vol III Development:
Chapter 3: Cybernetics
page 9: Evolution
The mechanism of evolution
Evolution has three elements, reproduction, variation and selection. It first entered the scientific fold through the word of Darwin and Wallace. Much of Darwin's inspiration came from the breeders of plants and animals. His close connection with breeders of plants and birds opened his eyes to the roles of variation and selection used by breeders to work their way toward their ideal creature. We may identify three phases in evolution, reproduction, variation and selection. Darwin: The Variation of Animals and Plants Under Domestication
Reproduction
We are imagining the world as a vast, layered network, analogous to engineered constructions like the internet. The core network function is reproduction, copying a message from one source to another. At the quantum level, the creation of particles may be accompanied by the annihilation of others. At a more complex stage molecules (replicators) may have emerged that are capable of catalyzing the production of copies of themselves. In the biological realm, reproduction may be sexual or asexual.
Asexual reproduction effectively annihilates the parent and creates two or more children. Sexual reproduction does not necessarily involve immediate annihilation of the parents, although in some species the egg laying partner may eat the source of sperm to increase its fitness. Although parents inevitably die in the long run, they may live long enough to feed and educate their young.
There are two divergent reproductive strategies among sexually reproducing species. On the one hand some species that lay eggs and disperse seeds may potentially have tens of thousands of offspring, which are left to take their chances in the environment. Only a tiny proportion survive, but because there are so many of them, the species is maintained. On the other hand mammals like ourselves have very few offspring but devote years to their care and education, so making certain that each child has a high probability of survival. r/K selection theory - Wikipedia
Mutation and variation
All information is embodied in a physical representative vehicle of some sort. Biological organisms effectively carry two copies of themselves, genotype and phenotype, both syntactic structures embodying meaning encoded by evolution. The genotype is highly compressed formal representation of the organism encoded in a nucleic acid, RNA or DNA. Its mass is generally only about 1% of the corresponding phenotype. It is well protected from the environment and surrounded by with error protection and correction mechanisms. The phenotype is much more subject to physical damage and ageing, and eventually dies from the accumulation of error. Nucleic acid - Wikipedia
The genotype is also subject to error from ionizing radiation and chemical noise. Copying the genotype may be also accompanied error, so an asexual organism may not reproduce identical copies of itself. In most cases genetic errors may be lethal or disabling, but sometimes they improve the ability of the child organisms to survive. Viruses have no genetic error control, and so mutate rapidly and, because they exist in vast numbers, they can evolve quickly. Mutation - Wikipedia
Sexual reproduction introduces further variation by randomly mixing genotypes, but it also provides an opportunity for error detection and correction by enabling comparison of two copies of each gene. The immune systems of multicellular organisms have variable elements in their genome to cope with the wide variety of the pathogens in the environment. They may have acquired this from viruses. David D. Chaplin: Overview of the Immune Response
Selection
Selection presupposes an established set of criteria. Natural selection “chooses” to breed from the progeny which are capable of producing fertile offspring. Selection is induced by limitation. In the biological world, only a fraction of the sperm, eggs, embryos and infants that come into existence are destined to find enough resources to reproduce themselves. Some, due to variation, are more likely to mature and reproduce than others. Natural selection -
Wikipedia, Jones: Almost like a Whale: The Origin of Species Updated
The modular nature of living systems opens the way for detailed selection operating, for instance, on visual acuity, speed, strength, and features which play a role in sexual selection. We have good evidence in increasing cranial capacity that our ancestors been strongly selected for improved cognitive abilities. Evolution works over long periods and in exquisite detail, so that we may suspect that almost every atom in a living creature system owes its place to some special role that it plays in the competition for survival and reproduction.
Death and recycling
Information is physical, so the exponential growth of living organisms would soon exhaust the physical ground for life if they did not die and release matter for recycling. All living things are sources of energy, and therefore food for other organisms. One of the principal marks of fitness is the ability to avoid being eaten,
Epochs of evolution
Although most work on evolution is done in a biological context, the proposal here is that all of the observed struture and communication in the Universe has been refined by evolutionary process. The observed world, that which is fit to survive, is thus an infinitesimal fraction of the possible worlds modelled by the transfinite network.
