Introduction To Conservation Genetics Pdf !!BETTER!! Download
Understanding the impact of, and factors influencing, inbreeding in populations of conservation concern has been identified as an important issue for conservation practitioners [23-25]. The need for a systematic review to assess the impacts of inbreeding on wild populations was discussed by the UK Conservation Genetics Working Group, which includes representatives from UK-based government and non-government conservation organisations and scientists working in the field of conservation genetics. Feedback from these meetings was used to shape the scope of review and develop a draft systematic review protocol. To maximise relevance to stakeholders this review protocol was peer-reviewed and published on-line in accordance with the guidelines for systematic reviews in environmental management .
Introduction To Conservation Genetics Pdf Download
The amount of primary literature documenting phenotypic consequences of inbreeding has increased in most years since 1993. The importance (and even the existence) of inbreeding depression in natural populations was questioned by some authors in the 1990s [31,32]. This corresponds to, and likely resulted in the initial increase in the rate of publications documented in this systematic map. Subsequent key studies and reviews (e.g. [18,19,33]) that demonstrated fitness costs associated with inbreeding in natural populations and validated its relevance to conservation have resulted in a continuous, and increasing number of publications on the topic. In addition, the subsequent recognition of conservation genetics as a distinct discipline within conservation biology and establishment of several journals devoted to this field are also likely to have facilitated the increasing rate of publication.
Adaptation is a genetic process that allows a species to persist for generations in a changing habitat. A central focus of traditional conservation genetics has been to ensure that populations maintain sufficient genetic variation to act as substrates for the process of adaptation. With the transition to modern high-resolution genomic data, conservation researchers can not only assay overall levels of genetic variation, but also identify specific alleles that may be adaptive. Such data can provide managers with useful information when they need to prioritize populations for protection or need to make decisions regarding which individuals to translocate so as to boost diversity in a declining population.
Although the examples we have identified thus far represent applications targeting single species, many researchers have begun to identify multiple species concurrently by using taxonomically general PCR primers paired with cloning and Sanger sequencing (Minamoto et al. 2012) or high-throughput sequencing (HTS; Thomsen et al. 2012b). These efforts have been referred to as metagenomics, metagenetics, metasystematics, or metabarcoding (Taberlet et al. 2012). Ongoing debate about the most apt name for this effort notwithstanding (Esposito and Kirschberg 2014), the ability to use eDNA to detect many species simultaneously inspires considerable conservation appeal (Yoccoz 2012). The ability to survey multiple species within a single sampling effort using eDNA makes surveys more efficient and economical. Furthermore, the use of increasingly general primers or shotgun sequencing (i.e. without taxonomically general PCR) opens up the possibility that managers and researchers do not need to choose target organisms a priori, thus facilitating detection of unexpected endangered or introduced species. Finally, species interactions represent an important consideration for conservation efforts, and understanding the distributions of multiple interacting species in a single survey could contribute to the maintenance of intact communities.
Beyond presence/absence and abundance information, is there more information to be gained from eDNA surveys? The study of population genetics with eDNA samples represents one exciting possibility. Advances in noninvasive genetic methods, such as the collection and population genetic analysis of hair, feathers, eggshells, feces, and other samples have been lauded by the wildlife research and conservation community (Beja-Pereira et al. 2009). However, the leap in complexity when moving from sampling specific materials (e.g. trapped clumps of fur) to the analysis of mixed genetic materials of various quality contained within bulk environmental samples used in eDNA analyses portends considerable hurdles to population genetic and genomic analyses. The same complexity differential applies between, for example, pollen from one plant and a pollen mixture collected by insects.
Whereas previous, primarily metazoan, eDNA assays have depended almost exclusively upon species identification based on mitochondrial DNA (mtDNA), conservation interest in identifying and distinguishing species hybrids, populations, evolutionarily significant units, and individuals based on eDNA will require improved resolution before eDNA methods can adequately assess fine levels of genetic variation or estimate population genetic measures such as effective population size or genetic fixation. Decay and fragmentation of extraorganismal DNA presents one challenge, but noninvasive genetics and paleogenetics have demonstrated remarkable persistence of short nucleic acids (Hofreiter et al. 2001). Perhaps a greater challenge arises from the high probability that multiple individuals and species contribute DNA to any given environmental sample. Such environmentally pooled DNA from an unknown number of individuals complicates distinguishing between individual organisms and estimating classical population genetic parameters, particularly those that rely on allele frequency (Toulza et al. 2012). Standard tools for generating population genetic data also are not generally designed with the high sensitivity and specificity necessary to isolate single-species markers from a complex multi-species mixture. Anecdotally, we have had limited success amplifying