Analogy vs Homology
Species 1: Humans (Homo Sapiens)
Description: Humans are primates who happen to be highly intelligent beings known for their advanced abilities and complex social structures. They have various different ethnic groups/types of people who live in different environments. Humans learn to use their different traits from a young age (birth) in order to further evolve/improve their traits such as using their hands for grabbing or their feet for walking (learning how to walk). They are mostly taught or shown examples of how to use them by their parents at a young age. Humans begin to learn new skills as they grow older in age.
Homology: Opposable Thumbs: Humans have opposable thumbs, allowing them to do most of their daily functions in life. Some tasks this trait is useful for is tool use, other complex tasks, and has a significant role in human evolution. They are taught to use their trait at a young age from grabbing and pulling and later on used for harder tasks like cooking or driving. They are structurally different physically and by eye from the opposable thumbs of a chimpanzee. Human hands/ thumbs are much larger, more muscular, mobile, and fully opposable thumbs combined with fingers that have shortened and straightened. However, they are still similar by being used to completing their daily tasks and how they go about completing them like grasping or holding onto something.
Common Ancestor: The common ancestor of humans and chimpanzees is believed to be Sahelanthropus tchadensis. Evidence from fossil records and genetic studies supports the presence of opposable thumbs in this common ancestor.
Picture:
Human
Species 2: Chimpanzees (Pan Troglodytes)
Description: Chimpanzees are closely related to humans and share a common ancestor as well. They mainly inhabit rainforests and are characterized by their abilities to use tools, social behavior, and just genetic similarities to humans as well. Their hands/thumbs are used for more vigorous or more physically challenging obstacles like climbing or swinging from trees. Also, for basic survival such as eating food or using them to help drink water. They have much longer fingers and shorter thumbs which is again perfect for swinging in trees but less useful for precision grasping. They are similar but also different from humans at the same time.
Homology: Opposable Thumbs: Chimpanzees also have opposable thumbs just as the humans do. The chimpanzees' thumbs are used for more vigorous activity such as climbing and swinging from tree to tree. Although they are very similar to those of a human at a glance their function as well as skeletal makeup are vastly different. With humans having generally a large and even hand with the abilities to accurately grasp anything while the chimps have larger fingers then thumbs which isn’t as good for precise grabbing but much larger physical activities. They also tend to have hairy hands and tend to be rougher than smooth like humans. Still similar in many ways as they use the basic function as humans do in order to complete daily tasks in life like eating or grasping something.
Common Ancestor: The common ancestor of humans and chimpanzees is believed to be Sahelanthropus tchadensis. Evidence from fossil records and genetic studies supports the presence of opposable thumbs in this common ancestor.
Picture:
Chimpanzee
Species 3: Flying Squirrels (Pteromyini)
Description: Squirrels are generally small rodents with slender bodies, bushy tails and large eyes. Their eyes are large which help them in flight and at night. The way to see which type of squirrel it is depends on their fur color and markings on them. They are the only mammal capable of gliding/flight with being able to open their arms to drop their almost loose skin feeling wings down and using them to control which direction to fly while in flight. They do however have a harder time reaching flight then the species of butterflies. While they have limbs like legs and feet, they still share similarities with butterflies even though their genetic traits weren’t passed down from a common ancestor but more created with evolutions over time.
Analogy: Wings: The two wings are similar in skeletal structure as they are both needed for both species to take flight. The ability for the two species to open up their wings and be able to flap them and use them to change direction mid-flight is what also makes them similar. It’s how they primarily travel when it comes to wanting to go further distances instead of walking/running. Although they are drastically different when it comes to receiving the same trait from an ancestor, they develop their skills of flight by going through convergent evolution. One being naturally able to fly at first creation while the other had to learn the skill first.
Both these species could have a common ancestor but most likely don’t. The reason for this is due to the different class these species fall into. It is more probable that due to the environment they were in they had to adapt and make some changes in order to survive, mostly coming from the squirrels. Regular squirrels are not capable of flight, so the genetic evolution happened somewhere along their line of evolution.
Picture:
Flying Squirrel
Species 4: Butterflies (Lepidoptera)
Description: Butterflies are winged insects from the lepidopteran suborder Rhopalocera, characterized by large and often brightly colored wings that often fold together when resting and a conspicuous, fluttering flight. They first start out as moths and later evolve into the creature known as the butterfly. This is an example of evolution as well. Without their ability of flight, the butterflies would most likely not survive and go extinct, so it is a crucial part of them and their survival. The butterfly wings are made up of a membrane and covered in scales to protect the delicate structure. They are different but also similar to the species of a flying squirrel due to their abilities to take flight.
