The modern cattle genome has been shaped by several natural and artificial evolutionary processes, as well as by economics driving the selection of production traits. Selective breeding has significantly increased phenotypic and genetic variation in modern cattle breeds. This phenotypic variety among and within breeds has created animals that are more adapted to specific climates and conditions. For example, hybrids of early taurine and indicine cattle have influenced the gene structure of modern cattle and have made them tolerant to hot, dry climates, ready for future changes in climate conditions. 

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Artificial selection and breeding systems like artificial insemination have greatly increased cattle productivity within the past few decades. The trouble with having highly productive breeds is that everyone wants to produce more. Therefore, breeding becomes focused on income rather than genetic diversity. For example, Holstein dairy cattle have rapidly spread from the USA to other countries which has greatly decreased diversity between breeds.