Punctuated Equilibrium support from research? Not!! (Introduction)

by David Turell @, Sunday, June 28, 2020, 15:30 (7 days ago) @ David Turell

New research on the same species Gould used says he was wrong with no support for his theory:


"Evolutionary biologists have for a long time disagreed on the rate of evolution when new species emerge. Are new species the result of gradual changes – as Charles Darwin suggested – or is evolution speeding up for short periods of time when new species evolve?

"World renowned paleontologist Stephen Jay Gould (1941-2002) formulated the theory of punctuated equilibrium together with Niles Eldredge (1943-) in 1972. The theory states that species remain more or less unaltered during their existence, with major evolutionary change happening during rapid events of speciation. As evidence for this view, Gould pointed to the fossil record.


"In a new paper from researchers at the University of Oslo, the authors claim to have found several methodological problems in the most famous and well-trusted example supporting the theory of punctuated equilibrium.

“'We find no evidence for punctuated evolution in our reanalysis of the most recognized dataset that Gould used to support his theory,” says Kjetil Lysne Voje at UiO’s Center for Ecological and Evolutionary Synthesis (CEES) at the Department of Biosciences.

"Fossils of the bryozoan genus Metrarabdotos – a group of aquatic invertebrates thoroughly investigated by the excellent paleobiologist Alan Cheetham – have been the prime example of punctuated evolution.

"Gould called Metrarabdotos “the most brilliantly persuasive, and most meticulously documented, example ever presented for predominant (in this case, exclusive) punctuated equilibrium in a full lineage”

“'We detected some critical methodological issues in the original work on Metrarabdotos. When we take the methodological issues into account, we do not find any evidence of punctuated evolution in our reanalysis of the Metrarabdotos data,” says Kjetil Lysne Voje


"The bryozoan genus Metrarabdotos has been used as a textbook example in evolutionary biology and paleontology, showing how evolution speeds up when new species form compared to a much slower evolution of already established species.

“'But our new results show nothing else than a gradual evolution of the bryozoan species both before, during and after the formation of new species,” emphasizes Voje.

"The idea of ​​fast-track evolution during speciation has been controversial. Critics of the theory of punctuated equilibrium found it difficult to believe that the evolutionary processes leading to new species should be markedly different from the processes that cause already existing species to change.

“'Species are continuously evolving and our results support the hypothesis that evolution does not “behave” differently when new species emerge,” says Voje."

Comment: regarding my bold we only know existing species adapt to change. Gould was concerned about the gaps all over the fossil record. This criticism is not surprising in view of the fact that Gould's Ph.D. thesis about snails has been shown to have errors. Science is self-correcting most of the time.

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