Prioritizing Populations for Conservation Using Phylogenetic Networks

In the face of inevitable future losses to biodiversity, ranking species by conservation priority seems more than prudent. Setting conservation priorities within species (i.e., at the population level) may be critical as species ranges become fragmented and connectivity declines. However, existing approaches to prioritization (e.g., scoring organisms by their expected genetic contribution) are based on phylogenetic trees, which may be poor representations of differentiation below the species level. In this paper we extend evolutionary isolation indices used in conservation planning from phylogenetic trees to phylogenetic networks. Such networks better represent population differentiation, and our extension allows populations to be ranked in order of their expected contribution to the set. We illustrate the approach using data from two imperiled species: the spotted owl Strix occidentalis in North America and the mountain pygmy-possum Burramys parvus in Australia. Using previously published mitochondrial and microsatellite data, we construct phylogenetic networks and score each population by its relative genetic distinctiveness. In both cases, our phylogenetic networks capture the geographic structure of each species: geographically peripheral populations harbor less-redundant genetic information, increasing their conservation rankings. We note that our approach can be used with all conservation-relevant distances (e.g., those based on whole-genome, ecological, or adaptive variation) and suggest it be added to the assortment of tools available to wildlife managers for allocating effort among threatened populations

Computational methods in biodiversity conservation

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Novel Split-Based Approaches to Computing Phylogenetic Diversity and Planar Split Networks

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Biodiversity Conservation and Phylogenetic Systematics: Preserving our evolutionary heritage in an extinction crisis

Biodiversity; Nature conservatio

Genealogical studies of selected Australian barramundi (Lates calcarifer) using mtDNA : Implications for stock transfer to the Kimberley region of Western Australia

This study resulted from concerns for the present and proposed movement of barramundi (Lates catcarifer) across presumed population genetic boundaries into the Kimberley region of Western Australia for net-pen aquaculture and a recreational fishery development in dams no longer available to seasonal barramundi dispersal. Direct DNA sequencing of the non-recombining, maternally inherited mitochondrial genome of barramundi thought to represent wild populations from a broad section of a still wider Australian range were used for phylogenetic reconstructions that support hypotheses for historic gene flow between Kimberley and other populations during Recent sea level fluctuations. Nil or low levels of genetic diversity in samples beyond the Kimberley were reflected in highly significant estimates of population genetic subdivision and low gene flow between the contemporary Kimberley population and elsewhere. The observed population genetic structure of western Australian barramundi is discussed with regard to the island and isolation by distance models, however limited sampling and an absence of demographic data leaves a conclusion problematic. Stochastic, but long distance gene flow is predicted within Kimberley barramundi, and is discussed in relation to a distinct east-trending environmental cline that is thought to influence habitat availability and subsequent juvenile dispersal. The effects of hybridization due to stock enhancement or escapement are discussed in the context of the management objective, which is to maintain genetic diversity. Given this, there are clear implications for hatchery practices and wild fishery management in the Kimberley, which leaves the present translocation of barramundi a questionable practice that should not occur unless no contravention of the management objective can be assured

Design of a Novel Skin-Stretching Device

In response to poor mechanical stability and long growth time of tissue-engineered skin substitutes, we present a novel skin-stretching device that mechanically stimulates engineered grafts during in vitro culture to accelerate growth. Mechanical loading increases epidermal proliferation, expression of growth factors, and mechanical stability. Our device loads engineered skin grafts at a customizable, cyclic waveform to ultimately lead to mechanically stable engineered skin grafts. ANSYS modeling approximated the maximum force to be applied at 0.2N. The device was fabricated and tested on porcine and chicken skin. After initial testing it was apparent the device could apply multiaxially load samples during culture. In addition, testing cycles can be varied to suit the user’s needs