1211: "Birds and Dinosaurs"

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Misanthropic Scott
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Re: 1211: "Birds and Dinosaurs"

Postby Misanthropic Scott » Tue May 14, 2013 9:12 am UTC

ijuin wrote:
WriteBrainedJR wrote:
Misanthropic Scott wrote: Actually, I'm going to need to ask for a link to something backing up that claim about insects. They may be the most diverse group of animals. They are certainly not more numerous than bacteria.


A major problem with determining the number of bacteria species is that the classic definition of "species" (i.e. the ability/inability to interbreed) does not properly apply to creatures that almost exclusively reproduce asexually. Thus, we have to fall back on genetic analysis and make something of an arbitrary distinction regarding how different two bacterial strains must be in order to qualify as distinct species.


That old definition of species doesn't work even for sexually reproducing species. We've learned a lot since then. For example, many black duck females prefer the showier mallard males. They breed fertile offspring and are still recognized as different species, even with the existence of hybrids. Similarly, homo sapiens interbred with homo neanderthalensis. No one suggests that these are the same species.

So, the whole concept of species has gotten somewhat muddled and is somewhat subjective for closely related species. That's why groups formerly called subspecies may now be granted full species status and vice versa. The lines are being redrawn in light of new information and subjective analyses. Gorillas used to all be considered the same species with separate subspecies. Now we recognize mountain gorillas, western lowland gorillas, and eastern lowland gorillas as three separate species.

So, even within hominoidia, the lines are not clear.

I expect such debates will go on for quite some time, sometimes in light of our changing understanding of the relationships between species, sometimes without changing our understanding of such relationships at all, merely reflecting growing understanding of what it means to be a species.

The problem actually stems from the entire Linnean system of classification. There is no way in this system to express intermediate species. Every species gets a full binomial name. A third name may indicate subspecies. But still, each and every individual ends up classed into one definitive bucket. Perhaps an increased understanding will replace the Linnean system with an updated and more expressive system. For now, expect continued confusion about naming even when all relationships are well known.

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Re: 1211: "Birds and Dinosaurs"

Postby Diadem » Tue May 14, 2013 9:56 am UTC

ahammel wrote:How about "the rules of modern systematics prevent biologists from defining a taxon which includes Stegosaurs and Tryranosaurs but excludes modern birds"?

This is only true if you require every taxon to be a clade. However if you do that, you are begging the question, because that is precisely the point where the disagreement is about.

A taxon is just a group of one or more populations of organisms. While modern biology generally tries to do taxonomy according to evolutionary links, there is no formal requirement for such a link when defining taxons, and there is certainly no requirement for a taxon to be monophyletic. If you're only interested in the evolutionary history of life on earth, then monophylecity is the way to go. But taxonomy is not just about evolutionary distance, it's about describing similarities and differences between species.

Evolution isn't a constant factor that makes all species diverge exactly as fast all the time. Sometimes one species in a group of related species diverges much more rapidly from the others than the others diverge from each other. If you want to do serious taxonomy you have to recognize this, and thus you have to introduce paraphyletic groups.

Taxonomy without paraphyletic groups is not taxonomy at all. It is just describing evolutionary relatedness.

I don't know about birds and dinosaurs. I'm no expert in that particular area. But the idea that birds have to be dinosaurs because otherwise dinosaurs are paraphyletic is just silly.
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Re: 1211: "Birds and Dinosaurs"

Postby arthurd006_5 » Tue May 14, 2013 11:08 am UTC

Davidy wrote:
jpk wrote:Yes, and the average dinosaur? You see why I'm having trouble with this - talking abut "the average dinosaur" seems to me on a par with not labeling your axes...

To determine the mode we'd need to line up all the dinosaurs that ever lived and determine which measurement occurred most often.... In short, there is no meaningful answer to the question regarding "the average dinosaur" unless you define exactly what it is that you're asking.

I'm picking that dinosaur sizes would be multi-modal, so even after that one's specified, a single answer's still a bit silly.

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Re: 1211: "Birds and Dinosaurs"

Postby The Cat » Tue May 14, 2013 12:36 pm UTC

Pickup trucks didn't evolve from hatchbacks.

Cladistics works in evolution because all life really is related. The cladogram expresses the evolutionary relationship of each species to any other. In theory, there is one true perfect cladogram that would express life on this planet. In practice, we may not get it wholly correct. Also, in practice we may find a few interesting bits that are a bit harder to classify, like the fact that those of us who are descended from people who left Africa a very long time ago have a bit of Neanderthal DNA.


Think ive met a few. Hard to classify Xtra chromosomes. I believe they're classified as lunks and assholes. Interestingly the same things found in a hot dog.

I was.


me too.

