Genetics solve causation issues by putting "correlation does not equal causation" at the start of their paper and then writing the rest of it as if it did equal causation.
I don't fault them much, it's kind of hard to do an experiment here, but don't believe their results too hard.
The fun thing is that they drift. So you might breed orange cats by selecting cats that are orange but over time the correlation to the genome might become weaker. It happens quite a bit in livestock genetics.
Yeah, not even DNA is fully in control. Michael Levin's planarian worms experiments show that he can use an electromagnetic field for a short time in a certain way, and create a two-headed worm (normally it's one of course) that will persist to all it's offspring even though there's been ZERO alterations to DNA. So there is still much about the emergent complexity that we do not know.
Even weirder conceptually than that: you have the same dna in all your cells. So why is your brain your brain, your eyes your eyes, and so on? Then you learn that not all genes are expressed all the time. Then you learn even among those expressed genes that they could have been spliced differently and resulted in completely different protein structures. No magnets needed for this example of phenotypes extending beyond mere dna sequence, just a mirror to look at yourself.
I don't fault them much, it's kind of hard to do an experiment here, but don't believe their results too hard.