Now imagine a practical scenario. At an airport, a passenger's luggage has an animal pelt. The customs officer suspects it is from an endangered species. How do we know whether the traded parts are illegal or legal? For example, tigers are endangered and hence transporting tiger parts across international borders is illegal. Given the Wildlife Protection Act in India, being in possession of tiger parts is illegal within the country as well. On the other hand, someone might take a dog hide and paint it with tiger stripes, trying to pass it off as a tiger. In this case, while the intent is bad, the person has not actually committed a crime because he/she is not in possession of/trading an endangered species. Trying to understand which species are being traded, and which populations these traded parts are coming from falls within the purview of wildlife forensics. The key to answering these questions is cutting-edge methods like genetics and genomics. A sort of real-life version of CSI, but for wildlife!

Wildlife forensics has two main goals. First, identify the species that the confiscated material belongs to, and second, identify the source population, or the origin of that material. For both of these purposes, genetics serves as an indispensable tool. We know that DNA is the blueprint of life, and our DNA sequence or our genome is in each cell of our body. DNA is made from one of four letters A, T, C and G. Thanks to new technologies that exploit the chemical properties of DNA, its sequence can be read. Almost 200 years ago, Darwin realized that all life on earth can be attributed to the evolutionary process: new variation crops up, and it is inherited within families. Since variation accumulates over time, animals, with common origins/family trees have more similar DNA than those who are not part of the same family tree. In other words, I am more similar to any other human on earth, compared to a chimpanzee. So, if we can read the DNA sequence common to all humans but different in chimps, I can identify the species that the DNA came from. In other words, if I read the DNA from the confiscated skin and compare it to known DNA sequences from endangered species, I could figure out which species it is from.

Similarly, populations also have genetic signatures. Again, using the DNA from a confiscated skin, we could read several different sequences and compare them to sequences known to occur in different locations. If we have a match, we can figure out which location the confiscated skin is from. This will help enforce better protection when we find, for example, which population the confiscated samples are from.

Despite CITES, populations of many species like rhinos and elephants continue to decline. In the case of elephants, this is even more complicated because many elephants are in captivity. Making extensive databases of geographically linked genetic variation --- wild individuals from different populations along with all captive individuals --- would be a critical part of any baseline database.

In a forward-thinking move, the government of India has recently started a project that aims to sample all captive elephants and make a database of their genetic variation. Another critical component of an accurate database for forensics is geographically linked genetic data. Several recent studies and older studies have investigated genetic variation in Asian elephants across their range of standardized non-invasive methods to work with a handful of genetic sequences or markers. Internationally, studies on African elephants have successfully used a handful of genetic variants with a large database of geographically linked elephants to trace confiscated ivory seizures.

But the situation gets a whole lot more complicated when there are many individuals who have been born in captivity. For example, Armstrong and others found that captive tigers in the US are completely mixed up! What if Indian captive elephants have parents from the Northeast and southern India? How will we identify them? This is where the power of big data comes in. When ancestry gets complex, we need more markers or more genetic variants to answer the question.

Recent genome sequencing of elephants across India, carried out by scientists from the National Centre for Biological Sciences, TIFR and Centre for Ecological Sciences, IISc, has already yielded fascinating insights, that populations and landscapes have distinct genetic variations, and elephant populations have more variation than others. Genomics-based approaches will be very critical for wildlife forensics in the future. This growing field needs to rapidly ratchet into the big data world to be effective.

Effective identification of source locations of illegally traded animals can help implement better protection. Ultimately, the protection of ecologically relevant species like elephants contributes towards healthier ecosystems, critical aspects of buffering the negative effects of climate change. Nature and healthy populations and ecosystems are the only insurance against a rapidly changing world.

Uma Ramakrishnan is a professor at the National Centre for Biological Sciences, TIFR, Bengaluru. She is a molecular ecologist and has been involved in understanding endangered species through a genetic lens for two decades. She worked on elephants early in her career and has just completed work identifying vulnerable/high conservation priority elephant landscapes based on whole genomes from across India.