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Re: 1211: "Birds and Dinosaurs"

Postby hadrian » Tue May 14, 2013 12:55 pm UTC

I suggest we award the debate victory to Pfhorrest and Diadem for pointing out and arguing that a name for a species can very well exclude descendents, or subgroups.

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Re: 1211: "Birds and Dinosaurs"

Postby mathmannix » Tue May 14, 2013 1:11 pm UTC

Like it or not, paraphyletic groups are the best ways to describe most things in our experience. In addition to the fish, monkey, etc. groups of animals explored thoroughly above, let us presuppose that all humans are descended from humanlike ancestors living in Africa. (I don't think this is universally accepted.) Then, if we consider Africans (that is, people who live in Africa) to be a monophyletic group, it should include all humans. Which is obviously ridiculous. Clades might be nice for thinking in evolutionary terms, but they don't relate to what we can actually observe of the world around us.
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Re: 1211: "Birds and Dinosaurs"

Postby gmalivuk » Tue May 14, 2013 1:18 pm UTC

mathmannix wrote:(I don't think this is universally accepted.)
Among people who know what they're talking about, it pretty much is.

And the argument isn't about whether paraphyletic terms are objectively acceptable, but whether they're okay for use in describing biological species. The fact that we're all descended from Africans but aren't all Africans ourselves is no more relevant to this point than the fact that I'm descended from Latvians but am not myself Latvian.
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Misanthropic Scott
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Re: 1211: "Birds and Dinosaurs"

Postby Misanthropic Scott » Tue May 14, 2013 1:59 pm UTC

mathmannix wrote:Like it or not, paraphyletic groups are the best ways to describe most things in our experience. In addition to the fish, monkey, etc. groups of animals explored thoroughly above, let us presuppose that all humans are descended from humanlike ancestors living in Africa. (I don't think this is universally accepted.) Then, if we consider Africans (that is, people who live in Africa) to be a monophyletic group, it should include all humans. Which is obviously ridiculous. Clades might be nice for thinking in evolutionary terms, but they don't relate to what we can actually observe of the world around us.

Actually, we are an African species. We did evolve from hominids in Africa. It is accepted by the vast majority of anthropologists and biological evolution scientists. And, genetically, 95% of the entire human gene pool exists in Africa. There are a few genes that came later, including those from Neanderthals, which is why people who left Africa more recently do not have Neanderthal DNA.

As for words like reptile and fish, they simply become non-scientific terms by excluding members of the group. Reptile is really not a family of organisms because it excludes dinosaurs. Saurapsid is the term that does include the whole family. If we use the word dinosaur to exclude birds, we make it an utterly non-scientific term and then must use dinosauria when speaking scientifically. So, it depends how we want to define the word and whether we want it to make sense.

Ape is similarly a family only for those of us who include humans. We are, of course, apes. So, for any definition of ape that does not include human, that definition is simply non-scientific. English is full of such stupidity poorly defined words.

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Re: 1211: "Birds and Dinosaurs"

Postby PolakoVoador » Tue May 14, 2013 2:38 pm UTC

Misanthropic Scott wrote:English Non-scientific/mathematical languages are full of such stupidity poorly defined words.


FTFY. It can be even worse with other languages. In Portuguese we don't even have two different words for monkey and ape, we just sort of lump everything under macaco (which is usually translated to monkey)

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Re: 1211: "Birds and Dinosaurs"

Postby JudeMorrigan » Tue May 14, 2013 3:01 pm UTC

Misanthropic Scott wrote:Similarly, homo sapiens interbred with homo neanderthalensis. No one suggests that these are the same species.

Eh? Is that a relatively recent development? I was taught that it was relatively common (but not a universal practice) the latter as a subspecies of homo sapiens.

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Re: 1211: "Birds and Dinosaurs"

Postby WriteBrainedJR » Tue May 14, 2013 3:09 pm UTC

Misanthropic Scott wrote:
WriteBrainedJR wrote:I'm still not convinced that classifying animals based only on genetic lineage is the way to go. According to that tree of life site, whales are closely related to hoofed mammals. I guess that's pretty cool. And if your interests lie in learning how whales evolved, that's highly relevant information.

However, if your interests lie in anything related to animals other than their evolutionary history, genetic classification is not very useful. Sperm whales and camels may have a relatively recent common ancestor, but for most practical purposes, they're rather dissimilar.


Interesting thought. I agree with the first paragraph in its entirety. The second paragraph leaves me thinking that Whale medical researchers (meaning actual whales studying medicine for themselves) would actually care very much about the proximity of relationships to whales as they perform their medical tests on increasingly closely related species, just as we do.

