claim : all living organisms with skeletons are related, but some are more closely related than others
evidence: many animals have similar bone structure, they have bones that have different uses, but they are similar looking and formed. they evolved to change and have different uses but still are related to the common ancestors.
reasoning: this is seen by millions of years of evolution, and dna
I believe that the answer is “ they aren’t sufficiently brief” because the irony is that he’s expected to make brief summaries so since they aren’t brief then that’s irony.