570 Biowissenschaften; Biologie
Refine
Document Type
- Article (4) (remove)
Keywords
- consciousness (2)
- evolution (2)
- Bewusstsein (1)
- Biowissenschaften (1)
- DNA (1)
- Evolution (1)
- Homo sapiens (1)
- Kosmologie (1)
- Naturwissenschaft und Mathematik (1)
- Naturwissenschaften (1)
Has Fulltext
- yes (4)
Institute
The short paper introduces the concept of possible branches of double-stranded DNA (later sometimes called palindromes): Certain sequences of nucleotides may be followed, after a short unpaired stretch, by a complementary sequence in reversed order, such that each DNA strand can fold back on itself, and the DNA assumes a cruciform or tree-like structure. This is postulated to interact with regulatory proteins.
Abstract (ger): Reichweite und Grenzen naturwissenschaftlicher Erklärungen ergeben sich zum einen aus der universellen Gültigkeit physikalischer Gesetze, zum anderen aus intrinsischen Grenzen, zumal bei selbstbezüglichen Fragestellungen. In diesem Essay geht es um deutungsoffene Grundfragen in Zusammenhang mit der Beziehung von Wissenschaft und Religion: Der Unterscheidung von Tier und Mensch, der Entstehung der mentalen Fähigkeiten der biologischen Spezies „Mensch“, den naturgesetzlichen Voraussetzungen eines „lebensfreundlichen“ physikalischen Universums, und den Grenzen einer naturwissenschaftlichen Erklärung von menschlichem Bewusstsein. Naturwissenschaft kann auf der philosophischen, kulturellen und religiösen Ebene die Mehrdeutigkeit der Welt nicht auflösen. Agnostische und religiöse Grundauffassungen werden auf Dauer ko-existieren, und die Wahl ist nicht nur eine Frage des Wissens, sondern besonders auch der Weisheit und der Lebenskunst.
Biological evolution and technological innovation, while differing in many respects, also share common features. In particular, the implementation of a new technology in the market is analogous to the spreading of a new genetic trait in a population. Technological innovation may occur either through the accumulation of quantitative changes, as in the development of the ocean clipper, or it may be initiated by a new combination of features or subsystems, as in the case of steamships. Other examples of the latter type are electric networks that combine the generation, distribution, and use of electricity, and containerized transportation that combines standardized containers, logistics, and ships. Biological evolution proceeds, phenotypically, in many small steps, but at the genetic level novel features may arise not only through the accumulation of many small, common mutational changes, but also when distinct, relatively rare genetic changes are followed by many further mutations. New evolutionary directions may be initiated by, in particular, some rare combinations of regulatory sections within the genome. The combinatorial type of mechanism may not be a logical prerequisite for biological innovation, but it can be efficient, especially when novel features arise out of already highly developed systems. Such is the case with the evolution of general, widely applicable capabilities of the human brain. Hypothetical examples include the evolution of strategic thought, which encompasses multiple self-representations, cognition-based empathy, meta-levels of abstraction, and symbolic language. These capabilities of biologically modern man may have been initiated, perhaps some 150 000 years ago, by one or few accidental but distinct combinations of modules and subroutines of gene regulation which are involved in the generation of the neural network in the cerebral cortex. This hypothesis concurs with current insights into the molecular biology of the combinatorial and hierarchical facets of gene regulation that underlie brain development. A theory of innovation encompassing technological as well as biological development cannot per se dictate alternative explanations of biological evolution, but it may help in adding weight and directing attention to notions outside the mainstream, such as the hypothesis that few distinct genetic changes were crucial for the evolution of modern man.
The topic of this article is the relation between bottom-up and top-down, reductionist and “holistic” approaches to the solution of basic biological problems. While there is no doubt that the laws of physics apply to all events in space and time, including the domains of life, understanding biology depends not only on elucidating the role of the molecules involved, but, to an increasing extent, on systems theoretical approaches in diverse fields of the life sciences. Examples discussed in this article are the generation of spatial patterns in development by the interplay of autocatalysis and lateral inhibition; the evolution of integrating capabilities of the human brain, such as cognition-based empathy; and both neurobiological and epistemological aspects of scientific theories of consciousness and the mind.