This is one of the many reasons why we care so deeply about the proximity of our relationship to mice, rats, guinea pigs, rabbits, monkeys, and apes. This is also one of the reasons we're horribly cruel to these animals. When whales study medicine, let's be glad that they will be more interested in the ungulates from whom they are descended than in homo horribilis.

I think whales testing drugs would be interested in finding similar animals. For humans, genetic similarity and physical or functional similarity tend to go hand-in-hand, because we evolved in a similar environment to many other mammals. That's not true for aquatic mammals. If you test a drug on pigs, and it turns out that one of the drug's side effects is that the patient can't hold his or her breath, you wouldn't find out about it, because pigs don't hold their breath. Test that drug on a duck, and you'd find out pretty quick.

tigerhawkvok wrote:
WriteBrainedJR wrote:
tigerhawkvok wrote:On the flip side, you can't define "dinosaurs" without incidentally including "birds". You just can't.

Given the flexibility of language and the breadth of human creativity, I think statements in the form of "you can't say A without mentioning B," are almost always bad bets.

While I am willing not to argue with people who say birds are dinosaurs, the term "non-avian dinosaurs" fills me with rage. That term describes the vast majority of all dinosaurs that ever lived (and conventional wisdom says that it describes ALL the dinosaurs), and defines them as being "not this other tiny, short-lived minority group of dinosaurs that not everyone can agree are dinosaurs." It's the equivalent of some gilded-age anthropologist who classifies the world's various ethnic groups as being either "white" or "non-white."

Find a better word for it.

No good reputable authority doesn't believe that birds aren't dinosaurs (eg, pretty much just Alan Fedducia and his acolytes disagree at this point)

Also, if we're talking about described species .... birds vastly outnumber non-avian dinosaurs.

That's kind of like comparing apples and uncut diamonds. To describe new species of birds, you have to go out in the rainforest with a tranquilizer gun. To describe a new species of dinosaurs, you have to be lucky enough to find the remnants of bones that are tens to hundreds of millions of years old. They were the dominant terrestrial animals on the planet for over 150 million years, though. There were probably more species of them, and certainly more individuals.

ijuin wrote:
WriteBrainedJR wrote:While I am willing not to argue with people who say birds are dinosaurs, the term "non-avian dinosaurs" fills me with rage. That term describes the vast majority of all dinosaurs that ever lived (and conventional wisdom says that it describes ALL the dinosaurs), and defines them as being "not this other tiny, short-lived minority group of dinosaurs that not everyone can agree are dinosaurs." It's the equivalent of some gilded-age anthropologist who classifies the world's various ethnic groups as being either "white" or "non-white."

In that case, let's also find a better word than "invertebrates" for the 96% of the known species of the Kingdom "Animalia" who lack a spinal column.

Sounds like a fine project for someone with an interest in both invertebrates and language.

Misanthropic Scott wrote:
WriteBrainedJR wrote:I don't know which scientists don't consider birds to be dinosaurs. I don't know which do, either. Like I said, it's not my area of expertise, and even if it were, I'm terrible with names, and also I don't really care. For the purposes of a purely scientific classification system, I think birds probably are dinosaurs.


The American Museum of Natural History in NYC has birds squarely and solidly represented in the Hall of Saurischian Dinosaurs. There may still be a few outlier scientists going from some perceived differences in bones. But, birds are dinosaurs, in particular, they are maniraptors.

I've already conceded that birds are probably dinosaurs. It's not really the point I care about.

Birds are dinosaurs in the sense that sliders are hamburgers. If you ignore size, sliders look a lot like hamburgers. Their internal structures are nearly identical to those of hamburgers. But if I order a hamburger and you give me a slider, you'll have a dissatisfied customer on your hands. Same thing with birds and dinosaurs.

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Re: 1211: "Birds and Dinosaurs"

Postby ijuin » Tue May 14, 2013 3:20 pm UTC

Quicksilver wrote:
Copper Bezel wrote:I actually thought Quicksilver was playing on Brit slang, where bird can mean a hot, young, single female.
I was.

I believe the closest Yank (American) term would be "chick", used to refer to a young woman.

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Re: 1211: "Birds and Dinosaurs"

Postby Himself » Tue May 14, 2013 3:29 pm UTC

WriteBrainedJR wrote:Birds are dinosaurs in the sense that sliders are hamburgers. If you ignore size, sliders look a lot like hamburgers. Their internal structures are nearly identical to those of hamburgers. But if I order a hamburger and you give me a slider, you'll have a dissatisfied customer on your hands. Same thing with birds and dinosaurs.


Though many dinosaurs were actually quite small. Look an anchiornis. We just tend to think about the big ones more.

