Within Creation Science, is there an objective meaning to biological taxonomy?

Recently, I was discussing with some other users on this site the question of whether birds are dinosaurs or not. *(If you have a strong opinion on that, no need to leave a comment on this post - the discussion is in this chatroom .)* This leads to a slightly different topic, i.e. how organisms are classified in the first place. For the evolutionist, the question of whether birds are dinosaurs is a question of fact. In evolutionary biology, taxonomy is meant to reflect the family tree of organisms descended from a common ancestor. Therefore, a grouping is a claim of objective fact. Granted the *rankning* of taxa as "genus" or "family" etc. is subjective, but there is an objectively correct nesting based on ancestry. For instance, the category of "Mammalia" is all the descendants of the ancestral mammal. "Chiroptera" is all the descendants of the ancestral bat. When evolutionists classify bats as mammals, they are making the factual claim that the ancestral bat is descended from the ancestral mammal. (And of course, the existence of an objectively correct nesting should never be interpreted to mean that it can always be accurately discerned.) For the creationist, on the other hand, I don't see any apparent objective standard for classifying organisms that aren't descended from a common ancestor. On the topic of birds and dinosaurs, for instance, many creationists hold that birds are definitely not dinosaurs. Of these, Answers in Genesis is probably the most hardcore. They claim that this position is necessitated by Scripture , and go so far as to accuse young-earth creationists who believe otherwise as compromising with evolutionists and label them "Young Earth Evolutionists". They argue as follows: > Dinosaurs are land-dwelling animals. That means they were made on day six of creation (Genesis 1:24–25). Almost all birds are flying creatures to some degree, and they all have wings. Therefore, they most likely were all made on day five (Genesis 1:20–22). By saying or agreeing with the evolutionary claim that birds are dinosaurs or are most similar to dinosaurs, Dr. McLain is mixing groups made on different days of creation. However, AiG are somewhat inconsistent on this standard, as pointed out by this blog post by Joel Duff. The Bible classifies bats as birds (Leviticus 11:19), while Answers in Genesis is happy to teach children that bats are not birds but mammals. Also, other creation science organizations are more open minded. For instance: > However, the Bible uses functional classifications, according to the mode of locomotion and where they live, not anatomical ones...So on Day 5, the air creatures are called *‘ôph*, a generic word for flying creatures. This includes not only birds, but also bats and pterosaurs. Feathers are not mentioned. Similarly, there is nothing about the Day 6 land creatures that says that they cannot have feathers. **Thus creationists can’t rule out ‘feathered dinosaurs’ from Scripture alone.** > > "Did dinosaurs evolve into birds? " by Carter and Sarfati, published by Creation Ministries International. [emph. add] All this raises the question of how animals (or plants) can be classified objectively. It is not apparent what criteria are being used to determine whether bats are birds or mammals, other than the subjective judgment that they seem more mammalish than birdish. **Is there an objective standard which determines that traits like fur and lactation are more fundamental for classification than wings and flight?** Within the context of creation science, is the claim that bats are birds not mammals a claim of some objective reality? AiG does have an article related to this topic: "How Should Christians View Biological Classification? " by Henry F. Sanders, III. This goes at great lengths to criticize the evolutionary assumptions behind modern taxonomy, and calls for a return to Linnaeus's original idea. However, they give no argument that Linnaeus's system is *actually* correct. Sanders's conclusions are a little hard for me to construe. To those who would throw out taxonomy altogether, he says: > Some Christians have rejected taxonomy entirely in favor of a purportedly more biblical system. However, this position is functionally untenable. (I'm not sure exactly what he's referring to here.) His concluding argument in favor of Linnean taxonomy is based solely on practicality: > Having a system of classification, **however arbitrary,** is better than the abject disorder that would result without it. Removing the Linnaean system would return taxonomy to the veritable “Wild West” that it was before Linnaeus published his work, with names at the discretion of the taxonomist. This is certainly not a desirable outcome, nor could a Biblical replacement be achieved under the current ruling paradigm in the scientific community. > > [emph. added] They don't go as far as to say Linnean taxonomy is *actually* arbitrary, but make the softer claim that even if it is, it's still useful. So that's all building up to my main question: **For the Creation Science movement, is there an objective meaning to Linnean taxa (above the *baramin*-level)? Or are higher-level taxa indeed arbitrary?**