HYDERABAD: A genomic study by CSIR-Centre for Cellular and Molecular Biology (CCMB) and Indian Institute of Science Education and Research (IISER) Thiruvananthapuram has found that parasitism originated and diversified more than 100 million years ago.
The team, led by Siddharth Kulkarni, a Ramanujan faculty member at CCMB, along with three IISER undergraduates, analysed 90 arachnid genomes — the largest dataset studied so far — to trace ancient evolutionary links. By examining gene order on chromosomes, the researchers identified two distinct arachnid groups that evolved independently from different ancestors: Acariformes, which include most mites, and Parasitiformes, comprising ticks and the remaining mites.
Explaining the findings, Dr Kulkarni said, “Think of it like a deck of cards. Over millions of years, the cards (genes) get shuffled. But if you find two different groups of mites that have the exact same ‘hand’ of cards in the same order, you know they share a common ancestor”.
The study helps untangle long-standing evolutionary relationships among arachnids such as camel spiders, mites and horseshoe crabs. Researchers said mapping these links could aid in predicting the spread of infections and identifying potential new disease vectors before outbreaks occur.