Rate variation during molecular evolution: creationism and the cytochrome c molecular clock

Molecular clocks based upon amino acid sequences in proteins have played a major role in the clarification of evolutionary phylogenies. Creationist criticisms of these methods sometimes rely upon data that might initially seem to be paradoxical. For example, human cytochrome c differs from that of an alligator by 13 amino acids but differs by 14 amino acids from a much more closely related primate, Otolemur garnettii. The apparent anomaly is resolved by taking into consideration the variable substitution rate of cytochrome c, particularly among primates. This paper traces some of the history of extensive research into the topic of rate heterogeneity in cytochrome c including data from cytochrome c pseudogenes

The legacy of natural species and substantial form for Thomistic evolution

Exploration of theistic evolution within a Thomistic framework has taken on the label of Thomistic evolution. Although the conceptual boundaries of this approach are not precise, a historical trajectory of its scholastic methodology can be traced back to the views of Aquinas himself. An enduring central concept in this tradition has been the idea of substantial form. For Aquinas, distinct substantial forms were associated with the kinds of animals and plants that have no prior ancestry and are ascribed to God\u27s production during the Genesis days of adornment. Later in the tradition, the early twentieth century Jesuit Erich Wasmann referred to these taxa as natural species with human beings serving as his paradigmatic example. As the evolutionary history of life becomes known in more and more detail, the existence of natural species and Wasmann\u27s associated concept of polyphyletic evolution have become increasingly difficult to sustain. The historical linkage between substantial forms and natural species highlights the fact that, even if the idea of natural species is abandoned, the incorporation of substantial forms into the evolutionary process is problematic. Although recent philosophical reassessments of Aristotelian essentialism are relevant and intriguing, discrete substantial forms are not easily embedded within the evolutionary continuum of genetic mutation and phenotypic change

The Evolving Taxonomy of Progressive Creation

This essay is a critique of a version of progressive creation developed by Michael Chaberek, O. P. He holds that there are exceptions to evolutionary descent due to the supernatural production of “natural species,” taxa that allegedly do not have biological ancestry, are theologically identified with biblical kinds, and are metaphysically characterized by distinct substantial forms. Chaberek’s assertion that these natural species correspond “roughly” to the Linnaean taxa of biological families contradicts modern scientific conclusions regarding the continuity of evolutionary descent. To illustrate this conflict, I examine some of the extensive evidence for the evolutionary origins of families within the Feliformia sub-order. I conclude that Chaberek’s assertion of supernatural progressive creation is a God-of-the-gaps theology burdened by a defensive stance with respect to scientific progress

Thomistic Hylomorphism and Theistic Evolution

Working within the framework of Thomistic metaphysics, Mariusz Tabaczek O. P. has developed a version of Catholic theistic evolution that includes speciation, human origins, and the origin of life. He assigns biological evolution to the domain of divine governance rather than that of creatio ex nihilo which only applies to primitive matter and human souls. This article reviews Tabaczek’s work with an emphasis on his argument for the compatibility of hylomorphism and evolutionary change through the eduction of novel substantial forms

Catholicism and Evolution: Polygenism and Original Sin (Part I)

Theological attention to the Catholic doctrine of original sin has a history that extends from the letters of Saint Paul through the Council of Trent and Pius XII’s 1950 encyclical, Humani generis. The doctrine has traditionally been articulated through the Genesis narrative of Adam and Eve as the first human beings from whom all others descend, an account known as monogenism. In the course of the nineteenth century, scientific research into human origins increasingly relied upon polygenism, the descent of humanity from non-human ancestors through a transitional population. Subsequent Catholic engagement with evolution included resistance to polygenism from the Vatican due to a perceived conflict with the doctrine of original sin. Humani generis included a prohibition that remains in place today in spite of widespread de facto acceptance of polygenism among theologians. Understanding the origin and persistence of this disparity stands to benefit from comparison to a corresponding ambivalence toward the sixteenth century Copernican hypothesis of a moving earth, only conclusively resolved in 1992. In Part I of this essay I introduce this historical comparison and describe the origins of monogenism and polygenism terminology in nineteenth century debate over the unity of the human race. I then describe the conceptual changes that transpired during the first half of the twentieth century and the resulting role of polygenism in the nouvelle théologie of the decade prior to Humani generis. Subsequent developments and implications follow in Part II

A Benchmark of GW Methods for Azabenzenes: Is the GW Approximation Good Enough?

