Migration challenges Neodarwinism

-


Article:"The genetics and epigenetics of animal migration and orientation: birds, butterflies and beyond" by Merlin and Liedvogel (2019)

Animal migration is a complex behavior that has developed independently multiple times across the animal kingdom. This Homoplasy is in opposition to a Darwinian tree of common ancestors. Migration is characterized by a seasonal movement to escape unfavorable environmental conditions and reach more-favorable sites during the inimical season. Migration can be extremely demanding, and animals often travel hundreds or even thousands of kilometers to reach their destinations.

While the environmental cues that trigger migration have been well-studied, the genetic and epigenetic basis of migration remains relatively poorly understood. However, recent advances in genomics and epigenomics have begun to shed light on the molecular mechanisms underlying this remarkable behavior.

One of the most promising emerging model systems for studying the genetics and epigenetics of migration is the European blackcap (Sylvia atricapilla). Blackcaps are small songbirds that breed in Europe and migrate to Africa in the winter. Different populations of blackcaps exhibit different migratory phenotypes, with some populations migrating long distances and others migrating short distances.

Genetic studies have identified a number of genes that are associated with migratory behavior in blackcaps. For example, one study found that a gene called ADCYAP1 is involved in regulating the timing of migration. Another study found that a gene called COMPASS is involved in regulating the direction of migration. These genes are turned on and off by epigenetic "tags."

Epigenetic studies have also shown that DNA methylation plays a major role in regulating migratory behavior in blackcaps. For example, one study found that DNA methylation patterns in the brains of blackcaps differ between migratory and non-migratory individuals.

Another promising emerging model system for studying the genetics and epigenetics of migration is the North American monarch butterfly (Danaus plexippus). Monarch butterflies are long-distance migrants that travel thousands of kilometers each year from their breeding grounds in North America to their overwintering grounds in Mexico.

Genetic studies have identified a number of genes that are associated with migratory behavior in monarch butterflies. For example, one study found that a gene called CRY1 is involved in regulating the circadian rhythm, which is essential for migration. Another study found that a gene called CLOCK is involved in regulating the expression of other genes involved in migration. Again epigenetics regulate them.

Epigenetic studies have shown that DNA methylation plays a role in regulating migratory behavior in monarch butterflies. For example, one study found that DNA methylation patterns in the brains of monarch butterflies differ between migratory and non-migratory individuals.

Overall, research on the genetics and epigenetics of animal migration is still in its early stages, but recent advances have begun to shed light on the molecular mechanisms underlying this remarkable behavior. By studying emerging model systems such as the European blackcap and the North American monarch butterfly, researchers are gaining new insights into the complex genetic and epigenetic architecture of migration.

Future directions for research

The authors of the article outline a vision for the future of migration genetics research, emphasizing the need for integrative approaches that combine genomic and epigenomic datasets with behavioral assays. This will allow researchers to identify and functionally validate candidate genes and epigenetic changes that are involved in migration.

In addition, the authors call for more research on the genetic and epigenetic basis of variation in migratory behavior within and between species. This research will help us to understand the evolutionary forces that have shaped animal migration and to predict how migration patterns will respond to future environmental changes.

Migration challenges neoDarwinism:

In addition to the epigenetic complexity of migration, there are a number of other ways in which the study of migration challenges neo-Darwinism. For example, some migratory species exhibit a remarkable degree of navigational accuracy, which is difficult to explain in terms of random mutation and natural selection. Additionally, some migratory species have developed  the ability to learn and transmit migration routes to their offspring, which suggests that cultural epigenetics plays a role in migration.

Lastly homoplasy of these different organisms are not explained by NeoDarwinism. Homoplasy is the development of organs or other bodily structures within different species, which resemble each other and have the same functions, but did not have a common ancestral origin. 

Overall, the study of animal migration provides a number of challenges to neo-Darwinism. These challenges highlight the need for a more comprehensive understanding of the evolutionary forces that have shaped this complex and fascinating behavior.

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