In this issue of Hacettepe Journal of Biology and Chemistry, we would like to present our contribution to the celebration of one of the greatest naturalist of the history of science, Charles Darwin’s 200th birthday and the 150th years of publication of his opus magnum, shortly known as “The Origin of Species”. Undoubtedly, starting indeed the evolutionary biology as a science and establishing its very basic tenet of the variation in the organisms as the object of change that may lead finally to new species, Darwin’s lasting impact and the heritage of the Origin mostly determines what we know of evolution both in the field and the laboratory. Though Darwin proposed strict scenarios of natural selection for the shaping of the organisms that varied, his plurality and deep insight has given impetus to a structure of evolutionary theory with great moves both with selective and nonselective dynamics such as random genetic drift that have accomplished a great deal to understand nature since the publication of the Origin 150 years ago. With fully acknowledging this arsenal of theory and practice, here we would like to present articles from the broad scope of scientists using evolution in their studies at different scales. 

The 200th anniversary of the birth of Charles Darwin falls on 12 February 2009. This special issue of our faculty’s official journal, Hacettepe Journal of Biology and Chemistry, is dedicated to the honor of Charles Darwin, an exceptional scientist who has an impact on the natural and social sciences, politics, religions, and philosophy, on art and cultural relations. 

Dear readers of the Hacettepe Journal of Biology and Chemistry,

2009 was the 150th anniversary of the publication of “On the Origin of Species” (24 November 1859) and 200th anniversary of Darwin’s birth (12 February 1809). This special issue of the Hacettepe Journal of Biology and Chemistry is dedicated to Charles Darwin who changed te direction of modern thought by establishing the basis of evolutionary biology. This issue brings together the researchers working on areas related to Darwinism and evolution education. The editorial board would like to exend warm and sincere thanks to all who participated in this issue and contributed to its success. 

In his satirical novel of University life, Changing Places, David Lodge writes of a game played by Professors of English literature, in which each player is challenged to confess that he or she has not read some well known literary work. The players are stunned into silence when one of them confesses to never having read Shakespeare’s Hamlet. Were evolutionary biologists to play a similar game honestly, they would almost all confess that they have not read Darwin’s Origin of Species from beginning to end. Some of the most honest of them would admit to never having even opened the book. Yet Darwin is the most famous biologist who ever lived. Reference is made over and over in both scientific and popular writings to “Darwinism”, “Darwinian evolution”, “Darwin’s theory of evolution”, and “the Darwinian revolution” and he is usually described as the founder of evolutionary biology. In the process of identifying “evolution” with Darwin there has grown up a large body of misunderstanding of the place of the Origin of Species in the history of the idea of evolution, of the role of Darwin’s work in the justification of what came to be called “social Darwinism”, of Darwin’s analysis of the process of organic evolution and, ultimately, a confusion about the meaning of “theory” in science. 

There are many remarks about Darwinian concepts of “selection” and “nature” in social science literature especially in the 19th century philosophy. Social sciences such as sociology, psychology and economics have been developed in the 19th century mainly imitating and trying to be similar with natural sciences methodologically.

Scientific developments begin with the protruding of the principle of inferring the knowledge on the world of objects through inspection and experiment. Classically, it was Bacon who was the most provocative philosopher of his era insisting on the value of this kind of knowledge. Bacon’s major argument was to analyze the objects as they are and to research on the comprehension possibilities of humans on that matter; but not to try to pursue how to reach the God in a transcendentally and search for wisdom by equipping objects with meaning like scholastics such as Thomas Aquinas and Tertulianus1. Scientific/positivist epistemology developed on this basis. Understanding the nature, by first examining the object, trying to settle the relationships among objects via tools out of transcendental processes going through independent from those objects and reaching general conclusions were the basic aims of this new methodology. 

