Journal ArticleHeat shock protein (HSP) 70 gene is a member of HSPs sub-family that act as molecular chaperons whenever animals come under thermal assault , they fulfill essential roles of providing cellular protection, immune response, protein synthesis, protein folding and unfolding, protection proteins from cellular stress, inhibitory apoptosis and adaptation during thermal assault. A total of ninety (90) bulls from across four extant breeds of Nigerian Zebu cattle comprising of White Fulani (25), Sokoto Gudali (21), Red Bororo (21) and Ambala (23) sampled from northern parts of Nigeria. We report from the findings that the rooted evolutionary study based on Neighbour-joining dendrogram of HSP70 sequences of White Fulani, Ambala, Sokoto Gudali and Red Bororo Nigerian Zebu breeds of cattle revealed that HSP 70 sequences of four Nigerian cattle breed showed shared homology which is suggestive of common ancestral lineage. Similarly, nucleotide sequences of HSP70 in four Nigerian B. Indicus and those of goat, sheep, yak, buffalo, camel, horse and taurine demonstrated common clade architecture, therefore suggesting evolution from common ancestor. Phylogenetic analyses of four breeds of Nigerian cattle and comparative homology between four Nigerian breeds of cattle and those of goat, sheep, yak, buffalo, camel, horse and taurine at HSP 70 gene locus suggested that these animals had shared ancestral lineage and common evolution. Therefore, the degree of relatedness of HSP 70 gene established within four Nigerian breeds of cattle and those of selected mammalian species suggested that HSP 70 gene is conserved among wide range of animals and as such it can be used as bio-marker for marker assisted selection of thermo-tolerance in wide range of livestock animals under thermal assault.