Introduction

The article explores how understanding cancer as an evolutionary disease can offer new insights into evolutionary biology itself. It argues that the study of cancer, particularly the rapid and large-scale genomic changes seen in tumor cells, provides models for understanding macroevolution in a broader biological context.

Key Concepts

1. Macroevolution vs. Microevolution

Cancer progression is characterized by macroevolution, involving large-scale genomic rearrangements (karyotype changes), rather than microevolution, which focuses on localized mutations.

Chromothripsis and Chromoplexy

Two distinct forms of rapid genome restructuring are discussed:

• Chromothripsis: “Chromosome shattering,” where chromosomes are fragmented and reassembled in a single event.
• Chromoplexy: “Chromosome weaving,” involving multiple linked rearrangements across different chromosomes without duplications.

These phenomena illustrate how cells can rapidly reorganize their genomes in response to stress, suggesting similar mechanisms might operate in broader evolutionary contexts.

3. Genome Restructuring and Cancer Evolution

Cancer cells can undergo dramatic genome reorganizations, which are often triggered by cellular stress, leading to new cancerous traits such as malignancy or treatment resistance. This indicates that eukaryotic cells possess ancient, conserved mechanisms for major genome changes.

4. Lessons for Evolutionary Biology:

• Rapid Genome Restructuring: The capability of cancer cells to rapidly reorganize their genomes offers a model for understanding punctuated evolutionary changes, such as those seen in the fossil record after mass extinctions.
• Stress-Induced Evolution: Stress-induced processes, like the formation of polyploid giant cancer cells (PGCCs), provide evidence that genomic changes can be a response to environmental pressures.

Implications for Evolutionary Theory

The study of cancer biology suggests that macroevolutionary events might occur more frequently and more rapidly than previously thought, driven by stress and facilitated by specific, evolved cellular mechanisms. This has implications for how we understand evolutionary processes, particularly the potential for rapid adaptation and speciation in response to environmental challenges.

Conclusion

The integration of insights from cancer biology into evolutionary theory emphasizes the need to rethink some traditional views of evolution, particularly the rate and mechanisms of significant genomic changes. Understanding these processes could also have practical implications in oncology, guiding more effective treatment strategies to avoid promoting further cancer evolution.

Reference

Shapiro, J. A. (2021). What can evolutionary biology learn from cancer biology?. Progress in Biophysics and Molecular Biology, 165, 19-28.