Ecological genetics
Encyclopedia
Ecological genetics is the study of genetics
in natural populations.
This contrasts with classical genetics
, which works mostly on crosses between laboratory strains, and DNA
sequence analysis
, which studies genes at the molecular level.
Research in this field is on traits of ecological significance — that is, traits related to fitness
, which affect an organism's survival and reproduction. Examples might be: flowering time, drought
tolerance, polymorphism
, mimicry, avoidance of attacks by predators.
Research usually involve a mixture of field and laboratory studies. Samples of natural populations may be taken back to the laboratory for their genetic variation to be analysed. Changes in the populations at different times and places will be noted, and the pattern of mortality
in these populations will be studied. Research is often done on insects and other organisms that have short generation times.
biologist E.B. Ford (1901–1988) in the early 20th century. Ford was taught genetics at Oxford University by Julian Huxley
, and started research on the genetics of natural populations in 1924. Ford also had a long working relationship with R.A. Fisher. By the time Ford had developed his formal definition of genetic polymorphism, Fisher had got accustomed to high natural selection
values in nature. This was one of the main outcomes of research on natural populations. Ford's magnum opus was Ecological genetics, which ran to four editions and was widely influential.
Other notable ecological geneticists would include Theodosius Dobzhansky
who worked on chromosome
polymorphism
in fruit flies
. As a young researcher in Russia, Dobzhansky had been influenced by Sergei Chetverikov
, who also deserves to be remembered as a founder of genetics in the field, though his significance was not appreciated until much later. Dobzhansky and colleagues carried out studies on natural populations of Drosophila species in western USA and Mexico over many years.
Philip Sheppard, Cyril Clarke
, Bernard Kettlewell
and A.J. Cain were all strongly influenced by Ford; their careers date from the post WWII era. Collectively, their work on lepidoptera
, and on human blood groups, established the field, and threw light on selection in natural populations where its role had been once doubted.
Work of this kind needs long-term funding, as well as grounding in both ecology and genetics. These are both difficult requirements. Research projects can last longer than a researcher's career; for instance, research into mimicry started 150 years ago, and is still going strongly. Funding of this type of research is still rather erratic, but at least the value of working with natural populations in the field cannot now be doubted.
Genetics
Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....
in natural populations.
This contrasts with classical genetics
Classical genetics
Classical genetics consists of the technique and methodologies of genetics that predate the advent of molecular biology. A key discovery of classical genetics in eukaryotes was genetic linkage...
, which works mostly on crosses between laboratory strains, and DNA
DNA
Deoxyribonucleic 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...
sequence analysis
Sequence analysis
In bioinformatics, the term sequence analysis refers to the process of subjecting a DNA, RNA or peptide sequence to any of a wide range of analytical methods to understand its features, function, structure, or evolution. Methodologies used include sequence alignment, searches against biological...
, which studies genes at the molecular level.
Research in this field is on traits of ecological significance — that is, traits related to fitness
Fitness (biology)
Fitness is a central idea in evolutionary theory. It can be defined either with respect to a genotype or to a phenotype in a given environment...
, which affect an organism's survival and reproduction. Examples might be: flowering time, drought
Drought
A drought is an extended period of months or years when a region notes a deficiency in its water supply. Generally, this occurs when a region receives consistently below average precipitation. It can have a substantial impact on the ecosystem and agriculture of the affected region...
tolerance, polymorphism
Polymorphism
Polymorphism or dimorphism may refer to:-Biology:* Polymorphism , including:** having multiple phenotypes within a population; the switch that determines which phenotype an individual displays can be genetic or environmental...
, mimicry, avoidance of attacks by predators.
Research usually involve a mixture of field and laboratory studies. Samples of natural populations may be taken back to the laboratory for their genetic variation to be analysed. Changes in the populations at different times and places will be noted, and the pattern of mortality
Death
Death is the permanent termination of the biological functions that sustain a living organism. Phenomena which commonly bring about death include old age, predation, malnutrition, disease, and accidents or trauma resulting in terminal injury....
in these populations will be studied. Research is often done on insects and other organisms that have short generation times.
History
Although work on natural populations had been done previously, it is acknowledged that the field was founded by the EnglishUnited Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
biologist E.B. Ford (1901–1988) in the early 20th century. Ford was taught genetics at Oxford University by Julian Huxley
Julian Huxley
Sir Julian Sorell Huxley FRS was an English evolutionary biologist, humanist and internationalist. He was a proponent of natural selection, and a leading figure in the mid-twentieth century evolutionary synthesis...
