cow_750

To drive home the message of similarity between humans and cows, and urge all states to ban cow slaughter, Home Minister Rajnath Singh said on November 6, 2016: "Cows and humans share 80% of the same genes. So there is not much difference between us."

"As far as cow is concerned, it is not just a cultural issue, it is an issue of faith," said Singh. "But besides being an issue of faith, it is also an issue which should be viewed from economic, historical and scientific perspective."

Singh is right on fact but misleading in scientific perspective.

Cows and humans do indeed share 80% of their DNA, the building block of all life on earth, according to this 2009 study in the journal Science. But humans are genetically closer to a host of species than they are to cows, including cats, dogs, horses, and our closest relatives, apes.

Humans are genetically closest to chimpanzees and bonobos--a smaller relative of chimps--sharing almost 99% of genes, as Science reported in 2012. Gorillas are next with 98% of genes similar to humans.

Source: Science, 2012; Science, 2009; Seattle Pi; Genome Research; National Geographic

Humans share DNA with thousands of living things, from bananas to worms to yeast. This is because all plants, animals and fungi evolved from a common ancestor more than 1.5 billion years ago.

So, humans share 24% of their genes with grapes, 24% with rice, 38% with roundworms and 44% with honey bees.

Genetic similarities are overshadowed by the instruction genes received to diverge into different types of living things. Humans and chimpanzees may share 99% of their genomes--their collective genetic blueprint--but that 1% difference is the key.

From a scientific perspective, the key is to understand how genes code for humans, chimpanzees or cows. That is something science has yet to understand.

(Varma is a freelance journalist based in Andhra Pradesh. He writes on science, with a special interest in climate science, environment and ecology.)

GBSNP Varma