I could picture some future species evolving to build a civilization with paleontologists. They study mammals and everyone is abuzz about elephants and bears while hardly anyone gives a second thought to mice.
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Re: 1211: "Birds and Dinosaurs"

Postby The Cat » Tue May 14, 2013 3:35 pm UTC

Only in xkcd can you find such interesting topics...

who was/is the pitcher for the blue jays who throws a mean slider? interviewed on 60 minutes...

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Re: 1211: "Birds and Dinosaurs"

Postby PolakoVoador » Tue May 14, 2013 3:51 pm UTC

Himself wrote:
WriteBrainedJR wrote:Birds are dinosaurs in the sense that sliders are hamburgers. If you ignore size, sliders look a lot like hamburgers. Their internal structures are nearly identical to those of hamburgers. But if I order a hamburger and you give me a slider, you'll have a dissatisfied customer on your hands. Same thing with birds and dinosaurs.


Though many dinosaurs were actually quite small. Look an anchiornis. We just tend to think about the big ones more.

I could picture some future species evolving to build a civilization with paleontologists. They study mammals and everyone is abuzz about elephants and bears while hardly anyone gives a second thought to mice.


They would also love how awesome birds were, but probably ignoring humming birds and robins:

Image

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Re: 1211: "Birds and Dinosaurs"

Postby AlexTheSeal » Tue May 14, 2013 4:30 pm UTC

Misanthropic Scott wrote: Similarly, homo sapiens interbred with homo neanderthalensis.

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Re: 1211: "Birds and Dinosaurs"

Postby Pfhorrest » Tue May 14, 2013 5:12 pm UTC

Copper Bezel wrote:In the strictest usages, reptiles are really just the sauropsids, which don't include any ancestors of mammals, as has been said.

The problem with that usage is it entails telling people this guy was not a reptile, but this guy is, which puts us back at using common words in a way that conflicts with common understanding, instead of inventing new words for new categories and keeping the old ones as consistent with their previous usage as possible. And if we're going to exclude the sparrow and his kin, then the group is already paraphyletic, and there's no reason not to let dimetrodon and his kin back in (all amniotes) and just exclude mammals along with birds.
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Re: 1211: "Birds and Dinosaurs"

Postby Tolf » Tue May 14, 2013 6:43 pm UTC

For anyone who hasn't decided if sharks are fish or not, I give you this: http://simple.wikipedia.org/wiki/Shark
"Sharks are in a class of fish called Chondrichthyes, with skeletons made of cartilage instead of bone."

(Not just wikipedia, the simple english wikipedia.)

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Re: 1211: "Birds and Dinosaurs"

Postby Misanthropic Scott » Tue May 14, 2013 6:48 pm UTC

WriteBrainedJR wrote:I think whales testing drugs would be interested in finding similar animals. For humans, genetic similarity and physical or functional similarity tend to go hand-in-hand, because we evolved in a similar environment to many other mammals. That's not true for aquatic mammals. If you test a drug on pigs, and it turns out that one of the drug's side effects is that the patient can't hold his or her breath, you wouldn't find out about it, because pigs don't hold their breath. Test that drug on a duck, and you'd find out pretty quick.


1. Whales don't "hold their breath". Whales take each breath consciously. If you don't think about breathing, you breath. If any cetacean doesn't think about breathing, he or she suffocates. This was made abundantly clear when someone once attempted to tranquilize a dolphin. Bad idea. And, a fatal one for the dolphin.
2. Whales would still have to care about both proximity of relationship and effects on a sea dwelling creature. Side effects on a duck are unlikely to be similar to those of a cetacean for the same reason we don't use birds in our medical tests. They're rather distantly related to us. The effects would not be likely to be similar. Perhaps you should have chosen another aquatic mammal. There are rather a lot to choose from. However, to my knowledge, cetaceans are the only aquatic or marine ungulates. Hippos might be as close as you could get with today's non-cetacean ungulates.

WriteBrainedJR wrote:Birds are dinosaurs in the sense that sliders are hamburgers. If you ignore size, sliders look a lot like hamburgers. Their internal structures are nearly identical to those of hamburgers. But if I order a hamburger and you give me a slider, you'll have a dissatisfied customer on your hands. Same thing with birds and dinosaurs.


Oy! Hamburgers didn't evolve. Can we please stick to analogies within the field of biological evolution.

As for birds and dinosaurs, how about a velociraptor? They were only about the size of chickens. Lots of dinosaurs were smaller, as has also been pointed out by others. If I asked you to pass me a bird, I would not know whether to put out my hand for a hummingbird or an ostrich. So, why the big deal about big versus small dinosaurs? Being a size queen is not going to win you a lot of points in a scientific debate.

