Coloration evidence for natural selection InCharles Darwin set out his theory of evolution by natural selection as an explanation for adaptation and speciation. He defined natural selection as the "principle by which each slight variation [of a trait], if useful, is preserved". As long as there is some variation between them and that variation is heritablethere will be an inevitable selection of individuals with the most advantageous variations.
Several humans love dolphins among all the sea animals because they come across as friendly and entertaining. However, where did these dolphins come from, and how old are they in reality? The dolphins could have come from animals that existed in the Arabian Gulf Sea and the Mediterranean Sea, which is also known as the ancient Tethys Sea.
It could have been more than 50 million years ago that these animals were first seen. Due to the volcanic activity around the world the size of the sea could have been expanded and hence the dolphins also spread as animals.
However, where the first cetaceans developed from their ancestors did is a very mystical fact and there is no fossil or evidence of this transformation.
Were there even ancestors for the animal or it is in the same form ever since is also a question that has been unanswered. The most primitive form of cetaceans was found to have elongated bodies and they were completely aquatic.
Also they were well adapted to the oceanic environment. The oldest fossils were found in Egypt, and could have had similar behavioral characteristics. The natural selection process at this time preferred faster and more agile fish. Dolphin developed those characteristics and even today if you notice it is a very agile creature and can swim at incredible speeds.
The modern dolphins are completely evolved creatures which have several differences in features compared to its ancestors including the skull bone and intelligence level also.Dolphin Facts and Information for Kids.
Dolphin Facts and Information for Kids. Dolphin Evolution Evolution of Dolphins. When it comes to evolution, it is very fascinating, and collecting the data to back up the theories can be time consuming. What has been noted about evolution is that there are signs of it with just about every living thing in the world.
The dolphins could have come from animals that existed in the Arabian Gulf Sea and the Mediterranean Sea, which is also known as the ancient Tethys Sea. It could have been more than 50 million years ago that these animals were first seen.
The evolution of whales The first thing to notice on this evogram is that hippos are the closest living relatives of whales, but they are not the ancestors of whales.
In fact, none of the individual animals on the evogram is the direct ancestor of any other, as far as we know. Dolphin Evolution With permission of Lauren Anderson (initiativeblog.com) Around 50 million years ago, certain four legged land creatures started spending more and more of their time in water.
River dolphins are a group of fully aquatic mammals that reside exclusively in freshwater or brackish initiativeblog.com are an informal grouping of dolphins, which is a paraphyletic group within the infraorder initiativeblog.com river dolphins comprise the extant families Platanistidae (the Indian dolphins), Iniidae (the Amazonian dolphins), and Pontoporiidae (the brackish dolphins).