Project Gutenberg
Attributed to Thomas Gill by Goldsmiths' Library. Dated 1789 by Goldsmiths' Library. Book.
0000 - Gale Group | The Making of Modern World
... have a colourful, elongated caudal appendage, termed a sword, that is absent in females. In laboratory tests of female preference for male sword length in the green swordtai, Xiphophorus helleri, females ... pair of males differing naturally or experimentally in sword length to test the hypothesis that the elaboration ... different pairs of males were conducted in which sword differences between paired males varied from 6 to ... all five tests, females preferred males with longer swords. Female preference was shown to be an increasing ...
Tópico(s): Amphibian and Reptile Biology
1990 - Elsevier BV | Animal Behaviour
Book.
0000 - Gale Group | Sabin
... males with an at:C1chc::d, arrificia.!, colored sword whc:n given a choice: bc:rwo:n ... males and males with an arrificia.!,rransparc:nr sword as a controL Because: swordlessness is the: ancc: ... rh.ar fanale: pn:fc:rc:nce: for swords predateS the: evolurion of the: sword and concludes thar coc:volutionary modds of sc:: ... ar fc:m.alesarc:ac:raacd ro the: sword per sc: and nor the: com:cxt in which the: sword is displayai This is an importanr distinction, beaus rhing a sword co areas other than the: lower edge of ...
Tópico(s): Neurobiology and Insect Physiology Research
1991 - American Association for the Advancement of Science | Science
Book.
0000 - Gale Group | Sabin
Alexandra L. Basolo, Brian C. Trainor,
... helleri, possess a preference for the multicomponent male sword. Previous work suggests that this female preference is ... of a pre-existing receiver bias favouring a sword and has contributed to sword evolution via intersexual selection. We use video presentations ... respond to components of this composite trait. Complete swords in this species have at least four individual ... response to video stimuli depicting males with intact swords and males in which sword components were digitally manipulated, it appears that males ...
Tópico(s): Insect and Arachnid Ecology and Behavior
2002 - Elsevier BV | Animal Behaviour
Project Gutenberg
Photograph by Linnaeus Tripe (1822-1902) Who Was an Official Photographer for the British Government, Employed to Document Southern Indian Archaeological ...
0000 - Gale Group | NCCO Photography
Gil G. Rosenthal, William E. Wagner, Michael J. Ryan,
... of female pygmy swordtails, Xiphophorus nigrensis, for the sword, a conspicuous extension of the caudal fin in ... to show a preference for conspecific males with swords when presented with live males naturally varying in sword length, with live males of manipulated sword length, and with synthetic animations of males expressing natural variation in sword length. Females showed a significant bias against swords when presented with synthetic animations bearing supernormal sword characteristics. The reduced preference for swords, relative to ...
Tópico(s): Marine and fisheries research
2002 - Elsevier BV | Animal Behaviour
Photograph by Linnaeus Tripe (1822-1902) Who Was an Official Photographer for the British Government, Employed to Document Southern Indian Archaeological ...
0000 - Gale Group | NCCO Photography
Hans Zauner, Gerrit Begemann, Manuel Marí‐Beffa, Axel Meyer,
... understand the evolutionary history of this so‐called sword molecularly, it is of interest to unravel the developmental pathways responsible for extended growth of sword rays during development of swordtail males. We isolated ... and showed that they are differentially regulated during sword outgrowth. During sword growth in juvenile males, as well as during testosterone‐induced sword development and fin ray regeneration in the sword after amputation, expression of msxC is markedly up‐regulated in the sword forming fin rays. In contrast, msxE/1 is ...
Tópico(s): Reproductive biology and impacts on aquatic species
2003 - Wiley | Evolution & Development
Book.