If you want to discuss what is unexpected about birds, try feathers. Oh wait! They found non-avian dinosaurs, or perhaps semi-avian would be a better term, with feathers. So, what would you call such intermediate species that are, of course dinosaurs, but may or may not be classed as birds depending on exactly where you draw the line. What would you say about Hoatzins (living birds) that have claws on their wings at the time they hatch? Are they semi-dinosaurian birds? See how much confusion this causes?

The clear way to manage such language and terminology is to have terms that map to the commonly discussed clades. So, ape includes humans, dinosaur includes birds, and perhaps we should even update reptile to include all dinosaurs. That last would probably be a harder sell. But, I'd certainly approve of the change. The term reptile really bothers me.

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Re: 1211: "Birds and Dinosaurs"

Postby Misanthropic Scott » Tue May 14, 2013 7:12 pm UTC

JudeMorrigan wrote:
Misanthropic Scott wrote:Similarly, homo sapiens interbred with homo neanderthalensis. No one suggests that these are the same species.

Eh? Is that a relatively recent development? I was taught that it was relatively common (but not a universal practice) the latter as a subspecies of homo sapiens.

Homo sapiens neanderthalensis is still listed as a synonym for homo neanderthalensis. I'm not sure how recently the change was made. I think it had to do with the more advanced (evolutionarily) structure in their sinuses. Note that in evolution, advanced feature just means new feature. Our sinuses are still in the primitive state, meaning unchanged. It's not a quality judgement.

I apologize. It seems there is in fact still some debate about whether neanderthals were a subspecies. The mainstream opinion is that they were a separate species. However, I was wrong to state that no one suggests they are the same species. Apparently people still do. Here's a link to the current state of the debate.

http://en.wikipedia.org/wiki/Neanderthal#Classification

So, I'll stick with mainstream thought on the subject and call neanderthals a separate species. Interbreeding has long since been given up as the definition of a species, as I stated with regard to black ducks and mallards. And, I'll prepare to admit I was wrong if the debate goes solidly the other way. Meanwhile, I'll make sure everyone knows, I am not a scientist. I am glad to be able to read and understand a significant percentage of scientific publications for a general audience. I am glad to be able to understand at some level what the truly smart people on the planet are doing. But, I don't claim to be one of them. I'm so glad I'm a Beta.

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Re: 1211: "Birds and Dinosaurs"

Postby chenille » Tue May 14, 2013 7:20 pm UTC

Misanthropic Scott wrote:Oy! Hamburgers didn't evolve. Can we please stick to analogies within the field of biological evolution.

But then people just focus on phylogenetics and assume everything needs to be clades, and so keep missing WriteBrainedJR's point, which is that for most purposes you care at least as much about the characteristics of the things you're describing as its lineage. That the term reptile bothers you, for instance, suggests you spend more time thinking about evolution than you do actually working with turtles, lizards, and crocodiles. Herpetologists do both and don't seem so uncomfortable.

By the way, I would apply medical results from seals or manatees to whales with some trepidation, but I would be even more concerned applying results from hippos, let alone cows and giraffes. Because despite their ungulate lineage, whales have a completely different physiology, diet, and life style, which after all is the idea of evolution in the first place.
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Re: 1211: "Birds and Dinosaurs"

Postby Diadem » Tue May 14, 2013 7:23 pm UTC

Misanthropic Scott wrote:As for words like reptile and fish, they simply become non-scientific terms by excluding members of the group.

Non-scientific is not a synonym for 'things I disagree with'.

You are entirely ignored the two points I raised. First of all, taxonomy is not just about describing evolutionary relatedness. It's about making a sensible system describing which organisms are like each other, and which aren't. Secondly, evolution doesn't work the way you seem to think it works. Not all species evolve away from each other at equal rates. The rate of change can change from species to species and from time to time. Just because three species share the same common ancestor doesn't mean all three are exactly equally far away from each other. Sharks and bony fish share lots of similarities, and are much more similar to each other than either is to us. Insisting that we are fish, or that sharks aren't fish, is just silly and, dare I say it, unscientific.

And it's equally silly to insist that birds must be dinosaurs just because they evolved from them.

Misanthropic Scott wrote:Ape is similarly a family only for those of us who include humans. We are, of course, apes. So, for any definition of ape that does not include human, that definition is simply non-scientific. English is full of such stupidity poorly defined words.

Pfah! Families should be named after the dominant species. We are not apes, apes are human.
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Re: 1211: "Birds and Dinosaurs"

Postby Pfhorrest » Tue May 14, 2013 7:35 pm UTC

Diadem wrote:We are not apes, apes are human.

And dinosaurs are birds.

