Homolgous Trait and Analogous Traits
a) The Echidna and the Platypus are both (only) Mammals that are able to lay eggs even though they both look completely different you would not have expected them to be so closely related.
b) The Echidna is very closely related to the anteater which in fact does not lay eggs. They both have the same unique tongues that are very long and able to get into small places since their diet consist of ants and termites. The Platypus is a very strange egg-laying looking mammal that seems to be a mixture of a duck, beaver and an otter. The Platypus has a unique feature and thats producing a venom composed largely of defensin-like proteins around the ankle. To scientist the Platypus plays a big role in the study of evolutionary biology. Even though these two mammals look completely different and you would never assume they were related at all, their homologus trait of being the only mammals that are able to lay eggs shows the common genetic relationship they both have.
c) The common ancestor of these two species is Teinolophos and Steropodon (both extinct monotremes) they evolved from water foraging ancestors which returned to living completely on land.
d)
2) Analogous Traits: Platypus (mammal) and the duck (bird)
a) Both the Platypus and duck look somewhat similar rather than the Enchidna and the Platypus and they both carry an analogous trait which is they both lay eggs even though ones a bird and the other is a mammal.
b) Their both egg laying creatures with webbed feat and a rubbery snout. They look very similar and they swim about in waters. They both are able to lay eggs, they nostrils are located on top of their beaks and eyes above it. They both have extremely the same features, but are different species.
c) Yes, I do believe the common ancestor of these two traits possess this analogous traits because even though the Platypus were very poorly understood and account of the low numbers of extant species, scientist insist that the duck billed Platypus is an evolutionary link between mammals and birds.
d)
Awesome Diana! Great animal choices, I completely forgot about the platypus, he seems to be either homologous or analogous with many animals huh?
ReplyDeleteVery interesting. The echidna and platypus look different, but I can understand how they are related in some way. Their faces look a lot alike, but anyways great post. This statement blew me away, "The Platypus is a very strange egg-laying looking mammal that seems to be a mixture of a duck, beaver and an otter." Crazy!!!! Never look at it until you said this.
ReplyDeleteI really like your animal choices! It is really interesting to learn about such odd animals lie the Platypus and the Echidna because they aren't brought up very often. The comparison between the two animals with the Platypus is very interesting. Good job!
ReplyDeleteStarting with the analogous traits, the choice of platypus and ducks is a great choice, but remember what it means to share analogous traits. It will mean that the common ancestor will NOT share the trait, or even if it does, it did not pass that trait down both descent lines. The trait needs to have evolved independently in at least one of the species in order for these traits to be analogous.
ReplyDeleteI'm not sure which scientist insists that the platypus is a link between mammals and birds. The evolutionary line of mammals and birds is well understood and monotremes (platypus) is a branch off of mammals. Do you have a source?
The trait of egg laying in the echidna and the platypus isn't really a homologus trait because it is the same trait. There aren't significant differences in this trait resulting from different selective pressures. good tracing of the ancestors and great images.