Ecology and biogeography in the introduction to “De bestiis marinis” by Georg Wilhelm Steller

2019 ◽  
Vol 46 (1) ◽  
pp. 63-74
Author(s):  
Stefano Mattioli
Keyword(s):  
Body Size ◽  
Phenotypic Plasticity ◽  
Geographical Distribution ◽  
Functional Traits ◽  
Marine Mammals ◽  
Main Part ◽  
Wide Distribution ◽  
Restricted Range ◽  
Direct Influence ◽  
Modern Biology

The rediscovery of the original, unedited Latin manuscript of Georg Wilhelm Steller's “De bestiis marinis” (“On marine mammals”), first published in 1751, calls for a new translation into English. The main part of the treatise contains detailed descriptions of four marine mammals, but the introduction is devoted to more general issues, including innovative speculation on morphology, ecology and biogeography, anticipating arguments and concepts of modern biology. Steller noted early that climate and food have a direct influence on body size, pelage and functional traits of mammals, potentially affecting reversible changes (phenotypic plasticity). Feeding and other behavioural habits have an impact on the geographical distribution of mammals. Species with a broad diet tend to have a wide distribution, whereas animals with a narrow diet more likely have only a restricted range. According to Steller, both sea and land then still concealed countless animals unknown to science.

scholarly journals Drought responses and phenotypic plasticity of Maprounea guianensis populations in humid and dry tropical forests

Rodriguésia ◽  
2021 ◽  
Vol 72 ◽  
Author(s):  
Marília Grazielly Mendes dos Santos ◽  
Alexsandro dos Santos Sousa ◽  
Sâmia Paula Santos Neves ◽  
Davi Rodrigo Rossatto ◽  
Lia d’Afonsêca Pedreira de Miranda ◽  
...  
Keyword(s):  
Phenotypic Plasticity ◽  
Water Potential ◽  
Functional Traits ◽  
Environmental Parameters ◽  
Wide Distribution ◽  
Seasonal Rainfall ◽  
Northeastern Brazil ◽  
Plant Responses ◽  
Rainy Period ◽  
Dry Tropical Forests

Abstract The wide distribution of Maprounea guianensis populations in contrasting environments (dry and humid forests) in the Chapada Diamantina, northeastern Brazil, can indicate the phenotypic plasticity of this species in relation to seasonal rainfall, drought regimes, and soil characteristics at different sites. Functional traits were measured in five individuals in each vegetation types. Water potential, succulence, thickness and density leaf, were evaluated during the dry and rainy periods; wood density and the saturated water content of the wood were evaluated in rainy period. Rainfall was monitored monthly for two years. The functional traits and the phenotypic plasticity indices (PPI) were submitted to analysis of variance. Our results demonstrated seasonal and spatial variations in plant functional traits. We found a low capacity for storing water in leaves and woody tissues, associated with soil properties and the seasonal rainfall/drought regimes, conditioning water potential variations that were greatest during the rainy season. Local environmental parameters influenced variations in the functional traits of M. guianensis populations, reflecting phenotypic plasticity. We highlight the connections between drought regimes and plant responses, demonstrating the importance of functional traits associated with water availability (especially water potential). Our study evidences the factors associated with the wide distribution of M. guianensis.

scholarly journals The isotopic niche of Atlantic, biting marine mammals and its relationship to skull morphology and body size

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Massimiliano Drago ◽  
Marco Signaroli ◽  
Meica Valdivia ◽  
Enrique M. González ◽  
Asunción Borrell ◽  
...  
Keyword(s):  
Body Size ◽  
Atlantic Ocean ◽  
Fisheries Management ◽  
Marine Mammals ◽  
Trophic Position ◽  
Sympatric Species ◽  
Isotopic Niche ◽  
Apex Predators ◽  
Skull Morphology ◽  
Ecosystem Based Fisheries Management

