... first Int. Sem. Landscape Ecol. Vol. I: 5-15. ... Stille, B., Madsen, T. and Nicklasson, M. 1... more ... first Int. Sem. Landscape Ecol. Vol. I: 5-15. ... Stille, B., Madsen, T. and Nicklasson, M. 1986. Multiple pa-ternity in the adder, Vipera berus. - Oikos 47: 173-175. Wallace, B. 1975. Hard and soft selection revisited. - Evolu-tion 29: 465-473. Williams, GC 1975. Sex and evolution. ...
MALES of most animal species will enhance their reproductive success if they mate often and with ... more MALES of most animal species will enhance their reproductive success if they mate often and with many different partners, whereas promiscuous mating is unlikely to increase a female's reproductive success. Why then is multiple copulation by females so common1-6? Many theoreticians have suggested that multiple copulations might enhance the viability of a female's offspring, either because of inadequate quantities of sperm from the first mating1,7, additional nutrients derived from the seminal fluid7,8 or some genetic advantage9-14. Our field studies on Swedish adders provide the first empirical evidence that multiple copulations, with different partners each time, increase offspring viability. This advantage apparently results from more intense sperm competition in the female's reproductive tract, resulting in a higher proportion of her ova being fertilized by genetically superior males.
Exotic animal and plant species introduced into the Australian continent often imparted catastrop... more Exotic animal and plant species introduced into the Australian continent often imparted catastrophic effects on the indigenous fauna and flora. Proponents of biological control introduced the South American Cane Toad (Bufo marinus) into the sugar cane fields of Queensland in 1935. The Cane Toad is one of the most toxic bufonids, and when seized by naïve Australian predators, the toxin usually kills the attacker. One group of Australian squamate reptiles that are very susceptible to Cane Toad toxins is varanid lizards. Prior to Cane Toad invasion of our study area, the Adelaide River floodplain of the Northern Territory of Australia, annual mortality of adult male radio-tagged Yellowspotted Goannas (Varanus panoptes) was very low (two deaths recorded among 20 lizards over three years). After the arrival of the toads in October 2005, all radio-tracked goannas were found dead in August 2006 (nine out of nine lizards), most likely after attempting to feed on toads. Our results suggest t...
We introduce and study a notion of invariant intrinsic torsion geometry which appears, for instan... more We introduce and study a notion of invariant intrinsic torsion geometry which appears, for instance, in connection with the Bryant-Salamon metric on the spinor bundle over S^3. This space is foliated by six-dimensional hypersurfaces, each of which carries a particular type of SO(3)-structure; the intrinsic torsion is invariant under SO(3). The last condition is sufficient to imply local homogeneity of such geometries, and this allows us to give a classification. We close the circle by showing that the Bryant-Salamon metric is the unique complete metric with holonomy G_2 that arises from SO(3)-structures with invariant intrinsic torsion.
Using PCR, the complete mitochondrial genome was sequenced in three frillneck lizards (Chlamydosa... more Using PCR, the complete mitochondrial genome was sequenced in three frillneck lizards (Chlamydosaurus kingii). The mitochondria spanned over 16,761bp. As in other vertebrates, two rRNA genes, 22 tRNA genes and 13 protein coding genes were identified. However, similar to some other squamate reptiles, two control regions (CRI and CRII) were identified, spanning 801 and 812 bp, respectively. Our results were compared with another Australian member of the family Agamidae, the bearded dragon (Pogana vitticeps). The overall base composition of the light-strand sequence largely mirrored that observed in P vitticeps. Furthermore, similar to P. vitticeps, we observed an insertion 801 bp long between the ND5 and ND6 genes. However, in contrast to P vitticeps we did not observe a conserved sequence block III region. Based on a comparison among the three frillneck lizards, we also present data on the proportion of variable sites within the major mitochondrial regions.
... first Int. Sem. Landscape Ecol. Vol. I: 5-15. ... Stille, B., Madsen, T. and Nicklasson, M. 1... more ... first Int. Sem. Landscape Ecol. Vol. I: 5-15. ... Stille, B., Madsen, T. and Nicklasson, M. 1986. Multiple pa-ternity in the adder, Vipera berus. - Oikos 47: 173-175. Wallace, B. 1975. Hard and soft selection revisited. - Evolu-tion 29: 465-473. Williams, GC 1975. Sex and evolution. ...
