Lamarck's theory of evolution was discredited because it didn't have a __________ basis. What word completes the sentence?

Lamarck's theory of evolution was discredited because it didn't have a scientific basis.

Lamarck proposed that organisms could pass on traits acquired during their lifetime to their offspring. For example, he suggested that if a giraffe stretched its neck to reach higher leaves, its offspring would inherit a longer neck. This idea did not align with the principles of heredity discovered later, which showed that traits are passed through genetic information rather than acquired characteristics. The theory was unable to withstand empirical scrutiny and lacked the rigorous scientific methodology needed to be validated. Later theories of evolution, particularly Darwin's theory of natural selection, provided a more robust scientific framework that accounted for variations in species through genetic inheritance and environmental adaptation.