Do the Bahá'í Writings on evolution allow for mutation of species within kingdoms but not across kingdoms?
One of the most important aspects of the teachings embodied in Bahá'í writings are elimination of prejudice. Prejudice is considered to be source of dissension and conflict which as Bahá'u'lláh has indicated is "categorically forbidden in this cause". Normally when one thinks of prejudice, one imagines racial, class, religious, gender or national prejudices as main reasons for contention and strife in human society. Abdu'l-Bahá in his writings has given equal weight to the subject of harmony of science and religion and he has emphasized the fact that the lack of unity between science and religion as a major cause of contention and strife. He went as far to say that when unity of science and religion is acknowledged" then differences of belief will disappear. All will become as one family, one people." 
As one surveys the challenges of reconciling scientific thought with religious beliefs, one becomes aware that the subject of evolution stands alone as the most challenging area for harmonizing religion ad science. The problem is even more amplified when one takes into account the ever-changing flood of new scientific data coupled with the problem of reconciling the various (and sometimes contradictory) systems of religious thought. It is difficult to underestimate the divisiveness that permeates the debate on this subject. Both sides in this debate seem to have dug in their heels incapable of hearing the other side's arguments and each side seem to be equally to blame in contributing to the contentious atmosphere surrounding this debate. The advocates of religion often get caught up in dogma and fail to see the "inner" and "symbolic" meaning behind many of their religious scripture. Scientists on the other hand seem to shun and reject any reference of God to creation and consider the introduction of divinity to creation unscientific and unworthy of consideration.
Scholars studying the Bahá'í views on evolution will find themselves fortunate, as they will find a rich collection of Bahá'í scared writings elaborating on this subject. But studying Bahá'í writings is not without its challenges. One has to be careful not to jump into conclusions by reading specific quotations, since it may lead to erroneous conclusions. One may, for example, come to a conclusion that man was first an animal by reading this passage "but these only appeared by degrees: first the mineral, then the plant, afterward the animal, and finally man"  , but then reading quotation such as "Nevertheless, from the beginning of the embryonic period he is of the species of man" one realizes the complexity of analyzing Bahá'í writings on Evolution. 
The purpose of this essay is to attempt to provide some additional insight on the Bahá'í perspective on evolution, specifically by analyzing the Bahá'í writings in regards to "parallel evolution" and to also explore the spiritual implications of the Bahá'í view on evolution.
II. Evolution as discussed in Bahá'í Writings
As one reads Bahá'í writings on evolution, one comes across a specific line of argument presented by Abdu'l-Bahá that indicates that man from the beginning of its existence has been a distinct species. Adbu'l-Baha uses the analogy of a child growing at womb of mother repeatedly in presenting his arguments. For example we read in the following passage,
"But from the beginning of man's existence he is a distinct species. In the same way, the embryo of man in the womb of the mother was at first in a strange form; then this body passes from shape to shape, from state to state, from form to form, until it appears in utmost beauty and perfection. But even when in the womb of the mother and in this strange form, entirely different from his present form and figure, he is the embryo of the superior species, and not of the animal; his species and essence undergo no change. Now, admitting that the traces of organs which have disappeared actually exist, this is not a proof of the impermanence and the non-originality of the species. At the most it proves that the form, and fashion, and the organs of man have progressed. Man was always a distinct species, a man, not an animal. So, if the embryo of man in the womb of the mother passes from one form to another so that the second form in no way resembles the first, is this a proof that the species has changed? that it was at first an animal, and that its organs progressed and developed until it became a man? No, indeed! How puerile and unfounded is this idea and this thought! For the proof of the originality of the human species, and of the permanency of the nature of man, is clear and evident" 
This repeated line of discussion by Abdu'l-Bahá has been a central theme in many of his writings and talks and thus has provided the basis for many scholars analyzing Bahá'í scriptures in this area. Many believe that this indicates a biologically separate line evolution for the human species parallel to the animal kingdom. In this parallel mode of evolution it is believed that from the beginning of man's appearance on earth he evolved through a single and separate biological line, always retaining its human identity. Many others have rejected this line of argument and make the case that this does not negate the possibility that anatomically humans may have an origin in the animal world, and indicate that this analogy is meant to convey a "philosophical concept of the origin of complex order in our world and the purposefulness of our cosmos based on God's plan" . They interpret Abdu'l- Baha's statements as concerning mainly to the spiritual essence and spiritual evolution of humanity separate from underlying biological evolvement of human species. 
