The methionine to isoleucine substitution (M637I) in
Hipposideros has also arisen independently in the yangochiropteran species
Pteronotus parnellii but not in its congeners
P. quadridens or
P. macleayii. It is therefore interesting that
P. parnellii is the only species of non-rhinolophoid bat to have evolved Doppler-shift compensation in echolocation, a feature that it shares with the genus
Hipposideros. A striking example of rapid
FoxP2 evolution is that of the yangochiropteran genus
Nycteris, which, unlike its closest surveyed relatives, shows independent evolution of nasal emission, multi-harmonic call structure and prey location by passive listening
[38],
[64].
Nycteris also shows the highest rate of non-synonymous change at exon 17 of all species surveyed, differing from both the mammalian consensus and its closest relative by eight amino acids (V678A, A680T, T692A, E698A, L699F, D701E, I705E, L710S;
table S4). Prior to this study, data on
FoxP2 in bats was limited to a partial sequence of exon 7 in a single individual (
Tadarida sp., family Molossidae)
[3],
[4]. Two amino acid differences at exon 7 (A307V and L292S) between the published
Tadarida sequence and its close relative
Chaerephon plicata (family Molossidae) further highlight the high degree of non-synonymous diversity in this order.