There are two theories among biologists regarding the creation of the living beings including plants and animals.
A) Transformism: The doctrine that living organisms have evolved from previously existing forms of unicellular beings that existed in oceans or in the mud deep underwater. This change is also called mutation. That is to say lifeless beings were put to special condition which led to emergence of living organisms. These living organisms gradually evolved and changed from one form of animal into another. The most perfect of the instance of evolution are the present human beings who emerged out of monkeys or animals that resembled monkeys.
B) Fixism: The theory that the species alive today were identical to those of the past and that evolution does not happen. According to fixism, no species turned into a variant form of animals. Naturally, human beings had an independent existence ever since it was created.[1]
Darwin's evolution theory has been one of the most controversial and very much debated topics in late centuries with some opposing it and others favoring it. In addition to separate books written for and against the theory, some others have also touched this subject on various occasions.
Among Muslim scholars who have discussed this subject is the author of Tafsir al-Manar and Maraghi etc. who subscribe to the theory and seems to be so much influenced by it that he considers it to be one of the divine traditions. He has even tried to interpret some verses in such a way as to signify evolution. He has assumed it as being one of the innovative views of the Quran rather than Darwin's initiative.[2]
Origin of evolution
Natural scholars such as Lamarck, Darwin and their followers consider evolution to be a natural requirement, struggle for survival, adaptation to the environment and survival of the fittest. They have concluded that these factors have led to variation of the forms and physical features of the animals. The capable is perfected and the incapable is doomed to destruction. Since these animals have started their motion and perfection from need and struggle, therefore they were able to make a choice and to adapt to the environment.[3]
Proponents' arguments
The arguments put forth by proponents of evolution can be easily summed up in three parts:
1. Arguments they have brought forth from paleontology (study of fossils) i.e. the petrified skeletons of living things in the past. They believe that the study of various layers of earth show that living beings have changed from simpler forms into more perfect and complex ones. The evolution theory is the only way to interpret this variation and difference of the fossils.
2. There are evidences gathered from "comparative anatomy" which shows a lot of resemblances between the bones and skeletons of animals. These bones and structures, when compared with one another, show that they have been taken from the same origin.
3. There are evidences which they have obtained from embryology and they believe that if the animals are put together whilst they are in the embryonic state, then we will come to know that the embryos are, when they are mother's uterus or in eggs, very similar to one another before evolution. This is also affirming that all of them are derived from the same origin.
Answers given by proponents of fixism
The fixists or those, who believe that the species alive today were identical to those of the past, have given a general answer to all the arguments and that is, none of those arguments are convincing. In fact, we cannot deny the fact that these three evidences justify the possibility of evolution as a mere "probability" but the evidences are never assuring.
In other words, to prove the evolution theory and turn it from a mere theory into a scientific and decisive law, there is a need for rational proof or else the theory must be proved through experiments and sense and there is not a third way.
However, there is no room for any rational and philosophical reasons to be presented here in connection with evolution, not to mention the fact that experiment does not have access to things which existed millions of years ago.  What we feel through the senses and experimentation are superficial changes which take place as "mutations" in animals and plants. For example, a sheep is born to a generation of sheep whose wool is quite different from the wool of ordinary sheep i.e. it is wool is more delicate and softer. That change is the cause of the birth of a generation of sheep called "Merinos Sheep". That is because of the wool.
Perhaps, some animals have different eye colors or finger or skin and the likes due to mutation but no one has seen mutation in a metamorphic way in the sense that substantial change may have occurred with the main organs of animal or that a species may have ended up becoming a completely variant form of animal.
Therefore, we can simply guess that the accumulation of mutations might one day lead to a metamorphic change and result in a variant form such as a reptile becoming a bird but this is never a decisive guess and it is only a conjecture because we have never encountered such mutations in the concrete external world.
We conclude from the foregoing explanation that transformists cannot take this theory farther than a simple theory. It is for the same reason that those discussing this issue continues to term it as a theory, not as an established law or principle.[4]
It appears from the outward meaning of the verses of the Quran about creation of Adam that he was first made of mud. After completion of his body, soul was blown into it whereupon all angels except Iblis prostrated themselves in front of him. The Quran's explanation in this regard shows that there had not been other genre or kinds of animals in between the creation of man and his present form. [5]
For further information in this regard, refer to the following books:
1. Makarem Shirazi, Naser, Tafsir Numunah.
2. Taleqani, Sayyid Mahmood, Pertowi az Quran.
3. Tusi, Muhammad bin Hasan, Al-Tebyan fi Tafsir al-Qur'an (Introduction to the Book).
4. Najafi Khomeini, Muhammad Jawad, Tafsir Asaan.
5. Fazlullah, Sayyid Muhammad Hussein, Tafsir min Wahy al-Qur'an
6. Behzad, Mahmoud, Darwinism.
7. Makarem Shirazi, Naser, Akharin Farziyah Takamul (The Last Theory of Evolution).
8. Musavi Sabzevari, Sayyid Abdul A'laa, Mawahib al-Rahman fi Tafsir al-Qur'an.
9. Najafi, Muhammad Reza, A Criticisms of Darwin's Philosophy (Arabic).
10. Balaghi Najafi, Muhammad, Alaa al-Rahman fi Tafsir al-Qur'an.

---