“What is the one thing that comes to mind when you think of biology?”

When the first year undergraduate students at Azim Premji University’s Bhopal campus were posed this question during a classroom activity, the room erupted with a variety of responses. Some stuck to the basics (‘disease’, ​‘plants’, ​‘body’) and few were more daring (‘art’), but there was one response that left everyone momentarily gobsmacked: ​‘numbers’. Heads turned and a few scattered chuckles followed once the undergraduate students realised that it was none other than their biology professor, Achyut Kumar Banerjee, who had quipped thus.

Achyut later disclosed that it was not at all his intention to be cheeky or to catch his students off-guard. Having pursued quant-heavy ecological research for many years, he recognises numbers to be an integral part of biology. This is also probably why he was assigned to teach the Quantitative Thinking for Biologists course to the first batch of biology majors at the Bhopal Campus.

When Achyut joined the Agricultural and Ecological Research Unit at Indian Statistical Institute (ISI), Kolkata, in 2010, he realised that he stood out as a rare biologist in a sea of statisticians. At ISI, he learnt the basics of collecting and analysing biological data. Later, while pursuing his postdoctoral studies in China, Achyut joined hands with some of his colleagues back home to launch the Indian aLien flOra infoRmAtion (ILORA) database, a platform providing ecological, socio-economic, and geographic attributes for more than 1,700 alien plant species ever reported from India.

Data for change

‘Invasive alien flora’ is a phrase used to describe plant species that are introduced into places outside their natural range, negatively impacting native biodiversity, ecosystem services or human well-being. Their threat is well-recognised in the US, Europe and Australia, but less so in India. Recent studies show that India has lost trillions of rupees to bioinvasion and stands to lose much more unless interventions are put in place. 

For governments and policymakers to sit up and take notice, someone needs to gather the numbers. How many invasive species exist in India, and how are they spreading? This is where ILORA comes in. Achyut and his colleagues curated data from various sources to collate them into a giant database containing information regarding each invasive plant species. 

The next and crucial step was to make interpretations from this data. And this is where Achyut’s number-crunching skills were especially useful. ​“We can analyse specific variables from the ILORA data, such as those that deal with how the alien flora are being sold in the Indian market,” he says. Such analyses can be extremely revealing. For instance, they were able to show that the widespread invasive plant lantana was being sold at very low prices in online nurseries, in spite of the threat it poses to our native vegetation. ​“Based on this, we proposed some steps that policymakers could follow to manage the situation,” he says.

Despite its reputation as a descriptive science, there has always been an important quantitative aspect to biology. The so-called father of modern genetics Gregor Mendel wouldn’t have achieved his groundbreaking results with pea plants if not for his use of numbers and probabilities. And this was way back in the 1800s! 

It may not have been complex maths, but there has always been some quantification in biology, according to Priya Tamma, Achyut’s colleague and fellow ecologist who works at the university’s Bangalore campus. ​“People tend to forget that ecology is a science,” Priya says. ​“If you want to scientifically examine a pattern or a phenomenon, then you have no choice but to use a quantification or analytical tool.”

Measurements, GPS and algorithms

Priya has engaged with numbers in multiple ways over her research career. During her PhD at the National Centre for Biological Sciences (NCBS), she investigated the biogeographic patterns of small mammals in the Himalayas. She used geospatial data to create species distribution maps, and she also had to develop expertise in morphometry. 

Morphometry encompasses taking measurements of the physical forms of organisms and analysing them using software. This allows scientists to describe and compare the morphology of related species more faster, accurately and thoroughly than could ever be possible by mere observation. 

To get a better understanding of small mammals in the area, Priya also mastered phylogenetics, a field of biology that uses either morphology or genetic data to reconstruct a sort of evolutionary tree of species. ​“Mostly, it’s the computer that does the maths for you, but a basic understanding of the mathematics that underlies the computer algorithm can help you interpret the results well,” she says. 

A few more years at a mathematical ecology lab at the Indian Institute of Science (IISc) set Priya up for a career in quantitative biology. For the past few years, she and her collaborators have been using geospatial data, mathematical ecology, and analytical methods such as time-series analysis to quantify the resilience of our forests. 

“We want to know how quickly our ecosystem recovers from disturbance,” she explains. Though this involves a lot of computation and mathematical modelling, Priya’s work remains fieldwork-intensive. ​“Ultimately, how much ever maths you do, you are exploring living systems, right? You have to go back and make sure that the numbers match the real world.” 

Like most biology teachers of today, Priya and Achyut frequently encounter maths-phobia in their classrooms. ​“Many undergraduate students choose biology believing that it is a way to avoid maths, so they are disappointed to find out this was not the case,” Achyut says. Shedding these inhibitions is part of the reason Achyut designed an online workshop titled ​‘Bridging Nature with Data Science’ (June 2024). It is targeted at undergraduate, postgraduate and PhD students. 

Beyond the pixels

Such efforts do pay off. Priya, for instance, has witnessed a change in mindset in some biology students over time. A number of them have consulted her to strengthen their honours projects with new quantitative techniques. 

In one case, she helped a student use morphometry to compare the movement of a spider with that of an ant that it was mimicking. Another student approached her to construct a phylogenetic tree to help determine whether an unidentifiable worm she discovered in a nearby pond belonged to a new species. 

Despite their embracing of numbers, both ecologists stress that quantification is not the only way to understand nature. ​“There are other ways to engage with nature that are not necessarily scientifically oriented, but are equally valid,” says Priya. ​“A naturalist may look at a patch of forest without knowing anything about the abundance distribution of the trees in that patch, and still come away with a lot of understanding about that forest.”

“Some people are analytical in their approach to nature, while others are on the other end of the spectrum — they just enjoy the magic and beauty of nature. Then there are the people who are a lovely fusion of both,” she adds. Achyut believes he falls somewhere in between the spectrum. ​“I am a botanist at heart so that part of ecology still lives in me. I don’t need to measure the height or the weight of a particular plant species to acknowledge the beauty of a flower that blooms,” he says, with a quiet smile. 

About the Author

Nandita Jayaraj is a Science writer and Communications Consultant at Azim Premji University.