Keyvan Khosh Abady

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Texas A&M engineers trace how thymine shielded early DNA from UV light

Co-author of the PNAS study

For decades, biologists puzzled over a chemical swap at the heart of heredity. When life moved from RNA to DNA, the base uracil was replaced by thymine—even though thymine absorbs more ultraviolet damage, and early Earth had no ozone layer to block the sun's radiation.

Updated Oct 17

Notable Quotes

We found that thymine tends to direct UV damage into a more reversible form, suggesting that early genetic molecules may have survived intense sunlight not by avoiding damage, but by controlling it and making it easier to self-repair.

from Texas A&M engineers trace how thymine shielded early DNA from UV light · Updated Oct 17

We hope to explore whether life's chemical building blocks formed and assembled entirely on Earth or whether some were delivered to our planet from elsewhere by meteorites.

from Texas A&M engineers trace how thymine shielded early DNA from UV light · Updated Oct 17