In which example are the proximate cause and the ultimate cause of morphological evolution correctly matched? Proximate: cis-regulatory elements are found upstream of a gene; ultimate: cis-regulation is required to activate a gene Proximate: changes in gene regulation lead to changes in morphology; ultimate: natural selection favors morphologies that work best in their environment Proximate: point mutations in protein coding genes affect protein function and structure; ultimate: chemical and physical configuration of a protein affect its function Proximate: natural selection favors gene combinations that have high fitness in their environment; ultimate: genetic changes alter morphology and fitness Proximate: natural selection causes morphology to differ among species; ultimate: natural selection prevents morphological variation within a species