All articles tagged with #cetaceans
This review traces cetacean evolution from early Eocene land- and river-edge ancestors in Indo-Pakistan to today’s diverse baleen and toothed whales, highlighting major transitions (limb reduction, aquatic locomotion, high-frequency hearing and echolocation, and feeding innovations) and macroevolutionary patterns that shaped their diversification, while outlining unresolved questions and guiding priorities for future research.
UC Berkeley researchers studied 15 sperm whales over four years, attaching underwater microphones and analyzing codas; they found two frequency-based, vowel-like click types (a and i) that can form diphthongs, with different pods using distinct frequencies—suggesting regional accents and a highly complex system similar in pattern to human speech, published in Proceedings of the Royal Society B.
New analysis of 3,948 sperm whale codas from 15 individuals finds two formant-based coda types (a-codas and i-codas) with timing and contextual rules resembling human phonology, indicating a highly structured communication system that stops short of being language. Project CETI frames this as a major step toward decoding whale speech and understanding language evolution.
Researchers filming off Dominica captured a rare birth of a sperm whale in which surrounding females—related and unrelated—cooperated to support the laboring mother and calf, a first documented instance of birth assistance in non-primates, with vocal changes suggesting coordinated care.
Field observers off Dominica in July 2023 captured an 11-whale group from two matrilines coordinating a calf’s birth and postnatal care, with a core quartet lifting and maintaining the newborn at the surface for breathing while the wider group stayed cohesive; the study, aided by machine learning and computer vision to track individuals, provides rare quantitative evidence of allocare and complex sociality in sperm whales and was published in Science Advances.
In 1984, scientists at the NMMF observed unusual human-like vocalizations from beluga whales, especially NOC, who could mimic speech by manipulating his nasal passages and melon shape, highlighting the complex vocal abilities of belugas and their unique communication methods.
The discovery of the Indohyus fossil in the Himalayas has provided crucial insights into the evolutionary journey of cetaceans, such as whales and dolphins, from land to sea. Indohyus, a small, deer-like creature, shares anatomical features with modern cetaceans, including a thick ear bone used for underwater hearing. This fossil, along with others like Ambulocetus, highlights the transition of some terrestrial mammals back to aquatic environments, leading to the evolution of today's marine cetaceans.
Scientists from Brazil's University of Campinas Institute of Biology have discovered that the large size variation among cetacean species is largely explained by the activity of specific gene regions, shedding light on the genetic basis of giant ocean creatures. The study focused on the promoter region of a gene called NCAPG, revealing that it plays a crucial role in causing cetaceans to grow to enormous sizes. The research may also advance cancer treatments, as the regulatory sequences identified could influence the animals' ability to suppress cancer. This new understanding of cetacean genetics could potentially lead to the development of future cancer treatments through the activation or inhibition of specific regions of the genome.
Researchers from the Pelagos Cetacean Research Institute discovered a dolphin off the coast of Greece with strange, hooked thumbs carved out of its flippers. This is the first time such a flipper anomaly has been observed in 30 years of surveys in the open sea. The deformity is likely the result of rare and irregular genes that emerged from constant interbreeding. While all dolphins have thumbs, they are usually concealed by their flippers. The thumbed dolphin in question is missing fingers and some tissue that would usually encase them, but it is still thriving.
Scientists have made a surprising discovery in Greece, where they found a dolphin with what appears to be a pair of "thumbs" on its flippers. This is the first time such an anomaly has been observed in 30 years of research. The dolphin, believed to be the result of genetic aberration caused by inbreeding, seems to be accepted by its pod and shows no signs of illness. All cetaceans possess human-like forearms and "fingers," but they are usually concealed within flippers. The thumb-like appendages on this dolphin are non-functional and serve no identifiable purpose.
A scientific report reveals the diverse and inventive methods of sexual engagement among animals. Serotine bats have been found to mate without penetration, transferring semen through contact with the vulva. Dolphins engage in mass orgies on the move, while whales engage in foreplay for hours and exhibit homosexuality. Octopuses and cuttlefish have unique mating rituals, and walruses possess the largest penis bones among mammals. Birds also have peculiar mating behaviors, such as dunnocks inducing females to expel sperm from previous partners and female muscovy ducks evolving incompatible vaginas to avoid unwanted attention. Humans, too, are animals, and sex remains an improbable arrangement across species.