There is a term called "Heterosis" where you cross organisms with unrelated geographic forms ( Not to be confused with hybridizing where you cross species ), same species but from distant locals to each other or intergrating subspecies. This causes a larger, more vigorous, more fertile and more aggressive form through genetic overdominance. The different alleles mix and the more dominant forms are selected making for a much more robust organism.
An example here is where I took seed of the False Indigo (Amorpha Fruiticosa), one from Texas-bottom...the other from California-top. The resulting offspring is in the middle.
Notice it is larger, with more leaflets. The plant grows faster and in time would replace the parent plants. This was with only one cross. I have now acquired seed from N.J., Wisconsin, Ohio and Florida. All these will be established in colonies together where they can all cross pollinate.
This plant is supposed to be native here but I have never seen it. But the releases of these seedlings have been amazing. To be a native plant it is downright super invasive. Being a nitrogen fixing plant it will improve the soil it occurs in and is a great butterfly plant. So using this technique you can help increase populations of dwindling or endangered species.
To the "purists" out there that argue that this degrades the genetics of the organism...how can they be more aggressive and take over if they have been degraded? If they are truly hindered in some way nature would naturally weed out any defective offspring.
More on this later as we discuss natives and exotics that can be used to renaturalize areas damaged by the trash and filth that have no regard for the environment. The number of species this tactic can be used on is only limited by the number of species that have a wide range and multiple subspecies....so mind boggling in other words.