The Genes We Lost Along the Way
PBS Eons・2 minutes read
Geneticist Susumu Ohno discovered molecular fossils in our genome, such as the GULOP gene on the 8th chromosome, which became non-functional around 61 million years ago, causing our primate ancestors to rely on dietary sources for vitamin C. The inactivation of genes like UoX, responsible for breaking down uric acid, and taste receptor genes has shaped our evolutionary history, impacting our ability to detect toxic compounds and store fat.
Insights
- Geneticist Susumu Ohno discovered molecular fossils in our genome, akin to extinct species' remains, shedding light on our evolutionary history shaped by thousands of dead genes, including non-functional pseudogenes.
- The inactivation of genes like GULOP and UoX in our primate ancestors, leading to the loss of vitamin C production and high uric acid levels, respectively, showcases how mutations and gene death can offer evolutionary advantages, such as aiding fat storage during food scarcity, and influence our ability to detect toxic compounds in plants as our diet changes.
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Recent questions
What are molecular fossils in our genome?
Remnants of extinct genes in our DNA.
How did our primate ancestors produce vitamin C?
Through the GULOP gene on the 8th chromosome.
What is the significance of gene death in our genome?
Shapes our evolutionary history.
How did changes in diet influence taste receptors?
Led to the loss of bitter taste receptor genes.
What led to high uric acid levels in hominoid apes?
Inactivation of the UoX gene.
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Summary
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Evolutionary gene deaths shape human history.
- Geneticist Susumu Ohno in 1972 highlighted the presence of molecular fossils in our genome, comparing them to extinct species' remains.
- GULOP, a gene on the 8th chromosome, was once crucial for early primate ancestors to produce vitamin C but became a non-functional pseudogene around 61 million years ago.
- Our primate lineage lost the ability to produce vitamin C due to the inactivation of GULOP, leading to a reliance on dietary sources for the vitamin.
- Thousands of dead genes, including pseudogenes, are present in our genome, shaping our evolutionary history.
- Gene death occurs due to mutations, which can either reduce fitness and be eliminated by natural selection or spread through genetic drift or selection if fitness is unaffected.
- The loss of the GULOP gene around 61 million years ago may not have reduced fitness as our ancestors likely obtained vitamin C easily from their diet.
- The UoX gene, responsible for breaking down uric acid, became a pseudogene around 17 million years ago in our hominoid ape ancestors, leading to high uric acid levels and potential diseases like gout.
- The loss of the UoX gene may have provided an evolutionary advantage by aiding fat storage during times of fruit scarcity, as uric acid promotes fat accumulation.
- Changes in diet have influenced the evolution of taste receptors, with bitter taste receptor genes dying out as our eating habits shifted, leading to the loss of the ability to detect toxic compounds in plants.
