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The evolutionary processes that led to the assembly of the diverse Neotropical tree flora are complex and poorly understood. It remains unclear at what pace this superlative diversity was accumulated, as do the causes of poor phylogenetic resolution and gene tree incongruence, which are commonly found when reconstructing the phylogeny of rainforest tree species. In addition, the role that introgression has played in the diversification of Neotropical trees and its effect on phylogeny remains enigmatic. The Brownea clade (Leguminosae) are a group of tree species characteristic of Neotropical rainforests, and so serve as an excellent study group with which to approach questions about the diversification of Neotropical trees. This investigation aimed to infer the rates of diversification and biogeographical history of the Brownea clade following the estimation of a phylogenetic tree for the group. The relationships between species within Brownea were then examined using phylogenomic methods to quantify gene tree incongruence, and phylogenetic model testing was used to ascertain whether this incongruence was better explained by incomplete lineage sorting (ILS) or introgression. Finally, two Brownea species found in sympatry were used to examine the impact of introgression on divergence, and whether species boundaries are maintained despite gene flow. More specifically, this study assessed whether genomic loci differed in the degree to which they introgress when compared to the genome-wide average, which would be expected if species boundaries were being maintained by selection. Furthermore, loci which were candidate regions for selection, and those associated with different aspects of the environment and morphology, were inferred in order to determine possible factors maintaining the divergence between the two species.

BACKGROUND: This is the record of a process extending over thirty years. It deals with the exploration of a somewhat complex theme. In the present document we have to look at the two main aspects of this work: the conceptualisation of internal dialogues and the conceptualisation of the spiritual realm, which we shall call the transpersonal. This will be done through giving an account of how they emerged in my work, particularly in the two books of mine which are relevant: Subpersonalities: The People Inside Us (1990) and The Transpersonal: Spirituality in Psychotherapy and Counselling (2,'ld edition) (2005a). First we shall look at the internal dialogue, the general term we shall be using to cover the broad and highly complex world of multiplicity within the normal psyche. THE INTERNAL DIALOGUE This is the theme of my book Subpersonalities. The concept of an internal dialogue is of course a familiar one. In literature it is a common theme, and in everyday life it is often mentioned. Most of us have had conversations with ourselves at times. It is not so commonly recognised in psychology, however, probably because there is no one great man associated with this way of thinking about the person. I became interested in it, after ten years of work in social psychology, in the early 1970s. I named this area of study 'subpersonalities', because at the time this seemed the most useful term. I first reported on it at the Annual Conference of the British Psychological Society in 1975, in a paper entitled "The internal society". I continued to publish articles and conduct workshops in this area, including at an Annual Conference of the British Association for Counselling, and taught many people how to use the idea. After a while I noticed that there was still no book on this 2 subject, and no references to subpersonalities in any textbook of personality. So I decided to write a monograph myself to put the concept on to the map. This book (Rowan 1990) covers the history, the practice, the research and the philosophy relevant to the topic. The book came out in 1990, and so far has had nothing but favourable reviews. There is still no reference to subpersonalities (or any of its 24 synonyms) in any widely used textbook of personality known to me, though as we shall see, the concept of a self-schema is beginning to creep in. But again there has been a good deal of interest in this from other countries, and particularly from the US. This leads me to believe that this part of my work will have more influence in the future. Recently I have co-edited (with Mick Cooper, 1999) an academic book on the plural psyche, which has some excellent contributors, and which I hope will take the field forward still further. It has become clear that the idea of subpersonalities (or more generally, some form of internal dialogue) can be used in place of the concept of the unconscious, for those who find the whole concept of the Freudian unconscious a stumbling block. Instead of a single entity, the unconscious, it refers to many internal entities, each of them with a history and a way of seeing the world and a motive for being there. It offers a way of exploring psychodynamics in a transparent yet effective way. It does this by using the method of personification. If we find that a person has any kind of division or split within themselves, we can as therapists suggest to the client that they put one side of the split on to one chair, and the other side on to another, and assume or pretend that these are two people who can talk to one another. This personifies the split. In other words, we turn the theory of internal dialogue into an active method of work in psychotherapy or counselling. One of the clearest writers on this topic is the Jungian Robert Thompson (1986), and there is a good deal of coverage in the work of the psychosynthesis school (Whitmore 2004). Very often the pursuit of this dialogue results in some kind of resolution or even transformation, which moves the therapy on. Perhaps the best description of how this can happen is to be found in the