Protein based Inheritance outside of Neo-Darwinism

Protein-based inheritance is a type of epigenetic inheritance in which changes in the structure or function of proteins are passed on to subsequent generations. This type of inheritance is not dependent on changes in DNA sequence, and can therefore occurs  independently of neo-Darwinian evolution.

There are several different mechanisms of protein-based inheritance. One mechanism is through the process of prion propagation. Prions are misfolded proteins that can induce other proteins to fold in the same conformation. This can work with the DNAs chromatin to guide changes for thousands of generations.


Another mechanism of protein-based inheritance is through the process of RNA interference (RNAi). RNAi is a gene silencing mechanism that involves the degradation of RNA molecules. RNAi can be triggered by the presence of double-stranded RNA, which can be generated by the cleavage of RNA by an enzyme called Dicer.

Protein-based inheritance has been shown to play a role in a variety of biological processes, including aging, development, and disease. It is also thought to be a potential mechanism for the inheritance of acquired traits.

The discovery of protein-based inheritance has challenged the traditional view of neo-Darwinian evolution, which holds that genetic inheritance is the only mechanism for the transmission of traits from parents to offspring. Protein-based inheritance provides a new way to think about how evolution can occur, and it may open up new possibilities for the development of new therapies for diseases.

Here are some specific examples of protein-based inheritance outside of neo-Darwinism:

  • In yeast, the prion [PSI+] can cause a change in the phenotype of cells, making them more resistant to stress. This change can be inherited by subsequent generations of cells, even though the DNA sequence of the cells does not change.


  • In plants, the RNAi pathway can be used to silence genes that are involved in flower development. This can be used to create plants with novel flower colors or shapes.

  • In humans, the prion protein PrP is involved in a number of diseases, including Creutzfeldt-Jakob disease. Mutations in the PrP gene can lead to the formation of misfolded PrP proteins, which can then propagate through the brain, causing damage and eventually death.

These are just a few examples of the many ways in which protein-based inheritance can occur outside of NeoDarwinism. As research in this area continues, we are likely to learn more about the role that protein-based inheritance plays in a variety of biological processes.

Article Snippets

"Protein-based inheritance"

Epigenetic mechanisms of inheritance have come to occupy a prominent place in our understanding of living systems

There has been considerable and lively discussion of the possible evolutionary significance of transgenerational epigenetic inheritance.

One particular type of epigenetic inheritance that has not figured much in general discussions is that based on conformational changes in proteins, where proteins with altered conformations can act as templates to propagate their own structure

An increasing number of such proteins – prions and prion-like – are being discovered.

Phenotypes due to the structurally altered proteins are transmitted along with their structures

Charles Darwin never completely dismissed the possibility of some Larmackian mechanism operating along with natural selection acting on inherited variation.

Indeed, his panspermia theory of inheritance through gemmules could accommodate the idea without much difficulty,

with the development of classical, population and molecular genetics leading to the elaboration of Neo-Darwinian evolutionary theory, Lamarckian inheritance acquired virtual untouchability status

Epigenetics remains somewhat vaguely defined, meaning different things to different people

The term was coined by Waddington [3], who defined it as “the branch of biology that studies the causal interactions between genes and their products which bring into being the phenotype”, primarily with reference to the unfolding of embryonic development through the interaction of genes with the cellular environment of the embryo

Nanney [4], who proposed that epigenetic mechanisms “allow the perpetuation of phenotypic differences in the absence of DNA differences

Riggs and colleagues defined it as “the study of mitotically and/or meiotically heritable changes in gene function that cannot be explained by changes in DNA sequence

Broadly, the term epigenetics is currently most often considered to mean heritable transmission of altered traits or gene expression states not based on changes in DNA sequence

Much of epigenetic transmission is mitotic and occurs between cells of an individual (is ‘intragenerational’)

Epigenetic inheritance has, however, in a rapidly growing number of cases, also been found to be transgenerational, and transmitted through meiosis.

journal Heredity (Aug 10 2018) on “Evolutionary consequences of epigenetic inheritance”

These developments have led to challenges to the standard Neo-Darwinian view, including calls for an “extended evolutionary synthesis” (EES), incorporating epigenetic aspects of inheritance into evolutionary theory

The case for and against the need for such a revision of evolutionary theory leading to an EES has been debated by prominent evolutionary biologists in the pages of Nature [17], and the evolutionary implications of epigenetic mechanisms discussed in Science [18].

protein-based inheritance. Here, traits are transmitted directly by proteins through changes in their structure, rather than indirectly by modifying the expression of genes (as occurs with chromatin-based epigenetic mechanisms

Altered cellular states occur as a result of conformational changes in proteins, which are independent of any sequence changes in the encoding DNA; the conformationally altered proteins act as templates to propagate their structure by inducing “normally” folded proteins to adopt the alternate structure.

Information is transmitted in these cases not through sequence, as with nucleic acids, but through protein conformation.

another landmark paper published by Wickner marshalled evidence that suggested the URE3 phenotype was transmitted by a protein

Significantly, regulators of gene expression and nucleic acid binding proteins are strongly over-represented among prion-forming proteins.

The prions described in the past decade now include not only the growing number characterised in fungi, but in prokaryotes and multicellular eukaryotes as well.

Furthermore, it is emerging that the aggregation and self-templating properties of prions are not restricted to amyloid-forming proteins, but include a much wider range of proteins with so-called intrinsically disordered domains (IDDs).

The dust has not yet settled on the nomenclature for proteins that can transmit information epigenetically.

With a number of non-amyloid proteins also showing aggregation, templating and self-propagating behaviour, these recently discovered examples are generally still cautiously referred to as “prion-like”.

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