We might identify seven epochs in the evolution of the universe:
(1) The early stages emerging in the initial differentiation of the initial singularity from which emerged the laws of physics now understood to be the four fields, gravity, electromagnetism, strong and weak, and the corresponding fundamental particles. The first steps in this process appear to have been the emergence of energy and spacetime. We imagine that this process generated the layered structure of the universal network. Each layer serving as a resource from which the layer above it is built as, for instance, molecules are built from atoms. Kauffman: At Home in the Universe: The Search for Laws of Complexity
(2) The origin of replicators, molecular chemical systems able to selectively catalyse the reproduction of copies of themselves. Annette F. Taylor: Small molecular replicators go organic
z(3) Genetic evolution of unicellular organisms, sometimes sped up by sharing genes through conjugation, viruses, transposons, or plasmids. Julian Davies and Dorothy Davies : Origins and Evolution of Antibiotic Resistance
.
(4) Multicellular organisms and the evolution of the immune system. Immune system - Wikipedia
(5) Epigenesis, ie control of previously evolved protein coding genes to produce heritable “Lamarkian” genetical changes in individuals. Only about 2% of the human genome encodes proteins. The other 98% performs various regulatory tasks. Epigenetics - Wikipedia
(6) Culture in which the “genes” are cultural information passed from generation to generation. Axelrod: The Evolution of Cooperation, Sociocultural evolution - Wikipedia
(7) Academia, whose genes are literature, varied and selected by conjecture and refutation. Academia supersedes the pragmatic epistemology of business and survival with the scientific epistemology of truth. Wissenschaft - Wikipedia, Philosophy - Wikipedia, History of science - Wikipedia
The formal foundations of evolution
Western theological tradition holds that the world as we know it pre-existed in its complete form in the mind of God. At the time of creation, God said "Let there be light" and there was light (Genesis 1:3). This world is a product of the omniscience and omnipotence of God. Aquinas, Summa, I, 14, 8: Is the knowledge of God the cause of things?
The knowledge of God is considered to be so complete that it knows (and therefore causes) future contingent events, like my choice of the next work in this sentence. Aquinas, Summa I, 14, 13: Does God know future contingent things?
From a cybernetic point of view, such knowledge is impossible because it implies formal inconsistency and we wish to maintain that reality is self-consistent. The problem for God, and anybody else, is the cybernetic principle of requisite variety which tells us that system A cannot control system B unless the the complexity (variety) of system A is equal to or greater than the variety of system B. Gregory Chaitin has shown that this principle derives from Gödel's incompleteness theorem. This theorem maintains that there are true statements which cannot be proven using the methods of consistent mathematics. Chaitin shows that the conclusion of any mathematial proof cannot contain any more information that the axioms and other inpust to the proof. Gregory J. Chaitin: Gödel's Theorem and Information
It is a fundamental conclusion of traditional theology that God is absolutely simple. In other words the complexity of God is zero. This contradicts the notions that God is omniscient and in complete control of our enormously complex universe. It does, however, provide a foundation for the conclusion at the root of this site, that God and the Universe are identical. The general theory of relativity indicates that the universe began as an initial singularity which had the properties identical to the traditional god: it is absolutely simple, and it is the source of the universe. Hawking & Ellis: The Large Scale Structure of Space-time
The limits of computation
The transfinite oscillator serves as a space for all possible formal systems, that is for all of mathematics. The Universe we inhabit seems very much simpler than the transfinite replication and complexification envisaged in the transfinite oscillator. From a formal point of view there is no limit to the complexity represented by the Cantor Universe, but physical limitations serve to cut this infinity down to size by natural selection. Formally, these physical limited appear to be implemented by the limits on computation.
Complex systems without control act at random. Since a perfect coin is symmetrical, the probabilities of it landing heads or tails when tossed are equal. The limiting feature of the transfinite network is computing
power. Of the unlimited number of functions that can be represented
in the Cantor Universe, only ℵ0 are computable. This does not mean that other functions are not possible and they might even be true, just that they cannot be computed. Evolution is made possible by the fact that random events take us to places where causally deterministic computation cannot go. Although the vast majority of these places will be dead ends, some will be consistent with their environments and thus selected to survive.
