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Dolphins, bats and the evolution of echolocation
While both bats and dolphins use ecolocation to hunt down prey, patterns of echolocation vary greatly among species. Depending on what they eat and where they live, species produce sounds at different frequencies – from “broadband” calls that encompass a wide range of frequencies, to constant-frequency calls emitted at one particular frequency. Researchers from the UK, Italy and Denmark got together to look for genetic evidence of convergent evolution between these very different groups. Previous research had already determined which genes are involved in echolocation in both dolphin and bat species. While, other studies have shown that different bat species have undergone changes that resulted in strong similarities in the genes that govern hearing. These findings set the stage for Joe Parker, Georgia Tsagkogeorga and others to begin examining the entire genomes of selected echolocating species.
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The mystery of the disappearing elephant tusk
Give it a few thousand years, and tusks could completely disappear from the Asian elephant (Elephas maximus). The beautifully smooth, elongated ivory incisors neatly bordering a long trunk are iconic in the public mind. The reigning hypothesis is that tusks evolved to help male elephants fight one another, as demonstrated when males compete over females in estrus. However, a recent study published in the journal Animal Behaviour has shown that tusks may not be key factors in tussles, at least as far as elephants are concerned.
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Are sea turtles responsible for lower fish catches in India?
Fishing communities on Agatti Island in Lakshwadeep, India, blame their reduced fish catch on green turtles; according to them, green turtles chomp their way through the seagrass beds lining the shallow reef waters that are essential for fish to breed. This leads some in the community to clandestinely kill sea turtles and destroy their nests. Wildlife happens to intrude on human “space” mostly while searching for food, and this can result in human deaths, or destruction of human livelihood. The perception of people living close to wildlife in such conflict areas shapes the interaction between them and the wildlife.