My apologies if this has been discussed elsewhere, but I've been unable to find much in the way of information on the relationship between the gravel and asphalt genes (as well as the highway and freeway morphs.) I know that they are allelic genes in the yellowbelly complex and visually indistinguishable from yellowbelly. Other than that though, what, if anything, distinguishes them? Is this a banana/ coral glow or lesser/ butter type of situation with different lines of essentially the same gene, or is more comparable to cinnamon/ black pastel, etc.? Is there any sort of shared lineage between the two, or were they developed independently? Thanks in advance!