Many-body perturbation theory in the GW approximation is a useful method for describing electronic properties associated with charged excitations. A hierarchy of GW methods exists, starting from non-self-consistent G0W0, through partial self-consistency in the eigenvalues (ev-scGW) and in the Green function (scGW0), to fully self-consistent GW (scGW). Here, we assess the performance of these methods for benzene, pyridine, and the diazines. The quasiparticle spectra are compared to photoemission spectroscopy (PES) experiments with respect to all measured particle removal energies and the ordering of the frontier orbitals. We find that the accuracy of the calculated spectra does not match the expectations based on their level of self-consistency. In particular, for certain starting points G0W0 and scGW0 provide spectra in better agreement with the PES than scGW

Balloon borne Antarctic frost point measurements and their impact on polar stratospheric cloud theories

The first balloon-borne frost point measurements over Antarctica were made during September and October, 1987 as part of the NOZE 2 effort at McMurdo. The results indicate water vapor mixing ratios on the order of 2 ppmv in the 15 to 20 km region which is somewhat smaller than the typical values currently being used significantly smaller than the typical values currently being used in polar stratospheric cloud (PSC) theories. The observed water vapor mixing ratio would correspond to saturated conditions for what is thought to be the lowest stratospheric temperatures encountered over the Antarctic. Through the use of available lidar observations there appears to be significant evidence that some PSCs form at temperatures higher than the local frost point (with respect to water) in the 10 to 20 km region thus supporting the nitric acid theory of PSC composition. Clouds near 15 km and below appear to form in regions saturated with respect to water and thus are probably mostly ice water clouds although they could contain relatively small amounts of other constituents. Photographic evidence suggests that the clouds forming above the frost point probably have an appearance quite different from the lower altitude iridescent, colored nacreous clouds

Contribution of outgrowth endothelial cells from human peripheral blood on in vivo vascularization of bone tissue engineered constructs based on starch polycaprolactone scaffolds

In the present study we assessed the potential of human outgrowth endothelial cells (OEC), a subpopulation within endothelial progenitor cell cultures, to support the vascularization of a complex tissue engineered construct for bone. OEC cultured on starch polycaprolactone fiber meshes (SPCL) in monoculture retained their endothelial functionality and responded to angiogenic stimulation by VEGF (vascular endothelial growth factor) in fibrin gel-assays in vitro. Co-culture of OEC with human primary osteoblasts (pOB) on SPCL, induced an angiogenic activation of OEC towards microvessel-like structures achieved without additional supplementation with angiogenic growth factors. Effects of co-cultures with pOB on the vascularization process by OEC in vivo were tested by subcutaneous implantation of Matrigel! plugs containing both, OEC and pOB, and resulted in OEC-derived blood vessels integrated into the host tissue and anastomosed to the vascular supply. In addition, morphometric analysis of the vascularization process by OEC indicated a better performance of OEC in the co-cultures with primary osteoblasts compared to monocultures of OEC. The contribution of OEC to vascular structures and the beneficial effect of the co-culture with primary human osteoblasts on the vascularization in vivo was additionally proven by subcutaneous implantation of pre-cellularized and pre-cultured SPCL constructs. OEC contributed to the vascular structures, by generating autogenic vessels or by incorporation into chimeric vessels consisting of both, human and mouse endothelial cells. The current data highlight the vasculogenic potential of OEC for bone tissue engineering applications and indicate a beneficial influence of constructs including both osteoblasts and endothelial cells for vascularization strategies.The authors would like to thank B. Malenica, C. Braun, L. Meyer, K. Molter, M. Muller. J. Alonso-Monje for their excellent technical assistance. This work was financially supported by grants from the European commission (HIPPOCRATES N degrees NMP3-CT-2003-505758; EXPERTISSUES Contract nr.: 500283-2) and BMBF-Grant for German-Chinese Cooperation in Regenerative Medicine (grant number 0315033)