It’s not at all like the growth of a baby. A baby starts out human and remains human at every stage.
All science is not an art. The soft sciences are, hence the term soft.
I could have used the example of a loaf of bread, where it starts out all gooey and ends up light and fluffy... evolution is a slow and gradual process, a continuum, where we can only observe snapshots taken at time points that are very far apart.
I don’t know what you call “soft” science, unless you’re referring to things like sociology, which I don’t consider a science at all.
Most people would consider my discipline—Biochemistry and Molecular Biology—a “hard” science. I can assure you, from years of experience, that it is more of an art than anything else. There are very few scientific questions that have straight up or down answers. Experiments designed to give a straightforward answer don’t. Data is always interpreted with caveats reflecting the understanding that someone else could always come along with another interpretation that withstands testing. And so forth. Trying to determine which interpretation is closest to the truth really is an art.