Two species that possess the same homologous traits would be:
- Horses and Zebras -
A horse comes from the family Equidae. Horses have evolved over the past 55 million years. Humans began to domesticate horses back in 4000BC. A horses anatomy enables them to use their speed to escape from predators and they have an amazing developed sense of balance. Horses are capable of sleeping by standing or lying down. A horses life span ranges from 25 - 30 years. The size of a horse varies and is also influenced by nutrition intake. Horses have 64 chromosomes and contains 2.7 billion DNA pairs which is larger than a dogs genome, but smaller than a human. The horse has an average of 205 bones in its skeletal system.
Another species that possesses the same homologous trait would be a Zebra. A zebra also come from the family Equidae. A zebra has their distinctive black and white stripes. The name Zebra perhaps originates from the Latin word equiferus meaning "wild horse". The stripes on a zebra go vertical for the most part, as it may help hide them in grass by disrupting its outline. The stripes may also help to confuse a predator, for instance, if a group of zebras are standing close together, from a distance it may seem to a predator that they are a much larger group due to the stripes and colors and how they seem close together. Zebras have excellent eye sight. Like horses, zebras can turn their ears in alomost any direction.
The difference in the homologous trait of both the horse and zebra...
Apart form the size, shape and stripes, there are a number of distinguishing features between a horses and zebras.
1. The bone structure of both the animals is different. Zebras have a solid tail unlike a horses.
2. The anatomy of a horse makes them use speed to run away from predators. They have a well developed sense of balance. Like horses, zebras walk, trot, canter and gallop. They are generally slower than horses, but their great stamina helps them outpace predators. When chased, a zebra will zig-zag from side to side, making it more difficult for the predator. When cornered the zebra will rear up and kick or bite its attacker.
3. Zebras have excellent eyesight. It is believed that they can see in color. Zebras also have night vision, although not as advanced as that of most of their predators.
4. Zebras have excellent hearing, and tend to have larger, rounder ears than horses. Like horses and other ungulates, zebra can turn their ears in almost any direction. In addition to eyesight and hearing, zebras have an acute sense of smell and taste.
5. Female zebras mature earlier than the males, and a mare may have her first foal by the age of three. Males are not able to breed until the age of five or six. Mares may give birth to one foal every twelve months. She nurses the foal for up to a year. Like horses, zebras are able to stand, walk and suckle shortly after they are born. A zebra foal is brown and white instead of black and white at birth.
1. The bone structure of both the animals is different. Zebras have a solid tail unlike a horses.
2. The anatomy of a horse makes them use speed to run away from predators. They have a well developed sense of balance. Like horses, zebras walk, trot, canter and gallop. They are generally slower than horses, but their great stamina helps them outpace predators. When chased, a zebra will zig-zag from side to side, making it more difficult for the predator. When cornered the zebra will rear up and kick or bite its attacker.
3. Zebras have excellent eyesight. It is believed that they can see in color. Zebras also have night vision, although not as advanced as that of most of their predators.
4. Zebras have excellent hearing, and tend to have larger, rounder ears than horses. Like horses and other ungulates, zebra can turn their ears in almost any direction. In addition to eyesight and hearing, zebras have an acute sense of smell and taste.
5. Female zebras mature earlier than the males, and a mare may have her first foal by the age of three. Males are not able to breed until the age of five or six. Mares may give birth to one foal every twelve months. She nurses the foal for up to a year. Like horses, zebras are able to stand, walk and suckle shortly after they are born. A zebra foal is brown and white instead of black and white at birth.
The early ancestors of the modern horse walked on several spread-out toes, an accommodation to life spent walking on the soft, moist grounds of primeval forests. As species who preferred grass began to appear, the diets shifted from foliage to grasses, leading to larger and more durable teeth. At the same time, as the climate and terrain changed, the horse's predecessors needed to be capable of greater speeds to outrun predators. This was attained through the lengthening of limbs and the lifting of some toes from the ground in such a way that the weight of the body was gradually placed on one of the longest toes, the third.
Two species that possess the same homologous traits would be:
- Platypus & Duck -
Although ducks are birds and platypuses are mammals, they have a limited number of similarities. Both are warmblooded vertebrates that breathe using lungs and a respiratory system. Ducks and platypuses both lay eggs, although ducks lay hard-shelled eggs and platypuses lay soft-shelled, leathery eggs. Ducks and platypuses both have a bill, but the platypus's bill is broader and flatter than a duck's bill, and it is equipped with electro-receptors for detecting tiny electrical impulses from crustaceans and larvae that live on the bottom of creeks and rivers. Both ducks and platypuses make frequent dives to find food. In the case of the platypus, however, it will make hundreds of dives a day in order to find the food it needs. Both creatures have webbed feet, but again there is a difference, because the webbing on platypuses feet is retractable, allowing them to use their sharp claws to dig burrows.
A duck is a bird. It has feathers and can fly. A Platypus is a completely different animal. It is a monotreme (egg-laying mammal) with a bill, fur and a thick, beaver-like tail.
Other differences include:
Excellent detail in your homologous pairing for your opening description. No question of the similarities and common ancestry of these two organisms.
ReplyDeleteThe assignment asks that you pick one homologous trait and focus on that. You have provided a list of differences between the horse and the zebra, but there are a few issues with it. Zebras do not have one solid bone for their tail. Other than that, all of the "differences" you highlight are generally shared traits of both horses and zebras, with the exception of the ear shape and perhaps the issue of speed vs. stamina. You don't provide a functional explanation for the ears but you do for the speed vs. stamina, so I will focus on that.
Horses may have greater speed for artifical reasons, since they have been subjected to artificial selection from humans to increase their speed since domestication. Zebras may have developed a balance between optimal speed and sturdiness of their legs... lighter, longer thinner legs (like in the horse) may give greater speed but are not built for the rough savannah life. Better to have less speed and more stamina, as you suggest.
For the analogous traits, again, you need to focus on one. We are not surprised to see differences in distantly related organisms, so we are looking for the similarities and trying to understand the functional/evolutionary reasons for those similarities.
So you mention the similarities in the bill. What are the functional reasons for the duck and the platypus developing bills? How does this help them survive in their given environments? That was the explanation we are looking for. A similar comparison could have also been presented on the presence of their webbed feet.
With regard to ancestry, yes, the duck is a bird and the platypus is a monotreme, but the question is, what is the origin of the analogous trait? Again, we need to pick a trait first! If you are discussing the webbed feet, for example, did the common ancestor possess this trait? Or do we know enough about either organism to know that these traits evolved independently long after the split from that common ancestor? This information is required to confirm that these are indeed analogous traits and not simply shared, inherited traits.
Great post. You seem to always go above and beyond the assignment. You go into great detail with every animal. I especially enjoyed the your list of differences between horses and zebras.
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