Blogpost on Homology and Cognacy
Homology is a fundamental concept in evolutionary biology. As is the concept of cognacy in historical linguistics. While both concepts describe similar relations, they are by no means identical, since homology is used to address all instances of common descent, including instances of lateral transfer, while cognacy excludes it. Nevertheless, most computational applications in historical linguistics just treat the two terms as being equal. In my opinion, this may be dangerous, since it can easily lead to wrong analyses, especially when working with software tools that were originally designed for studies in evolutionary biology.