Bateson-Dobzhansky-Muller Model
Encyclopedia
The Bateson-Dobzhansky-Muller Model is a model of the evolution of genetic incompatibility. The theory was first described by William Bateson
in 1909 , then independently described by Theodosius Dobzhansky
in 1934 , and later elaborated by Herman Muller
.
The model attempts to explain how incompatibilities between closely related species develop without either of them going through an adaptive valley
. In its simplest form the model shows that changes in at least two loci are required to cause hybrid incompatibility, or at least a decrease in fitness between individuals from two ancestrally identical, but allopatric populations. This is based on the idea that a new allele which has arisen at one locus in one population should not cause decreased fitness when placed into the identical (except for one allele) genetic background of the second population. Therefore another allele at a second locus which is incompatible with the first must have arisen.
William Bateson
William Bateson was an English geneticist and a Fellow of St. John's College, Cambridge...
in 1909 , then independently described by 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...
in 1934 , and later elaborated by Herman Muller
Hermann Joseph Muller
Hermann Joseph Muller was an American geneticist, educator, and Nobel laureate best known for his work on the physiological and genetic effects of radiation as well as his outspoken political beliefs...
.
The model attempts to explain how incompatibilities between closely related species develop without either of them going through an adaptive valley
Fitness landscape
In evolutionary biology, fitness landscapes or adaptive landscapes are used to visualize the relationship between genotypes and reproductive success. It is assumed that every genotype has a well-defined replication rate . This fitness is the "height" of the landscape...
. In its simplest form the model shows that changes in at least two loci are required to cause hybrid incompatibility, or at least a decrease in fitness between individuals from two ancestrally identical, but allopatric populations. This is based on the idea that a new allele which has arisen at one locus in one population should not cause decreased fitness when placed into the identical (except for one allele) genetic background of the second population. Therefore another allele at a second locus which is incompatible with the first must have arisen.