adapt to disturbances in weather, climate change, and diseases. Greater biological diversity also supplies us with a wide range of medicine and foods.

Measuring biodiversity is a complex matter. Biodiversity has a quantitative as well as qualitative aspect. Take the example of the platypus. The platypus is a genetically unique species. But because it is unique and peculiar, we associate a greater biodiversity value with it as compared to that of a species living among several similar species. We assign a greater biodiversity value to a peculiar, unique species because those species preserve a special part of our Earth’s evolutionary history.

The easiest way to describe the biodiversity of an area is by counting species. Experts estimate that the global species diversity is somewhere between 13 and 14 million. However, out of this total number, scientists have been able to describe only around 1.5 million species. They believe that roughly a third of these species are currently at risk of extinction.

Source: https://css.umich.edu/factsheets/biodiversity-factsheet

Diversity among biological populations is highest in the tropics. Biodiversity progressively declines towards the poles. This means that diversity is not evenly distributed on the Earth. For example, the blue jay, a bird that is endemic only to North America. Endemic species means species found in just one location. In the same way, the Asiatic lion is endemic to India. Hotspots refer to areas that have a high level of biodiversity or endemism. These include most islands of the world.

Where Biodiversity Came From?

The biodiversity that the Earth currently hosts is the result of 4 billion years of evolution. Biological organizations diversified through the change in inherited traits of a species across generations. 600 million years ago, life existed only as single-celled organisms.

The history of biodiversity starts with the Cambrian explosion of life – the period in Earth’s history which witnessed the appearance of multicellular organisms. Global populations showed very little diversity over the 400 million years that followed the Cambrian explosion. Periodic losses of life termed ‘mass extinctions’, also marked this period. The largest among the mass extinctions occurred at the boundary of the Permian and Triassic, 250 million years ago. This mass extinction killed 96% of marine species and almost 70% of land species. Species were able to rebound from this ‘Great Dying’ only after the next 4 to 6 million years. The last mass extinction occurred 65 million years ago, ending the reign of the dinosaurs.

Scientists still do not fully understand the exact causes of the previous mass extinctions. But they know that the extinctions were triggered by long-term stresses such as climate change. The Earth has witnessed five mass extinction events since its formation. Of these five events, only four were caused by global warming due to greenhouse gas emissions.

A majority of scientists and biologists agree that the world is now living in the era of sixth mass extinction. They termed our period as the ‘Holocene extinction.’ And the reason for this mass extinction couldn’t be more obvious – it is us, humans. We’ve caused our planet to warm at a rate unprecedented throughout history. We’ve caused habitat and biodiversity loss and wildlife destruction. Our way of life will eliminate most species on Earth within the next century. All these reasons compel us to understand the importance of biodiversity and take action to preserve it.

Why Biodiversity Matters?

We depend on biodiversity for our survival. Diversity among ecosystems provides us with a stable climate, air that is breathable, and water that is drinkable. When diseases strike croplands, the diversity among the crops and insects that pollinate them save them from a complete collapse. Food crops supply us with food. Diversity among plants and animals provides us with medicine. Most of the natural compounds we use in medicine are impossible to synthesize in a laboratory. Apart from agriculture and medicine, we humans also obtain food from wild sources such as fish. But despite best efforts, very few fisheries in the world run sustainably. The over-harvesting of one particular fish species leads to a restricting of entire marine ecosystems. One species becomes so over-harvested that it becomes a minor player, ecologically.

We cannot quantify the importance of biodiversity and its benefits to our society. But we know for a fact that they are truly vast. Right from prehistoric times, humans have never lived in a world with low biodiversity- and we shouldn’t be living in one anytime soon. Our physical, spiritual, and psychological health depend on a varied and rich environment.

Biodiversity plays a significant role in improving soil fertility, recycling nutrients, regulating pests and diseases, and crop and tree pollination. Without biodiversity, ecosystems would collapse. Diversity among biological groups makes populations, species, and ecosystems more resilient to environmental stresses. Let us imagine for a minute a world without biodiversity. Imagine a world in which all individuals belonging to a species have the exact same characteristics with no variation in traits. If a disease or some sort of environmental stress were to affect this world, every population would die out. Because there is no variation among them and they all have the same characteristics, the stress would affect all of them in the same way.

Diversity among biological groups does not let entire populations collapse. This forms the basis of the importance of biodiversity. Because we have variation, the stress will affect species differently. Some may die out, while some may adapt and continue to live on. The generation of species that spring from the generation that survived the stress will inherit the resilient characteristics of their parents. Thereby helping them to better adapt to future changes in environmental conditions. Genetic diversity provides the raw material for a species to adapt to changing environmental conditions. The survival of every species, including our own, is dependent on variety among biological groups. We must understand the importance of biodiversity in the adaptation and survival of organisms, including us humans, before it’s too late.