GaryGaulin
Posts: 5385
Joined: Oct. 2012
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Humorously fascinating!
| Quote | The evolution of caffeine in coffee started when the gene for an N-methyltransferase mutated, changing how the enzyme behaved. Later, the plants accidentally duplicated the mutated gene, creating new copies. Those copies then mutated into still other forms.
“They’re all descendants of a common ancestor enzyme that started screwing around with xanthosine compounds,” said Victor A. Albert, an evolutionary biologist at the University at Buffalo and co-author of the new study.
Scientists had already determined that caffeine was also made in other plants, like tea and cacao, by N-methyltransferases. But by sequencing the coffee genome, Dr. Albert and his colleagues were able to make a more detailed comparison of the genes in different species. They discovered that in cacao, the enzymes manufacturing caffeine did not evolve from the same ancestors as those in coffee.
In other words, the coffee plant and cacao plant took different evolutionary paths to reach the same destination. Evolutionary biologists call this sort of process convergent evolution.
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Coffee plants also use caffeine to ward off insects that would otherwise feast on their leaves and beans. At high doses, caffeine can be toxic to insects. As a result, insects have evolved taste receptors that help them avoid ingesting caffeine.
But coffee and a number of other plants also lace their nectar with low doses of caffeine, and in that form, it seems to benefit the plants in a different way.
Plants make nectar to feed insects and other animals so they’ll spread their pollen. When insects feed on caffeine-spiked nectar, they get a beneficial buzz: they become much more likely to remember the scent of the flower. This enhanced memory may make it more likely that the insect will revisit the flower and spread its pollen further. |
How Caffeine Evolved to Help Plants Survive and Help People Wake Up
Now I need another coffee!
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The theory of intelligent design holds that certain features of the universe and of living things are best explained by an intelligent cause, not an undirected process such as natural selection.
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