Lamarcks Phenotypic Plasticity explains Darwin's Homology and Common Ancestry


Convergent evolution is the process by which unrelated species independently evolve similar traits in response to similar environmental pressures. For example, the wings of bats and birds are both used for flight, but they evolved independently from each other.

Convergent evolution is a challenge to neo-Darwinism because it suggests that natural selection can sometimes produce similar results even when the starting points are very different. Neo-Darwinists argue that convergent evolution is not a problem for their theory because it can be explained by natural selection acting on genetic variation. They point out that there is a limited amount of genetic variation available to any species, and that this variation is often limited to certain functional areas. This means that it is more likely for unrelated species to evolve similar traits if those traits are beneficial in a particular environment.

However epigenetic phenotypic plasticity better explains how limited genetic variation can produce different phenotypes without Darwin.


Critics of neo-Darwinism argue that convergent evolution is too common to be explained by natural selection acting on limited genetic variation. They point out that there are many examples of convergent evolution that involve complex traits that are not easily explained by natural selection. For example, the eyes of octopuses and vertebrates are very similar in structure, even though they evolved independently from each other.

The debate over convergent evolution is ongoing, and there is no clear consensus on whether or not it is a challenge to neo-Darwinism. However, the fact that convergent evolution is so common suggests that natural selection as has challenges explaining these species when they do not share a common ancestor.

Here are some examples of convergent evolution:

  • The eyes of octopuses and vertebrates.

  • The wings of bats and birds.

  • The flippers of whales and dolphins.

  • The trunks of elephants and tapirs.

  • The spines of cacti and rose bushes.

These are just a few examples of the many cases of convergent evolution that have been documented. Convergent evolution is a challenge to neo-Darwinism and natural selection.

Here are some examples of homology that do not support common ancestry:

  • The eyes of vertebrates and cephalopods. Vertebrates and cephalopods (such as squid and octopuses) both have eyes, but the eyes of these two groups of animals are not homologous. The eyes of vertebrates evolved from a light-sensitive patch of skin, while the eyes of cephalopods evolved from a different structure. This means that the eyes of vertebrates and cephalopods are analogous structures, not homologous structures.

  • The wings of birds and bats. Birds and bats both have wings, but the wings of these two groups of animals are not homologous either. The wings of birds evolved from forelimbs, while the wings of bats evolved from fingers. This means that the wings of birds and bats are analogous structures, not homologous structures.

  • The swim bladders of fish. Fish have a variety of different types of swim bladders, and some of these swim bladders are not homologous. For example, the swim bladders of lungfish and bony fish are not homologous, even though they both serve the same function. This is because the swim bladders of lungfish evolved from the lungs, while the swim bladders of bony fish evolved from the gut.

The statement homology is a strong indicator of common ancestry is not foolproof.

Here are some additional challenges of convergent evolution to NeoDarwinism:

  • The frequency of convergent evolution. NeoDarwinism predicts that convergent evolution should be rare, because it requires that the same mutations happen independently in different lineages. However, there are many examples of convergent evolution, both at the morphological and genetic levels. For example, there are many different species of fish that have evolved the ability to swim at high speeds, and these species have all independently evolved the same body shape and swimming muscles.

  • The lack of a clear selective advantage. In some cases, it is not clear what the selective advantage is for convergent evolution. For example, there are many different species of plants that have evolved the ability to produce spines, but it is not clear why this trait is so beneficial.

  • The problem of homology. Convergent evolution can make it difficult to determine homology, which is the relationship between similar structures in different species. For example, the wings of birds and bats are both used for flying, but they are not homologous structures. The wings of birds evolved from forelimbs, while the wings of bats evolved from fingers.

The Darwinian statement "homology implies common ancestry" is indeed circular reasoning if it is defined as follows:

  • Homology: Similarity due to common ancestry.

  • Common ancestry: The shared evolutionary history of two or more species.

Under this definition, the statement "homology implies common ancestry" is true by definition. 


Until the field of paleo epigenetics is developed we can not make conclusions about similar looking fossils. But this field is limited to 150,000 years due the aging of DNA and epigenetic marks in the soil.

Here's why epigenetic phenotypic plasticity explains the illusion of common ancestry and homology.

Scientists discovered different species of ants in amber. Eg



They carbon dated them to be thousands of years apart. They figured they were homologous species of ants with Darwinian common ancestry. 

An evolutionist believing in convergent evolution and Darwinisn homology would  agree.

But I wasn't totally honest. These are modern ants with the same identical genetics. 




How can this be!? It's because the caste system of social insects varies the environment (niche theory) to cause different epigenetic phenotypes for the same genotype. 

This has been shown in many species e.g. Darwin's Finches, Chilids, bees etc. The more scientist look the more this is the case.


There are many examples of species with phenotypic plasticity. Here are a few:

  • Acyrthosiphon pisum, the pea aphid, is a small insect that can switch between asexual and sexual reproduction depending on the environmental conditions. In crowded populations, the aphids will develop wings and fly to new plants, where they can start a new colony. This is an example of adaptive phenotypic plasticity, as it allows the aphids to spread to new areas and avoid overcrowding.

  • Sticklebacks are fish that live in a variety of habitats, including freshwater, saltwater, and brackish water. The morphology of sticklebacks can change depending on the environment they live in. For example, sticklebacks that live in freshwater have shorter fins and thicker bodies than sticklebacks that live in saltwater. This is an example of adaptive phenotypic plasticity, as it allows the sticklebacks to better survive in their different habitats.

  • Dandelions are plants that can grow in a variety of conditions, including full sun, partial shade, and even in cracks in the sidewalk. The morphology of dandelions can change depending on the amount of sunlight they receive. For example, dandelions that grow in full sun will have larger leaves and flowers than dandelions that grow in partial shade. This is an example of non-adaptive phenotypic plasticity, as it does not seem to confer any particular advantage to the dandelions.

  • Humans are also capable of phenotypic plasticity. For example, our body weight can change depending on our diet and exercise habits. This is an example of adaptive phenotypic plasticity, as it allows us to adapt to different environmental conditions.

These are just a few examples of the many species that exhibit phenotypic plasticity. Phenotypic plasticity is a widespread phenomenon that allows organisms to adapt to their environment in a variety of ways.


Just another reason Darwin's convergent evolution fails. 

Comparing old fossils without DNA & epigenetic tags is a fool's errand

These are just some of the challenges that convergent evolution poses to NeoDarwinism.

Here are some additional resources that you may find helpful:

  • Convergent Evolution: An Overview: https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/convergent-evolution

  • The Challenges of Convergent Evolution to neo-Darwinism: https://evolutionnews.org/2015/02/problem_7_conve/

  • Convergent Evolution and the Limits of Natural Selection: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3310996/

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