But you knew that already.
The Coffea canephora Genome has been sequenced. This is probably more important than the Human Genome project because humans are completely useless first thing in the morning, but coffee is very important first thing in the morning.
Some important plant evolution involves wholesale duplication of large parts of the genome. This does not appear to be the case with coffee. Rather, diversification of single genes characterizes the genome, so, according to the paper reporting these results in Science, "...the genome includes several species-specific gene family expansions, among them N-methyltransferases (NMTs) involved in caffeine production, defense-related genes, and alkaloid and flavonoid enzymes involved in secondary compound synthesis."
Also of great interest is the apparent fact that caffeine related genes either evolved separately from, or engaged in the important work of making caffeine separately from similarly functioning sets of genes in tea and cacao (chocolate). I had always suspected tea was ... different.
So, not at all unexpectedly, the most important molecule on earth evolved more than once!
Elizabeth Pennisi also has a writeup here.
It's Robusta. Unless you're drinking rot gut instant coffee grown in Vietnam for pennies per pound and chemically treated to taste more like "coffee", it's not the Arabica you're thinking of.
If we're going to be about science, let's acknowledge that the difference between Robusta and Arabica is the difference between humans and Neanderthals.
Greg, Coffea canephora is what the scientist sampled, and how they reported it. It is also a synonym for C. canephora so the balance is restored.
Vietnam produces mostly this type of coffee, and most of it these days comes from Vietnam. Robusta, which is what I both grew and processed in the Congo, is stronger than Arabica, the latter being the whimpier variety. Robusta is what one normally uses to make espresso, 10-20% or so.
Instant coffee, as I understand it, is usually made from Robusta, at least back in the days when i was hanging around on coffee plantations.
For people with hard-to-control hypertension, a sudden, big dose of caffeine may boost blood pressure because caffeine constricts blood vessels. But decaf is fine in that respect. And even caffeinated coffee doesn't increase blood pressure much once you drink it for a week or so, said Van Dam. In fact, the caffeine in coffee seems to have less of an effect on blood pressure than the caffeine in colas because there are so many other substances in coffee that have the opposite effect physiologically from caffeine.
I engoy it