gene flow

Urban reserves have the potential to retain relatively high biodiversity. However, populations of the taxa within them can have reduced genetic diversity and, if gene flow between populations is inhibited by urbanised surroundings, can become genetically differentiated. Here we determine whether differences in population genetic differentiation and diversity can be observed in the leaf litter inhabiting weevil Geochus politus along the urban-rural gradient spanning Waitākere Ranges Regional Parkland and suburbs of west Auckland, New Zealand.

 In New Zealand, mice in reserves can complicate the control of mammalian predator invasion by masking scent and eating baits. Eradicating mice allows predator invasions to be more readily detected and managed, but removal of mice is only feasible if recolonisation is rare. We used genetics and morphology to assess whether the mouse population on Waikawa Island was isolated from the mainland population. A sample of mitochondrial DNA sequences revealed that at least four female mice must have founded the Waikawa population, but that gene flow between island and mainland mice is limited.

Population structure, diversity and gene flow in four populations of Aciphylla glaucescens were studied using allozymes. Six of the seven putative loci were polymorphic in at least one population. Within populations the mean percentage of polymorphic loci was 68%. Gene diversity for Aciphylla glaucescens (H-e = 0.258) was greater at the species level compared with other outcrossing, wind pollinated plant species (H-e = 0.162). The mean diversity among populations of A.