Balance Pose - Balance Pose - an exercise for good posture 1. Stand on the floor, straighten your back, connect your feet, lower your arms along the body.2. Shifting body weight to left leg, lift straight left hand up.3. Bend your right leg at the knee, grab it with your right palm

social dynamics- study of society's ability to respond to internal and external changes and deal with its regulatory mechanisms.

The evolutionary model is partial and gradual changes that are carried out as fairly stable and constant tendencies to increase or decrease any properties, qualities, elements in various social systems, and acquiring, in connection with this, an upward or downward direction.

Revolutionary - Emphasizes the magnitude and radicalness of change. Emphasizes the violence produced by the changes. Emphasizes prerequisites and conditioning

the linear model presupposes the existence of universal stages of successive sociocultural development.

the multilinear one is associated with the assumption of the possibility of a multitude of approximately equivalent paths of sociocultural development and is not oriented towards the establishment of universal laws of evolution.

Social determinism(lat. determinare - determine) - one of the basic principles sociology expressing the universal interconnection and interdependence of social phenomena.

Stochastic dynamics

1) change in the properties or parameters of the system under the influence of many random factors or fluctuations, characterized by an irregular, aperiodic change in the states of the system.

5. The concept of "punctuated equilibrium" n. Eldredge and s. Gould.

Theory of punctuated equilibrium (Theory of quantum evolution) is a theory in the field evolution living organisms, which states that the evolution of sexually reproducing creatures occurs in jumps, interspersed with long periods in which there are no significant changes. According to this theory, phenotypic evolution, the evolution of properties encoded in genome, occurs as a result of rare periods of formation of new species ( cladogenesis), which proceed relatively quickly compared to the periods of stable existence of species.

The theory of punctuated equilibrium was proposed in 1972 paleontologists Niels Eldredge and Stephen Gould.

punctuated equilibrium

Based on a detailed study of fossil fossils, Gould and Eldridge concluded that there was no gradual evolution of species. . On the contrary, the fossil record shows that usually a given species remains in an unchanged, "equilibrium" state for a long time, and then, very rarely, this equilibrium is suddenly interrupted by rapid evolutionary change. Gradual evolution is never observed on fossil remains. Gould writes:

The history of most fossil species has a number of properties that are in no way compatible with gradualism: (1) Statics: Most species do not undergo any changes during their entire existence on Earth. By the time a species appears in the fossil record, its fossil remains are not much different from those that appear at the time of its extinction; morphological changes are insignificant and not directed. (2) Sudden occurrence: No species arises gradually, as a result of the continuous transformation of the kinship chain of its predecessors; on the contrary, it appears in the fossil record immediately as a fully formed species.

Theory of punctuated equilibrium (Theory of quantum evolution) is a theory in the field of the evolution of living organisms, stating that the evolution of sexually reproducing creatures occurs in jumps, interspersed with long periods in which there are no significant changes. According to this theory, phenotypic evolution, the evolution of properties encoded in the genome, occurs as a result of rare periods of formation of new species (cladogenesis), which proceed relatively quickly compared to periods of stable existence of species.

It is customary to contrast the theory of punctuated equilibrium with the theory of phyletic gradualism, which states that most of the evolutionary processes proceed evenly, as a result of the gradual transformation of species (anagenesis).

The punctuated equilibrium theory was proposed in 1972 by paleontologists Nils Eldridge and Stephen Gould.

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• - by Donald Prothero
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Literature

• Adler, J. and Carey, J. (1982) Newsweek March 29, 1982.
• Brett, C. E., L. C. Ivany, and K. M. Schopf (1996) "Coordinated stasis: An overview." Palaeogeography Palaeoclimatology Palaeoecology 127 (1-4): 1-20.
• Erwin, D. H. and R. L. Anstey (1995) New approaches to specification in the fossil record. New York: Columbia University Press.
• Fitch, W. J. and F. J. Ayala (1995) Tempo and mode in evolution: genetics and paleontology 50 years after Simpson. Washington, D.C.: National Academy Press.
• Gersick, C. J. G. (1991): Revolutionary Change Theories: A Multilevel Exploration of the Punctuated Equilibrium Paradigm. The Academy of Management Review 16(1), pp. 10-36.
• Ghiselin, M.T. (1986) The New York Times, December 14, 1986.
• Givel, Michael (2006) . Policy Studies Journal 43(3): 405-418
• Gould, S. J. (1992) "Punctuated equilibrium in fact and the ory." In Albert Somit and Steven Peterson The Dynamics of Evolution. New York: Cornell University Press. pp. 54-84.
• Gould, S. J. and N. Eldredge (1993) Nature 366 (6452): 223-227.
• Mayr, E. (1963) Animal Species and Evolution. Cambridge MA: Harvard University Press.
• Rhodes, R. H. T. (1983) Gradualism, punctuated equilibrium and the Origin of Species.» Nature 305 (5932): 269-272.

