The plates of the endoskeleton are reduced and contained inside a soft, muscular body wall in *
sand dollars
Sea cucumbers
sea urchins
brittle stars

there really is life in the deepest part

small, big, or no change could occur in the phenotype. it could cause something as simple as a cats ears to curl backwards or something as frighting as death. it could also occur in the protien-coding area and have an effect on that but no effect on the amino acids. what has to occur is a changing in the hox gene or the control gene.