Scientists have long struggled to establish where bats first originated, with previous hypotheses proposing Africa, Asia and North America.
A new research has rewritten the evolutionary history of bats, providing evidence the winged mammals most likely originated in Europe during the late Palaeocene, some 65-60 million years ago.
By combining genomic data from all living bat families with ancient fossil records, an international team of 137 researchers from 64 countries working as part of the Bat1K consortium, a global initiative dedicated to sequencing the genomes of all living bat species have reconstructed the evolutionary history of the world's only mammals capable of true powered flight.
The landmark study published in Nature magazine analyzed 103 bat genomes, including 42 newly generated chromosome-level assemblies, representing all 21 recognized bat families.
This was combined with evidence from 44 fossil bats. The results provide a clearer picture of where and how this remarkable lineage emerged.
The researchers found that bats most likely first evolved in Europe during the late Palaeocene. And from there, their descendants spread into Africa.
As bats diversified, different groups then expanded independently into the Americas, Asia and Australia, eventually giving rise to the major bat groups found around the world today.
“The approach we used to model the evolution of fossil and living species together can do what other methods cannot - identify the oldest group of fossil bats while taking the genomic data into account, and uncover when and where bats originated,” said senior author Professor Liliana M Davalos from Stony Brook University.
Computationally reconstructing the genome of the ancient ancestor from which all living bats descended, researchers are able to offer a glimpse into the genetic make-up of one of the earliest flying mammals.
This new genomic resource will allow scientists to investigate the genetic changes behind bats' extraordinary diversity and adaptations, including flight, echolocation, longevity and resistance to disease, as well as their remarkable resistance to disease and exceptionally long lives, for their size.
Bats are among the most extraordinary mammals on Earth. They are the only mammals capable of true powered flight. Most bats orient and hunt in complete darkness using sound alone, and they account for one fifth of all living mammals, playing a vital role in maintaining healthy ecosystems across the globe.
Many bat species show remarkable resistance to disease and live exceptionally long lives for their size.
Yet despite their unique biology and ecological importance, scientists have struggled for decades to answer some of the most fundamental questions about their evolution.
“It is extraordinary, after decades of research and conflicting findings, we finally have a robust phylogenetic tree that we can now use to properly understand how and where bats’ unique traits evolved,” said leading senior author and co-founding Director of Bat1K Professor Emma Teeling, from the UCD School of Biology and Environmental Science.
“We also have the genomes to uncover the molecular basis of these spectacular mammalian adaptations and know where the fossil bats fall in this tree.”
This new study represents the largest combined bat genome and fossil study ever undertaken, drawing on samples collected over decades from bats around the world, including some of the rarest and unusual species found only in the most remote locations.