Actually, I could maybe be down with that.
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Re: 1211: "Birds and Dinosaurs"

Postby Copper Bezel » Tue May 14, 2013 7:38 pm UTC

Yeah, maybe. = ) I actually do sort of think that theropods at least need to belong to the out-group if there's anything paraphyletic going on. Sorry to hammer on with this - I know that Diadem at the very least is much more likely than me to be right on this subject, particularly in terms of intuitions, and yet I'm posting.

Dimetrodon looks quite a bit like what we think of as a reptile, but it's already thermoregulating and doesn't have scales. I mean, obviously, there's a value to intuitive definitions - we haven't decided to define reptiles as synonymous with cetaceans or something. But I really do think it's useful to keep relationships in mind even in relatively everyday speech (that is, people who aren't experts in the field.) I have to admit that I'm even more resistant to treating dinosaur as a grade than I am to treating reptile as such, and not necessarily for sensible reasons; dinosaurs sans birds are a paraphyletic grouping, and so are amniotes less birds and mammals, so they're more or less equally weird or arbitrary. But defining reptiles that way means deciding where the base of the tree is, rather than just deciding whether or not to clip this or that branch (which cuts both ways, I know, since either definition has to make a choice there) and moving down the tree on the basis of shared basal characters just seems fuzzier to me.

I'm not really uncomfortable with treating amphibians as a grade instead of limiting them to lissamphibia, either, so maybe I'm just a bit mental. I just don't think I could accept that true reptiles start that early on, so long before many of their stand-out diagnostic characters, like the scales. It's easier to think of there having been a reptile line and a to-mammals line. But then, mammals are just the one very derived group we have left of a very diverse lineage that never quite diversified as much as the sauropsid line or became quite as successful, so trying to pin that lineage down in a particular way simply because it has mammals in it is a little strange. If we were dinosaurs and the synapsid line had died off with the cynodonts, I don't think it would be important to exclude the synapsids from reptiles.

I mean, I'm aware that the chance of natural history affects what groups seem "natural" - if certain groups had survived, we would have drawn the lines differently; if Dimetrodon descendants had survived and kept their early-amniote flavor, we'd probably have always called them reptiles and wouldn't be questioning the term, while if another line of cynodonts had survived, they'd probably just be treated as mammals. (It's already weird that monotremes count, isn't it?) The terminology is also pushed around by the chance of our history in the order and completeness with which extinct species were discovered, so that no one is moving to exclude all dinosaurs from reptiles. And if there were an abundance of toothy, scaly-faced things with bony tails that were otherwise birds hopping around in the present, and we always knew that some dinosaurs were small and had feathers, those lines or distinctions could have been drawn anywhere.

I don't know; I guess that if a change is sudden enough over geological time and makes a dramatic enough change in the visible phenotype and the niche occupied by a population, it starts to make sense to single out that group as something different enough that there's value in contrasting it to its parent clade as if they're two separate things on equal footing. We have enough granular detail about the appearance of bird characteristics that it doesn't seem so sudden, but that's probably an effect of just having that that granular detail (the opposite of what we have, say, for the separation of Opisthokonta or the algal groups from protists) that makes the transition seem less sudden.

It does not seem natural to me to draw the line for the dinosaur grade where we usually do. I understand why we choose to define birds the way we do, but theropods (intuitively) seem at least as different from other dinosaurs as birds seem from other theropods. If something needs to stop being a dinosaur, I just don't think that starts with the bird crown group.

Augh - but even here, I'm having trouble finding a tactful and succinct way to say "dinosaurs and descendants," because it really is useful to have a simple, single word for that grouping when I'm talking about things like this.
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Re: 1211: "Birds and Dinosaurs"

Postby Pfhorrest » Tue May 14, 2013 8:02 pm UTC

Copper Bezel wrote:Augh - but even here, I'm having trouble finding a tactful and succinct way to say "dinosaurs and descendants," because it really is useful to have a simple, single word for that grouping when I'm talking about things like this.

I definitely agree that regardless of how "dinosaurs" gets defined, we need a single word for "dinosaurs and their descendents". I suggested earlier, along the same lines of the "dinosaurs are birds" comment, that "avesaurs" or something like that could be good: the birds and their close relatives (including T. Rex and Stegosaurus as "close" for these purposes), in the same way that apes are humans and their close relatives.
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Re: 1211: "Birds and Dinosaurs"

Postby Misanthropic Scott » Tue May 14, 2013 8:24 pm UTC

chenille wrote:
Misanthropic Scott wrote:Oy! Hamburgers didn't evolve. Can we please stick to analogies within the field of biological evolution.

But then people just focus on phylogenetics and assume everything needs to be clades, and so keep missing WriteBrainedJR's point, which is that for most purposes you care at least as much about the characteristics of the things you're describing as its lineage. That the term reptile bothers you, for instance, suggests you spend more time thinking about evolution than you do actually working with turtles, lizards, and crocodiles. Herpetologists do both and don't seem so uncomfortable.