, and started research on the genetics of natural populations in 1924. Ford also had a long working relationship with R.A. Fisher. By the time Ford had developed his formal definition of genetic polymorphism, Fisher had got accustomed to high natural selection
Natural selection
Natural selection is the nonrandom process by which biologic traits become either more or less common in a population as a function of differential reproduction of their bearers. It is a key mechanism of evolution....
values in nature. This was one of the main outcomes of research on natural populations. Ford's magnum opus was Ecological genetics, which ran to four editions and was widely influential.
Other notable ecological geneticists would include Theodosius Dobzhansky
Theodosius Dobzhansky
Theodosius 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...
who worked on chromosome
Chromosome
A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...
polymorphism
Polymorphism (biology)
Polymorphism in biology occurs when two or more clearly different phenotypes exist in the same population of a species — in other words, the occurrence of more than one form or morph...
in fruit flies
Drosophila
Drosophila is a genus of small flies, belonging to the family Drosophilidae, whose members are often called "fruit flies" or more appropriately pomace flies, vinegar flies, or wine flies, a reference to the characteristic of many species to linger around overripe or rotting fruit...
. As a young researcher in Russia, Dobzhansky had been influenced by Sergei Chetverikov
Sergei Chetverikov
Sergei Sergeevich Chetverikov was one of the early contributors to the development of the field of genetics...
, who also deserves to be remembered as a founder of genetics in the field, though his significance was not appreciated until much later. Dobzhansky and colleagues carried out studies on natural populations of Drosophila species in western USA and Mexico over many years.
Philip Sheppard, Cyril Clarke
Cyril Clarke
Sir Cyril Astley Clarke KBE, FRCP, FRCOG, FRC Path, FRS was a British physician, geneticist and lepidopterist...
, Bernard Kettlewell
Bernard Kettlewell
Henry Bernard Davis Kettlewell was a British geneticist, lepidopterist and medical doctor, who carried out research into the influence of industrial melanism on natural selection in moths, showing why moths are darker in polluted areas.-Early life:Kettlewell was born in Howden, Yorkshire, and...
and A.J. Cain were all strongly influenced by Ford; their careers date from the post WWII era. Collectively, their work on lepidoptera
Lepidoptera
Lepidoptera is a large order of insects that includes moths and butterflies . It is one of the most widespread and widely recognizable insect orders in the world, encompassing moths and the three superfamilies of butterflies, skipper butterflies, and moth-butterflies...
, and on human blood groups, established the field, and threw light on selection in natural populations where its role had been once doubted.
Work of this kind needs long-term funding, as well as grounding in both ecology and genetics. These are both difficult requirements. Research projects can last longer than a researcher's career; for instance, research into mimicry started 150 years ago, and is still going strongly. Funding of this type of research is still rather erratic, but at least the value of working with natural populations in the field cannot now be doubted.
See also
- Antibiotic resistanceAntibiotic resistanceAntibiotic resistance is a type of drug resistance where a microorganism is able to survive exposure to an antibiotic. While a spontaneous or induced genetic mutation in bacteria may confer resistance to antimicrobial drugs, genes that confer resistance can be transferred between bacteria in a...
- Genetic monitoringGenetic monitoringGenetic monitoring is the use of molecular markers to identify individuals, species or populations, or to quantify changes in population genetic metrics over time...
- Peppered moth, Biston betulariaPeppered mothThe peppered moth is a temperate species of night-flying moth. Peppered moth evolution is often used by educators as an example of natural selection.- Distribution :...
, - Pesticide resistancePesticide resistancePesticide resistance is the adaptation of pest population targeted by a pesticide resulting in decreased susceptibility to that chemical. In other words, pests develop a resistance to a chemical through natural selection: the most resistant organisms are the ones to survive and pass on their...
- Polymorphism (biology)Polymorphism (biology)Polymorphism in biology occurs when two or more clearly different phenotypes exist in the same population of a species — in other words, the occurrence of more than one form or morph...
Further reading
- Cain A.J. and W.B. Provine 1992. Genes and ecology in history. In: R.J. Berry, T.J. Crawford and G.M. Hewitt (eds). Genes in ecology. Blackwell Scientific: Oxford. Provides a good historical background.
- Conner J.K. and Hartl D.L. 2004. A primer of ecological genetics. Sinauer Associates, Sunderland, Mass. Provides basic and intermediate level processes and methods.