Step 1: Understanding the Problem:
The famous double-helix structural model of DNA was proposed by James Watson and Francis Crick in 1953. This model integrated critical findings from several other pioneer scientists.
Step 2: Approach and Formula:
Review the historical timeline of genetic discoveries and identify which scientists contributed to the structural blueprint of DNA versus those who contributed to understanding its replication mechanism later.
Step 3: Detailed Explanation:
- Maurice Wilkins and Rosalind Franklin utilized X-ray crystallography to produce high-resolution diffraction images of DNA, revealing its helical nature and physical dimensions. This was crucial for the model.
- Erwin Chargaff established the chemical base-pairing rules (Chargaff's rules), demonstrating that Adenine pairs with Thymine and Guanine pairs with Cytosine, forming the model's core internal structure.
- Matthew Meselson and Franklin Stahl conducted their famous density gradient centrifugation experiment in 1958. Their work proved that DNA replicates semi-conservatively. Since their experiment was conducted years {after} the double-helix model was established in 1953, they had no direct contribution to its initial development.
Step 4: Final Answer:
Meselson and Stahl had no contribution in the development of the model.