If someone claimed that nature has been understood and mapped in entirety, that was not a scientist.
Or was a completely idiotic one stating their own personal subjective opinion.
Actual science does *not* try to have this claim nope.
As for consciousness: it is not explained by science, no. But if there'll be an explanation one day (idk), then it will not be this type of simplified reductionism - science makes more complex explanations than this (luckily).