writings of Alvin Mahrer (e.g. 1989). Perhaps that is enough to delineate the basic idea of an internal dialogue. Now let us equally briefly introduce the basic idea of the transpersonal. PSYCHOSPIRITUAL DEVELOPMENT This is the central topic of my book The Transpersonal. The transpersonal is in general the realm of spirituality, including mysticism. But it attempts to be more precise and more clearly defined than the term 'spirituality' allows. WHAT THE TRANSPERSONAL IS NOT Sometimes it helps to set some boundaries to a concept, so that we can tell more easily what it is not. Here are some of these boundaries, which are helpful, I believe, in defining the transpersonal. First of all, to layout the basic model, it is helpful to distinguish between the prepersonal, the personal and the transpersonal. The personal is the ordinary everyday consciousness with which we are all familiar; the prepersonal is all that comes before that in the process of psychospiritual development, and is well described in developmental psychology generally (e.g. Craig 1992); and the transpersonal is that which genuinely goes beyond the personal into the realm of the sacred, the divine. (See Appendix and Figure 1 for some details of this). But let us look at some of the boundaries which are not so often referred to or described. The trans personal is not the extrapersonal A distinction has been drawn by Alyce and Elmer Green (1986) between the extrapersonal and the transpersonal. Some of the contrasts are laid out in Table 1 in Appendix C. Green & Green (1986) originally supplied the evidence on which this table is based, and they suggest that the basic distinction is that in the transpersonal there is something divine, whereas the extrapersonal is basically nondivine. This may be a tricky way of making the distinction, because how can anything be nondivine, strictly speaking? But I think it can be helpful in pointing in the right direction. The point is that the extrapersonal can sometimes be simply a gift that the person has. It can simply be a wild talent, perhaps present from an early age. These talents can also be attained as a result of transpersonal development, and then they are often called siddhis. "All the major systems of mystical spirituality agree that such powers do exist, but maintain they have nothing to do with attaining gnosis or realization or ultimate spiritual reality." (Anthony et a11987, p.21) These systems of mystical spirituality generally take it that the ultimate aim is to know reality in a direct way, not through the mediation of the senses or the thoughts or even the imagination. Another way of putting it is to say that even when these skills or abilities do emerge from spiritual practice, they can be described as "mysticism with one foot still in the gross" (Wilber 1995, p.609)

The first five chapters of the thesis review the literature on intracranial pressure, the cerebral circulation and their interrelation and set the scene for the experimental work which is described in chapters 6 to 11. Intracranial pressure is now measured routinely in many clinical centres but a great deal of caution is required in interpreting the results, particularly with respect to the method of measurement, the history of any raised pressure and the values of other physiological variables such as blood pressure and cerebral blood flow. The cerebral circulation itself displays a remarkable tendency to remain constant, the fundamental concept being that there exists a basic control mechanism which acts to maintain cerebral blood flow in order to meet the metabolic requirements of the brain. The methods used to measure cerebral blood flow in the work described are metabolically inert gas clearance techniques based on the Pick principle. Hemisphere blood flow in baboons was measured by the xenon-153 intracarotid injection technique while micro-regional blood flow was measured by the hydrogen clearance technique utilising inhalation of hydrogen gas. All pressures were measured by the use of in-dwelling fluid filled catheters and strain gauge pressure transducers. The effect of raised intracranial pressure on cerebral blood flow was examined in three animal models in which intracranial hypertension was created by different methods, viz:- general diffuse compression, focal supratentorial compression and focal infratentorial compression. These experiments confirm that the effect of raised intracranial pressure on the level of cerebral blood flow depends on the cause of the raised pressure. In each situation there are different effects on compensatory mechanisms such as blood pressure and cerebral resistance vessel diameter. The experiments on cerebrovascular pressures and resistances showed for the first time that intracranial pressure represents cerebral venous outflow pressure to within a few mmHg over a wide range of pressure values and also that outflow vascular resistance changes are independent of the cause of intracranial hypertension thus confirming that it is changes in prevenous cerebrovascular resistance which result in the different cerebral blood flow responses observed. The investigations into the blood pressure response observed during intracranial hypertension have demonstrated quite clearly that neither global cerebral ischaemia nor brain stem ischaemia is the trigger mechanism for the response. The results support the hypothesis that the initiating stimulus is local press\are changes both in the brain stem and spinal cord. Considerable doubt is also cast on the assumption that the role of the blood pressure response is to maintain cerebral blood flow in the face of rising intracranial pressure. Finally, it has been shown that an intact spinal cord is necessary for the maintenance of cerebral blood flow autoregulation to raised intracranial pressure, while autoregulation to blood pressure changes remains intact. This disassociation of the auto- regulatory function has not been previously demonstrated.