Electrophoretic markers of Andalusian horses: comparison of Spanish and Lusitanian lineages.

The research identifies unique genetic markers in Andalusian horses, comparing them across Spanish and Lusitanian lineages, and with other breeds. It reveals unexpected genetic similarities between Andalusian horses and Tarpans, suggesting convergent evolution rather than shared ancestry.

Identification of Unique Genetic Markers

• The researchers analyzed genetic variations at eight blood loci and found six rare markers in the Andalusian horse breed. These markers included variants J of transferrin, H of esterase, D and S of Xk, M and W of prealbumin.
• Two markers, TfJ and PrM, were identified as characteristic markers of the Andalusian breed.

Comparison Between Spanish and Lusitanian Horses

• The research involved comparing these genetic markers in Spanish and Lusitanian populations. This comparison revealed only minor differences in allelic frequencies between the two horse populations, despite a sample size of 300 Spanish horses and 100 Lusitanian horses.

Comparison with Other Breeds

• The research also compared these genetic markers with those of the Thoroughbred, Connemara, and Arab horse breeds, due to historical and presumed relationships.
• No visible similarities were found in the genetic profiles of these breeds when compared to Andalusian horses.

Unexpected Similarities with Tarpans

• The surprising result of the research was the discovery of genetic similarities between Andalusian horses and Tarpans.
• The study suggests that these similarities are more reflective of convergent evolution (where species develop similar traits due to similar environments or ecological niches, despite not being closely related) rather than a common ancestry.