Molecular ecology
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Molecular ecology is a field of evolutionary biology that is concerned with applying molecular population genetics, molecular phylogenetics, and genomics to traditional ecological questions (e.g., species diagnosis, conservation and assessment of biodiversity, species-area relationships, and many questions in behavioral ecology). It is virtually synonymous with the field of "Ecological Genetics" as pioneered by Theodosius Dobzhansky, E. B. Ford, and others. These fields are united in their attempt to study genetic-based questions "out in the field" as opposed to the laboratory. There is a scientific journal called "Molecular Ecology", and a quick look at any issue will provide a glimpse into the breadth of the field (see below). However, it should be noted that almost all scientific journals in evolutionary biology publish articles dealing with "molecular ecology".
Molecular Ecological techniques have recently been used to study "in situ" questions of bacterial diversity. This stems from the fact that many microorganisms are not easily obtainable as cultured strains in the laboratory, which would allow for indentification and characterisation. It also stems from the development of polymerase chain reaction, which allows for rapid amplification of genetic material.
The amplification of DNA from environmental samples using general of group-specific primers leads to a mix of genetic material that has to be sorted out before sequencing and identification. The classic technique to achieve this is through cloning, which involves incorporating the amplified DNA fragments into bacterial plasmids. More recent techniques such as temperature gradient gel electrophoresis, allow for a faster result.
The development of molecular ecology is also closely related to the use of DNA chips, which allows for the detection of specific organisms or genes in an environment.
One of the main issues related to the use of molecular techniques in microbial ecology is the problem of the presence in active or passive form of the organisms. This can be addressed in a number of ways, mainly :
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- By using reverse transcriptase in order to produce an impression of the active genes
- By using fluorescence in situ hybridization (FISH) as a way of detecting and counting the cells that contain specific genes
Molecular ecology combines methods of population genetics and evolution to study the relationship of organisms to their environment. Methods frequently include using microsatellites to determine gene flow and hybridization between populations. When populations are interbreeding they will maintain the same allele frequencies, according to Hardy-Weinberg Equilibrium. DNA microarrays or real-time polymerase chain reaction may be used to analyze gene expression as a result of changes in environmental conditions or different response by differently adapted individuals. Molecular ecology is related to the field of Conservation genetics. Relevant journals are Molecular Ecology [1] and Conservations Genetics [2].
The journal Molecular Ecology publishes papers that "utilize molecular genetic techniques to address consequential questions in ecology, evolution, behaviour and conservation. Studies may employ neutral markers for inference about ecological and evolutionary processes or examine ecologically important genes and their products directly. Research areas of interest to the journal include:
- population structure and phylogeography
- reproductive strategies
- relatedness and kin selection
- sex allocation
- population genetic theory
- analytical methods development
- conservation genetics
- speciation genetics
- individual and species identification
- microbial biodiversity
- genetic marker development
- evolutionary dynamics of QTLs
- ecological interactions
- molecular adaptation and environmental genomics
- impact of genetically modified organisms "