An excerpt characterizing the Theory of Punctuated Equilibrium

The turn of the 1960s-1970s is crucial moment in the development of evolutionary science. Starting from this moment, it is increasingly acquiring features that are characteristic of our days. First of all, it should be noted that the synthetic theory finally turns into a dogma and its postulates are more and more strongly criticized. In various biological disciplines, and primarily in molecular and biochemical genetics, a number of alternative hypotheses speciation and macroevolution, which reject the gradual cumulative nature of the formation of evolutionary hypotheses that break with the creative formative role natural selection and adaptive nature of the speciation process. These hypotheses state that most of the time species and the entire organic world, thanks to the action of normalizing selection, remain stable, and the transition to a qualitatively new state, which is observed in rare cases, occurs abruptly. In other words, Live nature lives in a rhythm of punctuated equilibrium.

In connection with the emergence of new concepts in evolutionary theory, a broad discussion is unfolding on cardinal problems relating to the continuity or discontinuity of evolution, the nature of evolutionary variability, the evolutionary role of the organization of genetic material, the nature and pace of the evolutionary process, the relationship between mono- and polyphyly, divergence and parallelism, dependence morphological evolution from genetic factors and etc.

Perhaps the most paradoxical feature of the moment under consideration is that it visually reproduces the spiral dialectical development: new evolutionary concepts are built on ideas that until recently were considered completely rejected, and their creators - criticized, ridiculed and forgotten. Now we will meet again with old acquaintances from the previous chapters, but they no longer appear " prodigal sons»science, but its real heroes are clairvoyants.

Among the recent hypotheses, the theory of punctuated equilibrium is the most holistic, comprehensive, and serious. Moreover, at least formally, it does not completely break with synthetic theory and Darwinism. In any case, this is how its authors want to present the matter.

Nils Eldridge (b. 1940)

At the very beginning of the 1970s, having studied the evolution of the Devonian genus of New York State trilobites, the American paleontologists N. Eldridge and S. Gould discovered a lack of gradualness in the transitions between successive forms. A species that had existed for millions of years without any significant changes suddenly disappeared in the overlying layers and was replaced by a new one with a completely different quantitative characteristic chief morphological trait. A similar pattern was established by Gould on one of the subspecies of the land snail from the Pleistocene of Bermuda, only for a shorter period of geological time. In a joint publication (Eldredge and Gould, 1972), the described process of alternation of a stable state (stasis) of a species and its rapid replacement by a new one was called punctuated equilibrium. According to this new model, evolution occurs in rare and fast shocks, it seems to pulsate, and the shocks themselves are fractions of a percent of stasis in time. The authors noted that the picture of "Punctuated Equilibrium is more in line with the process of speciation as understood by modern evolutionists" (ibid., p. 99). The new kind develops not in the area where his ancestors lived, but comes from outside.

Stephen Jay Gould (1941-2002)

The new concept was developed by only three paleontologists - Gould, Eldridge and Stanley - over a period of 10 years, and in addition to the already mentioned five main publications (Gould and Eldredg, 1977; Stanley, 1975, 1979; Gould, 1980, 1982b). At first skeptically met even by paleontologists, she received recognition only towards the end of the 70s, when she actually closed with the ideas molecular geneticists Carson, Bush, Wilson, White cytogenetics.

