Recasting the whale’s wonderful net
In: Science (Washington). American Association for the Advancement of Science: New York, N.Y. ISSN 0036-8075; e-ISSN 1095-9203, more
Related to:Lillie, M.A.; Vogl, A.W.; Jennings, S.G.; Raverty, S.; Shadwick, R.E. (2022). Retia mirabilia: Protecting the cetacean brain from locomotion-generated blood pressure pulses. Science (Wash.) 377(6613): 1452-1456. https://dx.doi.org/10.1126/science.abn3315, more
|  |
| Abstract |
More than 50 million years ago, terrestrial ancestors of dolphins and whales reinvaded the oceans in one of the most revolutionary events in mammalian history. The transition from land to sea required marked remodeling of the terrestrial mammalian form to withstand high hydrostatic pressures at depth, exponential increases in drag forces when moving locomotor appendages through water, and extreme breath-hold durations when diving (exceeding 3 hours in Cuvier’s beaked whales, Ziphius cavirostris) (1). The changes were so radical that evolutionary selection pressures seem insurmountable. Yet, the transitions did occur, resulting in 47 extant cetacean (dolphin and whale) family lineages that radiated throughout the global oceans (2). How this evolutionary leap was accomplished has been the subject of much speculation. On page 1452 of this issue, Lillie et al. (3) continue this multimillennial investigation on aquatic adaptations in cetaceans, detailing how specialized vascular networks provide protection for their brains during submergence |
|
