Deacon [1] considers that the reverse Baldwin effect can be one of the major forces in language evolution. The reverse Baldwin effect is essentially a redistributional process of genes as a result of environmental changes which mask and unmask selection pressures. Although Deacon indicates that in the case of language evolution, niche construction is deeply involved in masking and unmasking processes, neither specific explanations for the mechanism nor examples have been given. In this study we use evolutionary computation simulations to explore how niche constructing properties of language evolution can induce at least the masking effect, and hence lead to genetic degradation. The simulation demonstrates that the masking effect is indeed a part of the evolutionary process found in the normal Baldwin effect.