Our world is
inabited by discrete entities like ourselves, stars and grains of sand. Let us assume that each of these entities maintains its existence by a variety of feedback loops. When an organism feels itself being stressed, it reacts in a manner which reduces the stress. I eat when I am hungry; a steel girder resists when I try to bend it . Wiener: Cybernetics or Control and Communication in the Animal and the Machine, Ashby: An Introduction to Cybernetics
This leads us to the assume that effective survival demands error free communication. Shannon's mathematical theory of communication shows that error free messages can be transmitted over a noisy channel by appropriate coding. This coding requires computation, and more complex computations may reduce the probability of error. In this way we can link computing power and fitness through a "virtuous circle" which favours increasing complexity in surviving organisms. Claude Shannon - Wikipedia
Each
computation is a series of actions determined by an algorithm stored
in the computer's memory. Different algorithms may be available to
perform a particular task. Some of these algorithms may be more
efficient than others: they use less computing resources to perform
the same task. Algorithmic
efficiency - Wikipedia
When survival is at stake, we might expect the scarcity of computing resources to select for efficient algorithms. Those entities that are better able prevent error and control themselves with the available resources seem to have a better chance of survival. This process of selection, we can imagine, explains the enormous complexity and subtlety of the creatures, including ourselves, that inhabit the earth. We can see that over billions of years of evolution, systems have been turned to an atomic level of resolution, as, for instance, in the role of iron in the transport of oxygen in blood.
Information
In cybernetics we describe the world in terms of information and information processing rather than the energy and
energy processing studied by classical physics and engineering. Although information and entropy seem conceptually different, they are both measured simply by counting. Entropy - Wikipedia
The amount of information carried by any point in a certain space
is equal to the entropy of that space. The entropy of a space is a
count of the number of distinct independent points or states in the space.
Entropy first entered science through the study of heat engines which led to thermodynamics and statistical mechanics. Thermodynamically, entropy is the quantity which is conserved by a formal reversible heat engine like the the Carnot engine. Carnot
Entropy is a measure of the complexity of a system, usually expressed as a logarithm of the number of states the system can occupy. A reversible system is a system in which transformations occur at constant complexity.
In classical physics, each degree of freedom contributes equally to the complexity of the system, so that the calculation of entropy is a simple count, expressed as a logarithm for mathematical convenience. This is the Boltzmann entropy, expressed in the famous equation
S = k log W. Cercignani
where W is the number of 'complexions' or states of the
system to be measured.
Information theory adds a weighting to
this count to give us the Shannon entropy
H = Σi pi log pi
. Khinchin
When all the probabilities of the states, symbols or letters
pi are equal, H is at a maximum and the two
equations become the same.
The
classical second law of thermodynamics tells us that the entropy of a
closed physical system never decreases. No explanation is given for
this phenomenon, but it is seen to be closely linked to the direction
of time. Increasing time correlates with increasing entropy. Entropy
(arrow of time) - Wikipedia
A system is closed when it is not in communication with its
environment: effectively it has no environment. The Universe is such
a system, having, by definition, nothing outside it. We see the
second law as a consequence of Cantor's theorem: given any
transfinite cardinal, there is always a greater cardinal.
From the point of view of engineering thermodynamics, entropy has had bad press over the years, being associated with the 'heat death' of the Universe and bounds on the efficiency of heat engines. Heat death of the universe - Wikipedia
Here we are less interested in the energy-momentum physical view
of the Universe and more interested in its intelligence, complexity
and creativity. From a physical point of view, the second law of
thermodynamics seems to point to increasing disorder. From an
information theoretical point of view, however, entropy and
information are numerically the same thing.
The network model allows us to picture the flow of information in
the Universe as a flow of entropy. The flow of entropy is bandwidth,
and the Universe (as seen by physics) is an extremely broadband
system.
From a static (or spatial) point of view we would be inclined to give the initial singularity an entropy of zero, since it is only one state, and log(1) = 0 to any base. If we think of the singularity dynamically as a Turing machine executing NOPs, however, we might attribute to it an infinite sequence of states distinguished only by their position in the sequence with entropy in proportion to the length of the sequence.
We may then imagine the complexification of our model Universe as
the conversion of dynamic entropy into static entropy, or perhaps the
conversion of action into memory to produce the large scale durable
structures we see around us.
We
may see entropy as a measure of meaning. The 'amount of meaning' in
an event is its cardinal, and places it somewhere in the transfinite
hierarchy of meaning. The unreachable 'God' stands at the topless top
of this hierarchy, Cantor's Absolute. The absolute is a
mathematically impossible figment of the imagination that effectively
bounds mathematics and any mathematical representation of the
Universe. Hallett, Absolute infinite - Wikipedia
|
Copyright:
You may copy this material freely provided only that you quote fairly and provide a link (or reference) to your source.