... first Int. Sem. Landscape Ecol. Vol. I: 5-15. ... Stille, B., Madsen, T. and Nicklasson, M. 1... more ... first Int. Sem. Landscape Ecol. Vol. I: 5-15. ... Stille, B., Madsen, T. and Nicklasson, M. 1986. Multiple pa-ternity in the adder, Vipera berus. - Oikos 47: 173-175. Wallace, B. 1975. Hard and soft selection revisited. - Evolu-tion 29: 465-473. Williams, GC 1975. Sex and evolution. ...
MALES of most animal species will enhance their reproductive success if they mate often and with ... more MALES of most animal species will enhance their reproductive success if they mate often and with many different partners, whereas promiscuous mating is unlikely to increase a female's reproductive success. Why then is multiple copulation by females so common1-6? Many theoreticians have suggested that multiple copulations might enhance the viability of a female's offspring, either because of inadequate quantities of sperm from the first mating1,7, additional nutrients derived from the seminal fluid7,8 or some genetic advantage9-14. Our field studies on Swedish adders provide the first empirical evidence that multiple copulations, with different partners each time, increase offspring viability. This advantage apparently results from more intense sperm competition in the female's reproductive tract, resulting in a higher proportion of her ova being fertilized by genetically superior males.
Exotic animal and plant species introduced into the Australian continent often imparted catastrop... more Exotic animal and plant species introduced into the Australian continent often imparted catastrophic effects on the indigenous fauna and flora. Proponents of biological control introduced the South American Cane Toad (Bufo marinus) into the sugar cane fields of Queensland in 1935. The Cane Toad is one of the most toxic bufonids, and when seized by naïve Australian predators, the toxin usually kills the attacker. One group of Australian squamate reptiles that are very susceptible to Cane Toad toxins is varanid lizards. Prior to Cane Toad invasion of our study area, the Adelaide River floodplain of the Northern Territory of Australia, annual mortality of adult male radio-tagged Yellowspotted Goannas (Varanus panoptes) was very low (two deaths recorded among 20 lizards over three years). After the arrival of the toads in October 2005, all radio-tracked goannas were found dead in August 2006 (nine out of nine lizards), most likely after attempting to feed on toads. Our results suggest t...
We introduce and study a notion of invariant intrinsic torsion geometry which appears, for instan... more We introduce and study a notion of invariant intrinsic torsion geometry which appears, for instance, in connection with the Bryant-Salamon metric on the spinor bundle over S^3. This space is foliated by six-dimensional hypersurfaces, each of which carries a particular type of SO(3)-structure; the intrinsic torsion is invariant under SO(3). The last condition is sufficient to imply local homogeneity of such geometries, and this allows us to give a classification. We close the circle by showing that the Bryant-Salamon metric is the unique complete metric with holonomy G_2 that arises from SO(3)-structures with invariant intrinsic torsion.
Using PCR, the complete mitochondrial genome was sequenced in three frillneck lizards (Chlamydosa... more Using PCR, the complete mitochondrial genome was sequenced in three frillneck lizards (Chlamydosaurus kingii). The mitochondria spanned over 16,761bp. As in other vertebrates, two rRNA genes, 22 tRNA genes and 13 protein coding genes were identified. However, similar to some other squamate reptiles, two control regions (CRI and CRII) were identified, spanning 801 and 812 bp, respectively. Our results were compared with another Australian member of the family Agamidae, the bearded dragon (Pogana vitticeps). The overall base composition of the light-strand sequence largely mirrored that observed in P vitticeps. Furthermore, similar to P. vitticeps, we observed an insertion 801 bp long between the ND5 and ND6 genes. However, in contrast to P vitticeps we did not observe a conserved sequence block III region. Based on a comparison among the three frillneck lizards, we also present data on the proportion of variable sites within the major mitochondrial regions.
... first Int. Sem. Landscape Ecol. Vol. I: 5-15. ... Stille, B., Madsen, T. and Nicklasson, M. 1... more ... first Int. Sem. Landscape Ecol. Vol. I: 5-15. ... Stille, B., Madsen, T. and Nicklasson, M. 1986. Multiple pa-ternity in the adder, Vipera berus. - Oikos 47: 173-175. Wallace, B. 1975. Hard and soft selection revisited. - Evolu-tion 29: 465-473. Williams, GC 1975. Sex and evolution. ...
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