The Pentadcatyl Limb. M2
Many vertebrates in mammals have a similar bone structure despite looking different on the outside. This structure is called the pentadactyl limb –five fingered. This theory suggests that most of the vertebrates descended from the same common ancestors. Even in species such as the horse, which only has one "finger"(hoof). Scientists look at the fossil records and show how the ancestor of the horse originally had more fingers.
The Pentadcatyl Limb In a horse:
In the horse, the forelimbs are adapted for support and running by great elongation of the third digit bearing a hoof.Horses have only one finger or toe, modified to make a hoof, on each limb. The horse had a full five digit finger which slowly over the next million years changed the toes started to form into one, creating the hoof , due to the change in terrain so that the horse can go up and down hills etc in any weather such as snow, the main changes in the horse where its legs along with there pentadcatyl limb, 60 million years ago the horses leg hight was 0.5 meters , Then 40 million years ago it had grown to 0.6 meters, 10 million years later ( 30 million years ago) the leg then grew to 1.0 meters, then 10 million years ago the legs where still 1.0 meters tall bot the toes, had finally turned into a hoof, so the horse could easily manage rough terrain, and 1 million years ago, is when our modern horse was finally developed with a leg length of 1.6 meters and a full developed hoof.
The Pentadcatyl Limb in a Bat:
The bat's wing is homologous, like the human forearm and hand. Being a flying mammal and has thin soft membranes and bones this makes it's structure very fragile , The theory of the bats evolution says that bats have evolved as gliding mammals firstly, and lived in trees, having skin flaps much like flying squirrels. When gliding the bat would Extend and thin the skin, along with lightening and extending the bones and gave more control over when gliding, when eventually the bat was able to fly. The theory saying that bats could have evolved the same structures by way of running and leaping off the ground, perhaps into an up draft or off a cliff. Though bats cannot fly from the ground up, they must climb to a higher point to push off and sore, this is why bats sleep upside down, so they can take off easier if it encounters a predator.
The Pentadcatyl Limb In a horse:
In the horse, the forelimbs are adapted for support and running by great elongation of the third digit bearing a hoof.Horses have only one finger or toe, modified to make a hoof, on each limb. The horse had a full five digit finger which slowly over the next million years changed the toes started to form into one, creating the hoof , due to the change in terrain so that the horse can go up and down hills etc in any weather such as snow, the main changes in the horse where its legs along with there pentadcatyl limb, 60 million years ago the horses leg hight was 0.5 meters , Then 40 million years ago it had grown to 0.6 meters, 10 million years later ( 30 million years ago) the leg then grew to 1.0 meters, then 10 million years ago the legs where still 1.0 meters tall bot the toes, had finally turned into a hoof, so the horse could easily manage rough terrain, and 1 million years ago, is when our modern horse was finally developed with a leg length of 1.6 meters and a full developed hoof.
The Pentadcatyl Limb in a Bat:
The bat's wing is homologous, like the human forearm and hand. Being a flying mammal and has thin soft membranes and bones this makes it's structure very fragile , The theory of the bats evolution says that bats have evolved as gliding mammals firstly, and lived in trees, having skin flaps much like flying squirrels. When gliding the bat would Extend and thin the skin, along with lightening and extending the bones and gave more control over when gliding, when eventually the bat was able to fly. The theory saying that bats could have evolved the same structures by way of running and leaping off the ground, perhaps into an up draft or off a cliff. Though bats cannot fly from the ground up, they must climb to a higher point to push off and sore, this is why bats sleep upside down, so they can take off easier if it encounters a predator.