When significant evolutionary change occurs, the theory proposes that it is generally restricted to rare and geologically rapid events of branching speciation called cladogenesis.
Ketika perubahan evolusi yang signifikan terjadi, teori ini menjelaskan bahwa perubahan tersebut terbatas pada peristiwa spesiasi percabangan yang cepat dan jarang yang disebut kladogenesis.
In 1972, paleontologists Niles Eldredge and Stephen Jay Gould published a landmark paper developing their theory and called it punctuated equilibria.
Pada tahun 1972, paleontolog Niles Eldredge dan Stephen Jay Gould menerbitkan karya ilmiah yang mengembangkan teori keseimbangan filetik dan menyebutnya keseimbangan bersela.
Their paper built upon Ernst Mayr's model of geographic speciation, I. M. Lerner's theories of developmental and genetic homeostasis, and their own empirical research.
Karya mereka dibuat berdasarkan teori spesiasi geografis Ernst Mayr, teori homeostastis perkembangan dan genetik I. Michael Lerner, serta penelitian empiris mereka sendiri.
Eldredge and Gould proposed that the degree of gradualism commonly attributed to Charles Darwin is virtually nonexistent in the fossil record, and that stasis dominates the history of most fossil species.
Eldredge dan Gould mengemukakan bahwa gradualisme yang umumnya dikaitkan dengan Charles Darwin tidak dapat diamati dalam rekaman fosil, dan bahwa stasis mendominasi sejarah sebagian besar spesies.
Punctuated equilibrium differs from Mayr's ideas mainly in that Eldredge and Gould placed considerably greater emphasis on stasis, whereas Mayr was concerned with explaining the morphological discontinuity (or "sudden jumps") found in the fossil record.
Teori ini berbeda dari hipotesis Mayr karena Eldredge dan Gould lebih banyak menekankan kepada konsep stasis, sementara Mayr berupaya menjelaskan dikontinuitas morfologis (atau "lompatan mendadak") yang dapat ditemui dalam rekaman fosil.
Mayr later complimented Eldredge and Gould's paper, stating that evolutionary stasis had been "unexpected by most evolutionary biologists" and that punctuated equilibrium "had a major impact on paleontology and evolutionary biology.
Mayr nantinya memuji karya ilmiah Eldredge dan Gould dan menyatakan bahwa konsep stasis "tidak diduga oleh sebagian besar ahli biologi evolusioner" dan bahwa konsep keseimbangan bersela "berdampak besar pada paleontologi dan biologi evolusioner.
A year before his and Gould's 1972 paper, Niles Eldredge published a paper in the journal Evolution which suggested that gradual evolution was seldom seen in the fossil record and argued that Ernst Mayr's standard mechanism of allopatric speciation might suggest a possible resolution.
" Satu tahun sebelum karya ilmiah Eldredge dan Gould diterbitkan, Niles Eldredge menerbitkan karya ilmiah di jurnal Evolution yang mencantumkan bahwa evolusi gradual jarang terlihat dalam rekaman fosil dan menyatakan bahwa mekanisme standar spesiasi alopatrik Ernst Mayr mungkin merupakan jawabannya.
The Eldredge and Gould paper was presented at the Annual Meeting of the Geological Society of America in 1971.
Karya ilmiah Eldredge dan Gould disampaikan di Pertemuan Tahunan Masyarakat Geologi Amerika pada tahun 1971.
Tom Schopf, who organized that year's meeting, assigned Gould the topic of speciation.
Tom Schopf, penyelenggara pertemuan tersebut, menyerahkan topik spesiasi kepada Gould.
In his book Time Frames Eldredge recalls that after much discussion the pair "each wrote roughly half.
Eldredge dalam bukunya Time Frames menyebut bahwa "setelah banyak berbincang, masing-masing menulis sekitar setengah.
Some of the parts that would seem obviously the work of one of us were actually first penned by the other—I remember for example, writing the section on Gould's snails.
Bagian yang tampak jelas merupakan karya salah satu dari kita ditulis oleh yang lain - misalnya, saya ingat menulis bagian mengenai siput Gould...
Gould edited the entire manuscript for better consistency.
Gould menyunting seluruh manuskrip agar lebih konsisten.
The paleontologist George Gaylord Simpson, for example, believed that phyletic gradual evolution (called horotely in his terminology) comprised 90% of evolution.
Misalnya, George Gaylord Simpson meyakini bahwa evolusi gradual filetik (disebut horoteli olehnya) meliputi 90% evolusi.
This model was popularized by Ernst Mayr in his 1954 paper "Change of genetic environment and evolution," and his classic volume Animal Species and Evolution (1963).
