How is the term Cambrian explosion misleading? Distinguish between convergent evolution and divergent evolution. Which type of selection would you expect to be the major factor in convergent evolution? In divergent evolution? Why are mutations important in evolution? Natural selection can lead to the evolution of prezygotic isolating mechanisms, but not postzygotic isolating mechanisms? Explain. Solution A) The cambarian explosion is misleading because- Cambarian is considered as \"explosive\" and during this period the count of many animal phyla such as athropods,mollusks and vertebrates became increased and they became species rich. B) (1) CONVERGENT EVOLUTION : This occurs when the two species donot share common ancestors though they have similar characteristics. Here there is a small problem with this evolution that is,we should able to analyse clearly the difference between the species because we may be mistaken by seeing the features of both species. Ex: Humming bird and Humming bird moth are the best examples because though they look similar in size,sucking nector etc... they differ from each other. (2) DIVERGENT EVOLUTION : In this evolution, the species share similar characteristics from thier ancestors but they differ in similar characteristics.Darwins finches are the best example for this evolution. (3) Without mutation,there is no evolution because mutation is the only way that new alles and regulatoy regions are created. That is the reason why mutations are very most important in evolution. C) The imortant point for prezygotic isolating mechanism compared to post zygotic is it prevents hybrid from even happening in the first place and there is an overlap of habitat called the hybridization zone where the mating and interaction occurs. While coming to other isolation mechanism which is post zygotic, it is failed in keeping the species in reproductive isolation from each other and in this isolation,hybrids are produced but not tend to viable.The main drawback of postzygotic evvolution is they must relay on natural selection to correct the convergence of species..

1. How is the term Cambrian explosion misleading? Distinguish between convergent evolution and
divergent evolution. Which type of selection would you expect to be the major factor in
convergent evolution? In divergent evolution? Why are mutations important in evolution?
Natural selection can lead to the evolution of prezygotic isolating mechanisms, but not
postzygotic isolating mechanisms? Explain.
Solution
A) The cambarian explosion is misleading because- Cambarian is considered as "explosive"
and during this period the count of many animal phyla such as athropods,mollusks and
vertebrates became increased and they became species rich.
B) (1) CONVERGENT EVOLUTION : This occurs when the two species donot share common
ancestors though they have similar characteristics. Here there is a small problem with this
evolution that is,we should able to analyse clearly the difference between the species because we
may be mistaken by seeing the features of both species.
Ex: Humming bird and Humming bird moth are the best examples because though they look
similar in size,sucking nector etc... they differ from each other.
(2) DIVERGENT EVOLUTION : In this evolution, the species share similar characteristics from
thier ancestors but they differ in similar characteristics.Darwins finches are the best example for
this evolution.
(3) Without mutation,there is no evolution because mutation is the only way that new alles and
regulatoy regions are created. That is the reason why mutations are very most important in
evolution.
C) The imortant point for prezygotic isolating mechanism compared to post zygotic is it prevents
hybrid from even happening in the first place and there is an overlap of habitat called the
hybridization zone where the mating and interaction occurs. While coming to other isolation
mechanism which is post zygotic, it is failed in keeping the species in reproductive isolation
from each other and in this isolation,hybrids are produced but not tend to viable.The main
drawback of postzygotic evvolution is they must relay on natural selection to correct the
convergence of species.