Homologous & Analogous Traits

            The California sea lion and snow leopard have many homologous structures in common. Each of these structures evolved to fit their different environments. Each species is a mammal and have humeri, ulnas, radii, carpals, metacarpals, and phalanges.

            The California sea lion or Zalophus californianus are found from the pacific coast of Central Mexico to British Columbia, Canada. They enjoy eating sea food like squid, anchovies, and mackerels. Their ulna, humeri, radii, carpals, metacarpals, and phalanges are located in their frontal fins. Their fins can rotate forward which allows them to walk on land or swim in the ocean. The California sea lion is the fasted of all the sea lions and seals. They can swim up to 25 miles per hour.  They have an average lifespan of 20-30 years.

            The snow leopard or Panthera uncia are found in the mountains of Central Asia. They hunt creatures like deer, sheep, ibex, marmots, and hares. Their average lifespan in the wild is 15-18 years. The humeri, radii, ulna, carpals, metacarpals, and phalanges can be found in their front legs and paws. Their front legs are shorter than their back ones so that they can jump the air up to about 30 feet and climb trees. Their vocal cords are not fully developed, so they cannot roar.

            The California sea lion and snow leopards have a lot in common. They both belong to the animalia kingdom, chordate phylum, mammalia class, and carnivora order. The sea lions belong to the otariidae family, zalophus genus, and californianus species. Snow leopards belong to the felidae family, panthera genus, and uncia species. There is a debate among scientists if snow leopards should be a member of the panthera genus or be in their own genus. So, some scientist call them Panthera uncia and others call them Uncia uncia. Scientist believe that the otariidae family were the first to split off of the carnivora order about 23 million years ago. Snow leopards and sea lions have a common carnivore ancestor. The carnivora order split off to create creatures like cats, dogs, otters, weasels, bears, and raccoons. 

The California Sea Lion: on the right is a picture of a sea lion’s front fin showing the phalanges, carpals, metacarpals, and the beginning of it ulna and radius.

 

   

The Snow Leopard: The picture on the bottom shows that snow leopards and other big cats all have a humerus, radius, ulna, and phalanges.

   

            Snow leopards and California sea lions also share an analogous trait, they both have fur. The snow leopard lives in a very cold and snowy environment. Their fur evolved to be thick and long to keep them warm in the harsh winters in the mountains. Their fur is a greyish color with spots to camouflage them from their prey. The fur on their paws acts like snowshoes and allows them to walk on the snow. The California sea lion has brown fur. Their fur is sleek and waterproof to help them swim. Their fur is not used as insulation like the snow leopard. They evolved to have a layer of blubber under their fur to keep warm.

            The snow leopard and California sea lion shared a common ancestor because they have homologous and analogous traits. They are in the same domain, kingdom, phylum, class, and order. Their common ancestor was a carnivore and a mammal with fur. Their common ancestor evolved and split to create the cat, and dog-bear branches. The cat branch split creating cats, hyenas, civets, and mongooses. The dog and bear branch split and created seals, sea lions, bears, raccoons, dogs, and weasels.

 California sea lions hanging out on some rocks