Analogy: Wings: Both species have the ability to take flight, but does this mean they have a similar ancestor down the line probably not. This is due to the butterfly for as long as they have been studied for shows they are re-made from a moth to a butterfly with wings immediately. While the squirrels have to be able to one possess the ability of flight (It’s Wings) and two learn how to use them. Both species must have gone through some type of convergent evolution in order to get where they are today. These are only a few reasons why they don’t share a similar ancestor.
Picture:
Butterfly
Hi, I enjoyed reading through your blog. I found it to be a well-structured, informative blog post that effectively indentifies the concepts of homologous and analogous traits. Your explanation of opposable thumbs in humans and chimpanzees as a homologous trait was very clear and well-supported, mainly in highlighting the area of differences and similarities in their use and structure.
ReplyDeleteHey, Anonymous... Please reply with you name so that I know how to assign credit!
DeleteMake sure you are logged into your Blogger account before you comment so that your username shows up.
Richard, your text lost it's text-wrapping function. This is, unfortunately, a common problem if you create a document in Google Docs and then copy/paste it into Blogger. Both systems are created by Google, so I don't understand why this problem occurs, but regardless, you need to check your blog after you publish to make sure it publishes correctly. The simplest "fix" is to copy the text first into a "text only" program and then recopy/paste into Blogger. That allows the Blogger formatting to take precedence.
ReplyDeleteFor now, I will copy your text below so that it can be read (and graded). From now on, you are responsible for making these corrections on your own.
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HOMOLOGY:
Species 1: Humans (Homo Sapiens)
Description: Humans are primates who happen to be highly intelligent beings known for their advanced abilities and complex social structures. They have various different ethnic groups/types of people who live in different environments. Humans learn to use their different traits from a young age (birth) in order to further evolve/improve their traits such as using their hands for grabbing or their feet for walking (learning how to walk). They are mostly taught or shown examples of how to use them by their parents at a young age. Humans begin to learn new skills as they grow older in age.
Homology: Opposable Thumbs: Humans have opposable thumbs, allowing them to do most of their daily functions in life. Some tasks this trait is useful for is tool use, other complex tasks, and has a significant role in human evolution. They are taught to use their trait at a young age from grabbing and pulling and later on used for harder tasks like cooking or driving. They are structurally different physically and by eye from the opposable thumbs of a chimpanzee. Human hands/ thumbs are much larger, more muscular, mobile, and fully opposable thumbs combined with fingers that have shortened and straightened. However, they are still similar by being used to completing their daily tasks and how they go about completing them like grasping or holding onto something.
Common Ancestor: The common ancestor of humans and chimpanzees is believed to be Sahelanthropus tchadensis. Evidence from fossil records and genetic studies supports the presence of opposable thumbs in this common ancestor.
Species 2: Chimpanzees (Pan Troglodytes)
Description: Chimpanzees are closely related to humans and share a common ancestor as well. They mainly inhabit rainforests and are characterized by their abilities to use tools, social behavior, and just genetic similarities to humans as well. Their hands/thumbs are used for more vigorous or more physically challenging obstacles like climbing or swinging from trees. Also, for basic survival such as eating food or using them to help drink water. They have much longer fingers and shorter thumbs which is again perfect for swinging in trees but less useful for precision grasping. They are similar but also different from humans at the same time.
Homology: Opposable Thumbs: Chimpanzees also have opposable thumbs just as the humans do. The chimpanzees' thumbs are used for more vigorous activity such as climbing and swinging from tree to tree. Although they are very similar to those of a human at a glance their function as well as skeletal makeup are vastly different. With humans having generally a large and even hand with the abilities to accurately grasp anything while the chimps have larger fingers then thumbs which isn’t as good for precise grabbing but much larger physical activities. They also tend to have hairy hands and tend to be rougher than smooth like humans. Still similar in many ways as they use the basic function as humans do in order to complete daily tasks in life like eating or grasping something.
Common Ancestor: The common ancestor of humans and chimpanzees is believed to be Sahelanthropus tchadensis. Evidence from fossil records and genetic studies supports the presence of opposable thumbs in this common ancestor.
I had to break your post up into two comments as together they were too long.
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ANALOGY:
Species 3: Flying Squirrels (Pteromyini)
Description: Squirrels are generally small rodents with slender bodies, bushy tails and large eyes. Their eyes are large which help them in flight and at night. The way to see which type of squirrel it is depends on their fur color and markings on them. They are the only mammal capable of gliding/flight with being able to open their arms to drop their almost loose skin feeling wings down and using them to control which direction to fly while in flight. They do however have a harder time reaching flight then the species of butterflies. While they have limbs like legs and feet, they still share similarities with butterflies even though their genetic traits weren’t passed down from a common ancestor but more created with evolutions over time.