AbstractUnderstanding the trophic niches of marine apex predators is necessary to understand interactions between species and to achieve sustainable, ecosystem-based fisheries management. Here, we review the stable carbon and nitrogen isotope ratios for biting marine mammals inhabiting the Atlantic Ocean to test the hypothesis that the relative position of each species within the isospace is rather invariant and that common and predictable patterns of resource partitioning exists because of constrains imposed by body size and skull morphology. Furthermore, we analyze in detail two species-rich communities to test the hypotheses that marine mammals are gape limited and that trophic position increases with gape size. The isotopic niches of species were highly consistent across regions and the topology of the community within the isospace was well conserved across the Atlantic Ocean. Furthermore, pinnipeds exhibited a much lower diversity of isotopic niches than odontocetes. Results also revealed body size as a poor predictor of the isotopic niche, a modest role of skull morphology in determining it, no evidence of gape limitation and little overlap in the isotopic niche of sympatric species. The overall evidence suggests limited trophic flexibility for most species and low ecological redundancy, which should be considered for ecosystem-based fisheries management.

scholarly journals Threatened birds of Guatemala: a random subset of the avifauna?

2011 ◽  
Vol 22 (3) ◽  
pp. 348-353
Author(s):  
ANDREA NÁJERA ◽  
JAVIER A. SIMONETTI
Keyword(s):  
Body Size ◽  
Geographical Distribution ◽  
Scientific Information ◽  
Bird Species ◽  
Critically Endangered ◽  
Aquatic Species ◽  
Random Subset ◽  
The Pacific ◽  
Taxonomic Affiliation

SummaryIdentifying attributes that affect the vulnerability of a species to extinction is important as it allows conservation efforts to be focused on more susceptible species. We assessed whether threatened birds of Guatemala are a random subset of the avifauna, considering their taxonomic affiliation, body size, diet and geographical distribution. We found that threatened bird species in Guatemala were neither taxonomically nor geographically randomly distributed. Large-bodied species and Psittaciformes, Galliformes, Falconiformes and Ciconiformes were among the most threatened groups, and the Pacific slopes of the country hosted more threatened birds than would be expected. Published scientific information regarding Critically Endangered bird species in Guatemala is scant and biased against nocturnal and aquatic species. Research and conservation efforts ought to be oriented toward these species and regions to safeguard the Guatemalan avifauna. This study allows an overall consideration on whether we are conserving the species and areas that are important for threatened birds.

Nannizzia incurvata. [Descriptions of Fungi and Bacteria].

1965 ◽  
Author(s):  
P. M. Stockdale
Keyword(s):  
Great Britain ◽  
Geographical Distribution ◽  
Guinea Pigs ◽  
Tinea Capitis ◽  
World Wide ◽  
Skin Lesions ◽  
Wide Distribution ◽  
Tinea Corporis ◽  
Soil P ◽  
Infected Skin

Abstract A description is provided for Nannizzia incurvata. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Recorded only from man and dog (but see NOTES). Guinea-pigs have been experimentally infected. DISEASE: Ringworm (dermatophytosis, tinea). Nannizzia incurvata is present in soil and apparently only rarely a cause of disease. In man the scalp (tinea capitis) and glabrous skin (tinea corporis) may be infected. Skin lesions are inflammatory but details of known scalp infections are not available. In experimental inoculations of guineapigs (Rdzanek, pers. comm.) N. incurvata was intermediate between N. gypsea and N. fulva in virulence, the reaction varying from negative to strongly inflammatory. Ectothrix hyphae breaking up into large arthrospores were seen on some hairs, and infected hairs did not fluoresce under Wood's light. GEOGRAPHICAL DISTRIBUTION: Asia (India), Europe (Czechoslovakia, Great Britain and Ireland, Germany, Netherlands, Poland); U.S.A. (Tenn.); N. incurvata is probably of world-wide distribution in the soil.

Natural selection and adaptation

2018 ◽  
Author(s):  
Tim Lewens
Keyword(s):  
Natural Selection ◽  
Functional Traits ◽  
Evolutionary Biology ◽  
Skin Pigmentation ◽  
Essential Element ◽  
Natural World ◽  
Modern Biology ◽  
Biology Textbook ◽  
Selection For ◽  
The Relationship

