what is comparative morphology
Comparative morphology is used to provide evidence for evolution occurring over a long period of time in species of organisms. Comparative morphology includes:
(a) Homologous Structures
(b) Analogous Structures
(c) Vestigial organs/reflexes
(d) Comparative embryology ( as pi has pointed out below)
Homologous structures:
In comparative anatomy (or morphology), homologous structures are structures that have similar basic structures, even though they may carry out different biological functions. The flippers of whales and the wings of bats carry out completely different biological functions - however, there is a similarity in the basic bone structure of the wings and the bones in each respective species of organisms. This similar basic structure suggests that the two species have diverged from a common ancestral species long ago, thereby supporting the evolutionary theory.
Analogous Structures:In comparative anatomy, analogous structures are said to be structures that carry out similar biological functions, even if the structures do not have similar basic structures. For instance, the wings of a fly and the wings of a bat both carry out the same biological function - they permit the flight of both organisms. However, the basic structure of the wings of each respective species differs; the bat's wings are made mostly of bone, while the wings of flies are made of chitin (a polysaccharide). The similarity in the biological functions provides evidence for evolution; however, the differences in the basic structures of the structures suggests that the two species do not share a common ancestor.
Vestigial organs/reflexes:Vestigial organs are functionless and reduced remnants of organs present in a species of organism that were once functioning and carrying out a biological purpose in ancestral species of organisms. For instance, the flippers resemble reduced remnants of feet, indicating that a long time ago, whales were terrestrial organisms, and due to different selection pressures, these forelimbs were reduced to functionless remnants. This indicates that the species has evolved over time, supporting the evolutionary theory.
Comparative embryology:Comparative embryology (funnily enough) refers to comparing the embryos of different species of organisms to support the evolutionary theory. In the early stages of embryonic development of vertebrates - mammals, birds and reptiles - the embryos have gill-slits on the sides of the neck that disappear during foetal stages and when the baby is born. Furthermore, foetuses and newborn babies do not possess a tail; however, embryos in their early stages show a primitive tail. The comparison of embryos at this stage suggests an ancestral-descendent relationship between different species of organisms, supporting the evolutionary theory.
Hope this was helpful
Plus, I may not be right on some bits. If I'm wrong, could someone please correct it
Thanks!