0000 - Gale Group | The Making of Modern World
Alexandra L. Basolo, Guillermina Alcaraz,
... trait that could affect movement costs is the sword exhibited by male swordtail fishes: while longer swords may increase male mating success, they could negatively ... Here, we examine the energetic costs of the sword in Xiphophorus montezumae by experimentally manipulating sword length and measuring male aerobic metabolism during two ... of oxygen consumption indicate that males with longer swords expend more energy than males with shortened swords during both types of swimming. In addition, the sword increases the cost of male courtship. Thus, while ...
Tópico(s): Physiological and biochemical adaptations
2003 - Royal Society | Proceedings of the Royal Society B Biological Sciences
Proclaimed on September 29, 1660. Book.
0000 - Gale Group | The Making of Modern World
Cornelius Eibner, Silke Pittlik, Axel Meyer, Gerrit Begemann,
... fish of the genus Xiphophorus (Poeciliidae) possess a “sword” that is composed of several colored elongated ventral fin rays of the caudal fin. The sword is a secondary sexual trait that evolved through ... metamorphosis from a juvenile caudal fin to the sword, we have devised a transplantation protocol to assay ... those rays that develop into the two longest sword rays. This “sword organizer” causes adjacent fin rays to grow and become integrated into the sword and induces the development of an additional, typically ...
Tópico(s): Reproductive biology and impacts on aquatic species
2008 - Wiley | Evolution & Development
Project Gutenberg
"To which are prefixed the Constitution of the United States, and a synopsis of the legislation of Congress, respecting naval affairs, during the Revolutionary ...
0000 - Gale Group | Sabin
Nils Offen, Nicola Blum, Axel Meyer, Gerrit Begemann,
... of sexual selection through female choice was the "sword", a colourful extension of the caudal fin of ... have secondarily lost the ability to develop a sword. The sustained increase of testosterone during sexual maturation initiates sword development in male swordtails. Addition of testosterone also induces sword-like fin extensions in some platyfish species, suggesting that the genetic interactions required for sword development may be dormant, rather than lost, within ... Despite considerable interest in the evolution of the sword from a behavioural or evolutionary point of view, ...
Tópico(s): Developmental Biology and Gene Regulation
2008 - BioMed Central | BMC Developmental Biology
National Bureau of Economic Research (NBER)
... June 14, 1837 - Dec. 27, 1910. Expert on Swords. Born in Kochi, the Son of a Samurai ... Accounts Officer. He Was an Enthusiastic Collector of Swords, and Learned Appraisal of Swords from Heijuro Hon' ...
0000 - Gale Group | NCCO Photography
Alexander J. Baumgartner, Seth W. Coleman, Brook O. Swanson,
... of male caudal fin is extended into a 'sword', which serves to attract potential mates. However, bearing a long sword may increase drag and thus compromise a male' ... an instinctive escape behavior, in males with various sword lengths. We then removed males' swords and retested escape performance. We found no relationship between escape performance and sword length and no effect of sword removal on escape performance. While having a large sword may attract a predator's attention, our results suggest that sword size does not compromise a male's escape ...
Tópico(s): Avian ecology and behavior
2011 - Public Library of Science | PLoS ONE
Photograph. Photograph. Test of Swords and Bayonets. Soldiers with Swords and Bayonets, Sack in Corner. "Toy Soldiers with Bent Swords and Bayonets. Eleanor Henrietta White. ...
0000 - Gale Group | NCCO Photography
Marcin Biborski, Janusz Stȩpiński, Grzegorz Żabiński,
... newest research on the Szczerbiec -the Polish coronation sword.Technological examinations revealed that the blade was manufactured ... All this testifies to the authenticity of the sword as a genuine medieval weapon and not (as ... suggests a date of c. 1250 for the sword.As suggested by the lavishness of ornament and ... grip, the Szczerbiec may have been influenced by swords of the Mediterranean (especially Iberian) cultural sphere.The swords of Sancho IV of Castille and Léon, of ... Hohenstaufen, of the Comtés de Dreux and a sword from the Museo Arqueológico Nacional in Madrid seem ...
Tópico(s): Metallurgy and Cultural Artifacts
2011 - Spanish National Research Council | Gladius