III. Parallel Evolution
Most authors studying the Bahá'í scripture on this subject, whether believing in parallel evolution or not, believe that parallel evolution model assumes a separate and distinct line for every biological species. This essay is proposing that it is possible that what Bahá'í writings really indicate is the impossibility of mutation of species between kingdoms but allows mutation of species or forms within kingdoms. Bahá'u'lláh himself alluded to the mutation within kingdoms in the following passage..
"Is it within human power, O Hakim, to effect in the constituent elements of any of the minute and indivisible particles of matter so complete a transformation as to transmute it into purest gold? Perplexing and difficult as this may appear, the still greater task of converting satanic strength into heavenly power is one that We have been empowered to accomplish" .
Here Bahá'u'lláh is indicating examples of transformation in mineral kingdom and human kingdom. In the mineral kingdom he visualized a transformation or transmutation of elements and he describes a parallel spiritual transformation in the human kingdom.
Tree, a useful imagery
The use of tree is used repeatedly in Bahá'í scripture to convey spiritual truths about the human condition. The statements such as "Ye are the fruits of one tree, and the leaves of one branch" use tree as metaphor to convey the unity of the human race. Also in other passages tree is used convey unity between sexes where branches to are used to designate men, and leaves to designate women. Tree imagery has also used by Abdu'l-Bahá to describe structures within animal and vegetable kingdom.
"Furthermore, the forms and organisms of phenomenal being and existence in each of the kingdoms of the universe are myriad and numberless. The vegetable plane or kingdom for instance has its infinite variety of types and material structures of plant life, each distinct and different within itself, no two exactly alike in composition and detail, for there are no repetitions in nature, and the virtue augmentative cannot be confined to any given image or shape. Each leaf has its own particular identity, so to speak, its own individuality as a leaf. Therefore each atom of the innumerable elemental atoms, during its ceaseless motion through the kingdoms of existence as a constituent of organic composition, not only becomes imbued with the powers and virtues of the kingdoms it traverses but also reflects the attributes and qualities of the forms and organisms of those kingdoms. As each of these forms has its individual and particular virtue." 
In the passage just quoted Abdu'l-Bahá not only categorizes different types of biological beings within each kingdom, he also provides tree as a useful imagery to describe its structure. Here the whole tree represents the attributes of the vegetable kingdom as a whole and the leaves describe individual types and forms within the kingdom.
The same imagery is used to explain the evolution and structure in the human kingdom as we see in the following quotation.
"And if this prejudice be the prejudice of nationality consider that all mankind are of one nation; all have sprung from the tree of Adam, and Adam is the root of the tree. That tree is one and all these nations are like branches, while the individuals of humanity are like leaves, blossoms and fruits thereof" 
This tree analogy has been used in discussions by materialists on evolution. Neo-Darwinism visualizes a tree-like structure, where it is stipulated that human species and other animal species are branches within its model. It is by using this model that they come to the conclusion that humans evolved from the animal. What Bahá'í writings seem to indicate is that each kingdom has its own separate tree. Within each kingdom one can assume that mutations happened, but mutations between kingdoms is deemed an impossibility.
The impossibility of mutation between kingdoms is specifically mentioned in the Bahá'í scripture as we see in the following quotation.
"It is the same with the other beings: a mineral, however far it may progress in the mineral kingdom, cannot gain the vegetable power; also in a flower, however far it may progress in the vegetable kingdom, no power of the senses will appear. So this silver mineral cannot gain hearing or sight; it can only improve in its own condition, and become a perfect mineral, but it cannot acquire the power of growth, or the power of sensation, or attain to life; it can only progress in its own condition". 
IV. Structure and Dynamics of change within each kingdom
The dynamics of change within the mineral, vegetable and animal kingdom are generally well understood. The evolution of simple elements to more complex forms in the mineral kingdom is explained scientifically. The same holds true in the vegetable and animal kingdom. If it is assumed that human kingdom evolved through a separate path than other kingdoms, naturally the question arises, what are the dynamics of change in the human kingdom?
