You're giving nature too much credit. Nature doesn't try and balance life. Nature doesn't care- it throws asteroid impacts and supervolcanos and natural disasters all over the place. Life just happens to be very very resilient and consistently able to jump back and fill new niches. Nature also "created" us - were a product of the universe like everything else. If we are destabilizing, so is nature.
And most scientists do not assume they can blindly mess around. There was a whole section of this article related to ethics, they didn't let the fetus be born (which would definitely have been messing around). They're not trying to "do better" or control nature - they're just trying to understand what makes us tick. This is a mutation that already exists in humans. It might make us human. If anything, that makes nature the one that was blindly messing around.
And most scientists do not assume they can blindly mess around. There was a whole section of this article related to ethics, they didn't let the fetus be born (which would definitely have been messing around). They're not trying to "do better" or control nature - they're just trying to understand what makes us tick. This is a mutation that already exists in humans. It might make us human. If anything, that makes nature the one that was blindly messing around.