Wyniki wyszukiwania

1

Intensity of melanin-based color and risk of predation in the Barn Swallow Hirundo rustica

100%

Galvan I., Nielsen J. T., Moller A. P.

Acta Ornithologica

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2014

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tom 49

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nr 1

Predators are supposed to exert strong selection pressures on their prey, especially when phenotypic traits such as secondary sexual characters promote mating success at the expense of costs in terms of natural selection. Signaling theory predicts that individuals of superior phenotypic quality will enjoy an advantage in term of mating success, but also in term of natural selection, if such individuals are in prime condition both before and after development of exaggerated secondary sexual characters. We tested this prediction in the Barn Swallow Hirundo rustica being preyed upon by the Eurasian Sparrowhawk Accipiter nisus, using extensive samples of feathers from prey and non-prey. We measured tail length and coloration of outermost tail feathers in the black area of the proximal and distal part of tail feathers, but also the white spot of the tail feathers. Prey had significantly less dark distal, but not proximal parts of their tails, while there was no difference in coloration of the white spot between prey and non-prey. Prey had significantly paler tail feathers than non-prey, especially among long-tailed individuals. These results suggest that Barn Swallows with long tails that fail to deposit large amounts of melanin in their tail feathers run an elevated risk of predation.

2

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Evolutionary aesthetics as a meeting point of philosophy and biology

100%

Chmielewski A.

Acta Societatis Botanicorum Poloniae

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2012

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tom 81

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nr 2

Metaphysics, or the knowledge of what there is, has been traditionally placed at the pinnacle of philosophical hierarchy. It was followed by theory of knowledge, or epistemology. Practical knowledge of proper modes of conduct, ethics, came third, followed by aesthetics, treated usually in a marginal way as having to do only with the perception of the beautiful. The hierarchy of philosophical disciplines has recently undergone a substantial transformation. As a result, ethics has assumed a central role. The aim of this paper is to suggest that the hierarchy of philosophical disciplines is not yet complete and that one further step needs to be taken. According to the claim advocated here, it is not metaphysics, epistemology or ethics, but aesthetics that is the first and foremost of all philosophical disciplines. This claim is argued for by references to findings of evolutionary aesthetics, especially to Charles Darwin's idea of sexual selection as elaborated in The Descent of Man. I also argue that Darwinian approach to morality is, and should be, derivable from an Darwinian aesthetics which lies at the core of his conception of sexual selection.

3

Territory defence in male European roe deer (Capreolus capreolus) - a sexual ornament?

100%

Wahlstrom K.

Acta Theriologica

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2013

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tom 58

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nr 3

The function of male territoriality in roe deer has been debated for decades. There now seems to be consensus that it is a mating tactic. As such, it is highly untypical though. The reasons being, first, males neither conform to the typical ‘resource defence’ territoriality model nor to the ‘mate defence’ territoriality model; second, territory defence commences several months in advance of the breeding season; and third, the territorial system seems to be very rigid, as practically all studies that have described the social organisation of the species have reported adult males to be territorial. In spite of the general agreement that territoriality is a mating tactic, conclusive evidence on which selective forces are responsible for the prevalent pattern is still lacking. In the present paper, it is suggested that territorial defence serves as a sexual ornament, i.e. ‘cleanness’ of other males on the territory, in combination with size of the ‘clean’ area, and tenure length are parameters used by females to estimate male phenotypic quality. The hypothesis generates at least four predictions, and available data provide support. It is concluded that although a firm test of the hypothesis remains to be undertaken, existing data support this, just as well as any other, explanatory model and therefore it should be taken into consideration.

4

Differential male mating frequency depending on male number in the migratory locust

100%

Castro A. J., Pardo M. C., Lopez-Leon M. D., Cabrero J., Camacho J. P.

Folia Biologica

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1998

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tom 46

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nr 1-2

5

Enzyme heterozygosity and developmental stability

100%

Mitton J. B.

