In 1972, geneticist Susumu Ohno proposed that our genome contains "extinct genes."Pseudogenes are molecular fossils, non-functional sequences in DNA.
GULOP, on the 8th chromosome, used to enable vitamin C production in early primate ancestors.
Mutations cause gene inactivation, as in the case of GULOP around 61 million years ago.
Loss of the UoX gene, coding for uricase enzyme, occurred around 17 million years ago, impacting uric acid metabolism.
UoX's decline might have aided our ancestors' fat storage during fruit scarcity due to climate change.
Taste receptor genes are dynamic, reflecting dietary changes; humans have both active and dead taste receptor pseudogenes.
Our evolving diet, including increased meat consumption, influenced our taste receptor gene evolution.
Extinct genes are a record of our evolutionary history and offer insights into our ancestors' adaptations.