The idea of ​​the duration of stasis and the shortness of the jump to a new species, as we have seen, is by no means new. It was not alien even to Darwin, whose original evolutionary model recognized the exclusively sudden appearance of new species through saltations (Gall, 1987). Subsequently, Darwin moved to the positions of gradualism and in the Origin of Species repeatedly emphasized the gradualness of the evolutionary process. At the same time, however, he considered it expedient in all editions of this work, starting with the third, to keep next phrase: "The periods during which each species underwent changes, numerous and long, if measured in years, were probably short in comparison with those periods during which each species remained unchanged" (Darwin, 1939, p. 560 ). It is known that T. Huxley, being an ardent supporter of Darwinism, reproached Darwin for denying jumps (Huxley, 1901, p. 189).

We see, however, the merit of the punctualists in that they showed the contrast between the duration of stasis and speciation, and for the first time raised the question of the structure of the evolutionary process. It is fundamentally important to establish the very fact of the existence of stasis, which opposes the false idea of ​​the continuous evolutionary fluidity of life forms. Perhaps for the first time it was realized that the history of any group of organisms, in the words of the geologist D. Eiger, like the life of a soldier, “consists of long periods of boredom and short periods of fear” (cited in: Webb, 1986, p. 413). It is significant that the authors of punctualism understand stasis not as passive stability corresponding to the constancy of the environment, but as a genetically active state of the species.

According to the creators of the theory of punctuated equilibrium themselves (Stanley, 1979; Gould, 1986), the work of Mayr, Goldschmidt, Simpson, Grant, and partly Wright served as a starting point for them. From Mayr, they borrowed the allopathic model of geographic speciation based on the rapid transformation of small peripheral isolates, the concept of the genetic revolution, and the founder's principle. A particularly valuable source was the work of Mayr (Mayr, 1954) on the change in the genetic environment, where the idea of ​​discontinuous evolution was actually put forward based on the rapid reconstruction of the gene pool of an isolated population and a rational explanation was given for numerous gaps in the fossil record. However, if for Mayr it was a private and rare mode of speciation, which generally did not receive recognition then, then the punctualists turned it into a universal and trustworthy one.

The term "genetic revolution" was understood quite straightforwardly - as a rapid transformation of a budding subpopulation based on single mutations with a large phenotypic effect (macromutations). Such a transformation began to be most often described as quantum speciation, which entered the "discontinuous" model as its most important component.

Another source of the model was Goldschmidt's almost completely rehabilitated ideas about the emergence of a new taxon from "reassuring freaks" and about a complete break in micro- and macroevolution. Thus, considering the first idea quite acceptable, G. Bush (Bush, 1975a) and S. Gould (Gould, 1977b) admit that even one ugly individual could be the founder of a higher taxon. From here it's close to famous example Schindewolf about the first bird hatched from a reptile egg. According to Stanley (1979, p. 145), in the limiting case quantum leap a population of only ten individuals can make a new species within one or a few generations.

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Translation: Evgeny Galchenko, ed. Alexey Kalko ()
Translated with permission from creation.com

Comparative characteristics of phyletic gradualism and punctuated equilibrium: punctuated equilibrium is achieved due to fast and drastic changes in morphology.

The article deals with the concept of punctuated equilibrium (PR). It traces the development of the idea since its nomination by Stephen Gould and Nils Eldridge, as well as some contradictions. PR consists of two aspects:

1. observation - that the fossil record is characterized by

• (a) the sudden appearance of species, and
• (b) stasis, or the absence of significant change across species diversity in the fossil record; as well as

Gould and Eldridge stated that the sudden appearance of species could be explained by the fact that the transitions occurred quickly (in a geological sense), in small isolated populations, and thus the chances of preserving the remains transitional species were very small. They claimed that this theory followed from biology, but empirical biological basis there is no speciation for such events. It seems that this "mechanism" was adopted because it "explained" their observations of fossils (both scientists are paleontologists). Gould gave ground to the development of the ideas of macromutational changes to explain large transitions and the notion that the rapid speciation of PR is a kind of evolution called "promising monsters". Although Gould and Eldridge denied that they meant it.

The PR debate has drawn attention to the fact that stasis is a serious problem for the theory of evolution (how can you believe in evolution or change when fossil evidence shows static and no change?). Recognition of reality sudden appearance and stasis confirms what creationists have been saying since Darwin's time - that the facts correspond to special creation combined with the effects of a worldwide Flood. Wise's idea of ​​"creationist-style punctuated equilibrium" will also be considered in this context.

