About evolution
The question"Who we are, where we come from, where we were going ?” is probably as old as man. Darwin's theory of evolution, launched in 1859 through the book The origin of species has one of the most accepted answers to the popular question “How man appeared on earth?”. According to it, humanization is an evolutionary process, as is the emergence of any species on this planet. Living things evolve, change, species disappear or transform into other species, which are in turn subject to the mechanisms of evolution. What are these mechanisms of evolution?? what was he sayingDarwin?
Darwin's theory
Charles Darwin (1809-1882) it starts from the idea of the variation of individual characters within a population, thereby having the extraordinary merit of making the transition from typological thinking, dominant in biology in his era, to the population one. That is, there was a population of pigeons, from oi etc., not a type of individual that represents a particular species, of pigeon or sheep, let's say. These variations occur spontaneously, Darwin did not know by what mechanisms, but he was coming up with some assumptions. Individual variations were sufficient for evolution? Not. Darwin, like the co-discoverer of evolutionary theory, Alfred Wallace, advance the action of natural selection as a mechanism of evolution.
The Spectacular Effects of Artificial Selection, through which various varieties of plants and breeds of animals are created, sometimes so different from the original, so that they seem to belong to other species (eg dog breeds), they inspired Darwin. Also, had observed that all species have more offspring than they have the chance to survive in that environment. The theory of Thomas Malthus, according to which the population grows in geometric progression, but the resources in arithmetic progression, wars being in this case natural ways of regulating the effective population, would have influenced him as well. Natural selection, that occurs when the body interacts with the environment, would be the consequence of the struggle for existence in an environment that holds limited resources. Survival of the fittest (“survival of the fittest” – the phrase which, however, does not belong to Darwin, but to a Lamarckist) it would lead to the fixation of useful characters in that environment and the removal of less useful or disadvantageous ones. Actually, in nature not only the fittest survive, but a small advantage due to some hereditary character gives the bearer a chance of superior fitness (more viable offspring).
Regarding human evolution, Darwin treats it separately in a book "The descent of man" (1871), in which he expounds some ideas about the action of natural selection in human evolution. More, Darwin talks about sexual selection in humans, that is, about how women's sexual preferences would have influenced the evolution of male characters. Men with certain qualities would have been advantaged over others, being preferred by women, thus having more offspring. As with any animal, and in man, females carry out the selection, the object of selection being males. Now it all seems simple to a 21st century evolutionist, but Darwin made these claims in the 19th century, in a society dominated by tradition, in which the male sex was dominant.
Genetics and mutations
Darwin's theory was very simple, logic, but, although his contemporaries admitted the idea of evolution, they did not find the problem of natural selection very convincing. Because they didn't know, as Darwin did not know, how those individual variations occur. If only there was internet back then, things would have been different, but computer science was just beginning. Because a monk from today's Czech Republic, Gregor Mendel (1822-1884), he had discovered and published the laws of heredity (1866), though he too knew nothing yet of the material substratum of heredity, i.e. about nucleic acids. Darwin had observed the transmission of hereditary characters even in humans, but they were only empirical observations.
Mendel's discoveries were forgotten, but the laws of heredity were independently rediscovered by other researchers in the early 20th century. A new science, genetics, was born with the new century. The genes are revealed, but also their modifications, called mutations. These mutations, that appear under the influence of certain environmental factors (PHYSICAL, chemists, organic), but also spontaneously at a certain rate, they finally offered the object of character variability and therefore, of the selection. The discovery of mutations gave the real glory to Darwin's theory. In the 20th century, as a result of new discoveries, but based on Darwin's evolutionary theory, the synthetic theory of evolution or modern synthesis appears. This is actually the "official" evolutionary theory at the present time.
According to it, small mutations, INCIDENTAL, when they are inherited (when it affects reproductive cells) creates genetic variability, new variations being subject to natural selection. By accumulating (increasing incidence in a population) or their removal (decrease in incidence in a population) evolution takes place. The individual is the object of selection, but the population (species) evolve.
Besides selection there are other phenomena that occur at the population level, such as genetic drift (the fixation by pure chance of some characters in a population, without being linked to any advantage), the founder effect (imposition in a new environment, where a subpopulation migrated, of the statistical composition of its characters, although this is slightly different from that of the parent population) etc.
