Humans vs. Dogs
Humans belong to the kingdom of Animalia according to taxonomy. Dogs also are a species of the same kingdom. Humans are bipedal with imposable thumbs as opposed to their best friend the dog, who walk on all fours and have a tail.
Humans also have a tail. It is a vestigial structure known as the tail bone, or the coccyx. It is believed that humans possess the tail bone as a result of an ancient ancestor that once possessed a tail, just as a dog has today. Dogs today use their tails, or caudal vertebrae, today as a means of balance while humans have no beneficiary use of their tail bone.
Scientists believe that all mammals at one point used to be sea animals and eventually grew limbs to be able to walk on land.
The human eye vs the eye of an octopus
Humans are bipedal mammals that live on land. The octopus is an eight legged sea creature that lives in deep ocean depths
Although humans and octopus are very different species, they share a common trait amongst each other. Both the human and the octopus have eyes that they use for their sense of sight. Eyes serve as a the primary structure of interpreting what an organism can see.
I believe that both of the organisms did share an ancient organism with the shared trait. It's hard to imagine an organism that didn't have the trait of being able to see. The probability of an organism who can see versus another organism that can't see is astronomical except for some very extreme cases.
i like what you had to say about these particular traits that all "organisms did share an acient organism with a shared triat" and i also think that all mamals share a commen anscestor at on point in time. i also aree that the fact that humans have no use for their tail which enables us to walk upright whereas dogs walk on all four. good job.
ReplyDeleteI was very interested in reading your post! I had to laugh at first...it was kinda creepy comparing humans to octopus. I hadn't even considered the eye as being a common trait. Obviously, one can "see" that we do, indeed, have that trait in common. Thanks for your insight and motivating me to "Google" it further!
ReplyDelete@Karen I actually enjoyed looking all the information I could on the homologous as a trait that is structures as well as the analogous. So when i read an article somewhere that used ears and eyes as analogous structures i had to do the eye and made it more fun for me to research the assignment. At first, I did the same thing and didn't even consider similar structures that we have with other animals to be somehow related.
ReplyDeleteYou said, "Scientists believe that all mammals at one point used to be sea animals and eventually grew limbs to be able to walk on land."
ReplyDeleteThis is a little deceptive and I want to make sure you understand the problem with the wording here. If you go back in time to our amphibian ancestors, this is true. But our mammalian ancestors were land creatures, not sea creatures.
So what was likely the common ancestor between humans and dogs? Or how about other tailed creatures such as humans and monkeys?
Regarding the eye of the octopus, if the common ancestor shared the same trait and both octopus and humans inherited that trait from that common ancestor, that would make this a homologous trait, not analogous. The structure of the eye has evolved numerous times on earth, which means there are indeed organism who do not have light sensory organs of any kind, along with a whole range of organisms with differing abilities to see (light/dark, color, depth, detail). Seeing is only one way to take in information from the world around us. Don't assume all must have it. It's dependent on the environment.
Check this out:
http://www.theage.com.au/articles/2003/08/29/1062050667595.html