If you call the warm blooded, feathered, flying or flightless dinosaurs reptiles, all what’s left is to agree to disagree,
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But by that reasoning then crocodiles can’t be reptiles either…
Why not? In the traditional sense, some of the primary defining traits of reptiles are being cold blooded, having scales, and breathing with lungs/not possessing gills. Crocodiles have all of these traits, while birds do not (they are warm blooded and have feathers and no scales)
Birds have scales on their legs and feet.
Trivial point, but I make it only partly because I am so pedantic. The other reason is that I’ve seen the young-earth creationist argument “birds can’t be descended from reptiles/dinosaurs – have you ever seen a bird with both feathers and scales?” I really did read that. I wanted to respond, “Walk into a pet store and take a close look at the parakeets!” Young earth creationists are wrong, but we’re all often wrong about things. My frustration is, there are more intelligent ways to be wrong about this.
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I guess you are right about scales on birds feet, had never really thought of that as “scales” but I guess they could qualify as such. Not trying to start a debate, but even if you do not agree with creationism, dismissing it as being based on stupidity or ignorance is not accurate. For example, the evidence cited as proof of common ancestry across all life is not completely dismissed by Christians/creationists, but rather interpreted as the work of a “common creator” who designed similar structures across diverse lifeforms, which still have the ability to adapt/“horizontally evolve” into the extreme species diversity we have today.
Edit, I think I misread the above post, it was more criticizing that specific argument about birds and scales than calling creationists in general stupid. I definitely agree that arguing for creationism based on the presence or absence of scales on birds is not a good argument, to say the least. Unfortunately for adherents to belief systems considered controversial or non-mainstream by society as a whole, the weakest arguments are often the most publicized for purpose of ridicule
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This is part of the misunderstanding, no offense. Taxonomy began mostly with Carl Linnaeus as a way to classify according to physical attributes, before the theory of evolution. Now taxonomy is understood as classifying evolutionary lineages according to relationships between the lineages. Therefore birds and crocodiles are each others most closely related lineages, and as such birds should be treated as reptiles if crocodilians are imo.
I don’t think any of these traits are drastic enough to warrant treating birds or dinosaurs separately. Many reptiles have primitive methods for regulating body temperature (i.e. alligators, some turtles, and female pythons with eggs), and feathers (or fur for that matter) are basically just highly specialized scales.
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I’m aware that modern cladistic taxonomy treats crocodilians as being more closely related to birds than to lizards, my point was that this is yet another illustration of how traditional taxonomy is simply more practical and sensible to the average person than cladistic taxonomy. Crocodiles and other “traditional” reptiles such as lizards share more observable characteristics in common than they do with birds, therefore I would argue it makes more sense to group them the way they have been traditionally grouped. After all, taxonomy’s purpose is simply to help humans categorize things, and I believe basing this categorization on physical traits is more practical than basing it on theoretical evolutionary relationships. I am aware most scientists would disagree on this, but that’s my opinion
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I beg to differ. Science by definition assumes that there is objective truth, or a reality which exists independently of human perception. Also by definition, science can’t ever make a claim to an ultimate truth or reality (since it uses inductive reasoning), but that does not mean there is not an ideal for it to strive for.
Which is why it is inhibitive and unscientific to use early pre-evolutionary theory taxonomy and classify solely for the purpose of human categorization and cataloguing. So no, taxonomy is not simply to help humans categorize things.
That does not mean that in scenarios where the goal is public outreach to the uninformed (like iNat) this needs to be forcefully implemented, but among experts there should be an understanding of real taxonomic methods, and the implications of these methods (in this case that birds are archosaurian reptiles, like crocodilians).
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Note that I specified “young-earth creationists.” There are many flavors of creationism and some are entirely compatible with evolution as biologists understand it. Even within the forms that are not, there are ideas that although mistaken in some way are not unreasonable. Or they’re reasonable arguments based on incorrect information. (I have a very intelligent brother who is a creationist, not of course a young-earth creationist. Sometimes we disagree.)
That statement that “you’ve never seen a bird with both feathers and scales” statement was from a particularly unreasoned and uniformed but unfortunately well illustrated publication. In general, I spend my attention on better arguments than that. It’s just that that one particularly annoyed me because it took so little effort to see how uninformed it was. I mean, just look closely at any well focused photo that shows the feet!
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Didn’t we also evolve from reptiles?
The line that mammals belong to (synapsids) diverged long before the lines the lead to extant reptiles, dinosaurs, and birds. So mammals can be put into a monophyletic clade. When people say mammals evolved from reptiles, they are using a very loose sense of the term “reptiles”.