Teori ini dipopulerkan oleh Ernst Mayr dalam karya ilmiahnya yang berjudul "Change of genetic environment and evolution" (Perubahan lingkungan genetik dan evolusi, 1954) dan volume klasiknya "Animal Species and Evolution" (Spesies Hewan dan Evolusi, 1963).
New and even beneficial mutations are diluted by the population's large size and are unable to reach fixation, due to such factors as constantly changing environments.
Mutasi yang baru dan menguntungkan dilemahkan oleh populasi yang besar sehingga tak mampu mencapai fiksasi karena faktor seperti lingkungan yang berubah secara konstan.
If this is the case, then the transformation of whole lineages should be rare, as the fossil record indicates.
Jika hal tersebut benar, maka transformasi seluruh garis keturunan seharusnya jarang terjadi, seperti yang ditunjukkan oleh rekaman fosil.
Smaller populations on the other hand, which are isolated from the parental stock, are decoupled from the homogenizing effects of gene flow.
Di sisi lain, populasi yang lebih kecil dan terisolasi dari orang tuanya dipisahkan dari efek aliran gen yang homogen.
In addition, pressure from natural selection is especially intense, as peripheral isolated populations exist at the outer edges of ecological tolerance.
Lebih lagi, tekanan dari seleksi alam terasa kuat karena populasi yang terisolasi berada di luar toleransi ekologis.
If most evolution happens in these rare instances of allopatric speciation then evidence of gradual evolution in the fossil record should be rare.
Jika sebagian besar evolusi terjadi dalam mekanisme spesiasi alopatrik yang langka seperti itu, maka bukti evolusi gradual dalam rekaman fosil seharusnya jarang terlihat.
Gould, for example, was particularly attracted to Douglas Futuyma's work on the importance of reproductive isolating mechanisms.
Gould terutama tertarik dengan karya Douglas J. Futuyma mengenai pentingnya mekanisme isolasi reproduktif.
Gould was initially attracted to I. Michael Lerner's theories of developmental and genetic homeostasis.
Gould tertarik dengan teori homeostatis genetik dan perkembangan I. Michael Lerner.
However this hypothesis was rejected over time, as evidence accumulated against it.
Namun, hipotesis ini telah ditolak karena bukti menunjukkan hal yang sebaliknya.
Other plausible mechanisms which have been suggested include: habitat tracking, stabilizing selection, the Stenseth-Maynard Smith stability hypothesis, constraints imposed by the nature of subdivided populations, normalizing clade selection, and koinophilia.
Mekanisme lain yang telah diusulkan adalah: pelacakan habitat, seleksi penstabilan, hipotesis stabilitas Stenseth-Maynard Smith, batasan alam untuk populasi yang terbagi, seleksi klad penormalan, dan koinofilia.
But the change between generations does not accumulate.
Namun perubahan antar generasi tidak berakumulasi.
This interpretation has frequently been used by creationists to characterize the weakness of the paleontological record, and to portray contemporary evolutionary biology as advancing neo-saltationism.
Interpretasi ini sering kali disalahgunakan oleh kreasionis untuk menunjukkan kelemahan paleontologi dan menggambarkan evolusi kontemporer sebagai neo-saltasionisme.
In an often quoted remark, Gould stated, "Since we proposed punctuated equilibria to explain trends, it is infuriating to be quoted again and again by creationists – whether through design or stupidity, I do not know – as admitting that the fossil record includes no transitional forms.
Gould menjawab, "Karena kami mengusulkan keseimbangan bersela untuk menjelaskan suatu tren, adalah suatu hal yang menyebalkan untuk dikutip secara terus menerus oleh kreasionis - karena sudah direncanakan atau kebodohan, saya tidak tahu - hingga seolah saya mengakui bahwa rekaman fosil tidak menunjukkan bentuk transisional.
Quantum evolution was a controversial hypothesis advanced by Columbia University paleontologist George Gaylord Simpson, regarded by Gould as "the greatest and most biologically astute paleontologist of the twentieth century."
Evolusi kuantum adalah hipotesis kontroversial yang diajukan oleh paleontolog dari Universitas Columbia, George Gaylord Simpson.
Simpson's conjecture was that according to the geological record, on very rare occasions evolution would proceed very rapidly to form entirely new families, orders, and classes of organisms.
Ia menyatakan bahwa berdasarkan catatan geologis, dalam satu kesempatan yang sangat jarang evolusi akan berlangsung dengan sangat cepat hingga membentuk seluruh familia, ordo, dan kelas organisme yang baru.
Simpson's idea was principally concerned with evolution at higher taxonomic groups.
