Over the years, many models for classifying organisms have been touted as the next best one. Linnaeus's scheme of classifying everything into two kingdoms was the first real attempt, and it lasted for more than 200 years! However, because living organisms are so diverse, Linnaeus's classification system is considered inadequate today as a means of accurately representing the degree of relationship between organisms. More advanced thinking created first a five-, then a six-, then a three-kingdom classification system to include all the recent discoveries related to kinship. It is likely that as more discoveries are made and more data processed, the three-kingdom model may be in jeopardy