Isolation and characterization of eight polymorphic microsatellite loci in the rainforest canopy tree,Syzygium sayeri (Myrtaceae)

Eight polymorphic microsatellite loci were isolated from the rainforest canopy tree, Syzygium sayeri, in order to study parentage and subsequently pollen dispersal among individuals in wild populations. Screening of one natural population (n = 64) mapped in a 500 × 500 m area at Cape Tribulation, north Queensland, Australia, yielded two to 11 alleles per locus with observed levels of heterozygosity ranging from 0.07 to 0.70. One locus was significantly out of Hardy–Weinberg equilibrium after Bonferroni correction for multiple tests. These loci should provide a useful tool in further understanding the dispersal patterns of this species.     

Developmental plasticity in a meristic character: the number of tentacles in the lophophore of a bryozoan species

There is increasing interest among evolutionary biologists in developmental plasticity. Previously ignored by many as being irrelevant to evolution because a plastic response to an environmental change is not inherited, the current, more positive, view of plasticity focuses on the fact that, although any individual plastic response is nonheritable, the overall pattern of developmental response to environmental variation (i.e. the developmental reaction norm) is heritable and may vary among genotypes within a population. Characters subject to plastic variation, like those that are entirely genetically determined, may vary in continuous, meristic or discrete ways. Of these, the least work has been carried out on meristic variation. In the present study, we contribute to the rectification of this imbalance by examining the plastic response of the number of tentacles in the lophophore of a species of bryozoan, Membranipora membranacea, to three environmental variables: temperature, salinity and food concentration. Because the approach taken was an experimental one, unlike the majority of studies of bryozoan tentacles to date, we are able to make statements about the causality of variation in tentacle number. The main conclusions of the present study are: (1) that plastic responses occur to all three environmental variables; (2) that these are part of a more generalized plastic response in the overall development of the zooids rather than being lophophore‐specific; and (3) that the issue of whether the relevant developmental reaction norms are adaptive or not is an open (and interesting) question. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 104 , 541–551.     

Estimation of rates of predation on tsetse

The levels of natural predation of puparial and adult tsetse flies, Glossina pallidipes Austen, were investigated at Nguruman, Kenya, during January 1989. Puparial experiments involved the production, by individually tubed female flies, of naturally deposited, unhandled puparia in soil cores; handled puparia were obtained from groups of caged flies kept in the normal way. Equal numbers of handled and unhandled puparia were planted out at different densities (1, 2, 4 or 8 per linear metre) in fifty-one natural puparial sites in four major vegetation types. After 10 days puparia were recovered using a soil corer and sieving system. Average predation rates (adjusted for the displacement of puparia by vertebrate activity at the puparial sites) were 9.4% and 7.8% for the two types of puparia during the experiment, equivalent to an average loss of 23.7% of all puparia during a normal 30-day developmental period. Maximum potential predation rates of adult flies were investigated by pinning freshly killed adults at densities of 1, 2, 4 or 8 per m3 to natural vegetation and scoring the results after 24 h. 70% of flies were attacked during this time, by a variety of predators, thought to include both vertebrates and invertebrates. No density dependence was detected in the experiments, either because natural puparial densities were too low for it to occur at this stage of the life cycle or because adult predation levels were too high for it to be detected. Present results are compared and contrasted with previous results for this and another species of tsetse. Calculations of the life-time fertilities of female tsetse suggest that the levels of puparial predation revealed by the present experiments are entirely realistic. Behaviour of the adult flies allows them to escape most of the considerable predation pressure under which they live. How they do so remains a mystery.