Answer:
New genetic research showed that organisms with similar characteristics were not related to each other.
Step-by-step explanation:
Linnaeus system of classification was based on morphological features such as the morphology of stamen and carpels. however, with new genetic advancement, it was shown that two morphologically similar organisms may have a separate evolutionary history and were not related to each other. Hence, the three-domain system was introduced to classify organisms based on a large number of features (morphological, biochemical, molecular, etc.)