In the Light of Theosophy
[This article appeared in the February 2018 issue of The Theosophical Movement. For more articles published in this excellent magazine follow this link: http://www.ultindia.org/previous_issues.html ]

Giant tortoises are rare today but once roamed four continents. According to a new theory, tortoises evolved into giants on at least seven occasions and four continents, undermining the long-standing idea that tortoises become enormous only if they are stranded on remote islands. For instance, giant tortoises are found on the Galapagos Islands in the Pacific Ocean, and Seychelles islands in the Indian Ocean, having shells more than 120 centimeters long. It is amazing that though these islands cover an area of only a few thousand square kilometers, as contrasted with the Earth’s continents which cover around 150 million square kilometers, they are home to just one truly large tortoise, namely, the African spurred tortoise. This implies that tortoises are most likely to become huge when they live on islands, which is in line with a famous but controversial concept, the “island rule.” According to this rule, on islands, small animals tend to evolve larger bodies, while large animals evolve to be smaller.
However, fossils show that giant tortoises once roamed Africa, Eurasia and the Americas, suggesting that tortoises do not need islands to evolve to be larger. According to Yuval Itescu at Tel Aviv University, Israel, there are two competing hypotheses that seek to explain the presence of giant tortoises on remote oceanic islands: Either they were giants when they reached these islands, or they became giants on the islands. It is crucial to know what their ancestors were like.



















