Explained in example sentence
Nearly all of these proteins can be explained by a single gene family, so this means that the diversity of silk types we see today is encoded by one gene family, so presumably the original spider ancestor made one kind of silk, and over the last 380 million years, that one silk gene has duplicated and then diverged, specialized, over and over and over again, to get the large variety of flavors of spider silks that we have today.