1: Homologous traits: (Elephant and Manatee)
The two species that I selected for this portion of the assignment are the manatee and the elephant.
These two species are vastly different in size structure, and Habitat, however, they are both mammals that
descend from the same common ancestors. An elephant is a large herbivorous mammal that dwells the land.
A manatee is also a large, herbivorous, mammal, however, it is a marine-dwelling mammal. The front limbs of
these two different species are a shared homologous trait. A manatee’s flippers are non-weight bearing
structures that are utilized by the organism to propel and maneuver it through the water. An elephant's front limbs are weight bearing structures that the organism utilizes for locomotion and support. The shape,
size, and purpose of both organism’s front appendages are different because over the course of-of millions of
years they descended from a common ancestor known as a Moeritherium. We know that the Moeritherium
is a common ancestor between the elephant and manatee thanks to Molecular clocks, radiometric dating, and
stratigraphy.
These two species are vastly different in size structure, and Habitat, however, they are both mammals that
descend from the same common ancestors. An elephant is a large herbivorous mammal that dwells the land.
A manatee is also a large, herbivorous, mammal, however, it is a marine-dwelling mammal. The front limbs of
these two different species are a shared homologous trait. A manatee’s flippers are non-weight bearing
structures that are utilized by the organism to propel and maneuver it through the water. An elephant's front limbs are weight bearing structures that the organism utilizes for locomotion and support. The shape,
size, and purpose of both organism’s front appendages are different because over the course of-of millions of
years they descended from a common ancestor known as a Moeritherium. We know that the Moeritherium
is a common ancestor between the elephant and manatee thanks to Molecular clocks, radiometric dating, and
stratigraphy.
Manatee
Elephant
Moeritherium
2: Analogous Traits: (Butterfly and pigeon)
The two species that I selected for this portion of the assignment are a butterfly and a pigeon. A butterfly is a small
flying insect that feeds off of flower nectar and tree sap. A pigeon is flying bird that feeds off of fruits, seeds,
and plants. The analogous trait present between these two completely different species is their wings and their
ability to fly. The similarities between these two different species are not a result of a common genetic history.
These analogous traits are individually obtained adaptations that are known as parallel evolution. These two
organisms faced similar environmental stress but they do not a genetic or evolutionary relationship. The theory
of evolution recognizes that all life on earth shares a last universal common ancestor so if we were to trace the
lineage of both of this organism we would find a common ancestor, however, this does not indicate a genetic.
Through the utilization of molecular clocks, radiometric dating, and stratigraphy we can decipher if a trait is either
homologous or analogous.
flying insect that feeds off of flower nectar and tree sap. A pigeon is flying bird that feeds off of fruits, seeds,
and plants. The analogous trait present between these two completely different species is their wings and their
ability to fly. The similarities between these two different species are not a result of a common genetic history.
These analogous traits are individually obtained adaptations that are known as parallel evolution. These two
organisms faced similar environmental stress but they do not a genetic or evolutionary relationship. The theory
of evolution recognizes that all life on earth shares a last universal common ancestor so if we were to trace the
lineage of both of this organism we would find a common ancestor, however, this does not indicate a genetic.
Through the utilization of molecular clocks, radiometric dating, and stratigraphy we can decipher if a trait is either
homologous or analogous.
The Moeritherium reminds me a bit of Hippos and Rhinos. I wonder if Hippos are distantly related to elephants and Manatees... I suppose they wouldn't be that far off from whales and dolphins than either. And the analogous part with the butterfly and the pigeon made me laugh, because it reminded me of that one meme of that guy who gestures towards a butterfly and asks "is this a pigeon?"
ReplyDeleteLove it. Great analysis too!
I really like how you organized the homology section! You started with organisms who's ancestry you already understood and worked from there to identify the homologous trait. That is a very logical way to complete this assignment. You had good descriptions of your species, a clear connection made between the structure and function of the traits in question, and a well-described ancestry presented to your reader, explaining how you know that these traits are the result of common descent. Perfect.
ReplyDeleteFor the most part, on the right track with your analogous traits, with good descriptions on your species and your traits.
You wander off in the wrong direction on your ancestry, however. Molecular clocks, radiometric dating, and stratigraphy certainly help us read the fossil record, but those don't directly provide us with a "yes" or "no" answer on analogy or homology. We need to make a few deductions along the way.
For example: It is difficult to guess at what the common ancestor of the bird and butterfly looked like some 100's of millions of years ago... it may have possessed wings or it may not have, but fortunately, we don't need to know that to confirm that these traits are analogous. While it is possible that the butterfly inherited its wings from that common ancestor, what about the bird? We know quite a bit about bird and bird-wing evolution. Birds evolved wings as they split from reptiles, and this occurred long, long after the split with that common ancestor with the butterfly. This means bird wing evolution occurred independently from that common ancestor with the butterfly. That is sufficient to confirm that these are not the product of common descent and are indeed analogous.
Good images.
Your choices for the analogous structures portion of the assignment were interesting and similar to my own in that you focussed largely on the wings. Wings are really fascinating because of how many different wing types there seems to be to there, and how differently they've all grown apart or formed. Wings are actually similar to fins in many ways, however, similar to the structures you talked about, they seemed to have evolved into what they are separately. It says much about the physics of Earth! Great work, your post was a great read.
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