Practice question

An ecotype is a genetically differentiated population adapted to the characteristic conditions of a local habitat. Natural selection can favour different alleles in populations occupying contrasting soils, climates, elevations, or salinities, producing inherited differences in morphology, physiology, phenology, or stress tolerance. These traits remain when individuals are raised in a common environment, which distinguishes an ecotype from an ecad. An ecad is a reversible, environmentally induced phenotype generated by plasticity without stable genetic differentiation. A clone consists of genetically identical descendants and can display either plastic forms or mutations, but clonality itself does not mean adaptation to a specific environment. A morph is any distinguishable form and may be genetic, environmental, seasonal, or developmental. “Permanent” in this context means genetically fixed enough to be transmitted across generations, not evolutionarily unchangeable. Reciprocal-transplant studies often show local ecotypes achieving higher fitness in their home sites than foreign populations, providing direct evidence of adaptation. Gene flow can blur ecotype boundaries, yet sufficiently strong divergent selection may maintain them and, over longer periods, contribute to reproductive isolation and speciation.