Dear all
It is my pleasure to announce our new paper on the evolution of NBHF signals in toothed whales
Galatius A, Olsen MT, Steeman ME, Racicot RA, Bradshaw CD, Miller LA (2018) Raising your voice: Evolution of narrow band high frequency hearing in odontocetes.
Biological Journal of the Linnean Society, 126 (2): 213–224, doi:10.1093/biolinnean/bly194
Abstract: Cetaceans use sound for communication, navigation and finding prey. Most extant odontocetes produce broadband (BB) biosonar clicks covering frequency
ranges from tens of kilohertz to 150–170 kHz. In contrast, the biosonar clicks of some odontocetes are unique, being narrow in bandwidth with high centroid frequency (NBHF), peak frequencies being at 125–140 kHz and bandwidths of 11–20 kHz. Thirteen species
within four families (Phocoenidae, Pontoporiidae, Kogiidae, Delphinidae) are known to produce these signals, implying convergent evolution under strong selective drivers. Several hypotheses have been proposed, including acoustic crypsis to escape predation
by killer whales, but none has provided comprehensive explanation of the timing of NBHF evolution and the pressures driving sound production to such extremes. Using molecular phylogenetics and the cochlea anatomy of extinct and extant taxa, we demonstrate
that early NBHF adaptations occurred at least 10 Mya, and possibly up to 18 Mya, indicating that killer whales cannot have been the sole driving force of NBHF signals, but that now extinct odontocetes may have provided similar pressures. Using palaeoclimate
modelling, we further demonstrate that the upper advantageous spectral window for NBHF signals at around 130 kHz has persisted throughout most of the global sea area since the mid-Miocene, covering all known instances of NBHF evolution.
Please see https://academic.oup.com/biolinnean/article/126/2/213/5244783, or email
me for a pdf copy
Kind regards
Morten Tange Olsen
Morten Tange Olsen
Assistant Professor, Curator of Marine Mammals
Statens Naturhistoriske Museum
Københavns Universitet
Section for Evolutionary Genomics
MOB +45 42661525
