Homologous traits are those that are inherited from a common ancestor.
Berkshire pigs and bobcats share the
homologous trait of having four legs. Berkshire
pigs have firm bodies with short legs.
Berkshire pigs are black with white on their legs, face and tail. Their dark skin keeps them from being
sunburned. The Berkshire pigs are medium sized animals and weigh around 600
lbs.
Berkshire pigs were brought to the United States
in 1823. These pigs produce high quality meat and are
known for its texture, tenderness and juiciness.
Bobcats grow up to be about 41 inches long
and weigh about 25 lbs. They live about
12 years. Bobcats are carnivores and eat
small animals such as squirrels, birds, mice, and rabbits. They hunt deer,
sheep, and even young pigs.
The Berkshire pig uses his four legs to stand
and walk. Pigs often have structural
unsoundness of their legs which include buckling of the knees, bowed legs,
swollen joints and general lack of freedom in movement. The Berkshire pig moves
slowly in comparison to the bobcat. Bobcats use their legs to stand, walk, run,
and balance themselves. They are agile
and climb well. They are also excellent swimmers and hunters. The legs of the bobcat are long and lean
which give them power for jumping and running.
Bobcats hunt for their food in comparison to pigs which are raised on
farms and fed fresh vegetables.
Both
bobcats and pigs are mammals. They both are warm blooded vertebrate animals.
They breathe air with their lungs. Pigs
are part of the biological family of suidae (hogs and pigs) and bobcats are
from the biological family of felidae (cat family).
Birds and butterflies share the analogous
trait of wings. Birds have two wings and
in comparison butterflies have 4 wings (2 large and 2 small). Although they both have wings they are very
different species.
The evolution of birds is thought to have
begun during the Jurassic Period from a clade of theropoda and butterflies/insects appeared on Earth about 300 million years ago and evolved from Trichoptera. It is thought that the butterfly and the bird’s
common ancestor is a reptile which did not have wings.
Hey Susan
ReplyDeleteI really enjoyed reading your post especially the homologous section. It was nice to learn that bobcats and Berkshire pigs share an homologous trait. Good job
Homologous traits are inherited from a common ancestor but they are also traits that exhibit distinct structural differences due to functional differences.
ReplyDeleteYou worried me a little with your homologous pairings as it seemed like you were going to focus on simiilarities, but you did start to pull out structural differences. The point I would like you to remember is that with the pigs, we are no longer dealing with structure shaped by natural selection. The structure and function is due to artificial selection, so not as clean a comparison as you would get between two wild animals. Just make sure you understand that difference.
Both organisms are mammals, but four limbs is a very generalized trait that can be traced all the way back to amphibians. Definitely genetically related with differences resulting from both natural and artificial selection.
Wings of the butterfly and bird are a valid analogous trait. You focused a lot on their differences but remember that for analogs you need to demonstrate similarities due to similar environmental pressures, namely the advantage of flight for food, movement and avoidance of predators.
Reptiles are the ancestors of birds but not insects. To find the common ancestor, you have to go back 100's of millions years, and it is possible that the common ancestor had wings and passed them onto the butterfly descendents. Fortunately, we don't need to go back that far to confirm these are analogs because we have good information on bird evolution. Birds developed wings during their split from their reptilian ancestors, long after the split from insects. That means regardless of the common ancestor status, bird wings developed independently from that common ancestor, making these analogous traits.