Students of the natural world have long remarked on the fact that animals and plants are well suited to the demands of their environments. ‘Adaptation’, as it is used in modern biology, can name both the process by which organisms acquire this functional match, and the products of that process. Eyes, wings, beaks, camouflaging skin pigmentation and so forth, are all ‘adaptations’ in this second sense. Modern biological orthodoxy follows Darwin in giving a central role to natural selection in explaining the production of adaptations such as these. This much is uncontroversial. But a number of more contentious conceptual questions are raised when we look in more detail at the relationship between natural selection and adaptation. One of these questions concerns how we should define adaptation. It is tempting to characterize adaptations as functional traits – eyes are for seeing, large beaks are for cracking tough seed-casings. This in turn has led many commentators in biology and philosophy to define adaptations as those traits which have been shaped by natural selection for their respective tasks. Others – especially biologists – have complained that such a definition trivializes Darwin’s claim that natural selection explains adaptation. This claim was meant to be an important discovery, not a definitional consequence of the meaning of ‘adaptation’. These worries naturally lead on to the issues of how natural selection itself is to be understood, how it is meant to explain adaptation, and how it should be distinguished from other important evolutionary processes. These topics have a historical dimension: is Darwin’s understanding of natural selection, and its relationship to adaptation, the same as that of today’s evolutionary biology? Textbook presentations often say yes, and this is surely legitimate if we make the comparison in broad terms. But differences emerge when we look in more detail. Darwin, for example, seems to make the ‘struggle for existence’ an essential element of natural selection. It is not clear whether this is the case in modern presentations. And Darwin’s presentation is largely neutral on the inheritance mechanism that accounts for parent/offspring resemblance, while modern presentations sometimes insist that natural selection always implies a genetic underpinning to inheritance.

A new species of small Lepidodactylus (Squamata: Gekkonidae) from Salawati Island, Indonesia

2020 ◽  
Vol 66 (3-4) ◽  
pp. 180-189
Author(s):  
Denise Taimi Karkkainen ◽  
Stephen J. Richards ◽  
Fred Kraus ◽  
Burhan Tjaturadi ◽  
Keliopas Krey ◽  
...  
Keyword(s):  
New Species ◽  
Body Size ◽  
Wide Distribution ◽  
Mature Male ◽  
Unique Combination ◽  
Island Arcs ◽  
Land Bridge ◽  
West Papua ◽  
Larger Sample ◽  
A New Species

We describe a new species of gecko in the Lepidodactylus novaeguineae Group from Salawati Island, West Papua Province, Indonesia. The new species can be distinguished from all congeners by a unique combination of aspects of body size, shape, colouration, and scalation. The holotype and only known specimen is a mature male with a snout-vent length of less than 33 mm, suggesting it is the smallest species of Lepidodactylus; however, to confirm that, larger sample sizes of the nominate species and other species are required. The Lepidodactylus novaeguineae Group has a wide distribution across the western, northern, and eastern margins of New Guinea, but it seems to be most often associated with islands (including land-bridge islands) or geological terranes derived from former island arcs.

scholarly journals Resurgence of an apex marine predator and the decline in prey body size

2019 ◽  
Vol 116 (52) ◽  
pp. 26682-26689 ◽  
Author(s):  
Jan Ohlberger ◽  
Daniel E. Schindler ◽  
Eric J. Ward ◽  
Timothy E. Walsworth ◽  
Timothy E. Essington
Keyword(s):  
Life History ◽  
Body Size ◽  
Chinook Salmon ◽  
Marine Mammal ◽  
Marine Mammals ◽  
Size Structure ◽  
Economic Value ◽  
Killer Whales ◽  
Selective Predation ◽  
Marine Predator

In light of recent recoveries of marine mammal populations worldwide and heightened concern about their impacts on marine food webs and global fisheries, it has become increasingly important to understand the potential impacts of large marine mammal predators on prey populations and their life-history traits. In coastal waters of the northeast Pacific Ocean, marine mammals have increased in abundance over the past 40 to 50 y, including fish-eating killer whales that feed primarily on Chinook salmon. Chinook salmon, a species of high cultural and economic value, have exhibited marked declines in average size and age throughout most of their North American range. This raises the question of whether size-selective predation by marine mammals is generating these trends in life-history characteristics. Here we show that increased predation since the 1970s, but not fishery selection alone, can explain the changes in age and size structure observed for Chinook salmon populations along the west coast of North America. Simulations suggest that the decline in mean size results from the selective removal of large fish and an evolutionary shift toward faster growth and earlier maturation caused by selection. Our conclusion that intensifying predation by fish-eating killer whales contributes to the continuing decline in Chinook salmon body size points to conflicting management and conservation objectives for these two iconic species.

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