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Jan T. Lifjeld - One of the best experts on this subject based on the ideXlab platform.
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sperm head morphology is associated with sperm Swimming Speed a comparative study of songbirds using electron microscopy
Evolution, 2018Co-Authors: Hanna Nyborg Stostad, Jan T. Lifjeld, Arild Johnsen, Melissah RoweAbstract:Sperm exhibit extraordinary levels of morphological diversification across the animal kingdom. In songbirds, sperm have a helically shaped head incorporating a distinct acrosomal membrane or "helical keel," the form and extent of which varies across species. The functional significance of this helical shape, however, remains unknown. Using scanning electron microscopy, we quantified inter- and intraspecific variation in sperm head morphology across 36 songbird species (Passeriformes: Passerida). Using phylogenetic comparative methods, we investigated the relationship between sperm head morphology and both sperm Swimming Speed and the frequency of extra-pair young (EPY). We found that species whose sperm had a relatively more pronounced helical form (i.e., long acrosome, short nucleus, wide helical membrane, and a more pronounced waveform along the sperm head "core") had faster-Swimming sperm. We found no evidence of a relationship between interspecific variation in sperm head morphology and EPY, although we did find that among- and within-male variation in sperm head traits were negatively correlated with EPY. Applying principles of fluid mechanics, we discuss how the helical form of the sperm head may influence Swimming Speed, and suggest that further studies considering aspects of sperm morphology beyond sperm length are needed to improve our understanding of sperm structure-function relationships.
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comparative evidence for the evolution of sperm Swimming Speed by sperm competition and female sperm storage duration in passerine birds
Evolution, 2009Co-Authors: Oddmund Kleven, Geir Rudolfsen, Terje Laskemoen, Raleigh J. Robertson, Frode Fossøy, Jan T. LifjeldAbstract:Sperm Swimming Speed is an important determinant of male fertility and sperm competitiveness. Despite its fundamental biological importance, the underlying evolutionary processes affecting this male reproductive trait are poorly understood. Using a comparative approach in a phylogenetic framework, we tested the predictions that sperm swim faster with (1) increased risk of sperm competition, (2) shorter duration of female sperm storage, and (3) increased sperm length. We recorded sperm Swimming Speed in 42 North American and European free-living passerine bird species, representing 35 genera and 16 families. We found that sperm Swimming Speed was positively related to the frequency of extrapair paternity (a proxy for the risk of sperm competition) and negatively associated with clutch size (a proxy for the duration of female sperm storage). Sperm Swimming Speed was unrelated to sperm length, although sperm length also increased with the frequency of extrapair paternity. These results suggest that sperm Swimming Speed and sperm length are not closely associated traits and evolve independently in response to sperm competition in passerine birds. Our findings emphasize the significance of both sperm competition and female sperm storage duration as evolutionary forces driving sperm Swimming Speed.
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comparative evidence for the evolution of sperm Swimming Speed by sperm competition and female sperm storage duration in passerine birds
Evolution, 2009Co-Authors: Oddmund Kleven, Geir Rudolfsen, Terje Laskemoen, Raleigh J. Robertson, Frode Fossøy, Jan T. LifjeldAbstract:Sperm Swimming Speed is an important determinant of male fertility and sperm competitiveness. Despite its fundamental biological importance, the underlying evolutionary processes affecting this male reproductive trait are poorly understood. Using a comparative approach in a phylogenetic framework, we tested the predictions that sperm swim faster with (1) increased risk of sperm competition, (2) shorter duration of female sperm storage, and (3) increased sperm length. We recorded sperm Swimming Speed in 42 North American and European free-living passerine bird species, representing 35 genera and 16 families. We found that sperm Swimming Speed was positively related to the frequency of extrapair paternity (a proxy for the risk of sperm competition) and negatively associated with clutch size (a proxy for the duration of female sperm storage). Sperm Swimming Speed was unrelated to sperm length, although sperm length also increased with the frequency of extrapair paternity. These results suggest that sperm Swimming Speed and sperm length are not closely associated traits and evolve independently in response to sperm competition in passerine birds. Our findings emphasize the significance of both sperm competition and female sperm storage duration as evolutionary forces driving sperm Swimming Speed.
Frode Fossøy - One of the best experts on this subject based on the ideXlab platform.
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comparative evidence for the evolution of sperm Swimming Speed by sperm competition and female sperm storage duration in passerine birds
Evolution, 2009Co-Authors: Oddmund Kleven, Geir Rudolfsen, Terje Laskemoen, Raleigh J. Robertson, Frode Fossøy, Jan T. LifjeldAbstract:Sperm Swimming Speed is an important determinant of male fertility and sperm competitiveness. Despite its fundamental biological importance, the underlying evolutionary processes affecting this male reproductive trait are poorly understood. Using a comparative approach in a phylogenetic framework, we tested the predictions that sperm swim faster with (1) increased risk of sperm competition, (2) shorter duration of female sperm storage, and (3) increased sperm length. We recorded sperm Swimming Speed in 42 North American and European free-living passerine bird species, representing 35 genera and 16 families. We found that sperm Swimming Speed was positively related to the frequency of extrapair paternity (a proxy for the risk of sperm competition) and negatively associated with clutch size (a proxy for the duration of female sperm storage). Sperm Swimming Speed was unrelated to sperm length, although sperm length also increased with the frequency of extrapair paternity. These results suggest that sperm Swimming Speed and sperm length are not closely associated traits and evolve independently in response to sperm competition in passerine birds. Our findings emphasize the significance of both sperm competition and female sperm storage duration as evolutionary forces driving sperm Swimming Speed.
