Homologous
1. Whale fin and a human arm. They are both vertebrates and mammals.
2. The whale fin consists of a scapula (shoulder blade), humerus (upper arm bone), ulna and radius (fore arm bones), and a collection of metacarpals (wrist bones) and phalanges (fingers) that correspond to the hand and forearms.
The human arm consists of a clavicle, acromial end, acromion process, coracoid process, deltoid tubercle, humerus, capitulum, trochlea, radial tuberosity, semilunar notch olecranon process on the posterior side, radius and an ulna.
3. From what I have researched the whales and humans most common ancestor that has the same structure of the forearm is the chimpanzee (arm). Chimpanzee arms consist of everything that the human arm and whale fin consist of.
Analogous
1. Octopus eye and the human eye. The octopus is a cephalopod and the human is a mammal.
2. The human eye and the octopus eye are almost identical except for a few things. One of those things is that the octopus eye forms from an epidermal placode through a series of successful infolding. The human eye forms from the neural plate and induces the overlying epidermis to form the lens.
3. The common ancestor between the octopus and the human eye is known as the bilateria I believe that the common ancestor between the octopus eye and the human eye had the analogous trait. From what I have read it says that if the octopus eye genes are expressed in the homolog in the deuterostomes or out-group bilaterians then they say you could reasonably consider that the genes would have consisted in the last common ancestor.
Hello I never knew that about octopus and the human eye your I enjoyed reading it! I have learned something new today, who knew that the human eye and the octopus are almost identical.
ReplyDeleteNicely done. The only correction is that the chimpanzee wouldn't be considered an ancestor of both the whale and the human. The common ancestor of all three would have been very early mammals. That was as specific as you needed to get.
ReplyDeleteWow that is so weird to think that we are similar to whales! I mean, we don't look anything alike yet we've got so many similarities! So crazy. Great post. I learned a lot!
ReplyDeleteI also wrote about the octopus and human eye similarity. I found it very interesting. I actually never really pictured what an octopus' eye looked like up close, but after looking at a few different pics and reading explanations it is in fact very similar. Great job.
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