When phrases like transcriptome divergence, plasticity of opsid gene expression and symparitic speciation in a genus pop up, then molecular ecology is probably the culprit! It all begins with evolutionary biology, which is the study of species descent, then their change and development of diversity.
Molecular ecology is a subfield of evolutionary biology, an interdisciplinary field which involves scientists from many fields, including ornithology, herpetology, mammalogy and other specialized fields. It is easy to imagine that specialization is necessary in evolutionary biology and its sub fields, since it can take a lifetime to study just one segment of the rich, diverse complexity that is life on Earth.
One way of looking at molecular ecology is that traditional ecological study is revisited, with a focus on genetics: phylogenetics, population genetics and genomes in general. This study is applied to questions of ecology, evolution, behavior and conservation.
Another title: ecological genetics looks at genetic studies in the context of the ways in which organisms interact with each other and with their environment. While molecular genetics looks at the issue from the molecular level, ecological genetics looks at phenotypes or populations.
Molecular evolutionis the focus of molecular genetics where DNA is either used to study the evolution of organisms OR organisms are studied to understand the evolution of DNA. Inferences are made in terms of "process from pattern", or deductions are made from the patterns that are found in DNA variation.
Genomes change in ways that are described as "fluid". Molecular evolution is a way to examine the process and the fluidity of the change.
Students who work toward undergraduate degrees, such as at the University of Texas at Austin, in molecular biology will study in the areas of genetics, microbiology, evolution, developmental biology. There is also about a year of study in physical chemistry and a year in biochemistry. To support this heavy background in chemistry and biology, other physical sciences and especially mathematics is essential. Molecular biology majors are well suited for medical and graduate schools and for laboratory research careers. The progress toward the PhD includes more research, study of detailed coursework and even teaching.
From data entry to research; technician to scientist, the career opportunities for molecular biologists are booming. Biotechnology firms, government, museums, medical specialties such as immunology, non profits...the list is very large as far as career opportunities for educated molecular ecologists. Specific jobs are in a huge range of titles, from "genetic and metabolic engineer" to "postdoctoral fellow in algae-biofuels-microbial ecology". There is even a job for a senior scientist in "Gut microbial ecology and health".