Assessment of demographic bottleneck in Indian horse and endangered pony breeds.

This research examines the genetic bottlenecks, a decrease in genetic diversity caused by significant reduction in population size, in certain horse and pony breeds in India. The study stresses the importance of this analysis in determining conservation strategies, given the potential impact of bottlenecks on population sustainability.

Understanding Demographic Bottlenecks

• The research focuses on the concept of demographic bottlenecks. This is a crucial aspect in the study of conservation strategies, especially concerning continuously diminishing animal populations.
• Bottlenecks dramatically increase rates of inbreeding, loss of genetic variation, and fixation of deleterious alleles, consequently reducing an animal’s evolutionary potential. This impacts their ability to adapt to new pressures like climate change, changing availability of resources, and it increases the likelihood of population extinction.
• The negative genetic changes brought on by a bottleneck can lower a population’s chances of long-term survival. Many endangered or threatened populations are reported to have low genetic variation levels, evidencing the bottleneck effect.

Case Study: Indian Horse and Pony Breeds

• The study specifically looks at two horse (Marwari and Kathiawari) and four endangered pony breeds (Bhutia, Spiti, Manipuri and Zanskari) in India. These equid species have been seen to drop in numbers significantly, especially in the case of the pony breeds.
• The fall in population primarily draws from decreased utility and the rise of modern transport systems, even in difficult terrain. These factors have caused the population in some regions to dwindle to less than 1000.
• The researchers hypothesize the occurrence of a genetic bottleneck in these pony breeds due to the rapid population decline.

Conservation Importance and Methods Used

• Identifying bottlenecked populations is vital for the conservation of species. The loss of animal species or subspecies can present significant socio-economic issues, especially for developing countries reliant on these animals.
• Being a signatory to the State of the World Animal Genetic Resources, India has a responsibility to document and conserve its indigenous breeds.
• For the research, DNA-based molecular genetics methods were used for demographic history inference. These methods involved multi-locus genotypes from microsatellites used alongside three single-sample tests, namely heterozygosity excess, mode shift, and M-ratio tests for assessing bottleneck presence.