Analogous and Homologous Traits

1. For your homologous traits provide the following information (25 pts): 

a. Briefly describe (not just identify) the two different species that possess the homologus trait. (5 pts)

The tailbone of a human (the coccyx) and the tail of a monkey are examples of homology. The tailbone is called the tailbone because of the shared lineage.

b. Describe the homologus trait of each species, focusing on the differences in structure and function of the trait. Why do these homologus traits exhibit differences between the two species? Make sure your explanation is clear and complete. (10 pts)

The human tail bone and the ape tail share similar bone structure up to the actual extension of the tail from the human body. There are many shared muscle groups between apes and humans in the coccyx region, therefore indicating the two species likely shared a common ancestor but diverged as they evolved. The difference today is obviously that humans no longer utilize a tail.

c. Who was (generally, not specifically) the common ancestor of these two species and how do you know that ancestor possessed this homologus trait? (5 pts)

The common ancestor between humans and apes is whichever hominid accomplished the bridge to bi-pedal walking. That was the divergent breaking point in the evolutionary tree.

d. Provide an image of each species in this comparison. (5 pts) 

2. For your analogous traits provide the following information (25 pts): 

a. Briefly describe the two different species that possess the analogous trait. (5 pts)

The fins of a bird and the wings of a penguin are analogous traits. One is a bird and the other is not yet both possess fins to navigate a similar environment.

b. Describe the analogous trait of each species, focusing on the similarities in structure and function of the trait. Clearly explain why these analogous traits exhibit similarities between the two species. (10 pts)

Though the fin of a fish and the wing on a penguin are not evolved from the same ancestor but they serve the same function in their respective environments. The wings and the fins are structures almost exactly alike and are utilized for propulsion in water.

c. All pairs of organisms share some common ancestor if you go back far enough in time. Could the common ancestor of these two species have possessed this analogous trait? How do we know these traits are analogous and not genetically related from common descent? (5 pts)

It’s possible that they shared the trait. Though the mutual ancestor of penguins and fish was likely some type of flying reptile, so the function likely diverged for awhile until the timeline of the penguin lead it to adapt to a water environment from the air. 

d. Provide an image of each species in this comparison. (5 pts) 

 

Charles Darwin’s theory of evolution by the mechanism of natural selection seeks to add a sense of order to the way evolution has essentially played out over time. These mechanisms help explain the conditions and reasons as to why the course of change has occurred the way it has. Darwin's work paralleled the Thomas Malthus' viewpoints found in the published book "An Essay on the Principle of Population." In this book, Malthus argues that the human population will never outgrow its own ability to feed itself. Malthus' view of looking at human behavior as a group versus as an individual is what was groundbreaking at the time. Charles Darwin adopted this viewpoint when he developed his theory of evolution, taking humans and placing them under the same logic that applies to animals. This very idea takes into account the Darwinian mechanism of "Individuals do not evolve. Populations do." This concept played an integral role in the development of the theory. Without understand humans as a species, and not just as an individual, the rules and mechanisms would not be applicable. The church rejected Darwin and his theory seeing as it did not fall in line with the words of the bible, but that didn't stop Darwin from publishing his theory.

Source: http://evolution.berkeley.edu/evolibrary/article/history_07