Traditionally, the realistic view suggested that the language of science is only a simple, descriptive system that reports natural phenomena. By contrast, a recent view contends that science itself can be the focus of language analysis: the use of scientific language, such as metaphor, analogy, and rhetoric, may play an important role in the science activity. Here I examine the use of two famous metaphors in evolutionary biology ― the 'selfish gene' metaphor and 'spandrel' metaphor ― and their enduring influence on the subsequent development of the field. The 'selfish gene' metaphor simply means that the unit of natural selection, i.e., the level whose replication success is maximized over evolutionary time, is the gene, rather than the individual or the group. However, it came to be widely misunderstood as meaning "humans are innately selfish because of the dictatorship of the selfish gene". Interestingly, despite the metaphor's failure in making difficult concepts easy, it made a huge contribution to establishing the gene-centered view of evolution by arousing intense emotional responses to people's mind. For the case of the 'spandrel' metaphor, it did succeed in making ease the complicated concept that one should carefully discriminate a beneficial but incidental effect from a specific evolutionary function. However, perhaps because it did not lead to intense feelings from people, the influence of the metaphor was largely limited. This article highlights a potentially important issue of whether the use of metaphor in evolutionary biology is distinct from the use in other scientific disciplines.