The concept of punctuated equilibrium

Nils Eldridge (currently Curator of the Invertebrate Department American Museum Science in New York) and Stephen Jay Gould (Professor of Geology at the Museum of Comparative Zoology, Harvard University) originated the idea of ​​"Punctuated Equilibrium" at a Symposium on Paleontological Models in 1970 in University of Chicago. The study was published in 1972. The idea was born based on their recognition of stasis (lack of gradual change) in fossils. In other words, species have maintained a clear stability throughout their "history of existence", showing no significant changes from the moment they appeared in the fossil record to the moment they disappeared. Eldredge, in particular, has spent a great deal of effort looking for evidence of gradual evolutionary change linking trilobite species in the Devonian layer in the United States and Canada, but without success. For example, according to neo-Darwinian theory, the number of lenses in the eye should gradually change from one trilobite species to another, but this is not observed. Little change occurred over long periods of time, and the "species" seemed to simply appear and disappear.

Eldridge and Gould, as paleontologists, acknowledged that this model, with minor modifications, long time(according to the evolutionary interpretation of fossils), and the lack of evidence for the gradual transformation of one species into another were generally characteristic of the fossil record. This was not a unique feature of Devonian trilobites. New species "appear" in rock layers without any signs of gradual transitions from other forms. The fossil record is characterized by long periods of stasis, or equilibrium, when species are clearly identified and remain stable, and these periods are interrupted by occasional sudden, or "rapid" appearances of new species. Hence the name "Punctuated Equilibrium".

Paleontologists have usually justified the gaps in the fossil record (lack of evidence for gradual change and phylogeny) by its insufficient knowledge, as Darwin also spoke about. Eldridge and Gould recognized the fact that gaps are typical of the fossil record. Also, paleontologists have ignored stasis, considering it a "lack of data" of no interest. Gould and Eldridge acknowledged that "stasis is data". Gould and Eldredge considered species to be distinct entities, with a defined beginning (that is, the emergence of a species) and an end (extinction), which is contrary to the neo-Darwinian idea of ​​constantly transforming species without clear boundaries. Eldredge and Gould spoke of species as "separate entities". "Speciation" is to species what mutation is to individuals. Speciation is perceived as something random, like a mutation for an individual. New species are subject to natural selection, which weeds out those that are not viable. The original publication begins with a philosophical address about the reluctance of most evolutionists to acknowledge the absence of fossil evidence for gradualism. That is, the predominance of theory over "facts". Eldredge and Gould admit, as do other commentators scientific method that facts "say" only when they are consistent with the theory; otherwise, arguments are searched for to ignore them. They said they were proposing a new theory that would reconcile the facts of stasis and the sudden appearance of species in the fossil record with an evolutionary (i.e., naturalistic) paradigm. Until then, stasis had been ignored and gaps attributed to incomplete knowledge.

On the one hand, punctuated equilibrium (PR) is simply a description of the fossil record (assuming a geologic time scale, of course). On the other hand, this is evolutionary process, which Eldredge and Gould argue could explain the fossil situation. They stated that significant changes occurred in small isolated populations remote from the main populations (allopatric speciation by peripheral isolations). And that these changes occurred quite quickly (in the geological sense). This is the proposed mechanism to explain stasis and gaps in the fossil record. They wrote:

"Because speciation occurs rapidly in small populations occupying small areas away from the center of their ancestral range, finding such an event in the fossil record should be rare."

Another PR champion, Stephen Stanley, stated that

"Gradual evolutionary change by natural selection acts so slowly within established species that it cannot explain the basic features of evolution."

thus agreeing that the changes that give rise to new species occurred relatively quickly.

Punctuated equilibria or punctuated equilibrium

In their 1972 publication, Eldredge and Gould used the term "punctuated equilibria" to refer to their concept. Eldredge used the term in his writings, while Gould used "Punctuated Equilibrium" (compare, for example, the titles of the papers in footnotes 9 and 28). Their updated 1993 publication uses the term "Punctuated Equilibrium", so apparently that term has become.

Origin of the idea of ​​punctuated equilibrium

Other researchers also acknowledged that the fossils do not show signs of a gradual transition between taxa. For example, in 1940, Richard Goldschmidt argued that the transitions had to occur quickly, in jumps, because of which the transitional forms could not be petrified, since they never existed. Goldschmidt's ideas were ridiculed by most evolutionists in the 40s and 50s of the 20th century, since paleontologists still believed that transitional fossils would be found in future research. In addition, there was no biological basis for understanding how new species could arise as quickly as Goldschmidt suggested.

