Exactly, yes. That's my point. There's no evidence, so don't claim it's unsafe. Be honest. Say that we don't know for sure whether it's safe or not.
The fact that there is no evidence is precisely why it is unsafe.
No. No, it's not. You're just going in the other direction. "It's unsafe because we have no evidence that it's safe" and "it's safe because we have no evidence that it's unsafe" are equivalently invalid. You just chose the one you agreed with.
Absence of evidence of harm does not = evidence of absence of harm.
But, according to you, absence of evidence of safety = evidence of absence of safety. Do you see where the issue is?
It is perfectly valid to claim that genetic modification is unsafe, and I will explain why.
First, we must define safe. Google defines safe as "Protected from or not exposed to danger or risk; not likely to be harmed."
Because the effects of genetic modification are entirely unknown, we cannot assume that we are protected from danger or risk.
We can't assume that we're exposed to it either. We can't assume we're likely to be harmed.
When dealing with unknowns, we cannot assume that we are not likely to be harmed. Until we can be confident that we are protected from danger or risk and not likely to be harmed, the activity is unsafe.
Your first sentence went on too long. It should read, "when dealing with unknowns, we cannot assume." This whole time, I've been talking about evidence. "Unsafe" is not the default state in the absence of evidence of safety.
Suppose that there is a very tall tree by the river with a branch growing out over the water. You want to climb the tree and jump off of the limb into the water because it looks super exciting! The depth of the water is unknown. There is no way to determine the depth of the water at this time. There is also no way to determine what might be underneath the water, hidden from view. Perhaps there is a fallen tree under the water. Maybe there are rocks. Maybe there is an alligator. Given these circumstances, if someone told you that jumping is not safe, would you think "We don't know whether or not it is safe to jump." ? Until the depth of the water is known, jumping is not safe.
Actually, it could be perfectly safe. You don't know. If the water is deep enough, you are not exposed to harm. Your knowledge doesn't change that. It doesn't in any way affect the empirical safety of jumping. You went a bit nutty with the fallacies here. Argument from ignorance, bandwagon fallacy, and some bizarre, inverted appeal to consequences that I'm sure has a formal name.
The precautionary principle is not a challenging concept. I am convinced that most scientists and doctors today don't receive sufficient instruction on the philosophical disciplines of epistemology, logic, and ethics.
The precautionary principle is a policy methodology, and I've been focusing on scientific fact. However, even the precautionary principle isn't a blanket prohibition on activities that may cause harm. There is always a threshold of plausible risk. In the words of the EU, there need to be "reasonable grounds for concern." So you still need something besides your own opinion, though the burden of proof is lower.