Homologous and Analogous traits

Homologous: 

a.     Cats and dogs are both considered domesticated animals and they both share a homologous trait with their pelvises and paws. Cats usually have a small stature and are quick on their four legs. Some have tails and some don’t. They adapt quickly to their environment and are a form of a companion for humans. Because of their quickness, light on their four legs, and keen senses, cats are known to hunt, kill, and extinct small prey.

Dogs also move about on four legs. Because dogs are bred for various activities, their sizes, colors, and shapes vary. Humans have also considered them to be companions not only for personal but also for medical reasons such as depression. Dogs have been used for hunting, protection, and farming needs.

b.                                   The pelvis of the cat                   The pelvis of the dog

                          

Both animal's pelvises share a similar structure where the legs hook, backbone attaches partially, and the birthing canal is in the similar position within the dog and cat.

Paws from a cat and dog are homologous as well because both the dog cat uses the paw to balance, feel, and for stability. Dog’s paws are usually a little rough compared to the cat’s paws whose texture is softer. The dog’s pads are different by way of structure. The cat has 7 pads on front and 5 in the back, whereas a dog has 6 paws with declaws on front paws. The shape of the dog’s paw is oval and cats are round. Cats have retractable claws depending on how the cat feels. The dog claws are always extended. The purposes of the dog’s paws/ claws are to dig, play, and sweat. Cats’ use theirs to climb, play, protect themselves and get food.

  

           DOG                                  CAT

c.     Generally, the common ancestor of dog and cat was the Dormaalocyon latouri.
They were known to have lived over 56 thousand years. They were the earliest known carnivores.

             

Analogous:

a.     Two different species that portray analogous traits are butterflies and birds.

Butterflies are insects and at the adult stage, their wings are bright, bold, and colorful. Some; however, use their subdued wing color to camouflage them from their predators.

Birds are endothermic vertebrates. They live all over the world and come in a variety of shapes, sizes, and colors. Their wings are used for transportation, warning, others of danger, and mating call.

       

b.       They both have wings. The bird’s wings are attached below the neck and the butterfly’s wings are attached a second and third segment of the thorax. Structurally they are very different, wear as birds have feathers and bones, and butterfly wings are constructed of chitin and thin layers of scales. The similarities of a bird and butterfly are that they both have adapted to life in the air making it their main way of travel. Mating ritual is similar to the way of expanding the wings and sputtering them quickly appeal to the opposite sex in some cases.

c.       The common ancestor was hard to find, but I did see it mentioned that they inherited four limbs from a common ancestor. Birds’ ancestor was the Archaeopteryx which was a bird-like dinosaur. The Caddis fly was the ancestor of the butterfly. Both the Caddis fly and the Archaeopteryx derived from a terrestrial organism and is included in the tetrapod because of their four limbs that evolved.

                Archaeopteryx/ Caddis fly