Humans are genetically little diverged from their closest living relatives, chimpanzees. However, human anatomy, physiology and behavior show substantial divergence from those of chimpanzees and other primates. The evolutionary processes that generated this phenotypic divergence are still debated. Given the incomplete state of the hominid fossil record, genetic information is indispensible for studying human evolution. Recently, data from genome sequencing projects, gene expression profiling, and large-scale genotyping across multiple populations, has significantly improved our understanding of human origins, as well as the forces of selection, adaptation, and demographic forces that shaped human evolution. Recent multispecies comparative genomic studies indicate that random genetic drift, i.e. neutral evolution, is a leading evolutionary mechanism in shaping human protein coding sequences, as well as gene expression patterns. Still, there is also compelling evidence that a large number of human genes were affected by adaptive evolution. Genes involved in immunity, sensory perception, reproduction, and apoptosis appear among the most frequently positively selected classes. Likewise, comparative transcriptome studies indicate adaptive expression changes in human brain gene expression. Importantly, variants of both positively and negatively selected genes are frequently found to be responsible for human genetic diseases. Comparison of genetic diversity within and between human populations suggests that humans have been a relatively small, homogeneous species. Accordingly, patterns of genetic diversity are to large extent shaped by neutral, demographic processes. Meanwhile, genome scans and functional studies identify pathogens, diet, and environmental conditions as major selective forces driving genetic diversity in humans. These results portray human evolution as a complex process, simultaneously affected by forces of selection and drift. 

The study of geographic variation has probably taken up a well-known place in ornithology. For decades, most of researchers interested in evolutionary trends in birds focused on the study of geographic variation (e.g. Morrison 1983, Zink 1986, Atwood 1988, Johnson and Marten 1992, Johnston 1994, Roselaar 1995, Engelmoer and Roselaar 1998, Johnson 2002).

Study of the geographic variation in birds usually focused on morphologic variation, and the insights from the morphologic variation were used to solve the taxonomic problems (Johnson and Marten 1992, Escalente-Piliego and Peterson 1992, Johnson 2002). In addition to taxonomic problems, some other researchers of geographic variation in birds have also interested in the geography of intrapopulation variability to test ecological importance of morphological variation (James 1970, Aldrich 1984, Grant and Grant 1986, 1989, 2008, Kaboli 2007).

Thus, it is plausible to say that geographic variation is one of the most famous study topics in evolutionary biology. In this mini review, I concentrate on two main topics – taxonomy, and adaptation and speciation – and their relationships with geographic variation. 

Phlebotomine sandflies are delicate, hairy flies with long slender legs. Of the 1000 or so species, only about 70 species are thought to be involved in the transmission of disease to man. The flies are easily distinguished from other small Diptera when alive by the characteristic manner in which they hold their pointed wings above their body (like a vertical V), especially from other members of the family Psychodidae to which they belong. It is important to distinguish phlebotomine sandflies from other small biting flies known colloquially as 'sandflies' in certain parts of the world, especially midges of the genus Culicoides which abound in coastal areas of the southeastern United States, Central America and the Caribbean, and Simuliidae in Australasia. These other flies have very different biologies and medical importance from phlebotomines [1]. Phlebotomines are commonly known as sand flies, a reference arising from the phlebotomines-leishmaniasis associations studied extensively in the drier regions of the Mediterranean and Middle East. Unfortunately, this name is often confused with sand flies of the family Ceratopogidae, a family with very different behaviors and vector-disease associations. Second, phlebotomines in the western hemisphere have little association with sand. They are, instead, most commonly distributed in forest from southern United States to northern Argentina [2]. 

Old world ground squirrels (the genus Spermophilus sensu stricto), including 14 species, are one of the eight genera of ground squirrels previously included within the genus Spermophilus sensu lato (Helgen et al., 2009), which is among the most intensively studied groups of mammals with respect to its behaviour, ecology, and evolution. Among these genera of ground squirrels, only the genus Spermophilus sensu stricto (hereafter, Spermophilus) is restricted to Eurasia (Helgen et al., 2009). Old world ground squirrels (Spermophilus) are group-living, diurnal, hibernating marmotine sciurids inhabiting open habitats (grasslands, deserts, and tundra). They spend the majority of their lives sleeping and hibernating in underground burrows.