Acta Theriologica. Supplement

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1995

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nr 03

Regular development of morphology is challenged by any environmental influence that draines energy from developing individuals. For half a century biologists have recognized that developmental stability, measured as the capability to regulate development of normal morphological structures, is influenced by genetic variation. This review considers the influence of enzyme polymorphism upon developmental stability. Empirical studies in a wide variety of animals have reported morphological variability and bilateral asymmetry to decrase with the heterozygosity of enzyme polymorphisms. A controversy focuses on the question of whether enzyme polymorphisms directly influence energy budgets and metabolism, or whether the enzymes are neutral markers that either reveal variation in levels of inbreeding or are in linkage disequilibrium with genes directly influencing development. Another controversy focuses on whether the relationships between enzyme heterozygosity and development stability, most commonly reported in poikilotherms, will also be found in homeotherms. These controversies are addressed by considering recent empirical studies of enzyme polymorphism and developmental stability. Kinetic and physiological studies have now established that enzyme polymorphisms can have a major impact upon flux through metabolic pathways and physiological variation. Enzyme heterozygosity is associated with resistance to parasites, which may decrease developmental stability. Enzyme heterozygosity is also related to secondary sexual characters, such as the size and symmetry of horns in white-tailed deer and the size of horns in bighorn sheep. Because symmetry is so important in sexual selection, the development of secondary sexual characters may yield important insights to the relationship between heterozygosity and developmental stability. Many empirical observations are consistent with hypothesis that enzymes have a direct influence on developmental stability. It is not likely that the relationship between heterozygosity and developmental stability will differ substantially between poikilotherms and homeotherms.

6

Evolution of phenotypic sex differences in cooperative species: is competition an opposing force?

84%

Dias R. I.

Acta Ornithologica

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2018

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tom 53

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nr 2

Sexual selection is generally thought to be weak in cooperative breeding species, largely because polygamous mating patterns that drive sexual selection can erode the kin-selected benefits of cooperation. Social selection, on the other hand, is expected to be strong among cooperative species especially because of the intense competition over status and resource access. In support of this view, several studies have shown monogamous mating and little sex difference in cooperative species. However, most previous studies have focused on species with relatively simple social systems and few studies have examined how mating patterns, social organization and ecological attributes have influenced the evolution of ornamentation in cooperative species. Here I used secondary data to examine several hypotheses and shed some light on how social and sexual selection influenced the evolution of phenotypic sex traits in cooperatively breeding birds. Despite the broad assumption that cooperative breeding species are monomorphic, results demonstrate that sex differences and the presence of ornamentation are widely spread in the group. Stable environments with higher precipitation are associated to the strongest differences between sexes. Results indicate that although extrapair matings and environment attributes are determinant to the evolution of sex differences, males and females of cooperative species seem to be more alike than their non-cooperative counterparts. The extent of mutual ornamentation found in cooperative species indicates that the combination of both sexual and social selection are imperative to determine how evolution has shaped phenotypic attributes in cooperative species.

7

Does the major histocompatibility complex influence choice of mate in humans and other mammals? - a review

84%

Jaworska J., Rapacz-Leonard A., Janowski T. E., Jezierski T.

Animal Science Papers and Reports

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2017

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tom 35

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nr 2

Reproduction is one of the basic biological functions in animals and humans. Due to the high biological relevance of reproduction and energy investment in their rearing offspring need to be of the best genetic quality and fitness to ensure preservation of the species. Both males and females employ mating strategies that would promote reproduction success and survival of their offspring. Choosing a high-quality mating partner is considered to be the main strategy in the reproduction process. One of the factors influencing the partner’s attractiveness is Major Histocompatibility Complex class I (MHC I). The influence of MHC I on mate choice is well established in animals, whereas it is still questioned in humans, where the social status of a partner may strongly influence the mate choice. In this review the role of the MHC I on mate choice in animals and humans is discussed. The studies published so far show that all investigated mammalian species can detect fractions of the MHC I molecules in urine and other body fluids. The response to the signal carried by MHC I is context-dependent and varies not only between species, but also between genders and may be modulated by various socioecological factors in every phase of the reproduction process, until zygote formation. These results suggest that MHC plays an important role in the choice of a reproductive partner in all mammal species, including humans.