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comparative evidence for the evolution of sperm Swimming Speed by sperm competition and female sperm storage duration in passerine birds
Evolution, 2009Co-Authors: Oddmund Kleven, Geir Rudolfsen, Terje Laskemoen, Raleigh J. Robertson, Frode Fossøy, Jan T. LifjeldAbstract:Sperm Swimming Speed is an important determinant of male fertility and sperm competitiveness. Despite its fundamental biological importance, the underlying evolutionary processes affecting this male reproductive trait are poorly understood. Using a comparative approach in a phylogenetic framework, we tested the predictions that sperm swim faster with (1) increased risk of sperm competition, (2) shorter duration of female sperm storage, and (3) increased sperm length. We recorded sperm Swimming Speed in 42 North American and European free-living passerine bird species, representing 35 genera and 16 families. We found that sperm Swimming Speed was positively related to the frequency of extrapair paternity (a proxy for the risk of sperm competition) and negatively associated with clutch size (a proxy for the duration of female sperm storage). Sperm Swimming Speed was unrelated to sperm length, although sperm length also increased with the frequency of extrapair paternity. These results suggest that sperm Swimming Speed and sperm length are not closely associated traits and evolve independently in response to sperm competition in passerine birds. Our findings emphasize the significance of both sperm competition and female sperm storage duration as evolutionary forces driving sperm Swimming Speed.
Oddmund Kleven - One of the best experts on this subject based on the ideXlab platform.
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comparative evidence for the evolution of sperm Swimming Speed by sperm competition and female sperm storage duration in passerine birds
Evolution, 2009Co-Authors: Oddmund Kleven, Geir Rudolfsen, Terje Laskemoen, Raleigh J. Robertson, Frode Fossøy, Jan T. LifjeldAbstract:Sperm Swimming Speed is an important determinant of male fertility and sperm competitiveness. Despite its fundamental biological importance, the underlying evolutionary processes affecting this male reproductive trait are poorly understood. Using a comparative approach in a phylogenetic framework, we tested the predictions that sperm swim faster with (1) increased risk of sperm competition, (2) shorter duration of female sperm storage, and (3) increased sperm length. We recorded sperm Swimming Speed in 42 North American and European free-living passerine bird species, representing 35 genera and 16 families. We found that sperm Swimming Speed was positively related to the frequency of extrapair paternity (a proxy for the risk of sperm competition) and negatively associated with clutch size (a proxy for the duration of female sperm storage). Sperm Swimming Speed was unrelated to sperm length, although sperm length also increased with the frequency of extrapair paternity. These results suggest that sperm Swimming Speed and sperm length are not closely associated traits and evolve independently in response to sperm competition in passerine birds. Our findings emphasize the significance of both sperm competition and female sperm storage duration as evolutionary forces driving sperm Swimming Speed.
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comparative evidence for the evolution of sperm Swimming Speed by sperm competition and female sperm storage duration in passerine birds
Evolution, 2009Co-Authors: Oddmund Kleven, Geir Rudolfsen, Terje Laskemoen, Raleigh J. Robertson, Frode Fossøy, Jan T. LifjeldAbstract:Sperm Swimming Speed is an important determinant of male fertility and sperm competitiveness. Despite its fundamental biological importance, the underlying evolutionary processes affecting this male reproductive trait are poorly understood. Using a comparative approach in a phylogenetic framework, we tested the predictions that sperm swim faster with (1) increased risk of sperm competition, (2) shorter duration of female sperm storage, and (3) increased sperm length. We recorded sperm Swimming Speed in 42 North American and European free-living passerine bird species, representing 35 genera and 16 families. We found that sperm Swimming Speed was positively related to the frequency of extrapair paternity (a proxy for the risk of sperm competition) and negatively associated with clutch size (a proxy for the duration of female sperm storage). Sperm Swimming Speed was unrelated to sperm length, although sperm length also increased with the frequency of extrapair paternity. These results suggest that sperm Swimming Speed and sperm length are not closely associated traits and evolve independently in response to sperm competition in passerine birds. Our findings emphasize the significance of both sperm competition and female sperm storage duration as evolutionary forces driving sperm Swimming Speed.
Raleigh J. Robertson - One of the best experts on this subject based on the ideXlab platform.
