Final answer:
Enzyme specificity and function have evolved through gene duplication, mutation, and natural selection, leading to a high degree of substrate specificity. This evolutionary development is evidenced by the induced-fit model and the diversity of enzymatic activities that illustrate adaptive changes over time.
Step-by-step explanation:
The evidence that current enzyme function is a product of evolution comes from understanding the complex relationship between enzymes and their substrates. Enzymes are specific to their substrates; this specificity is not merely an intrinsic property of biochemistry but rather the result of evolutionary processes, such as gene duplication and mutation, that have led to a diversity of enzyme functions. Over time, slight changes, often through mutational events in duplicated genes, can result in novel enzymatic activities that may confer a selective advantage to the organism, thus being retained and refined through natural selection.
Moreover, the induced-fit model of enzyme action supports the evolutionary view by illustrating how enzymes actively adapt their shape to bind substrates, rather than having a fixed conformation. This flexibility allows for the development of enzyme variants with slight structural modifications that can catalyze different reactions, further evidence of evolutionary change. Historical biochemical pathways, adapted enzyme shapes for specific reactions, and the optimized efficiency of current enzymes are all evolutionary products rather than fixed biochemical destiny.