Further readingBooks
Click on the "Amazon" link below each book entry to see details of a book (and possibly buy it!)
Ashby, W Ross, An Introduction to Cybernetics, Methuen 1956, 1964 'This book is intended to provide [an introduction to cybernetics]. It starts from common-place and well understood concepts, and proceeds step by step to show how these concepts can be made exact, and how they can be developed until they lead into such subjects as feedback, stability, regulation, ultrastability, information, coding, noise and other cybernetic topics.'
Amazon
back |
Axelrod, Robert, The Evolution of Cooperation, Basic Books, Revised Edition 2006 'The Evolution of Cooperation provides valuable insights into the age-old question of whether unforced cooperation is ever possible. Widely praised and much-discussed, this classic book explores how cooperation can emerge in a world of self-seeking egoists-whether superpowers, businesses, or individuals-when there is no central authority to police their actions. The problem of cooperation is central to many different fields. Robert Axelrod recounts the famous computer tournaments in which the “cooperative” program Tit for Tat recorded its stunning victories, explains its application to a broad spectrum of subjects, and suggests how readers can both apply cooperative principles to their own lives and teach cooperative principles to others.'
Amazon
back |
Cercignani, Carlo, Ludwig Boltzmann: The Man Who Trusted Atoms, Oxford University Press, USA 2006 'Cercignani provides a stimulating biography of a great scientist. Boltzmann's greatness is difficult to state, but the fact that the author is still actively engaged in research into some of the finer, as yet unresolved issues provoked by Boltzmann's work is a measure of just how far ahead of his time Boltzmann was. It is also tragic to read of Boltzmann's persecution by his contemporaries, the energeticists, who regarded atoms as a convenient hypothesis, but not as having a definite existence. Boltzmann felt that atoms were real and this motivated much of his research. How Boltzmann would have laughed if he could have seen present-day scanning tunnelling microscopy images, which resolve the atomic structure at surfaces! If only all scientists would learn from Boltzmann's life story that it is bad for science to persecute someone whose views you do not share but cannot disprove. One surprising fact I learned from this book was how research into thermodynamics and statistical mechanics led to the beginnings of quantum theory (such as Planck's distribution law, and Einstein's theory of specific heat). Lecture notes by Boltzmann also seem to have influenced Einstein's construction of special relativity. Cercignani's familiarity with Boltzmann's work at the research level will probably set this above other biographies of Boltzmann for a very long time to come.' Dr David J Bottomley
Amazon
back |
Darwin, Charles, and Harriet Ritvo (Introduction), The Variation of Animals and Plants Under Domestication (Foundations of Natural History) , Johns Hopkins University Press 1998 ' "The Variation, with its thousands of hard-won observations of the facts of variation in domesticated species, is a frustrating, but worthwhile read, for it reveals the Darwin we rarely see -- the embattled Darwin, struggling to keep his project on the road. Sometimes he seems on the verge of being overwhelmed by the problems he is dealing with, but then a curious fact of natural history will engage him (the webbing between water gun-dogs' toes, the absurdly short beak of the pouter pigeon) and his determination to make sense of it rekindles. As he disarmingly declares, 'the whole subject of inheritance is wonderful.'.
Amazon
back |
Hallett, Michael, Cantorian Set Theory and Limitation of Size, Oxford UP 1984 Jacket: 'This book will be of use to a wide audience, from beginning students of set theory (who can gain from it a sense of how the subject reached its present form), to mathematical set theorists (who will find an expert guide to the early literature), and for anyone concerned with the philosophy of mathematics (who will be interested by the extensive and perceptive discussion of the set concept).' Daniel Isaacson.
Amazon
back |
Hawking, Steven W, and G F R Ellis, The Large Scale Structure of Space-Time, Cambridge UP 1975 Preface: Einstein's General Theory of Relativity . . . leads to two remarkable predictions about the universe: first that the final fate of massive stars is to collapse behind an event horizon to form a 'black hole' which will contain a singularity; and secondly that there is a singularity in our past which constitutes, in some sense, a beginning to our universe. Our discussion is principally aimed at developing these two results.'
