Futuyma said other insect species had shown increases in the proportion of darkened individuals in industrialized areas, a phenomenon known as industrial melanism.
12.
However this is a variable species and darker forms exist, including examples of industrial melanism which are prevalent in some towns and cities.
13.
This has led to the coining of the term " industrial melanism " to refer to the genetic darkening of species in response to pollutants.
14.
The most famous example of such evolution is industrial melanism in moths, in which dark forms that arise by mutation are selected for in polluted areas and selected against when the pollution goes away.
15.
Industrial melanism allows species such as the " Biston betularia " and the " Adalia bipunctata " to more efficiently warm their bodies in environments of reduced sunshine, increasing their mating activity and nutrition, thus increasing their fitness.
16.
During four years in the United States, Owen completed his doctoral project on owls and also researched insect ecology, collecting the first New World data on industrial melanism in the peppered moth as well as working on the ecological genetics of spittle bugs.
17.
Haldane also applied statistical analysis to real-world examples of natural selection, such as the Peppered moth evolution and industrial melanism, and showed that selection coefficients could be larger than Fisher assumed, leading to more rapid adaptive evolution as a camouflage strategy following increased pollution.
18.
In 1918, Fisher produced the paper " The Correlation between Relatives on the Supposition of Mendelian Inheritance, " which showed how the continuous variation measured by the biometricians could be the result of the action of many discrete evolution of industrial melanism in peppered moths.
19.
The study concluded that " industrial melanism in moths is the most striking evolutionary phenomenon ever actually witnessed in any organism, animal or plant . " It is now regarded as the classic demonstration of Charles Darwin's natural selection in action and one of the most beautiful experiments in evolutionary biology.
20.
The problem is that the dark forms of the moth may have evolved as an adaptation to rapidly changing environmental conditions, but that the specific conditions _ the soot-blackened tree limbs _ that had been regarded as the all-but incontrovertible proof of " industrial melanism " were not the cause after all.