The basic "mechanism" of speciation proposed by Eldridge and Gould was borrowed from other scientists. The concept of allopatric (geographical) speciation was previously recognized as a mechanism of evolutionary change, albeit acting gradually. In particular, Mayr developed this idea. Eldredge acknowledged that the history of the idea of ​​allopatric speciation can be traced back to pre-Darwinian biology. Eldredge and Gould made one controversial claim, namely that:

"Most evolutionary changes in morphology occur in a short period of time relative to the total lifetime of a species"

and argued that this is a logical conclusion from the theory of allopatric speciation in peripherally isolated populations. Although they acknowledged that

"No new theory evolutionary mechanisms cannot be developed on the basis of paleontological data”,

one might suspect that the idea of ​​rapid speciation arose from their reading of the fossil record rather than from any new understanding of allopathic speciation. Even the idea of ​​rapid speciation was not all that new. In addition to Goldschmidt, in the 1960s Soviet specialists suggested that change is usually concentrated in rapid speciation events, and that species are clearly stable after their formation.

Punctuated equilibrium in creationist style

Kurt Wise,* creationist paleontologist, has offered an alternative explanation for the sudden appearance of species and stasis that characterize the fossil record. Gould and Eldridge proceeded from the generally accepted interpretation of the stratigraphic column, according to which it is the result of long-term sedimentation of rocks, with each layer containing samples of life forms on earth that existed at that time. In this case, the fossil record resembles frame-by-frame replays of newsreels about life on earth (albeit with varying periods between frames). Wise showed that if most of stratigraphic record - the result of a single catastrophe, such as Global flood and its consequences, this may explain the situation with the sudden appearance of species and stasis in the fossil record. A sample of each species would be instantly captured by such an event, and thus the species would show static. Rare exceptions from stasis, namely, successive vertical gradients of change, such as increasing size as one goes up (a common observation called Cope's law), can be explained by sorting processes. Also, some patterns may reflect initial geographic or altitudinal morphology gradients. In addition, vertical gradients in shape could be the result of actual transitions during the catastrophe, but this could only happen with species that are resistant to catastrophe conditions and with a lifespan of one generation significantly shorter than the duration of the catastrophe itself (one year of the Flood). Wise suggested that an exception to stasis could be marine organisms with short duration generations. best example An exception to stasis known to Wise was the Permian foraminifera, a marine organism with a short lifespan of one generation, consistent with the catastrophic Flood model.

Wise wrote:

"The Rarity of Exceptions to Punctuated Equilibrium sensu stricto[i.e., stasis and sudden appearance of species] indicates that the model of catastrophic sedimentation of terrestrial rocks can be considered a mechanism for explaining the paleontological observations of the theory of punctuated equilibrium.

Gould, in particular, was annoyed that creationists were using his confessions about the lack of fossil evidence for phylogenesis and his sympathy for speciation through Goldschmidt's "prospective monsters". Creationists have widely cited Gould's statements made in the 1970s. Judging by a recent post, Gould appears to have "returned to starting point". He abandoned his early position that there were no undisputed examples of fossil transition sequences, whether they were interspecies transitions or transitions between the basic principles of organism structure, and turned to the story of the "walking whale" as proof of the transformation of one species into another. The evidence for this transition is weak, but Gould accepts the dreamy description of the ambulocetus without critical reflection. Ambulocetus natans who walked and swam, presented by Tewissen and etc. In the 1970s, other scientists put forward a number of examples of gradual changes in fossils to refute the PR theory (that is, in favor of gradualism). Gould and Eldridge denied these claims, arguing that

"that practically none of the examples presented to refute our model can be a confirmation of phyletic gradualism."

Suggested examples of transition sequences and intermediate forms met sharp criticism Gould in the 1970s, but he now describes the highly unconvincing story of whale evolution as

"the finest series of transitional fossils that an evolutionist can only dream of finding."

One need only read Gould's work to see how uncritically he takes the whole story. Also visible in the work is Gould's almost maniacal preoccupation with countering creationist claims that the fossil record does not show evolution and that there are no indisputable transitional forms—a claim that Gould himself made repeatedly in the 1970s when he promoted stasis and rapid change. and when, apparently, the creationists did not bother him so much.

