Homoplasy challenges NeoDarwinism


Neo-Darwinism is a term used to describe the synthesis of Charles Darwin's theory of evolution by natural selection with Gregor Mendel's theory of genetics. It arose in the early 20th century and became the dominant evolutionary theory by the mid-century.

Homoplasy is the development of similar traits in unrelated organisms. This can occur through convergent evolution, when two or more unrelated species evolve similar traits in response to similar environmental pressures. For example, the wings of bats and birds are both adaptations for flight, but they evolved independently from each other.

Here are 10 ways homoplasy challenges Neo-Darwinism:

  1. Homoplasy suggests that the environment plays a more important role in evolution than Neo-Darwinism allows for. In Neo-Darwinism, evolution is driven by natural selection, which is in turn driven by the physical environment. However, homoplasy suggests that the environment can also play a role in evolution by directing the course of convergent evolution.

  2. Homoplasy makes it difficult to reconstruct the evolutionary history of organisms. In Neo-Darwinism, the evolutionary history of organisms is reflected in their phylogenetic tree, which shows how different species are related to each other. However, homoplasy can lead to misleading phylogenetic trees, as unrelated species may appear to be more closely related than they actually are.

  3. Homoplasy suggests that evolution is not always gradual and progressive. In Neo-Darwinism, evolution is typically seen as a gradual process, with new species evolving from existing species through the accumulation of small changes. However, homoplasy suggests that evolution can also be rapid and punctuated, with new species arising through the sudden development of new traits.

  4. Homoplasy challenges the idea that evolution is always adaptive. In Neo-Darwinism, evolution is typically seen as a process of adaptation, with organisms evolving traits that help them to survive and reproduce in their environment. However, homoplasy suggests that evolution can also lead to the development of non-adaptive traits.

  5. Homoplasy suggests that evolution is not always driven by natural selection. In Neo-Darwinism, natural selection is the primary driver of evolution. However, homoplasy suggests that other factors, such as genetic drift and gene flow, can also play a role in evolution.

Overall, homoplasy is a complex phenomenon that challenges some of the key tenets of Neo-Darwinism. It is important to note that homoplasy suggest that the theory of Neo-Darwinism needs to be refined or replaced to account for the full range of evolutionary phenomena.

Here are some additional examples of homoplasy that challenge Neo-Darwinism:

  • The eyes of octopuses and humans are similar in structure and function, but they evolved independently from each other.

  • The wings of insects and bats are similar in structure and function, but they evolved independently from each other.

  • The thorns of cacti and euphorbias are similar in structure and function, but they evolved independently from each other.

  • The venom of snakes and spiders is similar in structure and function, but they evolved independently from each other.

These examples suggest that evolution is not always a gradual and progressive process, and that it is not always driven by natural selection. Instead, evolution can be rapid and punctuated, and it can be driven by a variety of factors, including the environment, genetic drift, epigenetics and gene flow.

Comments

Post a Comment

Popular posts from this blog

Natural Selection has not been accurately measured since Darwin

Image
Francis Crick's term "frozen accident" falsely described the seeming rigidity of the genetic code, its apparent inability to accommodate additional amino acids beyond the standard 20. This observation had puzzled scientists for decades, as the genetic code seems to have reached a plateau in its expansion despite the potential for incorporating new amino acids with novel properties. NeoDarwinian thinking reasoned greater natural selection could occur with more codons. Several hypotheses were put forward to explain this apparent standstill in the genetic code's evolution. Crick and others  eventually applied natural selection to think redundant codons were neutral as to account for neutral selection . The question of why the genetic code stopped incorporating new amino acids remained a fascinating topic in evolutionary biology till Cas9 Crispr. The redundancy of codons, where multiple codons can specify the same amino acid, has long been considered a neutr...
Read more

The Origin at 150: Charting a New Evolutionary Voyage on Post-Genomic Seas

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 are, if not outright overturned, replaced by a new and incomparably more complex vision of the key aspects of evolution. So, not to mince words, the Modern Synthesis is gone.” -EV Koonin, cited by over 250,000 scientists. The Origin at 150: Charting a New Evolutionary Voyage on Post-Genomic Seas As the 150th anniversary of Charles Darwin's epochal "On the Origin of Species" casts a long shadow, evolutionary biologist Eugene V. Koonin throws down a gauntlet in his essay "The Origin at 150: Is a new evolutionary synthesis in sight?" He contends that the Modern Synthesis, the reigning framework since the 1950s, has crumbled under the weight of post-genomic discoveries. This audacious claim compels us to ask: has the ship of evolutionary understanding truly run aground, and if so, can a new v...
Read more

Developmental Plasticity: A Worm's Eye View

Image
Imagine a world where your genes don't dictate your destiny. This isn't science fiction; it's the remarkable reality of developmental plasticity. While the blueprint of life lies within our genes, the environment can sculpt and refine that blueprint, shaping who we become. To understand this fascinating concept, let's shrink ourselves down to the size of a worm, in this case, the transparent roundworm Caenorhabditis elegans (C. elegans). These millimeter-long marvels hold the key to unlocking the secrets of developmental plasticity. C. elegans boasts a mere 1031 cells, each with a predetermined fate – or so we once thought. These worms develop in a remarkably consistent manner, following a precise cell lineage. However, this seemingly rigid program belies a surprising level of flexibility. Environmental cues, like temperature or food availability, can trigger dramatic changes in their development. For instance, when faced with limited food, C. elegans can en...
Read more