Homework SourseWhat recent experimental evidence suggests that all animal a
What recent experimental evidence suggests that all animal appendages may be homologous?
What recent experimental evidence suggests that all animal appendages may be homologous?
| a.new tests on fossils for common ancestral appendage types across phyla |
| b.the discovery of the \"distal-less,\" or Dll, gene in many different phyla |
| c.recent changes in model analyses of the morphological features of animal phyla |
| d.the discovery of a regulatory protein for muscles in many different phyla |
Solution
The correct answer is b) the discovery of the \'distal-less\' or DII gene in many phyla.
The origin and diversification of fins, wings and other appendages are now approached through developmental genetics. The modifications in appendage number and architecture in each phylum is correlated with regulatory changes in specific patterning genes. The HOX genes provides the basis for anterior-posterior axis specification throughout the animal kingdom. Distal-less genes have various developmental roles and are widespread throughout the animal kingdom, usually occurring as a single copy genes in non chordates and as multiple copies in most chordate genomes.
