Population Genetic Structure of Aldabra Giant Tortoises

Evolution of population structure on islands is the result of physical processes linked to volcanism, orogenic events, changes in sea level, as well as habitat variation. We assessed patterns of genetic structure in the giant tortoise of the Aldabra atoll, where previous ecological studies suggested population subdivisions as a result of landscape discontinuity due to unsuitable habitat and island separation. Analysis of mitochondrial DNA (mtDNA) control region sequences and allelic variation at 8 microsatellite loci were conducted on tortoises sampled in 3 locations on the 2 major islands of Aldabra. We found no variation in mtDNA sequences. This pattern corroborated earlier work supporting the occurrence of a founding event during the last interglacial period and a further reduction in genetic variability during historical time. On the other hand, significant population structure recorded at nuclear loci suggested allopatric divergence possibly due to geographical barriers among islands and ecological partitions hindering tortoise movements within islands. This is the first attempt to study the population genetics of Aldabra tortoises, which are now at carrying capacity in an isolated terrestrial ecosystem where ecological factors appear to have a strong influence on population dynamic

The Durrell Institute of Conservation and Ecology (DICE)

The evolution, establishment, development and activities of The Durrell Institute of Conservation and Ecology (DICE) are described and explained, concentrating particularly on the connection and close collaboration with the Jersey Wildlife Preservation Trust (JWPT), DICE evolved from the realisation that natural sciences and ecological understanding alone cannot sustainably conserve wildlife and ecosystems without an understanding of the social sciences, as well as the need for developing means of integrating both sciences with practical experience and effectiveness. Decision-makers have been unable to use the scientific knowledge-base developed over many decades because it was both inaccessible and inapplicable, Moreover most training courses and graduate programmes were not targeted at improving the ability of the students to do a job, and were inflexible in their structure and uncaring of the future support needed by students in their chosen careers, This state of affairs required a radical departure from the conventional institute, both in its philosophy and priorities, and a university capable of embracing it

The ecology of stability in Southeast-Asia forests: biodiversity and common resource property

It is clear that for decades the traditional, confrontational method of dealing with conflicts in interests over natural resources does not resolve problems. Most methods rely on one party or another fulfilling undertakings which can easily be broken without any framework of checks and balances which ensure consistency and homeostasis. At least two difficulties exist to providing a better basis for resolving conflict; some jurisprudence framework derived from natural sciences and socioeconomics concerning common resource property, and a clearer understanding of the definition of biodiversity. The absence of a decision-making environmental framework for resolving conflicts between environmental 'stakeholders', benefitting all parties, means that any conservation or sustainable use of natural resources will always be corrupted and fail. Moreover the way in which biodiversity is defined changes planning priorities. This chapter offers an insight into both the problems and possible solutions of biodiversity management, or conservation, and common resource property disputes

Environmental sex determination in reptiles

In recent years, representatives of more than 40 families of reptiles have been studied to understand how environmental parameters affect sex determination. In this review, we summarise the distribution and taxonomic pattern of sex determining mechanisms, outline the main hypotheses of the adaptive significance of temperature sex determination (TSD), and of skewed population sex ratios. We also examine the competing hypotheses of the physiological and molecular mechanisms involved in TSD