Why we need a new theory of Evolution

-



Why an extended evolutionary synthesis is necessary by

Gerd B. Müller.

The modern synthesis (MS) of evolutionary biology (THE theory of evolution) has been successful in the past century. However, recent advances in molecular biology, evo-devo, niche construction, epigenetics and other fields have revealed that the MS is incomplete and often inaccurate.

One of the main limitations of the MS is its gene-centeredness. The MS assumes that genes are the primary drivers of evolution, and that phenotypic variation is largely due to genetic variation. However, we now know that genes are not the only factors that influence phenotypic variation. Developmental plasticity, epigenetic inheritance, and niche construction can all play important roles.

For example, developmental plasticity is the ability of organisms to produce different phenotypes in response to different environmental conditions. This means that the same genotype can produce different phenotypes, depending on the environment. This is a major challenge to the gene-centered view of evolution, which assumes that a single genotype corresponds to a single phenotype.

Epigenetic inheritance is the transmission of non-genetic traits from one generation to the next. These traits are not encoded in DNA, but they can still have a significant impact on phenotype. Epigenetic inheritance is another challenge to the gene-centered view of evolution, because it shows that non-genetic factors can also play a role in evolution.

Niche construction is the process by which organisms modify their environment. These modifications can have a significant impact on the evolution of the organisms themselves. For example, beavers build dams, which create new habitats for other organisms. This is a challenge to the traditional view of evolution, which sees organisms as passive recipients of environmental change.

Another limitation of the MS is its focus on gradualism and adaptationism. The MS assumes that evolution proceeds through the gradual accumulation of small, adaptive changes. However, we now know that evolution can also occur through more rapid and less adaptive processes, such as large-scale mutations, hybridization, and symbiogenesis.

For example, large-scale biased mutations can lead to the formation of new genes and the disruption of existing genes. These mutations can have a major impact on phenotype, and they can lead to the rapid emergence of new species. Hybridization is the interbreeding of two different species. This can lead to the formation of new species with new traits. Symbiogenesis is the process by which two or more organisms merge to form a new organism. This is thought to have played a major role in the evolution of eukaryotes from prokaryotes.

Finally, the MS is limited in its scope. It does not adequately explain many important evolutionary phenomena, such as the origin of novelty, modularity, homology, homoplasy, and lineage-defining body plans.

For example, the origin of novelty is a major challenge for the MS. The MS cannot explain how new traits arise, especially traits that are complex and have no obvious adaptive function. Modularity is the organization of complex systems into smaller, independent units. Modularity is a common feature of biological systems, but the MS does not adequately explain how it arises. Homology is the shared ancestry of traits. Homology is a powerful tool for understanding the evolution of organisms, but the MS does not adequately explain the mechanisms that produce homology. Homoplasy is the independent evolution of similar traits in different lineages. Homoplasy is a challenge for the MS because it suggests that evolution is not always adaptive. Lineage-defining body plans are the basic body forms that characterize different lineages of organisms. The MS does not adequately explain the origin of lineage-defining body plans.

Müller argues that an extended evolutionary synthesis is necessary to address the limitations of the MS. An extended evolutionary synthesis would integrate the MS with other theoretical frameworks, such as evo-devo, niche construction, and systems biology. This would allow for a more comprehensive and nuanced understanding of evolution.

An extended evolutionary synthesis would have many benefits. For example, it would help us to understand the role of non-genetic factors in evolution, such as developmental plasticity, epigenetic inheritance, and niche construction. It would also help us to understand how evolution can occur through rapid and less adaptive processes, such as large-scale mutations, hybridization, and symbiogenesis. Finally, it would help us to understand important evolutionary phenomena that are not adequately explained by the MS, such as the origin of novelty, modularity, homology, homoplasy, and lineage-defining body plans.

Overall, Müller's argument for an extended evolutionary synthesis is persuasive. The MS has had some success, but it is clear that it needs to be updated to reflect the advances that have been made in evolutionary biology in recent decades. An extended evolutionary synthesis would provide a more comprehensive and nuanced understanding of evolution, and it would help us to address some of the most important challenges facing evolutionary biology today.


To summarize Müller argues that an extended evolutionary synthesis is necessary for a number of reasons.

