Molecular ecology
It is virtually synonymous with the field of "Ecological Genetics" as pioneered by Theodosius Dobzhansky, E. B. Ford, Godfrey M. Hewitt, and others.
The development of molecular ecology is also closely related to the use of DNA microarrays, which allows for the simultaneous analysis of the expression of thousands of different genes.
This approach has been enhanced over a number of years to allow researchers to sequence thousands of genes from a small amount of starting DNA.
The amplification of DNA from environmental samples using general or group-specific primers leads to a mix of genetic material, requiring sorting before sequencing and identification.
The classic technique to achieve this is through cloning, which involves incorporating the amplified DNA fragments into bacterial plasmids.
The use of high-throughput sequencing techniques has been widely adopted by the fungal ecology community since the first publication of their use in the field in 2009.
The locus of choice for a description of the taxonomic structure of fungal communities has traditionally been the internal transcribed spacer (ITS) region of ribosomal RNA genes [9] due to its utility in identifying fungi to genus or species taxonomic levels,[10] and its high representation in public sequence databases.
[16][17] The construction of sequence databases that have broad representation across fungi, and that are curated by taxonomic experts is a critical next step.
[27] In house wrens (Troglodytes aedon), extra-pair offspring were also found to be male-biased compared to within-offspring.
[29] The use of molecular data, specifically allele frequencies of individuals among populations in relation to their geographic distance help to explain concepts such as, sex-biased dispersal, speciation, and landscape genetics.
[2]: 135 There are three main factors that influence the chances of finding a correlation of IBD, which include sample size, metabolism, and taxa.
Therefore, in order for individual sub-populations to remain healthy, they must either have a large population size or have a relatively high rate of dispersal with other subpopulations.
In species which exhibit polyandry the females will search out for the most suitable males and re-mate until they have found the best sperm to fertilize their eggs.
To combat this time-consuming method, scientists have recruited several molecular ecology techniques in order to study sex-biased dispersal.
The sex that disperses more displays a lower FST value, which measures levels of inbreeding between the subpopulation and the total population.
Additionally, assignment tests can be utilized to quantify the number of individuals of a certain sex dispersing to other populations.
[26] This change in allele frequency causes a series of intermediate varying phenotypes that when associated with certain environmental conditions can indicate selection.
[43] This study sought to find if this phenotypic variation was due to selection by calculating the Qst values across the owl populations.
Because high gene flow was still anticipated along this cline, selection was only expected to act upon the QTLs that incur locally adaptive phenotypic traits.
This means that high gene flow was present allowing the neutral markers to be similar, indicated by the low Fst value.
But, local adaptation due to selection was present as well, in the form of varying plumage coloration since the Qst value was high, indicating differences in these non-neutral loci.
Larger FST values imply that the level of genetic differentiation between sub-populations within a total population is more significant.
[50] The decline in fitness due to outbreeding is attributed to a breakup of coadapted gene complexes or favorable epistatic relationships.
[51] Three main mechanisms influence outbreeding depression; genetic drift, population bottlenecking, differentiation of adaptations, and set chromosomal dissimilarities resulting in sterile offspring.
However, the population is likely to experience a multi-generational decline of overall fitness as selection for traits takes multiple generations.
Using neutral markers during unit identification can provide unbiased assumptions of genetic drift and time since reproductive isolation within and among species and populations, while using non-neutral markers can provide more accurate estimations of adaptive evolutionary divergence, which can help determine the potential for a conservation unit to adapt within a certain habitat.
[55] This detection of evolutionary significance can allow each population of salmon to receive customized conservation and protection based on their adaptive uniqueness in response to geographic location.
Not only does it include the study of the interactions between species, but it also focuses on ecological concepts such as mutualism, predation, and competition within communities.
Their method used temporal banding to make genus, family and order based on how many tens of millions of years ago the speciation event that resulted in each species took place.
[26] Barriers for terrestrial species can include mountains, rivers, roads, and unsuitable terrain, such as agriculture fields.