Amazon
back |
Jones, Steve, Almost like a Whale: The Origin of Species Updated, Doubleday 1999 An Historical Sketch: 'The Origin of Species is, without doubt, the book of the millennium. ... [This book] is, as far as is possible, an attempt to rewrite the Origin of Species. I use its plan, developing as it does from farms to fossils, from beehives to islands, as a framework, but my own Grand Facts ... are set firmly in the late twentieth century. Almost Like a Whale tries to read Charles Darwin's mind with the benefit of scientific hindsight and to show how the theory of evolution unites biology as his millenium draws to an end.' (xix)
Amazon
back |
Kauffman, Stuart, At Home in the Universe: The Search for Laws of Complexity, Oxford University Press 1995 Preface: 'As I will argue in this book, natural selection is important, but it has not laboured alone to craft the fine architectures of the biosphere . . . The order of the biological world, I have come to believe . . . arises naturally and spontaneously because of the principles of self organisation - laws of complexity that we are just beginning to uncover and understand.'
Amazon
back |
Khinchin, Aleksandr Yakovlevich, Mathematical Foundations of Information Theory (translated by P A Silvermann and M D Friedman), Dover 1957 Jacket: 'The first comprehensive introduction to information theory, this book places the work begun by Shannon and continued by McMillan, Feinstein and Khinchin on a rigorous mathematical basis. For the first time, mathematicians, statisticians, physicists, cyberneticists and communications engineers are offered a lucid, comprehensive introduction to this rapidly growing field.'
Amazon
back |
Wiener, Norbert, Cybernetics or Control and Communication in the Animal and the Machine, MIT Press 1996 The classic founding text of cybernetics.
Amazon
back |
Links
Absolute infinite - Wikipedia, Absolute infinite - Wikipedia, the free encyclopedia, 'The Absolute Infinite is mathematician Georg Cantor's concept of an "infinity" that transcended the transfinite numbers. Cantor equated the Absolute Infinite with God. He held that the Absolute Infinite had various mathematical properties, including that every property of the Absolute Infinite is also held by some smaller object.' back |
Algorithmic efficiency - Wikipedia, Algorithmic efficiency - Wikipedia, the free encyclopedia, 'In computer science, efficiency is used to describe several desirable properties of an algorithm or other construct, besides clean design, functionality, etc. Efficiency is generally contained in two properties: speed (the time it takes for an operation to complete), and space (the memory or non-volatile storage used up by the construct). Optimization is the process of making code as efficient as possible, sometimes focusing on space at the cost of speed, or vice versa.' back |
Annette F. Taylor, Small molecular replicators go organic, ' The emergence of complex, dynamic molecular behaviour might have had a role in the origin of life. Such behaviour has now been seen in a reaction network involving small, organic, self-replicating molecules of biological relevance.' back |
Aquinas, Summa I, 14, 13, Does God know future contingent things?, 'I answer that, Since as was shown above (Article 9), God knows all things; not only things actual but also things possible to Him and creature; and since some of these are future contingent to us, it follows that God knows future contingent things.' back |
Aquinas, Summa, I, 14, 8, Is the knowledge of God the cause of things?, 'Now it is manifest that God causes things by His intellect, since His being is His act of understanding; and hence His knowledge must be the cause of things, in so far as His will is joined to it. Hence the knowledge of God as the cause of things is usually called the "knowledge of approbation." ted above it follows that He occupies the highest place in knowledge.' back |
Carnot cycle - Wikipedia, Carnot cycle - Wikipedia, the free encyclopedia, 'The Carnot cycle is a theoretical thermodynamic cycle proposed by Nicolas Léonard Sadi Carnot in 1824 and expanded by Benoit Paul Émile Clapeyron in the 1830s and 40s. It can be shown that it is the most efficient cycle for converting a given amount of thermal energy into work, or conversely, creating a temperature difference (e.g. refrigeration) by doing a given amount of work.' back |
Claude Shannon - Wikipedia, Claude Shannon - Wikipedia, the free encyclopedia, 'Claude Elwood Shannon (April 30, 1916 – February 24, 2001), an American electrical engineer and mathematician, has been called "the father of information theory".