  • The modern synthesis (MS) is incomplete and in some cases inaccurate. The MS was developed in the 1940s and is based on the principles of population genetics and natural selection. However, recent advances in molecular biology, evo-devo, niche construction, and other fields have shown that the MS is not able to account for all of the observed patterns of evolution.

  • The MS is gene-centered. The MS assumes that genes are the primary drivers of evolution, and that phenotypic variation is largely due to genetic variation. However, we now know that genes are not the only factors that influence phenotypic variation. Developmental plasticity, epigenetic inheritance, and niche construction can all play important roles.

  • The MS is focused on gradualism and adaptationism. The MS assumes that evolution proceeds through the gradual accumulation of small, adaptive changes. However, we now know that evolution can also occur through more rapid and less adaptive processes, such as large-scale mutations, hybridization, and symbiogenesis.

  • The MS is limited in its scope. The MS does not adequately explain many important evolutionary phenomena, such as the origin of novelty, modularity, homology, homoplasy, and lineage-defining body plans.

An extended evolutionary synthesis would address the limitations of the MS by integrating it with other theoretical frameworks, such as evo-devo, niche construction, and systems biology. This would allow for a more comprehensive and nuanced understanding of evolution.

Some of the benefits of an extended evolutionary synthesis include:

  • A better understanding of the role of non-genetic factors in evolution, such as developmental plasticity, epigenetic inheritance, and niche construction.

  • A better understanding of how evolution can occur through rapid and less adaptive processes.

  • A better understanding of important evolutionary phenomena that are not adequately explained by the MS, such as the origin of novelty, modularity, homology, homoplasy, and lineage-defining body plans.

Overall, Müller argues that an extended evolutionary synthesis is necessary to provide a more accurate and complete understanding of evolution.

Comments

Post a Comment

Popular posts from this blog

No, the EES is not just a add on to Neo-Darwinism aka the Modern Synthesis

-
Image
" The summary of the state of affairs on the 150th anniversary of the Origin is somewhat shocking: in the post-genomic era, all major tenets of the Modern Synthesis fthe theory of evolution) are, if not outright overturned replaced by a new and incomparably more complex vision of the key aspects of evolution (EES). So, not to mince words , the Modern Synthesis is gone" -Eugene Koonin, an evolutionary biologist (Cited by over 270,000 evolutionary scientists.) The Extended Evolutionary Synthesis (EES) represents a significant departure from the traditional neo-Darwinian framework, also known as the Modern Synthesis . While both theories aim to explain evolutionary change, they differ fundamentally in their underlying mechanisms and the roles they assign to various biological processes. A crucial point of divergence lies in the interpretation and application of the term " evolutionary ," particularly concerning the incorporation of epigenetic mechanisms....
Read more

Is the random mutational model of evolution on its way out?

-
Image
While the random mutational model of evolution has long been a cornerstone of evolutionary biology, the Extended Evolutionary Synthesis (EES) and the study of epigenetics are challenging its core assumptions. The Random Mutational Model and Its Limitations The traditional view of evolution, often called the Modern Synthesis or neo-Darwinism , emphasizes random genetic mutations as the primary source of variation. Natural selection then acts upon this variation, favoring individuals with advantageous traits. This model has been successful in explaining some evolutionary phenomena, but it also has limitations: It struggles to explain complex adaptations: The idea that complex features like the eye or the immune system arose solely through random mutations seems statistically improbable. It overlooks the role of the environment: The traditional model treats the environment as a selective force, but it doesn't fully consider how organisms can actively respond to and s...
Read more

ERVs and Common Descent: A Reassessment in Light of Recent Findings

-
Image
Endogenous retroviruses (ERVs) have long been considered strong evidence for the common descent of humans and chimpanzees. These remnants of ancient viral infections, embedded in the genomes of both species, were once thought to be non-functional "junk DNA." The premise was that the shared presence of these seemingly random insertions in corresponding genomic locations could best be explained by a shared evolutionary history. However, recent research, such as the "Switching Sides" article published in May 2021, has challenged this assumption by demonstrating that ERVs play a functional role in the development of the human embryo and immune system. This discovery raises questions about the validity of using ERVs as primary evidence for common descent. The Traditional Argument for Common Descent The traditional argument for common descent based on ERVs rests on the following points: Random Insertion: Retroviral insertions are thought to occur randomly in...
Read more