Human evolution didn’t stop at split from chimpanzees, 155 tiny new genes identified: Study

Subject :Science and Technology

Context:

Humans have evolved to gain 155 tiny new genes, but their role in health and diseases is currently unclear, according to a new study.

Details:

Some of the new genes have evolved from scratch, building on ‘junk’ or non-coding DNA sequences.
- Non-coding sequences do not code for amino acids, the building blocks of protein.
Mutations can allow new genes to be born from a piece of DNA that was not previously a gene.
Alternatively, new genes can evolve from existing genes when they get accidentally duplicated. Over the years, they gather mutations to form a new gene.

Reference genome:

Researchers from Greece and Ireland studied the human ‘reference’ genome.
- It is not a DNA sequence of a single person but an accepted representation of the human genome sequence.
They compared this with the genomes of 99 vertebrate species and tracked the relationship of these genes across evolution. As many as 155 microgenes stood out as unique.
- Microgenes are simply very small genes.
- 44 of the 155 new genes are associated with growth defects.
- 3 of the 155 new genes have links with diseases such as muscular dystrophy, retinitis pigmentosa and Alazami syndrome.
It is possible that periods of environmental change are conducive to the evolution of new genes because they might be important for adaptation.