A) Planaria, insects, octopus and vertebrates all have eyes .can we group eyes of these animal together to establish a common evolutionary origin?justify your answer.
B) "Birds have evolved from reptiles" State evidence to prove the statement.
Answers
(a) The eyes seen in planaria, insects, octopus and vertebrates vary greatly in their structure. These organisms can be used for studying evolution of eyes as the eyes of planaria are simple without lens, insects have compound eyes and vertebrates have highly specialized eyes. However, all of them perform the same function of vision. Hence, a common evolutionary origin can be established.
(b) Birds like reptiles have developed wings. Although the way the wings are used is different because it was used for providing insulation from cold in case of reptiles whereas it is used for flight in case of the birds. But this shows that wings are analogous organs and the reptiles and birds adapted in a similar manner in hostile conditions.
A) The first eye was a photosensitive element which allowed the animal to trace light. Its said to be evolved in Ocean, most of the animals we see today have eyes. But the eyes are different, insects posses compound eyes, arachnids and crustaceans have ocelis and we have an auto focusing eye.
We could group these Organisms and establish that eyes are common to them and hence they have all evolved from a common ancestor. It is quiet sure that they do. But there may be a case that they must have come from some parellel evolution. Consider the case of wings, wings of insects, wings of birds and wings of bats they all evolved independently. There is no relations between insects, birds and bats in terms of aviation, three of them developed flight in there own means. Like this there may be some later development in Science which suggests that the eyes may be formed from any parallel evolution, we are forced to break down our theory.
Planaria, insects, octopus and vertebrates all have eyes. They also all live on earth. Discounting the theory of space squid, the simplest explanation is they all evolved here and if you go back far enough there is a common evolutionary origin for all terrestrial life.
B)Archaeopteryx, meaning "old wing", is a genus of bird-like dinosaurs that is transitional between non-avian feathered dinosaurs and modern birds. The name derives from the ancient Greek meaning "ancient", and , meaning "feather" or "wing
Archaeopteryx posses some same features like the teeth as in todays birds, hence xan be justified that birds have evolved from reptiles as Archaeopteryx also had wings and was a reptile too......
hope this helps you
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