Centennial of Wilhelm Waldeyer's introduction of the term "chromosome" in 1888

Why Do Heterosporous Plants Have So Few Chromosomes?

The mechanisms controlling chromosome number, size, and shape, and the relationship of these traits to genome size, remain some of the least understood aspects of genome evolution. Across vascular plants, there is a striking disparity in chromosome number between homosporous and heterosporous lineages. Homosporous plants (comprising most ferns and some lycophytes) have high chromosome numbers compared to heterosporous lineages (some ferns and lycophytes and all seed plants). Many studies have investigated why homosporous plants have so many chromosomes. However, homospory is the ancestral condition from which heterospory has been derived several times. Following this phylogenetic perspective, a more appropriate question to ask is why heterosporous plants have so few chromosomes. Here, we review life history differences between heterosporous and homosporous plants, previous work on chromosome number and genome size in each lineage, known mechanisms of genome downsizing and chromosomal rearrangements, and conclude with future prospects for comparative research.

Wilhelm Waldeyer-An Important Scientific Researcher of the 19th Century in the Context of His Memoirs and Major Monographies

Wilhelm Waldeyer was one of the most important anatomists of his time. The year 2021 marks the 100th anniversary of his death. His name not only lives on in terms such as “Waldeyer's pharyngeal ring” or “Waldeyer's fascia,” he also coined the terms “neuron” and “chromosome.” He produced monumental monographies such as “The Pelvis” and “Ovary and Egg”. Waldeyer's legacy is a large body of lifetime work that continues to impress to this day. However, he also published works that today would be described as racist. His view of a woman's role was and is also controversial. Nevertheless, reading his autobiography (Lebenserinnerungen) today is still beneficial because it vividly illustrates the academic life and a scholarly existence of that era.

Wilhelm von Waldeyer-Hartz-A Great Forefather: His Contributions to Anatomy with Particular Attention to "His" Fascia

Wilhelm Waldeyer was, at his time, one of the most well-known authors in the field of Anatomy, Pathology, and Embryology. He held various distinguished academic positions. He was Professor of (Pathological) Anatomy in Breslau, Strasbourg, and Berlin. He remained in Berlin for the unusually long period of 33.5 years, as Full Professor for Anatomy and Director of the Anatomical Institute. His great talent as a teacher ensured that his lectures were always filled to the brim. Between 1862 and 1920, he published 270 works, including classics such as “Das Becken” (The Pelvis). The portrayal of this most important area is counted as one of the most complete which has ever been accomplished in the field of topographic anatomy, it includes the description of the fascia of Waldeyer. He also coined the phrases “chromosome” and “neuron” with their anatomical–morphological concepts. Already during his lifetime, his teaching ability significantly preceded the research capacity. It would, however, be false to overshadow Waldeyer’s merits as a researcher. His main scientific merit is in his excellent summarizing interpretations of current questions of anatomy and evolution, which particularly shows his simultaneous gift as a researcher and a teacher.