That's not a bad analogy. Newton's equations are still quite adequate for NASA to launch satellites and steer probes to other planets. The algorithms for computing transfer orbits do not need to factor in relativity.
But at the fine level, relativity provides more precision, especially when dealing with extremes of velocity or gravity.
In a similar way, Darwin's primary hypothesis of variation and selection is still completely valid, but has been refined over the decades, and further refined by molecular biology.
And the parts of evolution that creationists are usually busy attacking are the parts that have been recognized by scientists as inadequate for 75 years and long ago updated.