- a. Briefly describe the two different species that possess the homologous trait.
- The two species that represent a homologous trait are bears and dogs. They both have a humerus.
- b. Describe the homologous trait of each species, focusing on the differences in structure and function of the trait. Why do these homologous traits exhibit differences between the two species? Make sure your explanation is clear and complete.
- The homologous trait of each species is the humerus. The humerus is the upper foreleg of a dog. The humerus is attached to the shoulder. They both have one because they share a common ancestor.
- c. Who was (generally, not specifically) the common ancestor of these two species and how do you know that ancestor possessed this homologous trait?
- The general ancestor of these two species is the carnivore. You can tell because a carnivore is mammal and that most mammals have a humerus.
- d. Provide an image of each species in this comparison.
1. For your analogous traits provide the following information:
- a. Briefly describe the two different species that possess the analogous trait.
- The species that possess the analogous trait is humans and snakes. They both have a femur, but used for different things.
- 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.
- The analogous trait is that humans are mammals and snakes are reptiles, but they still have a femur. The humans femur is attached to the pelvic girdle, and as for the snakes, it is part of the pelvic limb. The snakes femur is useless and just floats. Unlike the snakes, the human femur is used for walking and jumping.
- c.All pairs of organisms share some common ancestor if you go back far enough in time. Did the common ancestor of these two species possess this analogous trait? Why or why not?
- Yes, the common ancestor did possess this analogous trait. It did have a femur. Maybe before snakes could have walked, but changed over time to fit in their environment.
- d. Provide an image of each species in this comparison.
It makes a lot of sense when you think about it, but normally I would not think bears and dogs have much in common. I like your example for the analogus trait. For some reason I would not of thought of a snake having a femur.
ReplyDeleteThe humerus is a great example of a homologous trait between the bear and the dog, but how is this trait different between these two animals? How has it changed from their common ancestor?
ReplyDeleteThe bear is actually an omnivore, so I'm not sure I understand how you conclude that the ancestor must be a carnivore? The common ancestor was a mammal, and all mammals possess a version of the humerus.
The femur of snakes and humans are actually homologous because, as you correctly pointed out, their common ancestor (an ancient reptile) also possessed a femur. I like how you pointed out the differences between the two femurs. This would have been a great example for your homolog section!
Remember that analogs share common function but does not arise from a common ancestor.
I really liked your examples of analogy using the snakes and humans. I would of never thought snakes would have something in common with humans such as that. It really makes you wonder... even billions of years ago, who is that one common ancestor?
ReplyDeleteI really liked the way you compared a dog with a bear. It is very interesting to see that there are actually homologous traits between dogs and bears.
ReplyDeleteFor the second part of the post, I really liked the comparison between human and snake. It is very interesting to see the different functions a femur in humans and snakes.