That would seem a very silly point in the case of birds and dinosaurs which are so similar, no? That the term reptile bothers me actually means that I'm an anal-retentive geek and hate inconsistencies of this type. I probably spend about the same amount of time thinking about evolution and looking for and photographing or videotaping non-dinosaurian reptiles. The balance may be slightly toward thinking about evolution due to where I live. I'd probably spend more time with the herps if there were more of them in the northeast. We could use some crocodilians in Central Park, for example, to help thin the herd. But, I love turtles and frogs too.

chenille wrote:By the way, I would apply medical results from seals or manatees to whales with some trepidation, but I would be even more concerned applying results from hippos, let alone cows and giraffes. Because despite their ungulate lineage, whales have a completely different physiology, diet, and life style, which after all is the idea of evolution in the first place.


Hmm... That just means that the medical profession in cetaceans will have a difficult time finding any test subjects. Good news for the potential subjects. Alas, our own close relatives have not been so lucky.

But, no, that is not the idea of evolution. The idea of evolution is to track the lineage, period. Evolution does so exceedingly well, whether it is tracking the minor changes from chimp to human or the major ones from land animal to marine animal. The theories of natural selection and sexual selection do a far better job of giving reasons to the changes than does the mere fact of evolution.

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Re: 1211: "Birds and Dinosaurs"

Postby WriteBrainedJR » Tue May 14, 2013 8:28 pm UTC

Misanthropic Scott wrote:
WriteBrainedJR wrote:I think whales testing drugs would be interested in finding similar animals. For humans, genetic similarity and physical or functional similarity tend to go hand-in-hand, because we evolved in a similar environment to many other mammals. That's not true for aquatic mammals. If you test a drug on pigs, and it turns out that one of the drug's side effects is that the patient can't hold his or her breath, you wouldn't find out about it, because pigs don't hold their breath. Test that drug on a duck, and you'd find out pretty quick.


1. Whales don't "hold their breath". Whales take each breath consciously. If you don't think about breathing, you breath. If any cetacean doesn't think about breathing, he or she suffocates. This was made abundantly clear when someone once attempted to tranquilize a dolphin. Bad idea. And, a fatal one for the dolphin.
2. Whales would still have to care about both proximity of relationship and effects on a sea dwelling creature. Side effects on a duck are unlikely to be similar to those of a cetacean for the same reason we don't use birds in our medical tests. They're rather distantly related to us. The effects would not be likely to be similar. Perhaps you should have chosen another aquatic mammal. There are rather a lot to choose from. However, to my knowledge, cetaceans are the only aquatic or marine ungulates. Hippos might be as close as you could get with today's non-cetacean ungulates.

How is that any different from holding your breath?



Misanthropic Scott wrote:
WriteBrainedJR wrote:Birds are dinosaurs in the sense that sliders are hamburgers. If you ignore size, sliders look a lot like hamburgers. Their internal structures are nearly identical to those of hamburgers. But if I order a hamburger and you give me a slider, you'll have a dissatisfied customer on your hands. Same thing with birds and dinosaurs.


Oy! Hamburgers didn't evolve. Can we please stick to analogies within the field of biological evolution.

As for birds and dinosaurs, how about a velociraptor? They were only about the size of chickens. Lots of dinosaurs were smaller, as has also been pointed out by others. If I asked you to pass me a bird, I would not know whether to put out my hand for a hummingbird or an ostrich. So, why the big deal about big versus small dinosaurs? Being a size queen is not going to win you a lot of points in a scientific debate.

If you want to discuss what is unexpected about birds, try feathers. Oh wait! They found non-avian dinosaurs, or perhaps semi-avian would be a better term, with feathers. So, what would you call such intermediate species that are, of course dinosaurs, but may or may not be classed as birds depending on exactly where you draw the line. What would you say about Hoatzins (living birds) that have claws on their wings at the time they hatch? Are they semi-dinosaurian birds? See how much confusion this causes?

The clear way to manage such language and terminology is to have terms that map to the commonly discussed clades. So, ape includes humans, dinosaur includes birds, and perhaps we should even update reptile to include all dinosaurs. That last would probably be a harder sell. But, I'd certainly approve of the change. The term reptile really bothers me.

My point was not about unexpectedness (or size) so much as about disappointingness. I've already conceded more than once that from a scientific standpoint, birds are probably dinosaurs, so there's really no need to hammer away at that point, because 1. I never really disputed it, and 2. I was never really talking about it.

