Final answer:
Gregor Mendel contributed significantly to the foundations of population genetics by conducting experiments with pea plants and demonstrating the transmission of traits from parents to offspring.
Step-by-step explanation:
The scientist who contributed significantly to the foundations of population genetics is Gregor Mendel. Mendel conducted experiments with pea plants in the 19th century and demonstrated that traits are transmitted from parents to offspring independently and in dominant and recessive patterns. His work laid the foundation for the fundamental principles of heredity and formed the basis of classical genetics.