The dolphin and the cow: the bat and the shrew. These relationships have often been discussed in zoological and other circles. The bat and the whale, however, are another situation altogether. The authors of this almost bewildering paper have gathered all the current genome information that will soon be available for almost any animal or plant. At the moment, 6 bats and 1 whale (the dolphin, Tursiops truncatus) are covered to some extent, and 15 domestic and other mammals have been "begened" to the hilt. The human of course is one of these species.
The convergent evolution of echo-location in some bats and whales was the starter for Dr. Joe Parker and his colleagues' interests. Working in the Universities of London (Queen Mary), Cambridge, Copenhagen, Turin and Milan, they sought to prove that the echo-location function was recurrent in mammalian evolution.
Convergence itself now seems to be common in a small number of genetic sites on any given locus. The properties providing vision were also found to be a convergent function among the animals chosen. Echolocation in the two groups studied is independently evolved, as sets of high frequency-processing abilities, for example.
Bats have even evolved this twice, it now seems, because two groups' ancestry is split by species that are non-echolocating. Similar hearing and deafness gene loci were found regularly in both dolphin and the bats, along with vision genes. Sensory convergence is correlated with the strength of selection for these important functions. This takes place not only in bats and whales, but we can expect many mammal features to keep turning up in most mammalian Orders.
Putting it concisely, nearly 200 mammalian loci (places where genes are active) can be accused of having convergent signatures in their sequences of 805,000 amino acids and 2,326 coding gene sequences.
The journal Nature publishes the paper and findings.