8

Sexual selection and the evolution of song in birds of the genus Acrocephalus

84%

Borowiec M., Lontkowski J.

Biological Bulletin of Poznań

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2000

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tom 37

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nr 1

9

Bacular variation and allometry in the western marten Martes caurina

84%

Miller E. H., Nagorsen D. W.

Acta Theriologica

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2008

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tom 53

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nr 2

Many sexually-selected structures are variable and positively allometric relative to body size. For the western martenMartes caurina Merriam, 1890 from Vancouver Island, British Columbia, we investigated variation in the baculum compared with other bones and allometry of bacular to body size. Carcass length did not differ, and humeral and mandibular lengths differed little (< 1 and 2%, respectively), between age groupings < 1 and ≥ 1 yr old. In contrast, bacular length increased by 16%, and thickness by 29% (mid shaft) and 86% (basal) between those groupings, and thickness and mass continued to grow after the second year of life. Controlling for body size, bacular size varied more than humeral or mandibular size (CV for linear variables ∼4–8% for baculum, ∼2% for humerus or mandible). Some positive static allometry of bacular size to body size was found, but correlations between bacular and body size were weak (r=0.3–0.4). So penile size as related to bacular size could be a reliable but imprecise quality indicator during copulation. Weak polygamy (serial promiscuity), complex copulatory mechanisms, and high energetic costs of reproduction, likely select for multiple cues in mate-choice by females, not just penile cues affected by bacular size or shape.

10

Review of the genus Bantodemus Koch, 1955 (Coleoptera: Tenebrionidae: Platynotina)

67%

Iwan D., Banaszkiewicz M.

Annales Zoologici

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2006

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tom 56

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nr 4

The female genital structure of the genus Bantodemus Koch, 1955 is studied. The variability in the shape of sclerites in the bursa copulatrix is illustrated based on the species B. montanus. Two new species are described: B. durbaniensis sp. nov. and B. harmonius sp. nov. Separate keys for species determination are compiled for males and females. New localities data for B. caffer, B. furcatus, B. montanus, B. rudebecki, B. tristis are provided.

11

Africanacetus from the sub-Antarctic region: The southernmost record of fossil beaked whales

67%

Gol'din P. E., Vishnyakova K. A.

Acta Palaeontologica Polonica

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2013

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tom 58

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nr 3

We report two partial skulls of fossil beaked whales (Odontoceti, Ziphiidae) of uncertain age trawled from the sea floor of the sub−Antarctic Indian Ocean (58 to 60S), representing the southernmost record of the family. The skulls possess diag− nostic features of the genus Africanacetus, several specimens of which have been recovered from the sea floor off South Africa, but differ from the type and only known species Africanacetus ceratopsis in their larger size. This difference may either reflect intraspecific variation or indicate the existence of a hitherto unrecognised species. The two specimens are characterised by unusually developed mesorostral ossifications, combined with maxillary crests occurring in the facial re− gion. Both of the latter are found in a range of extant and extinct ziphiids, and known to be sexually dimorphic in extant beaked whales. These structures may be the result of hypermorphosis driven by sexual selection, and could be involved in male−specific behaviour.

Ograniczanie wyników

Intensity of melanin-based color and risk of predation in the Barn Swallow Hirundo rustica

Evolutionary aesthetics as a meeting point of philosophy and biology

Territory defence in male European roe deer (Capreolus capreolus) - a sexual ornament?

Differential male mating frequency depending on male number in the migratory locust

Enzyme heterozygosity and developmental stability

Evolution of phenotypic sex differences in cooperative species: is competition an opposing force?

Does the major histocompatibility complex influence choice of mate in humans and other mammals? - a review

Sexual selection and the evolution of song in birds of the genus Acrocephalus

Bacular variation and allometry in the western marten Martes caurina

Review of the genus Bantodemus Koch, 1955 (Coleoptera: Tenebrionidae: Platynotina)

Africanacetus from the sub-Antarctic region: The southernmost record of fossil beaked whales