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comparative evidence for the evolution of sperm Swimming Speed by sperm competition and female sperm storage duration in passerine birds
Evolution, 2009Co-Authors: Oddmund Kleven, Geir Rudolfsen, Terje Laskemoen, Raleigh J. Robertson, Frode Fossøy, Jan T. LifjeldAbstract:Sperm Swimming Speed is an important determinant of male fertility and sperm competitiveness. Despite its fundamental biological importance, the underlying evolutionary processes affecting this male reproductive trait are poorly understood. Using a comparative approach in a phylogenetic framework, we tested the predictions that sperm swim faster with (1) increased risk of sperm competition, (2) shorter duration of female sperm storage, and (3) increased sperm length. We recorded sperm Swimming Speed in 42 North American and European free-living passerine bird species, representing 35 genera and 16 families. We found that sperm Swimming Speed was positively related to the frequency of extrapair paternity (a proxy for the risk of sperm competition) and negatively associated with clutch size (a proxy for the duration of female sperm storage). Sperm Swimming Speed was unrelated to sperm length, although sperm length also increased with the frequency of extrapair paternity. These results suggest that sperm Swimming Speed and sperm length are not closely associated traits and evolve independently in response to sperm competition in passerine birds. Our findings emphasize the significance of both sperm competition and female sperm storage duration as evolutionary forces driving sperm Swimming Speed.
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comparative evidence for the evolution of sperm Swimming Speed by sperm competition and female sperm storage duration in passerine birds
Evolution, 2009Co-Authors: Oddmund Kleven, Geir Rudolfsen, Terje Laskemoen, Raleigh J. Robertson, Frode Fossøy, Jan T. LifjeldAbstract:Sperm Swimming Speed is an important determinant of male fertility and sperm competitiveness. Despite its fundamental biological importance, the underlying evolutionary processes affecting this male reproductive trait are poorly understood. Using a comparative approach in a phylogenetic framework, we tested the predictions that sperm swim faster with (1) increased risk of sperm competition, (2) shorter duration of female sperm storage, and (3) increased sperm length. We recorded sperm Swimming Speed in 42 North American and European free-living passerine bird species, representing 35 genera and 16 families. We found that sperm Swimming Speed was positively related to the frequency of extrapair paternity (a proxy for the risk of sperm competition) and negatively associated with clutch size (a proxy for the duration of female sperm storage). Sperm Swimming Speed was unrelated to sperm length, although sperm length also increased with the frequency of extrapair paternity. These results suggest that sperm Swimming Speed and sperm length are not closely associated traits and evolve independently in response to sperm competition in passerine birds. Our findings emphasize the significance of both sperm competition and female sperm storage duration as evolutionary forces driving sperm Swimming Speed.
Geir Rudolfsen - One of the best experts on this subject based on the ideXlab platform.
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comparative evidence for the evolution of sperm Swimming Speed by sperm competition and female sperm storage duration in passerine birds
Evolution, 2009Co-Authors: Oddmund Kleven, Geir Rudolfsen, Terje Laskemoen, Raleigh J. Robertson, Frode Fossøy, Jan T. LifjeldAbstract:Sperm Swimming Speed is an important determinant of male fertility and sperm competitiveness. Despite its fundamental biological importance, the underlying evolutionary processes affecting this male reproductive trait are poorly understood. Using a comparative approach in a phylogenetic framework, we tested the predictions that sperm swim faster with (1) increased risk of sperm competition, (2) shorter duration of female sperm storage, and (3) increased sperm length. We recorded sperm Swimming Speed in 42 North American and European free-living passerine bird species, representing 35 genera and 16 families. We found that sperm Swimming Speed was positively related to the frequency of extrapair paternity (a proxy for the risk of sperm competition) and negatively associated with clutch size (a proxy for the duration of female sperm storage). Sperm Swimming Speed was unrelated to sperm length, although sperm length also increased with the frequency of extrapair paternity. These results suggest that sperm Swimming Speed and sperm length are not closely associated traits and evolve independently in response to sperm competition in passerine birds. Our findings emphasize the significance of both sperm competition and female sperm storage duration as evolutionary forces driving sperm Swimming Speed.
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comparative evidence for the evolution of sperm Swimming Speed by sperm competition and female sperm storage duration in passerine birds
Evolution, 2009Co-Authors: Oddmund Kleven, Geir Rudolfsen, Terje Laskemoen, Raleigh J. Robertson, Frode Fossøy, Jan T. LifjeldAbstract:Sperm Swimming Speed is an important determinant of male fertility and sperm competitiveness. Despite its fundamental biological importance, the underlying evolutionary processes affecting this male reproductive trait are poorly understood. Using a comparative approach in a phylogenetic framework, we tested the predictions that sperm swim faster with (1) increased risk of sperm competition, (2) shorter duration of female sperm storage, and (3) increased sperm length. We recorded sperm Swimming Speed in 42 North American and European free-living passerine bird species, representing 35 genera and 16 families. We found that sperm Swimming Speed was positively related to the frequency of extrapair paternity (a proxy for the risk of sperm competition) and negatively associated with clutch size (a proxy for the duration of female sperm storage). Sperm Swimming Speed was unrelated to sperm length, although sperm length also increased with the frequency of extrapair paternity. These results suggest that sperm Swimming Speed and sperm length are not closely associated traits and evolve independently in response to sperm competition in passerine birds. Our findings emphasize the significance of both sperm competition and female sperm storage duration as evolutionary forces driving sperm Swimming Speed.
