Answer:
Another important reason why it is harder to cladistically classify extinct (fossil) forms compared to living forms is the lack of genetic information.
When classifying living organisms, genetic information plays a significant role in understanding their evolutionary relationships. DNA analysis and comparisons allow scientists to determine similarities and differences between organisms, helping in the construction of accurate phylogenetic trees and understanding their evolutionary history.
However, with extinct forms, the availability of genetic material is severely limited or absent altogether. Fossils provide information about the anatomical features of organisms, but the genetic material necessary for comprehensive genetic analysis is not preserved in most cases. This absence of genetic data makes it challenging to determine the exact evolutionary relationships and construct reliable phylogenetic trees for extinct forms.
While anatomical traits can still provide crucial information, they often require cautious interpretation due to convergent evolution, analogous structures, and incomplete fossil records. This can lead to uncertainties and difficulties in accurately classifying extinct forms cladistically.
Therefore, along with the incomplete nature of fossil evidence, the absence of genetic information stands as another important reason why it is harder to cladistically classify extinct (fossil) forms compared to living forms.