Other evolutionary theories
Lamarckismul
The idea of selection, developed by Darwin was not new, although apparently Darwin, but neither did the Wallaces know it. The British Wells and Matthew had advanced it in writings of very little popularity. But the idea of selection accompanies the first modern evolutionary theory, that of Jean Baptiste, knight of Lamarck (later known as Lamarck, for reasons of avoiding the consequences of noble origin during the French Revolution). Lamarck was not the first evolutionist, but the first to condense evolutionary ideas into a theory. Known by the simplistic phrase «the function creates the organ», which does not belong to the author, Lamarck's evolutionary theory, exhibited in "Philosophie zoologique", she was much more sophisticated. Lamarck had observed, among others, cave organisms, who become blind, lose color etc. These observations inspired him to advance his evolutionary principles. According to them, the environment acts directly on organisms, causing behavioral changes, which lead to poorer use of some organs, which results in their degeneration. For example, in the case of cave organisms, the eyes are out of use for a while, then they lose their functionality and disappear. The second principle stated by Lamarck is that these changes, results from interaction with the environment, are inherited. He mentioned selection within his theory, but considered it of secondary importance in evolution. Due to scientific incidents, Lamarck's theory fell into disuse in the early 19th century, and is currently considered unscientific, because there would be no evidence that the environment directly influences the organism, through changes in the genetic material that can be inherited. The reason is that no RNA has been discovered to be the vehicle of the changes determined by the environment and transmitted hereditarily. But these ideas were taken up by Darwin in later editions of the Origin… (make it), the supposed hereditary changes of organisms becoming the support of variability.
Theory of intermittent equilibria
Among modern evolutionary theories, it is worth mentioning that of intermittent balances (punctuated equilibria), issued by Eldredge and Gould in 1972. It complements Darwin's, with which it has little in contradiction. Starting from some studies, published in 1954, ale lui Ernst Mayr, one of the greatest biologists of the 20th century, relating to allopathic speciation (the appearance of several species from one), but especially peripatetic (from marginal populations), they tried with this theory to explain, among others, the absence of missing links, of intermediate forms in evolution, but also other aspects related to the fossil material. This theory holds that it opposes phyletic gradualism, from which he assumes that Darwin's theory starts. The term is invented by them, and is quite criticized. Richard Dawkins, a famous contemporary evolutionist, in «The blind watchmaker» he devotes a chapter to the criticism of Gould and Eldredge's theory. Its authors believe that Darwin would have believed that evolution proceeds in small steps, with an approximately constant speed (gradualismul filetic). What is true is that Darwin really assumed that evolution generally occurs with very small changes, over very long periods of time. This view is taken from geology. If pre-Darwin's era, the relief forms were considered to be the product of catastrophes, at the beginning of the 19th century, geologists appeared who advanced another origin for the landforms, namely the extremely small changes over millions of years (the example of cave formation through limestone erosion is conclusive). Darwin considers faith, that the changes in living organisms are small, over millions of years, the evolution over short periods being imperceptible.
But these steps are not necessarily equal. With quotations from Darwin, Dawkins shows that the father of evolution explains that sometimes evolution is extremely slow, other times there are veritable explosions of new species. More, he also shows the mechanisms proposed by Gould and Eldredge to explain such phenomena. They consider the marginal population, located at the edge of the mother population's area, is likely to undergo more changes during evolution than the general population, where a stronger gene exchange takes place. The phenomenon is similar to geographical isolation, for example on an island, where speciation occurs more rapidly. Marginal population also has the founder effect, where the statistical gene composition is slightly different from the mean of the parent population. Under these conditions, these marginal populations evolve faster (through the mechanisms of natural selection), accumulate more changes, which makes them phenotypically different from the population they come from, then they are likely to spread and occupy its area quite quickly, if they have selective advantages, eventually replacing it.
What they will reveal, in this case, the fossils? Rapid, a new species appeared out of nowhere. Actually, not in millions of years, but in 70000, which geologically means little, a fossil appears that looks different, it is therefore considered a new species, instead of the old one, which disappeared.
What is different about Gould and Eldredge versus Darwin ? Darwin believes that isolation is not absolutely necessary for speciation, that in fact large populations are more likely to evolve. Also, Gould and Eldredge accept selection in evolution up to the level of speciation, but in speciation an important role would be played by genetic drift, more precisely the incident. Marginal populations have a certain gene composition by chance.
The impasses of Darwin's theory and creationist theories
People would perhaps accept evolution, but the fact that the ancestor (the ancestors) to man there were some primates, that is, monkeys, it is not at all easy to digest, especially by people with a religious education (Christianize) solid. It is hard to find an animal more pathetic than the monkey in the view of many people. A monkey god in the image and likeness of which we were created is hideous.
Like any scientific theory, evolutionary theory has its problems. Scientists are not prophets, they have no visions, they compare facts, a multitude of facts, I draw conclusions, create models and make predictions. Darwin, although he had graduated from theology school, like most biologists of the time, he was a scientist and he too was subject to human error and failings. So are his descendants.
The so-called scientific creationist theories that emerged later speculate on every point of evolutionary theory, every discovery that comes, or seems to come, contradicts it, to strike him. But creationists do not provide evidence in support of creation, but evidence against evolution. That is, I start from the presumption of creation, any fact that disproves evolution as Darwin saw it becomes in their view an argument in favor of creation.