Shannon is famous for having founded information theory and both digital computer and digital circuit design theory when he was 21 years-old by way of a master's thesis published in 1937, wherein he articulated that electrical application of Boolean algebra could construct and resolve any logical, numerical relationship. It has been claimed that this was the most important master's thesis of all time.' back |
David D. Chaplin, Overview of the Immune Response, ' The immune system has evolved to protect the host from a universe of pathogenic microbes that are themselves constantly evolving. The immune system also helps the host eliminate toxic or allergenic substances that enter through mucosal surfaces. Central to the immune system’s ability to mobilize a response to an invading pathogen, toxin or allergen is its ability to distinguish self from non-self. The host uses both innate and adaptive mechanisms to detect and eliminate pathogenic microbes. Both of these mechanisms include self-nonself discrimination. This overview identifies key mechanisms used by the immune system to respond to invading microbes and other exogenous threats and identifies settings in which disturbed immune function exacerbates tissue injury.' back |
Entropy - Wikipedia, Entropy - Wikipedia, the free encyclopedia, 'Entropy is a thermodynamic property that can be used to determine the energy available for useful work in a thermodynamic process, such as in energy conversion devices, engines, or machines. Such devices can only be driven by convertible energy, and have a theoretical maximum efficiency when converting energy to work. During this work, entropy accumulates in the system, but has to be removed by dissipation in the form of waste heat.' back |
Entropy (arrow of time) - Wikipedia, Entropy (arrow of time) - Wikipedia, the fre encyclopedia, 'Entropy is the only quantity in the physical sciences that "picks" a particular direction for time, sometimes called an arrow of time. As one goes "forward" in time, the second law of thermodynamics says, the entropy of an isolated system will increase when no extra energy is consumed.' back |
Epigenetics - Wikipedia, Epigenetics - Wikipedia, the free encyclopedia, ' Epigenetics is the study of heritable phenotype changes that do not involve alterations in the DNA sequence. The Greek prefix epi- (ἐπι- "over, outside of, around") in epigenetics implies features that are "on top of" or "in addition to" the traditional genetic basis for inheritance. Epigenetics most often denotes changes that affect gene activity and expression, but can also be used to describe any heritable phenotypic change.' back |
Gregory J. Chaitin, Gödel's Theorem and Information, 'Gödel's theorem may be demonstrated using arguments having an information-theoretic flavor. In such an approach it is possible to argue that if a theorem contains more information than a given set of axioms, then it is impossible for the theorem to be derived from the axioms. In contrast with the traditional proof based on the paradox of the liar, this new viewpoint suggests that the incompleteness phenomenon discovered by Gödel is natural and widespread rather than pathological and unusual.'
International Journal of Theoretical Physics 21 (1982), pp. 941-954 back |
Heat death of the universe - Wikipedia, Heat death of the universe - Wikipedia, the free encyclopedia, 'The heat death is a possible final state of the universe, in which it has "run down" to a state of no thermodynamic free energy to sustain motion or life. In physical terms, it has reached maximum entropy. The hypothesis of a universal heat death stems from the 1850s ideas of William Thomson (Lord Kelvin) who extrapolated the theory of heat views of mechanical energy loss in nature, as embodied in the first two laws of thermodynamics, to universal operation' back |
History of science - Wikipedia, History of science - Wikipedia, the free encyclopedia, 'The history of science is the study of the development of science and scientific knowledge, including both the natural and social sciences (the history of the arts and humanities is termed history of scholarship). Science is a body of empirical, theoretical, and practical knowledge about the natural world, produced by scientists who emphasize the observation, explanation, and prediction of real-world phenomena.' back |
Immune system - Wikipedia, Immune system - Wikipedia, the free encyclopedia, 'The immune system is a host defense system comprising many biological structures and processes within an organism that protects against disease. To function properly, an immune system must detect a wide variety of agents, known as pathogens, from viruses to parasitic worms, and distinguish them from the organism's own healthy tissue.' back |
Julian Davies and Dorothy Davies, Origins and Evolution of Antibiotic Resistance, ' Summary: Antibiotics have always been considered one of the wonder discoveries of the 20th century. This is true, but the real wonder is the rise of antibiotic resistance in hospitals, communities, and the environment concomitant with their use. The extraordinary genetic capacities of microbes have benefitted from man's overuse of antibiotics to exploit every source of resistance genes and every means of horizontal gene transmission to develop multiple mechanisms of resistance for each and every antibiotic introduced into practice clinically, agriculturally, or otherwise. This review presents the salient aspects of antibiotic resistance development over the past half-century, with the oft-restated conclusion that it is time to act. To achieve complete restitution of therapeutic applications of antibiotics, there is a need for more information on the role of environmental microbiomes in the rise of antibiotic resistance. In particular, creative approaches to the discovery of novel antibiotics and their expedited and controlled introduction to therapy are obligatory.' back |