Gagasan Simpson terkait dengan evolusi dalam kelompok taksonomis yang lebih tinggi.
Second, Eldredge and Gould relied upon a different mechanism.
Kedua, Eldredge dan Gould menggunakan mekanisme yang sangat berbeda.
Despite such differences between the two models, earlier critiques—from such eminent commentators as Sewall Wright as well as Simpson himself—have argued that punctuated equilibrium is little more than quantum evolution relabeled.
Meskipun kedua model tersebut berbeda, kritikus awal - seperti Sewall Wright dan G. G. Simpson — menganggap keseimbangan bersela sebagai evolusi kuantum yang menggunakan nama lain.
Punctuated equilibrium is often portrayed to oppose the concept of gradualism, when it is actually a form of gradualism.
Keseimbangan bersela sering kali digambarkan sebagai lawan dari gradualisme, walaupun sebenarnya teori ini merupakan salah satu bentuk gradualisme.
This is because even though evolutionary change appears instantaneous between geological sedimentary layers, change is still occurring incrementally, with no great change from one generation to the next.
Meskipun perubahan evolusioner tampak instan dalam sedimen geologis, perubahan masih berlangsung secara bertahap, tanpa perubahan besar dari satu generasi ke generasi lain.
To this end, Gould later commented that "Most of our paleontological colleagues missed this insight because they had not studied evolutionary theory and either did not know about allopatric speciation or had not considered its translation to geological time.
Gould juga berkomentar bahwa "Sebagian besar rekan kami dalam bidang paleontologi tidak menyadari hal ini karena mereka tidak mempelajari teori evolusi dan tidak mengenal spesiasi alopatrik atau tidak mempertimbangkan penerapannya dalam skala waktu geologis.
Richard Dawkins dedicates a chapter in The Blind Watchmaker to correcting, in his view, the wide confusion regarding rates of change.
" Richard Dawkins dalam bukunya The Blind Watchmaker menulis satu bab untuk mengklarifikasi kesalahan umum mengenai laju perubahan.
His first point is to argue that phyletic gradualism—understood in the sense that evolution proceeds at a single uniform speed, called "constant speedism" by Dawkins—is a "caricature of Darwinism" and "does not really exist".
Argumen pertamanya adalah bahwa gradualisme filetik - bahwa laju perubahan evolusioner itu konstan (dijuluki "speedisme konstan" oleh Dawkins) - hanyalah merupakan "karikatur Darwinisme" dan "tidak sungguh ada."
Variable speedism may also be distinguished one of two ways: "discrete variable speedism" and "continuously variable speedism".
Speedisme variabel juga bisa terdiri dari dua: "speedisme variabel berlainan" dan "speedisme variabel berlanjut."
"Continuously variable speedists", on the other hand, advance that "evolutionary rates fluctuate continuously from very fast to very slow and stop, with all intermediates.
"Speedisme variabel berlanjut" di sisi lain menyatakan bahwa "laju evolusioner berfluktuasi secara terus menerus dari sangat cepat hingga sangat lambat dan berhenti.
" Richard Dawkins regards the apparent gaps represented in the fossil record as documenting migratory events rather than evolutionary events.
Richard Dawkins meyakini bahwa celah dalam rekaman fosil menunjukkan peristiwa migrasi daripada evolusioner.
In his book Darwin's Dangerous Idea, philosopher Daniel Dennett is especially critical of Gould's presentation of punctuated equilibrium.
Dalam bukunya Darwin's Dangerous Idea, filsuf Daniel Dennett mengkritik cara Gould mempresentasikan teorinya.
Dennett argues that Gould alternated between revolutionary and conservative claims, and that each time Gould made a revolutionary statement—or appeared to do so—he was criticized, and thus retreated to a traditional neo-Darwinian position.
Dennett menyatakan bahwa Gould berganti-ganti antara klaim revolusioner dan konservatif mengenai teori ini, dan bahwa setiap kali Gould membuat pernyataan yang revolusioner - atau tampak revolusioner - ia dikritik, dan maka kembali ke posisi neo-Darwin tradisional.
Punctuated equilibria - by Bruce Lieberman and Niles Eldredge All you need to know about Punctuated Equilibrium (almost) Archived 2017-04-27 at the Wayback Machine - by Douglas Theobald Enigmas of Evolution - by Jerry Adler and John Carey, Newsweek
Punctuated equilibria - oleh Bruce Lieberman dan Niles Eldredge All you need to know about Punctuated Equilibrium (almost) Diarsipkan 2017-04-27 di Wayback Machine. - oleh Douglas Theobald