Population irruptions of crown-of-thorns starfish (CoTS; Acanthaster spp.) are one of the foremost causes of coral loss and reef degradation throughout the Indo west-Pacific. The seemingly recent and/or increasing frequency and severity of CoTS population irruptions is often attributed to declining abundance or function of putative predators. Accordingly, there has been extensive research on, and an ever-growing list of, potentially important predators on CoTS. The latest candidates are eagle rays (family Myliobatidae), which were observed feeding among coral rubble in shallow reef areas in Kanaky New Caledonia (see Kayal and Lenihan 2025). Assuming that these large benthic feeders can detect and consume juvenile CoTS, eagle rays could have the necessary feeding capacity to effectively regulate CoTS populations and/ or contribute to suppressing local CoTS densities. There is however, considerable research needed to establish the functional importance of eagle rays and other putative predators. Most critically, rates of predation and corresponding mortality need to be ascertained, both in areas where there are sustained low densities of CoTS and where there is high incidence and predictable recurrence of population irruptions.
Despite their drastic impacts on coral reefs, outbreaks of the coral-feeding seastar crown-of-thorns starfish (COTS), Acanthaster, have remained a scientific enigma. Significant efforts in coral reef conservation science have been dedicated to identifying natural predators able to exert demographic control on COTS and prevent population outbreaks. These efforts are motivated by empirical evidence showing that reefs within marine protected areas are less prone to COTS outbreaks than reefs open to fishing where potential COTS predators have been reduced or removed functionally from food webs. Research findings point towards COTS’ early life-stages as a major demographic bottleneck for COTS populations, with various reef fish and benthic organisms identified as preying upon the seastar. Yet, no species or species groups have been clearly identified as exerting enough top-down control to influence COTS population increases or prevent outbreaks. We report the benthic scavenging behavior of eagle rays (family Myliobatidae), a large-bodied predator, feeding in coral rubble fields of Kanaky New Caledonia, critical habitats where juvenile COTS find refuge and food and accumulate to produce population outbreaks. We argue that with their effective substrate-sucking feeding behavior, similar to vacuums of the sea, eagle rays may be a hitherto unidentified predator able to exert significant control on COTS populations. Eagle rays and other large benthic scavengers were previously neglected in the search for major COTS predators. Relatively little existing data show that eagle ray populations in Kanaky New Caledonia’s lagoon are more abundant inside than outside marine protected areas, which concords with the hypothesis that they could be responsible for the mitigation of COTS outbreaks as reported within reserves. We advocate for further investigations on the role of eagle rays and other large benthic scavengers in controlling COTS outbreaks, and the importance of preserving the unique ecological function of sea vacuums for coral reef conservation.
While the established paradigm of human evolution asserts that the lineages leading to the extant great apes and Homo arose in Africa, the large number of fossil discoveries from Europe in recent decades support arguments for a European origin of the Hominidae (all great apes) and plausibly, also a European common ancestor of the Homininae (African great apes, Australopithecus species, and the genus Homo). Meanwhile, a lack of consensus remains regarding the phylogenetic placement of australopithecine fossil species in Africa, with substantial evidence indicating that some of them may align more closely to extant African great apes than to Homo. Based on a novel interpretation of existing fossil, genetic, paleogeographic and paleoclimatic evidence, this paper aims to put forward a new hypothesis regarding the separate divergences of Gorilla, Pan, and Homo. We support existing arguments that the last common ancestor of African great apes and Homo may have lived in Europe in the late Miocene, and we put forward a new hypothesis as to where, when, and why the separate lineages may have started to diverge. Extreme conditions during the Vallesian Crisis (11.6-8.0 Ma) and the Messinian Salinity Crisis (6.0-5.3 Ma) may have forced separate branches of European hominids to migrate out of the Mediterranean region. We argue that the lineages leading to Gorilla and Pan independently migrated into Africa, while the lineage leading to Homo went in another direction. Thereafter, the Zanclean Megaflood (5.3 Ma)--which caused the Mediterranean to refill very quickly--may have cut off the migration route between Eurasia and Africa at the Sinai Peninsula, isolating a small population (the putative Homo lineage) on the Arabian Peninsula / Red Sea coast during a period of hyperaridity. The other group (Pan lineage) crossed into Africa, where it subsequently diversified into various species of Australopithecus.
We suggest rethinking ecology as a set of continuous, interconnected dynamics and spatial networks that would represent an alternative framework to the traditional organizational levels—cell, organism, population, community, and ecosystem. We draw on unifying biological theories—information theory, cell theory, and metabolic theories—to propose a continuous space for living systems that avoids epistemological constraints imposed by a priori assumptions of discrete levels of biological organization. The discrete levels of organization that ecologists have traditionally envisioned can be viewed instead as coarse-grained, localized groupings within continuous dimensions of information (I), cell number (C), and energy flux (E). Moving from levels of organization to emergent properties of information, cells, and energy flux allows us to illustrate how diverse ecological and evolutionary phenomena—such as allometric and diversity-related scaling patterns, predator-prey dynamics, evolutionary trajectories, and alternative stable states—can be represented within the same continuum. We suggest that there may be structure within this information-cells-energetic flux (ICE) framework that unifies ecology from the beginning of life to the present and provides a useful lens through which patterns and processes in nature can be viewed.
A series of immersion experiments has indicated that humans are able to absorb sufficient fresh water from sea water by reverse osmosis through their eccrine sweat glands to remain fully hydrated without drinking anything at all. This unique facility would have enabled our ancestors to survive periods of severe drought.