The following two quotations shed some light on this subject
"Ye are all leaves of one tree and the fruits of one branch." By this it is meant that the world of humanity is like a tree, the nations or peoples are the different limbs or branches of that tree and the individual human creatures are as the fruits and blossoms thereof" 
Here one can see that different nations, races and peoples represent the limbs and branches of tree of humanity. One can see that different races evolved and changed through out time to form nations and peoples. This evolution changed the physical characteristic of humans as the statement by Bahá'u'lláh "ye are the leaves of one tree" states that we are one species, the species of the human race. This reality of oneness of mankind occupies a central position in the teachings of the Bahá'í Faith.
Now as alluded before, in the human kingdom what mutates and changes are spiritual attributes. What separates each human being from other is the degree which each person transforms or mutates their spiritual reality to a higher form , and as Bahá'u'lláh mentions the task of spiritual transformation or "mutation" of mankind to a higher form is what he is empowered to accomplish. The evolution of spiritual types also has evolved over time similar to the process of evolution of species in the animal and vegetable kingdoms. This following quotation make the contrast between mutations of species in animal and vegetable kingdoms and spiritual evolution in human kingdom.
"Sense-perception gives rise to desire, desire to will, will to action, and action again to sense-perception. This chain ever repeats itself, and so the powers of thought, memory, reason, and the emotional capacities are evolved in spirit. These power and capacities of spirit, expressed in individual human beings, constitute human characters. Through these successive evolutionary steps, spirit develops characters having Divine attributes. The positive, creative aspect of God is reflect in the them. Individuality is derived from expression in individual form. Self-consciousness accompanies individualised character, and the being thus endowed has the potentiality of rising to the knowledge of God. Characters inspired by the universal human spirit continue in lines of specific developing types, as did species in the vegetable and animal kingdoms" 
The Bahá'í writings on evolution seem to indicate separate paths of evolution between the mineral, vegetable, animal and human kingdoms. These teachings do not negate the possibility of mutation or transformation within each kingdom. But it seems to state the impossibility of mutation or evolution between kingdoms. This has important implications for study of human development. First one cannot use examples of mutation in animal kingdom to infer a mutation from animal kingdom to human kingdom. Hence this model would be in conformity with most scientific evidence, since most of the proofs cited for evolution involves the mutation paths with animal and vegetable kingdoms. Secondly it puts emphasis in spiritual evolution of humanity. In regards to human's physical attributes it stipulates that we are the same species, thus providing a scientific and moral grounds for elimination of prejudice. Here the different types, or "species" of humankind are its spiritual attributes. The evolution and differences in physical attributes of humans are deemed non-essential and irrelevant to the development of human race. Also to the individual human, it places the emphasis on development to spiritual development where the responsibility of transforming or mutating to a higher form is within the reach of all individuals irrespective of race sex or national origin. Thirdly it provides a holistic prospective for humanity. By looking at whole of humanity as one tree, as Abdu'l-Bahá reminds us in the following passage, one needs to acquires spiritual morals and values that requires us to spend our focus in assisting and regenerating whole of human race.
The Blessed Beauty said: "All are the fruits of one tree and the leaves of one branch." He likened the world of existence to one tree and all the souls to leaves, blossoms and fruits. Therefore all the branches, leaves, blossoms and fruits must be in the utmost of freshness, and the bringing about of this delicacy and sweetness depends upon union and fellowship. Therefore they must assist each other with all their power and seek everlasting life. Thus the friends of God must manifest the mercy of the Compassionate Lord in the world of existence and must show forth the bounty of the visible and invisible King. They must purify their sight, and look upon mankind as the leaves, blossoms and fruits of the tree of creation, and must always be thinking of doing good to someone, of love, consideration, affection and assistance to somebody. 
 Promulgation of Universal Peace P.65
 Some Answered Questions P. 199
 Some Answered Questions P. 193
 Some Answered Questions P. 184
 See Origin of Complex Biology …by Eberhard von Kitzing
 Gleanings of Writings of Bahá'u'lláh P. 200
 Foundation of world Unity
 Selection of Writings of Abdu'l-Bahá P. 299
 Some Answered Questions P. 230
 Abdu'l-Bahá, Bahá'í World Faith - Abdu'l-Bahá Section, p. 246
 Compilations, Bahá'í Scriptures, p. 301
 Abdu'l-Bahá, Bahá'í World Faith - Abdu'l-Bahá Section, p. 215