Analogy: Wings: The two wings are similar in skeletal structure as they are both needed for both species to take flight. The ability for the two species to open up their wings and be able to flap them and use them to change direction mid-flight is what also makes them similar. It’s how they primarily travel when it comes to wanting to go further distances instead of walking/running. Although they are drastically different when it comes to receiving the same trait from an ancestor, they develop their skills of flight by going through convergent evolution. One being naturally able to fly at first creation while the other had to learn the skill first.
Both these species could have a common ancestor but most likely don’t. The reason for this is due to the different class these species fall into. It is more probable that due to the environment they were in they had to adapt and make some changes in order to survive, mostly coming from the squirrels. Regular squirrels are not capable of flight, so the genetic evolution happened somewhere along their line of evolution.
Species 4: Butterflies (Lepidoptera)
Description: Butterflies are winged insects from the lepidopteran suborder Rhopalocera, characterized by large and often brightly colored wings that often fold together when resting and a conspicuous, fluttering flight. They first start out as moths and later evolve into the creature known as the butterfly. This is an example of evolution as well. Without their ability of flight, the butterflies would most likely not survive and go extinct, so it is a crucial part of them and their survival. The butterfly wings are made up of a membrane and covered in scales to protect the delicate structure. They are different but also similar to the species of a flying squirrel due to their abilities to take flight.
Analogy: Wings: Both species have the ability to take flight, but does this mean they have a similar ancestor down the line probably not. This is due to the butterfly for as long as they have been studied for shows they are re-made from a moth to a butterfly with wings immediately. While the squirrels have to be able to one possess the ability of flight (It’s Wings) and two learn how to use them. Both species must have gone through some type of convergent evolution in order to get where they are today. These are only a few reasons why they don’t share a similar ancestor.
Here is my feedback:
ReplyDeleteInitial comment: Your layout is a little confusing... when you talk about homologous and analogous traits, you are necessarily talking about comparing *at least* two different organisms. You treated each organism individually, but they *share* homologous (or analogous) traits and should be discussed together.
Homology:
Very good descriptions of your two organisms (humans and chimpanzees).
Excellent discussion on the analogous trait, though it would have been easier to follow your discussion if you had combined this into one single paragraph. Well done connecting the structure of the thumb with the function.
With regard to common ancestor, again there was no need to keep them separate. One paragraph would have sufficed and been less confusing. Yes, S. tchadensis is a *candidate* for a common ancestor, but do we need to be that specific to draw the necessary ancestral connections for this trait comparison? Both humans and chimpanzees are apes, and we know that archaic apes possessed the trait of opposable thumbs, passing on this trait to their human AND chimpanzee descendants, with differences arising due to environmental/functional differences. That is the connection we need to make here to confirm ancestry and support the claim of homology.
Analogy:
Very good detail on your description of your two species.
Excellent discussion on the analogous trait and the discussion of the similar environmental pressures that likely produced the convergent evolution.
Re: Ancestry... you say:
"Both these species could have a common ancestor but most likely don’t."
Ah, but they do! As explained in the guidelines, ALL organisms share a common ancestor if you go back far enough in time, even mammals and insects. But how do we use this ancestry to confirm analogy?
It is difficult to guess at what the common ancestor of the flying squirrel and butterfly looked like some 100's of millions of years ago... while I doubt that it had wings, 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 flying squirrel? We know quite a bit about the evolution of the wing-like structure of the flying squirrel. Squirrels are mammals, who generally don't have wings, though clearly there are exceptions. Mammals like bats and squirrels who evolved wings did so long after mammals split from reptiles, let alone from insects. This means evolution of the flying squirrel's "wings" 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.
This exploration into homology and analogy among humans, chimpanzees, flying squirrels, and butterflies offers a captivating glimpse into the evolutionary intricacies. The detailed comparison of opposable thumbs and analogous wings showcases fascinating adaptations shaped by environmental demands, while common ancestors and convergent evolution add depth to the narrative. Improved clarity in structuring could enhance overall readability.
ReplyDeleteHello Richard,
ReplyDeleteI enjoyed reading your post along with the main heading's image. The description was well in-depth and gave an excellent background coverage on human's structures and traits. I also believe your descriptions for the butterfly and squirrel are very in-depth. Having common traits for both of them while not sharing a common ancestor seemed interesting to me, but should have made sense to me in a way when you see how structurally different both of them are.