Our current knowledge of genetics might well tempt us to relegate the Mendelian rules of inheritance to an archaic period of genetic history. However, these rules remain the foundations on which our modern knowledge was built. Ortrun Mittelsten Scheid’s article exposes our current knowledge of genetics and inheritance. She argues towards Mendel’s meticulousness being instrumental in allowing him to reach his clear “black-and-white” findings. In addition, Mittelsten Scheid sustains that this same meticulousness allowed Mendel to avoid the pitfalls that might have well led him to findings that are difficult to interpret. In other words, Mendel’s agility and fortune probably allowed him to dodge findings that would fall under non-Mendelian inheritance.
In this article, Mittelsten Scheid dissects the types of non-Mendelian inheritance and historically traces them to times when they could be observed, but hardly explained. We learn that using pea plants might have benefited Mendel in many ways, but that non-Mendelian traits of inheritance also do occur in them. Mittelsten Scheid explains that non-Mendelian patterns of inheritance could be caused by factors beyond simple genetics. These notably include epigenetics and non-genetic factors that affect gene expression without changing the genetic information itself. Additionally, we learn that inheritance patterns that appear to violate the Mendelian rules could also be linked to exclusively genetic reasons. Following a detailed dive into these factors, Mittelsten Scheid concludes with the advantages of plant model organisms such as maize or thale cress that supplanted peas in modern research.
Let us imagine Gregor Mendel living among us today. From this perspective, Frédéric Berger speculates what field of research would have the potential of fascinating this modern Gregor Mendel. Despite the linear relation between modern molecular genetics and the work of the 19th century Mendel, Berger is tempted to guess that the interests of a 21st century Mendel might lie elsewhere. Notably, Berger highlights the limitations and challenges of the field but also notes that Mendel did not appear to show interest in disrupting nature’s laws with his experiments. Hence, Berger argues that manipulating gene activity through molecular genetics might not necessarily be a modern Mendel’s activity of choice.
Instead, Berger argues that the modern Mendel might be interested in population genetics and comparative genomics. The attractiveness of population genetics to a 21st century Mendel might well reside in its overall research strategy. In fact, this field shies away from genetic manipulation. Instead, it examines the variation of genes across populations of living organisms under evolutionary pressure, and thus derives detailed mechanistic knowledge. On the other hand, comparative genomics gives insights into the differences between life forms by comparing whole genomes of various organisms. To note, the genome is the integrity of the genetic material of an organism. Thus, the comparison of whole genomes allows for identifying conserved genes across species as well as individual genes expressing unique characteristics.