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I am a 6-day creationist. I do not reject science as a whole, but believe it is more limited than many people think, especially when it comes to attempts to explain phenomena that cannot be directly observed, such as what happened in the distant past. I am aware of the evidence cited for macroevolution, including fossil records, genetics, similarities between different types of organisms and more, but believe there are more ways to interpret said evidence than the interpretation that is currently accepted by most scientists. Ultimately, all worldviews come with assumptions and presuppositions, and as much as we like to think we are objective, every one of us (yes, including myself) is shaped by these presuppositions.
A good example of this is the hypothesis of abiogenesis, which despite lacking any solid evidence that it is even a possibility (there has been no experimental evidence that life itself, not merely the chemical building blocks of life, can ever arise from non-life), is presupposed to have happened by most mainstream scientists.
Not trying to turn this thread into a creation vs evolution debate, but just wanted to offer my perspective since the issue got brought up
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I disagree with you, of course, but I agree that abiogenesis is one of the better places to argue against evolution. We can’t and never will have direct evidence of how it happened. We can figure out what’s possible chemically, and whether there are situations on earth that allowed that. (There’s good reason to think that yes, it could happen.) Nick Lane’s book The Vital Question discusses this in detail, along with another of the better places to argue against evolution, the formation of the first eukaryotic cell. That process starts with something rare that has occasionally been observed, one prokaryote living as a parasite within another prokaryote. Then the situation becomes very complex because of the disruptions the parasite (and its viral parasites!) cause for the host cell and the evidence for that disruption. Fascinating stuff.
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Actually the evidence for evolution is incredibly strong regardless of exactly how life originated, which is indeed still a challenge to explain. Even if primitive life on earth was created, which demands its own explanation, the subsequent evolution of that life into more complex forms is supported by evidence. I don’t know any evolutionary biologists who have discarded their acceptance of evolution based on lack of understanding how it all got started.
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I find the recent scientific discoveries at the other end of the observation range very intriguing.
For example, the announcement a few weeks ago that the samples collected off the Bennu asteroid contained 14 of the 20 amino acids found in life on Earth. Could this lend credence to the theory that the seeds of life arrived here rather than evolved out of early terrestrial conditions?
Could confirming that the origin of life on earth actually to be of non-earth origin change the debate?
And then there’s the Webb telescope which is rapidly rewriting the whole timeline of events of the early universe. Plus other new evidence such as how extraterrestrial water may be much more abundant than we previously thought.
It’s interesting to me that space exploration and the biology that is now such a part of that research, brings together the need to understand both incredibly small and incredibly large things to move forward in understanding how it all came to be.
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It certainly is fascinating stuff, I can agree with you on that at least
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Which leads to the question, how are reptiles defined?
If mammals are defined by warm-bloodedness, lactation, and hair; and birds are defined by warm-bloodedness and feathers, what defines reptiles as distinct from synapsids?
A laundry list of things separate extant reptiles and birds from synapsids. A lot of our language that we use when talking about the taxonomy of extant groups isn’t suited to or even meant for long-extinct organisms. There are often so many gaps in the fossil record that clades aren’t assigned taxonomic levels in the same way they are for extant species.
So why is this conversation relevant for birds and not mammals? Because extant reptiles are not monophyletic without birds, but mammals are monophyletic, separate from all extant reptiles.
Note: this is just to explain why this same conversation doesn’t have the same relevance to mammals as it does to birds. I don’t really have an opinion on making reptiles monophyletic by adding birds vs. just accepting that reptiles are paraphyletic (as long as we know and acknowledge it as such).
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A paper from 2017 actually induced scale formation from feathers by editing specific genes in chicken embryos, and likewise, they were able to turn alligator scales into rudimentary structures that resembled feathers on the same gene. Both feathers and crocodilian scales are also made of the same thing- Beta-Keratin.
https://academic.oup.com/mbe/article/35/2/417/4627828?login=false
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It’s right there in the name…synapsid. A single skull opening (fenestra) low on the skull behind the eye. Birds are diapsids (two fenestrae). Reptiles are all either diapsids or secondarily anapsids (turtles). The parapsids (one upper fenestra) are all extinct.
In addition, jaw articulations in synapsids are vastly different with a ball-and-socket like articulation using the dentary and squamosal bones. In reptiles the articulation isn’t well developed and more just held together with ligaments (which is why reptiles can’t chew their food like mammals) using the quadrate and articular bones (and angular bone in things like snakes). The quadrate and articular were modified into our ear bones and is generally accepted as the defining trait for distinguishing early synapsids from sauropsids. Meaning those other traits (endothermy, hair) aren’t what defines a synapsid as a synapsid.
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