How to Save a Number of Species

Mathematics is the language of nature. If we are to have any chance of conserving the natural world, we must be fluent. In recovery plans for threatened and endangered species, delisting criteria typically involve achieving x number of individuals or populations. IUCN red list categories are largely determined on count based metrics. Biodiversity hotspots are demarcated based on the number of species present in a given area. I will always tell people I study snakes, sharks, and salamanders, but at the end of the day I am essentially just a glorified statistician.

Ecological statistics seek to find a signal amongst the noise, a definite pattern amongst the chaos. And living things can be pretty chaotic! Biology is the youngest of the sciences, but concerns itself with the most challenging puzzles posed by the universe. Indeed Carl Pantin scathingly opined “a physicist is a person who only tackles the easy questions on the examination paper set by nature.” Amen, brother. A platypus is far more complicated than a particle or a protein, that’s for sure. When faced with such formidable mysteries, it is important to walk before we can run.

If we count all the animals of one type, we call this population abundance, and how this number changes through time can be extremely informative. An overall declining trend, if steep enough, would qualify a species for endangerment status. This would subsequently trigger legal action that mandates federal funding to be invested in the species’ attempted recovery.  Alternatively, we can document where an animal occurs and where it is absent. Even with this simple binary data, we can create species distribution models that predict whether the animal is likely to exist in places we have yet to look. These models can also help us to map the spread of an invasive disease, or predict the success of conservation reintroduction efforts.

If we want to get more complicated, we can tally all the different types of animals; this gives us a measure of ‘species richness’. So far we have managed to elucidate that tropical rainforests have a higher species richness than the arctic tundra, but we are still not quite sure why; differences in ecosystem stability or productivity represent our best guesses. Again how this number changes over time can be extremely informative. Whether you are situated on the equator or at the poles, if habitat is destroyed, some species persist whilst others are immediately lost. Much can be gleaned from the predictability of such changes in species richness. In conservation the numbers are always our guide.

Given the pervasiveness of mathematics in ecology, it has always surprised me as to how statistically averse some biologists can be. Particularly in applied fields, mathematical competency often leaves a lot to be desired. To some extent it makes intuitive sense. Most people are attracted to these fields as a result of childhood experiences – camping, fishing, or hiking say. The love for the outdoors is what drives them; the love for the abacus does not come naturally, if at all. But if you are to have any chance of understanding living things, you must first understand numbers. 

Inadequate statistical training stems from the way we teach mathematics at school. To hear children complain that it is somehow dull or irrelevant to their lives is lamentable indeed. The same is true of history. History is everything that has ever happened. Yet if you ask most people, they will tell you history is boring. Clearly it is not history at fault, merely our ineffectual teaching methods. Pedagogical techniques must improve lest we stultify children. If students are permitted the freedom to apply mathematical logic to problems that actually interest them, if students are able to study history of their own choosing, their value will become self-evident. Indeed, very little instruction will be necessary.

Mathematics is the language of nature, but the majority of us continue to exhibit willful aphasia. In modern society, the absurdity of numbers associated with the wealth gap and overpopulation is matched only by people’s indifference. Statistically speaking, indifference is not acceptable. The same is true for the preservation of the natural world. Statistics makes clear the scale of the crisis faced. An area of forest the size of South Africa has been felled in the last 30 years. Since the 1970s, a third of all wetlands have been drained and global CO2 emissions have doubled. There are over 5,000,000,000,000 pieces of plastic in our oceans. But we must never forget that statistics, whilst grimly capturing the 6th mass extinction in real time, also help reveal the inner workings of the splendor around us. From the flowering dates of daisies to the march of emperor penguins, from the height of laurel pine to the clutch size of cod, each is numerical precision. Not every biologist needs to be fluent in mathematics, but at the very least, each should know some basic vocabulary that permits some semblance of a conversation with the biosphere. If not, we will continue fumbling about the forests, deaf, dumb, and blind.

Leave a Reply

Your email address will not be published. Required fields are marked *