Evolution of the pentadactyl limb in a Dolphin and Horse
Horse
Horse - The horse evolved from a dog sized animal to a horse known as what we have today, it came from the rainforest and it then evolved into living in the plains environment and growing more up to 2 meters higher, and in the rainforest made the animal have multi-toed feet and this was because it needed them to walk around in their environment and balance properly and this was best for the animal in that environment. It then evolved into a single toed animal which is known as a hoove today and this is because of their environment that they live in and it's best suited for this way of living in the country, this helps the animal move easier and be in control and also balance in this environment with these single toed hooves rather than having multi toed feet. the reason why they have changed and evolved to have different feet is because of the change of environment and it is needed so they can walk, balance, move properly in their environment. they have also adapted to support running on country grounds and this is due to the elongation of the third digit and this bares the hoof. before they evolved into the modern horse the horses leg was 0.5 meters and then it started to grow, 0.6 meters, 1.0 meters, and while their leg was the same their feet slowly turned into a hoof because of the rough terrain environment and now the modern horse is 16 meters and a fully developed hoof because of the way it's life style is which makes it easier for the horse.
This is a picture of the evolution of the horse an how it's evolved to the modern horse now.
Bat
Bats evolution is that it evolved as a gliding mammal and that they lived in tree areas they had skin flaps and this helped them to glide in the air, the bones are also very light also helping to keep them in the air for a longer period of time and give them more control as they could extend them and then it evolved it into a bat, also there is a theory that bats evolved from running and leaping off the ground from a cliff ect.. and now bats climb and get to a higher point to fly and this is the reason that the bats sleep upside down so they already have height to be able to fly when they wake up they don’t need to find higher grounds and it is easier for them to get away from danger that could happen. In the bat the wing is homologous and the wing in the bat is like the humans forearm and hand. The reason they have evolved is to live better in its environment, it's also for the safety of the bat as they sleep upside down if they didn't do this they would have to find higher ground to be able to fly away and this could threaten their species so them being able to fly rather than glide is better for the species and fly for longer periods of time and get away.