Molecular ecology is a field of evolutionary biology that is concerned with applying molecular
population geneticsPopulation genetics is the study of allele frequency distribution and change under the influence of the four main evolutionary processes: natural selection, genetic drift, mutation and gene flow. It also takes into account the factors of recombination, population subdivision and population...
, molecular phylogenetics, and more recently
genomicsGenomics is a discipline in genetics concerning the study of the genomes of organisms. The field includes intensive efforts to determine the entire DNA sequence of organisms and fine-scale genetic mapping efforts. The field also includes studies of intragenomic phenomena such as heterosis,...
to traditional
ecologicalEcology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...
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 DobzhanskyTheodosius Grygorovych Dobzhansky ForMemRS was a prominent geneticist and evolutionary biologist, and a central figure in the field of evolutionary biology for his work in shaping the unifying modern evolutionary synthesis...
, 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. Molecular ecology is related to the field of
Conservation geneticsConservation genetics is an interdisciplinary science that aims to apply genetic methods to the conservation and restoration of biodiversity. Researchers involved in conservation genetics come from a variety of fields including population genetics, molecular ecology, biology, evolutionary biology,...
.
Methods frequently include using microsatellites to determine gene flow and hybridization between populations. The development of molecular ecology is also closely related to the use of
DNA microarraysA microarray is a multiplex lab-on-a-chip. It is a 2D array on a solid substrate that assays large amounts of biological material using high-throughput screening methods.Types of microarrays include:...
, which allows for the simultaneous analysis of the expression of thousands of different genes.
real-time polymerase chain reactionIn molecular biology, real-time polymerase chain reaction, also called quantitative real time polymerase chain reaction or kinetic polymerase chain reaction , is a laboratory technique based on the PCR, which is used to amplify and simultaneously quantify a targeted DNA molecule...
may also be used to analyze
gene expressionGene expression is the process by which information from a gene is used in the synthesis of a functional gene product. These products are often proteins, but in non-protein coding genes such as ribosomal RNA , transfer RNA or small nuclear RNA genes, the product is a functional RNA...
as a result of changes in environmental conditions or different response by differently adapted individuals.
Bacterial diversity
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
strainsIn biology, a strain is a low-level taxonomic rank used in three related ways.-Microbiology and virology:A strain is a genetic variant or subtype of a micro-organism . For example, a "flu strain" is a certain biological form of the influenza or "flu" virus...
in the laboratory, which would allow for identification and characterisation. It also stems from the development of
PCR techniqueThe polymerase chain reaction is a scientific technique in molecular biology to amplify a single or a few copies of a piece of DNA across several orders of magnitude, generating thousands to millions of copies of a particular DNA sequence....
, which allows for rapid amplification of genetic material.
The amplification of
DNADeoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
from environmental samples using general of group-specific
primersA primer is a strand of nucleic acid that serves as a starting point for DNA synthesis. They are required for DNA replication because the enzymes that catalyze this process, DNA polymerases, can only add new nucleotides to an existing strand of DNA...
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
plasmidIn microbiology and genetics, a plasmid is a DNA molecule that is separate from, and can replicate independently of, the chromosomal DNA. They are double-stranded and, in many cases, circular...
s. More recent techniques such as
temperature gradient gel electrophoresisTemperature Gradient Gel Electrophoresis and Denaturing Gradient Gel Electrophoresis are forms of electrophoresis which use either a temperature or chemical gradient to denature the sample as it moves across an acrylamide gel. TGGE and DGGE can be applied to nucleic acids such as DNA and RNA,...
, allow for a faster result.
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