He continues with
"An April 2012 report out of UCLA provides further evidence that DNA determines intelligence, to a large extent"
And if you agree that intelligence is a large enabler of merit (I don't), then the connection between genes and meritocracy is blurred enough that you might be able to argue that good genes is correlated with more merit, or at least a larger potential for merit.
I don't think the author knows what "meritocracy" means. Someone with good genes "making it" is what a meritocracy is.