While pinpointing a single discoverer of chromosomes is challenging due to incremental discoveries over time, Walther Flemming is widely credited with the discovery.
Flemming's Contribution
Flemming, in 1882, identified and named the thread-like structures within the cell nucleus as "chromatin." His detailed observations of these structures during cell division significantly advanced the understanding of their role in heredity. Nature.com mentions this widely accepted attribution to Flemming. Further research by Flemming and others established their behavior during mitosis (cell division). Nature Scitable highlights the significance of Flemming's work in this context.
Earlier Observations
It is important to note that earlier researchers made observations that contributed to the eventual understanding of chromosomes. Karl Nägeli, in 1842, observed rod-shaped structures in plant cells, which he termed "transitory cytoblasts." These were later recognized as chromosomes. The provided text explicitly states this.
Subsequent Discoveries
Many scientists built upon Flemming's work. The accurate determination of the human chromosome number as 46 by Tjio and Levan in 1956 is a milestone example. PubMed documents this pivotal discovery. The discovery of the Philadelphia chromosome in 1960 by Nowell and Hungerford further advanced our understanding, linking a specific chromosomal abnormality to a type of cancer. Fox Chase Cancer Center describes this important finding. Later discoveries include the role of telomeres in protecting chromosomes. Nobel Prize details these later achievements.
In summary, while Flemming's work is generally recognized as the pivotal discovery of chromosomes, several other scientists contributed to our present understanding through subsequent observations and research.
