History of Snake in Timeline
Snakes are limbless reptiles belonging to the suborder Serpentes, characterized by elongated bodies and overlapping scales. They are ectothermic vertebrates with skulls adapted for swallowing large prey, possessing numerous joints. Internally, snakes feature serially arranged paired organs and typically a single functional lung. Some species retain vestiges of a pelvic girdle. Legless lizards, evolved independently through convergent evolution, share a resemblance with snakes. However, snakes lack eyelids and external ears, features present in many legless lizard groups.
1972: Wildlife Protection Act prohibits snake charming
In 1972, The Wildlife Protection Act in India technically prohibited snake charming in an effort to reduce animal cruelty. This has resulted in the profession dying out due to the competition from modern entertainment.
1972: Indian Wildlife (Protection) Act protects all snakes
In 1972, the Indian Wildlife (Protection) Act protected all snakes, leading the Irula tribe to transition from snake-skin harvesting to venom extraction for antivenom and research, while releasing the snakes afterward. The Irulas are also known for rat extermination and snake consumption.
2015: Discovery of Tetrapodophis Amplectus
In 2015, a 113-million-year-old fossil of a four-legged snake, Tetrapodophis amplectus, was discovered in Brazil, strengthening the snake evolution hypothesis. The fossil exhibits snake-like features and adaptations for burrowing, with evidence of preying on other animals. However, its classification as a snake remains uncertain.
2016: Studies link limb loss to DNA mutations
In 2016, two studies linked limb loss in snakes to DNA mutations in the Zone of Polarizing Activity Regulatory Sequence (ZRS) of the sonic hedgehog gene, which is crucial for limb development. While advanced snakes have no limb remnants, basal snakes have vestigial hind limbs, and python embryos show arrested limb bud development due to ZRS DNA mutations.
2021: Reclassification of Tetrapodophis
In 2021, a study reclassified Tetrapodophis, placing it within a group of extinct marine lizards from the Cretaceous period known as dolichosaurs, suggesting it is not directly related to snakes.
