Bat evolution linked to warming

A sharp rise in global temperatures about 50 million years ago may have been responsible for the evolution of bats, Science magazine reports. This warming is linked to an explosion in the diversity of other mammals, but little was known about bat evolution.

New DNA data traces the origin of four major bat lineages to a brief period in the Eocene Epoch when the average global temperature rose by about 7C. Bats make up 20% of mammals, yet their evolutionary history is poorly known. The scientists, led by Emma Teeling from University College Dublin, Ireland, estimate that around 60% of the bat fossil record is missing.

Writing in Science, the international team of researchers propose that bats originated in the ancient landmass of Laurasia, possibly in an area now located in North America. The gene sequencing data suggests bats split away on their own evolutionary path about 52-50 million years ago, at a time when the Earth experienced an event known as the Palaeocene-Eocene Thermal Maximum.

The warmer climate caused insects to flourish, and bats evolved unique aviation skills and echolocation to catch them, it is claimed. The results therefore support the theory that the group known as the megabats are nested among the four major microbat lineages which originated in the early Eocene.

BBC News
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