In 1982, Gould distanced himself from "promising monsters":

"Punctuated equilibrium is not a theory of macromutations, it is not a theory about any genetic process."

Gould admits he supported

"certain forms of macromutational theory ... but not in the context of punctuated equilibrium."

"This book - my version of the history of punctuated equilibria”… (emphasis added),

indicating his desire to distance himself from other versions. Regarding the lack of gradual change in the fossil record, Eldredge was less dogmatic than Gould in the 1970s. Eldridge wrote:

“gradualistic changes remain theoretically possible” and “… some gradualistic changes exist… But, in fact, it does not tell us about the emergence of something truly new. It doesn't really get us anywhere."

He noted the importance of allopatric (geographical) speciation in explaining gaps in the fossil record. That is, Eldridge believed that the main changes occur somewhere away from the main population, in small isolated populations, and therefore they (usually) do not persist, especially in the habitat parent view. He emphasized the theory of peripatric speciation (versions of allopatric speciation with peripheral isolation).

Eldredge objected to associating PR with the idea of ​​"promising monsters":

"The claim that punctuated equilibria represent the resurrection of Goldschmidt's 'macromutations' and 'promising monsters' remains the most serious and unfortunate misinterpretation of our ideas."

He also wrote that

"The most common misconception about 'punctuated equilibria' is that Gould and I proposed a saltationist model of change occurring instantly, supposedly as a result of sudden mutations with large-scale consequences (macromutations à la Richard Goldschmidt)...".

Eldredge said:

“The chosen changes are usually fast. But fast in context million years". (emphasis added).

21 years later, when reviewing their theory of PR, Gould and Eldredge lost ground so much that they proposed PR as a "complement to phyletic gradualism." This is a rather serious concession compared to the audacity of their statements in 1972, and especially those of Gould in 1980, as Levinton noted in a response to the review.

Is evolution by punctuated equilibrium a biological absurdity?

Gould and Eldridge write:

“Stasis, being obvious and observable in almost all cases (while fast transitions are usually, though not always, subtle), becomes the main empirical basis for the Study of Punctuated Equilibrium"

“... stasis, inevitably interpreted as the absence of evolution, has always been perceived as something insignificant. However, it is very strange to define the most common of all paleontological phenomena as something not worthy of interest or attention!”

What, in fact, are Gould and Eldredge saying? What is PR? In fact, PR is the supposed way evolution proceeds. What is evolution? Is not it change? PR is supposed to be a way for change to flow, but stasis is the confirmation of it. But what is "stasis"? Isn't it the absence of change? In this case, the absence of change (stasis) is the confirmation of change (evolution by PR)!

Ironically, the tautological nature of "survival of the fittest" as a definition of natural selection in neo-Darwinian evolution is beautifully preserved in Gould and Eldredge's extrapolation of this concept to species:

The geological record records episodes high mortality during which extinction-prone groups are likely to disappear, while extinction-resistant groups inherit life."

However, among evolutionary biologists or geneticists, PR is less accepted. For example, general attitude Maynard Smith is reduced to the fact that

"... we can forget about new paradigms and the death of neo-Darwinism."

About species selection he said:

"In any case, the idea never really made much sense."

Apparently, even the opponents of the PR have accepted the concept of stasis and even short periods rapid change, but they reject the anti-neo-Darwinian idea of ​​non-adaptive random occurrence of new species and species selection as a way of macroevolution. John Maynard Smith, for example, said:

However, it is quite possible to accept the assertion that typical model changes are long periods of stasis, interrupted by short periods of rapid change, not accepting the ideas of non-adaptive changes, species selection and the separation of macro- and microevolution. This is a matter for paleontologists to decide."

Curiously, in their 1993 review paper, Gould and Eldredge define macroevolution as the "culling of species" and, somewhat mildly, state that

"Darwinian extrapolation cannot fully explain massive changes in the history of life."

But what explains the massive change? They again state that

"Punctuated equilibrium has never been a saltationist theory [the theory of macromutations]".

They do not offer a biological basis for massive change. Really,

“Endless dissatisfaction, this time justified, is focused on claims that speciation causes significant morphological changes, because no evidence has been found for this”