Mutational Bias Challenges Neo-Darwinism

When I was pursuing my degree in biology in the late seventies on the way to my medical degree, neo-Darwinian “random mutations” were thought to be a “fact like gravity.” From a naturalistic perspective, evolution is driven by mutations, which stem from damaged, unrepaired DNA. The resulting genes provide the genetic variation found in all organisms.

It seems that things have changed, though not for gravity. Two new studies show that mutations are not random as neo-Darwinism holds. These discoveries challenge 100 years of evolutionary dogma.

Mutations and Genetic Consequences
The first research effort contests the prevailing axiom that mutations occur randomly with respect to their genetic consequences.¹ Some of those consequences include how organisms attain their genetic variability. The authors found that mutations occur less often in functionally constrained regions of the genome, such as gene bodies and essential genes. This discovery suggests that mutation bias is not random.

The findings of this study overturn the axiom of random mutations in two ways. First, they show that mutations are not evenly distributed throughout the genome, but are instead concentrated in certain regions. Second, they show that mutation bias is not simply a byproduct of natural selection, but is also an active force that helps to shape the evolution of genomes.

This advance has important implications for our understanding of evolution. It suggests that mutation bias is a powerful force that can help shape the evolution of genomes. This is because mutation bias can help to reduce the accumulation of deleterious (harmful) mutations, which can lead to the evolution of new and beneficial traits.

The researchers’ work also has implications for our understanding of human evolution. It’s reasonable to consider that mutation bias has played a role in the development of human traits, such as our large brains and our capacity for language. This active area of research is likely to yield further insight about the role of mutation bias in human evolution in the years to come.

Here are some of the key takeaways:

• Mutations do not occur randomly with respect to their consequences.
• Mutation bias can help to reduce the accumulation of deleterious mutations.
• Mutation bias may have played a role in the evolution of human traits.

As the authors note:

“Our discovery yields a new account of the forces driving patterns of natural variation (i.e. natural cellular mechanisms), challenging a long-standing paradigm regarding the randomness of mutation and inspiring future directions for theoretical and practical research on mutation in biology and evolution.”²

This study provides a significant contribution to our understanding of evolution, and it has the potential to change the way we think about the role of mutations in evolution.

Mutations May Not Be Random
A second research team found evidence that mutations may not be as random as previously thought. The study, led by researchers from the University of Haifa in Israel, found that the generation rate of the HbS mutation, which protects against malaria, is higher in people from Africa, where malaria is endemic, than in people from Europe, where it is not.³

This finding challenges the core assumption of neo-Darwinism, which states that mutations are random events that occur with equal probability in all genes. The researchers suggest that the HbS mutation may be generated preferentially in the gene and in the population where it’s of adaptive significance.

Here are two key takeaways from the study:

• Mutations are not as random as previously thought.
• The rate of generation of certain mutations may be influenced by environmental factors.

This discovery is the first to provide evidence of nonrandom mutation in human genes. This means that it has the potential to fundamentally change our understanding of evolution and the role of mutations in the process.

The study’s findings have been met with mixed reactions from the scientific community. Some scientists have hailed the study as a major breakthrough, while others have been more cautious in their assessment. It will be interesting to see how the research community responds to these findings in the coming years. For now, it appears that a major tenet of Darwinian evolution may be refuted. The words used to discuss genetic mutations (“preferentially,” “bias”), seem to point to the intentional design of a Creator.

Endnotes

1. J. Grey Monroe et al., “Mutation Bias Reflects Natural Selection in Arabidopsis thaliana,” Nature 602 (January 12, 2022): 101–105, https://doi.org/10.1038/s41586-021-04269-6.
2. Monroe et al., “Mutation Bias Reflects Natural Selection.”
3. Daniel Melamed et al., “De Novo Mutation Rates at the Single-Mutation Resolution in a Human HBB gene Region associated with daptation and Genetic Ddisease,” Genome Research January 14, 2022): 488–98, doi:10.1101/gr.276103.121.