Fields within Evolutionary Biology

Darwin s theory of evolution as originally advocated in his On the Origin of Species (1859) is actually a bundle of five separate but interrelated theories (Mayr, 1985). These five separate theories found in Darwin s 1859 book can still characterize areas within evolutionary biology today these are  

Evolution as such is the theory that states that all populations of organisms are changing over time, with the minimum time period being one generation. The theory is clearly nomological-deductive. 

Multiplication of species states that there is splitting of phylogenetic lineages as well as transformational change within a lineage. Hence evolutionary change includes two processes — phyletic evolution or transformation and speciation. Some workers would include extinction as a third process and others would include extinction under phyletic evolution. This theory is also nomological-deductive. 

Natural selection is Darwin s mechanism for phyletic transformation. Today this would be expressed as causes or mechanisms of evolutionary change, regardless of the diverse causes that different evolutionists would include this theory is clearly nomological-deductive. 

Thus it is clear that evolutionary theory or evolutionary biology is not just historical (see Bock and von Wahlert, 1963) and indeed that most aspects of evolutionary theory are not historical, but nomological-deductive. Many evolutionary biologists, especially system-atists, work in area b (common descent) dealing with historical evolutionary theory. This paper emphasizes historical evolutionary theory and how this is based on nomological evolutionary theory. 

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Fields within Evolutionary Biology Popper and Historical Analyses Explanations in Science... 

Within the past 50 years our view of Nature has changed drastically. Classical science emphasized equilibrium and stability. Now we see fluctuations, instability, evolutionary processes on all levels from chemistry and biology to cosmology. Everywhere we observe irreversible processes in which time symmetry is broken. The distinction between reversible and irreversible processes was first introduced in thermodynamics through the concept of entropy , the arrow of time as Arthur Eddington called it. Therefore our new view of Nature leads to an increased interest in thermodynamics. Unfortunately, most introductory texts are limited to the study of equilibrium states, restricting thermodynamics to idealized, infinitely slow reversible processes. The student does not see the relationship between irreversible processes that naturally occur, such as chemical reactions and heat conduction, and the rate of increase of entropy. In this text, we present a modem formulation of thermodynamics in which the relation between rate of increase of entropy and irreversible processes is made clear from the very outset. Equilibrium remains an interesting field of inquiry but in the present state of science, it appears essential to include irreversible processes as well. 

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