Scientific creationism has evolved in the meantime, the last species to emerge recently is intelligent design (intelligent design). This is a new evolutionary theory, but camouflaged creationist, which admits the involvement of evolutionary mechanisms up to a certain level, but some structures are too complicated to be the result of chance in Darwin's theory. In short, evolution is admitted at most in the appearance of other species, but not of man, in which an intelligent plan would also have intervened, it is not known whose. Mentioning the creator in this phenomenon is avoided.
It is clear that man has an intelligence far superior to any other animal, has self-awareness, other characters that are no longer found in other animals, and who could not, consider intelligent design followers, to appear only by chance, as evolutionism assumes.
Intelligent design has many followers, especially in the United States, where recently there was a trial related to the teaching of this theory in schools. It is interesting that this process was lost by these schools because in the States, the school is secular, religion is not taught in schools (separation of church and state, provided by the first amendment of the US Constitution), and this theory is not science, but religion, because it does not meet the objective conditions to be science. Also, in some southern states, it is insisted as in schools, even if Darwinism is taught, note that this is a theory, not a fact.
Indeed, it is very difficult to create experiments through which to directly demonstrate the action of evolution. Although such approaches have existed and had very convincing results. Populations of vinegar flies were obtained through selection Drosophila melanogaster very large or very long-lived. The emergence of antibiotic-resistant bacteria is direct evidence of evolution in action. Also, in crop plants we speak of incipient species. But most of the time, evolution works with circumstantial evidence, because evolution, especially in species with long lifespans and long reproductive cycles, it is a very slow process.
The big problems with current evolutionary theory is the lack of speciation in the lab (creation of artificial species, populations reproductively isolated from related ones) and conclusive experiences to show how life arose from non-living matter. New theoretical models, new hypotheses related to these phenomena, they will be able to lead to new experiments to solve these problems as well.
But the attacks of creationists and followers of intelligent design, if I am to the point, are beneficial to the science of evolution, which is thus subjected to a strong selective pressure of ideas, so it is bound to evolve further. I have personally read creationist books, because it inspires me to see the problems of evolutionary theory from the outside.
The civilization of hunger
What is new in this book?? As it appears in the title, presents a new approach, but very well documented, of humanization. It brings up new aspects of human metabolism and physiology (details that can sometimes be essential). Starting from these aspects, a new hypothesis of humanization was built, in which the "road" of adaptation to the environment is different from the one assumed so far. Of course, it benefits from new discoveries in molecular biology, biochemistry, GENETIC, neurology etc.. If only it had a name, this would be called "open biological systems theory", but it can be framed in neo-Lamarckism, that is, it would be a kind of Lamarckist "modern synthesis".. This refers to the fact that the environment can directly influence living organisms, causing changes that can be inherited. There are many data on this, these phenomena also occurring in the human species. Not only have types of RNA been discovered that would be involved in such processes, but they are not the only mechanisms (v. above). It has nothing to do with the idea of a giraffe growing a neck because it reached for leaves in tall trees, which compromised Lamarck. The changes are much more subtle, the gene level, whose expression is blocked or unblocked in the long term.
In short, this book hypothesizes that some specifically human characters, including brain growth, loss of fur etc., it would be due to adaptation to reduced resource consumption, imposed by environmental conditions. In fact, the alternation between periods of famine and relative abundance of resources would have determined some changes in the genetic material during periods of scarcity, which persisted in times of plenty. Through a kind of gap between the adaptation to famine and the emergence of abundance, the extraordinary development of some structures took place, the disappearance of others. This hypothesis points to a biochemical pathway of humanization, that is, a group of enzymes with cascade function, with important functions in the development and emergence of typical human characters.
Although it is mainly about human evolution, of that stage that separates man from other related primates, the mechanisms of evolution in general are also treated. It does not relate to selection and population-level phenomena, pointed out and explained by others long before. Although the author is rather a follower of the theory of intermittent balance (punctuated equilibria) of Gould and Eldredge, only tangentially discusses these mechanisms. But it does deal with the source of the changes, of variability, on which selection or other population phenomena then act, such as genetic drift. As Băsescu would say, selection is someone else's business, but the subject of variability is also the author's job. Because it's a boring job, by biochemist.
The next book, now being written, will also cover other topics related to evolution. But we hope this one, already appeared, answers important questions related to human evolution, but it will also lessen the criticism of evolution by those who think. This hypothesis does not contradict Darwinism, it is a complement to it. Probable, if Darwin lived, would accept it, although they would bring him some corrections and criticisms, but I think these would not be of the important ideas. Criticisms and corrections are intended for any scientific hypothesis or theory, who from birth must know what awaits her.