Marija Kundakovic and Frances A. Champagne, Early-life experience, epigenetics and the developing brain, 'Development is a dynamic process that involves interplay between genes and the environment. In mammals, the quality of the postnatal environment is shaped by parent–offspring interactions that promote growth and survival and can lead to divergent developmental trajectories with implications for later-life neurobiological and behavioral characteristics. Emerging evidence suggests that epigenetic factors (ie, DNA methylation, posttranslational histone modifications, and small noncoding RNAs) may have a critical role in these parental care effects. Although this evidence is drawn primarily from rodent studies, there is increasing support for these effects in humans. Through these molecular mechanisms, variation in risk of psychopathology may emerge, particularly as a consequence of early-life neglect and abuse. Here we will highlight evidence of dynamic epigenetic changes in the developing brain in response to variation in the quality of postnatal parent–offspring interactions. The recruitment of epigenetic pathways for the biological embedding of early-life experience may also have transgenerational consequences and we will describe and contrast two routes through which this transmission can occur: experience dependent vs germline inheritance. Finally, we will speculate regarding the future directions of epigenetic research and how it can help us gain a better understanding of the developmental origins of psychiatric dysfunction.' back |
Mutation - Wikipedia, Mutation - Wikipedia, the free encyclopedia, 'In molecular biology and genetics, mutations are changes in a genomic sequence: the DNA sequence of a cell's genome or the DNA or RNA sequence of a virus. They can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic chemicals, as well as errors that occur during meiosis or DNA replication. They can also be induced by the organism itself, by cellular processes such as hypermutation.' back |
Natural selection - Wikipedia, Natural selection - Wikipedia, the free encyclopedia, 'Natural selection is the differential survival and reproduction of individuals due to differences in phenotype; it is a key mechanism of evolution. The term "natural selection" was popularised by Charles Darwin, who intended it to be compared with artificial selection, now more commonly referred to as selective breeding. . . . Natural selection is one of the cornerstones of modern biology. The concept was published by Darwin and Alfred Russel Wallace in a joint presentation of papers in 1858, and set out in Darwin's influential 1859 book On the Origin of Species,[3] in which natural selection was described as analogous to artificial selection, a process by which animals and plants with traits considered desirable by human breeders are systematically favoured for reproduction.' back |
Nucleic acid - Wikipedia, Nucleic acid - Wikipedia, the free encyclopedia, ' Nucleic acids are the biopolymers, or small biomolecules, essential to all known forms of life. The term nucleic acid is the overall name for DNA and RNA. They are composed of nucleotides, which are the monomers made of three components: a 5-carbon sugar, a phosphate group and a nitrogenous base. If the sugar is a compound ribose, the polymer is RNA (ribonucleic acid); if the sugar is derived from ribose as deoxyribose, the polymer is DNA (deoxyribonucleic acid).' back |
Philosophy - Wikipedia, Philosophy - Wikipedia, the free encyclopedia, ' Philosophy (from Greek φιλοσοφία, philosophia, literally "love of wisdom") is the study of general and fundamental concerns such as existence, knowledge, matter, values, reason, mind, and language.The term was probably coined by Pythagoras (c. 570 – 495 BCE). Philosophical methods include questioning, critical discussion, rational argument, and systematic presentation.' back |
r/K selection theory - Wikipedia, r/K selection theory - Wikipedia, the free encyclopedia, ' In ecology, r/K selection theory relates to the selection of combinations of traits in an organism that trade off between quantity and quality of offspring. The focus on either an increased quantity of offspring at the expense of individual parental investment of r-strategists, or on a reduced quantity of offspring with a corresponding increased parental investment of K-strategists, varies widely, seemingly to promote success in particular environments.' back |
Sociocultural evolution - Wikipedia, Sociocultural evolution - Wikipedia, the free encyclopeia, ' Sociocultural evolution, sociocultural evolutionism or cultural evolution are theories of cultural and social evolution that describe how cultures and societies change over time.' back |
Wissenschaft - Wikipedia, Wissenschaft - Wikipedia, the free encyclopedia, ' Wissenschaft is the German language term for any study that involves systematic research. The term is sometimes roughly translated as science, although Wissenschaft is much broader and includes every systematic academic study of any area, for example, humanities like art or religion. Wissenschaft incorporates scientific and non-scientific inquiry, learning, knowledge, scholarship and implies that knowledge is a dynamic process discoverable for oneself, rather than something that is handed down.' back |
|
