What is it about?

"What makes the pseudomelanistic tigers of Similipal look the way they do?" We try to answer this question in our paper. 1. Similipal Tiger Reserve, Odisha is known for the presence of unique pseudomelanistic tigers, where the dark stripes on their coat become wider and denser, making the tiger look more 'black'. These tigers have frequently been camera-trapped in Similipal. They are also present in captive populations of Nandankanan Biological Park, Bhubaneswar, Arignar Anna Zoological Park, Chennai, and Bhagwan Birsa Biological Park, Ranchi. 2. Our study uncovers the genetic basis of pseudomelanism in tigers. Using the DNA sequences of captive tigers of Bhubaneswar zoo we show that all pseudomelanistic tigers must have a mutation on both copies of their Taqpep gene that they inherit each from their mother and father. 3. Using fecal and shed-hair samples of wild tigers, we show that this mutational variant of Taqpep is present in the wild only in Similipal at a relatively high frequency of 0.6, i.e., it is very common in Similipal tigers but completely absent in other tigers. 4. Population genetics analyses suggest that Similipal is a small tiger population geographically away from other source populations and hence genetically isolated. In such small and isolated populations, genetic drift, an evolutionary force that can bring change in the frequency of the variants of a gene in a population, can cause loss of genetic variation. 5. Population genetics simulations suggest that a founder effect (where very few ancestral individuals contribute to the genetic variation within a population) coupled with subsequent genetic drift and inbreeding in Similipal could result in the observed high frequency of pseudomelanistic tigers in Similipal. We highlight the need for maintaining the connectivity of Similipal with other source populations.

Featured Image

Read the Original

This page is a summary of: High frequency of an otherwise rare phenotype in a small and isolated tiger population, Proceedings of the National Academy of Sciences, September 2021, Proceedings of the National Academy of Sciences,
DOI: 10.1073/pnas.2025273118.
You can read the full text:

Read

Contributors

The following have contributed to this page