My point is that a classification system that puts birds and dinosaurs together is of little use to the general public. The general public needs a word similar to "ape" that does not include humans, because the treatment of those animals is a serious ethical issue, and within my lifetime, it will probably become a major legal/political issue. We already have plenty of laws about how to treat humans, but many fewer about how to treat animals that aren't humans, but are a lot like humans. We, speaking as a member of the general public who is not an evolutionary scientist, need a word for "animals but aren't humans, but are a lot like humans."

The general public already has a word for the ancient, semi-mysterious, thoroughly fascinating creatures that are the ancestors of birds. That word is "dinosaurs." If science wants to put dinosaurs and birds together in a clade, that's all well and good, but they can't expect the general public to start using the word they already have for one thing to describe something that, for their purposes, is very different. Birds are common, readily available, and generally considered to be boring.


TL;DR: Science and the general public have different needs for words. If scientists don't like the meaning of words, they can invent the words that they need.

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Re: 1211: "Birds and Dinosaurs"

Postby tofudragon7 » Tue May 14, 2013 8:32 pm UTC

My problem with this comic:

Eebster the Great wrote:I don't think there is any doubt, however, that T. Rex is more closely related to the sparrow than to Stegosaurus, which is all the cladogram shows. What specifically are you objecting to here?


Actually, there is plenty of doubt! Maniraptora (birds and raptors) and Tyrannosauroidea most likely diverged between 160 and 170 mya, to the best of my knowledge (with the first proper bird ancestors appearing in the late Jurassic). Putting Tyrannosaurus at 65 mya, Stegosaurus at 150, and the Saurischian-Ornithischian split around 230, this gives us 255-275 mya of distance between Tyrannosaurus and a sparrow, with only 245 mya of distance between Tyrannosaurus and Stegosaurus.

When you add in the fact that the T. rex - bird split contains more (and slightly more significant) extinction events and thus likely more adaptive radiation, Tyrannosaurus is almost certainly more similar to Stegosaurus than to birds!

If the comic were comparing a Tyrannosaur to a Triceratops [sic] (yes, it should be Torosaurus), I'd have far less to complain about—but this was clearly not a fact-checked comic, and I'm a bit disappointed that nobody has pointed out yet that Tyrannosaurus was in fact clearly more closely related to a Stegosaur.

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Re: 1211: "Birds and Dinosaurs"

Postby Pfhorrest » Tue May 14, 2013 8:58 pm UTC

WriteBrainedJR wrote:How is that any different from holding your breath?

I think the point is that humans automatically breath unless we make a conscious effort to stop breathing, while cetaceans do not breath unless they make a conscious effort to do so. For a human, "holding your breath" is an action that you do, in contrast to the normal, automatic state of breathing; for a cetacean, "breathing" is an action that you do, in contrast to the normal, automatic state of not breathing.
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Re: 1211: "Birds and Dinosaurs"

Postby RAGBRAIvet » Tue May 14, 2013 9:27 pm UTC

robmoss2k wrote:This is incorrect. The second fastest animal is Falco Peregrinus. The fastest animal is the human - specifically Felix Baumgartner. I don't see any peregrine falcons breaking the sound barrier unassisted.

Neither did Mr. Baumgartner — break the sound barrier unassisted, that is.  He had a little help, too.
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Re: 1211: "Birds and Dinosaurs"

Postby gmalivuk » Tue May 14, 2013 9:30 pm UTC

tofudragon7 wrote:Actually, there is plenty of doubt! Maniraptora (birds and raptors) and Tyrannosauroidea most likely diverged between 160 and 170 mya, to the best of my knowledge (with the first proper bird ancestors appearing in the late Jurassic). Putting Tyrannosaurus at 65 mya, Stegosaurus at 150, and the Saurischian-Ornithischian split around 230, this gives us 255-275 mya of distance between Tyrannosaurus and a sparrow, with only 245 mya of distance between Tyrannosaurus and Stegosaurus.
I'm under the impression that "mya" means "million years ago", right? Which means that if you're not talking about points in time but lengths of time, you should drop the 'a', because keeping it in makes it hella confusing to distinguish between when you're stating dates and when you're counting years.
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Re: 1211: "Birds and Dinosaurs"

Postby RAGBRAIvet » Tue May 14, 2013 9:39 pm UTC

wumpus wrote:
YttriumOx wrote:
tigerhawkvok wrote:To the best of my recollection, people aren't taught even in elementary school that sharks are fish (I certainly wasn't, anyway).

Culinarily speaking, sharks are usually referred to as fish (my favourite style of "fish and chips" is with shark meat). Other than in this narrow scope though, I don't think I was ever taught that a shark is a kind of fish.


Googling "largest fish" the first (non-image) hit is the whale shark wiki. I always learned that it was the largest fish, although now I'm not sure if a blue whale might be closer related to a trout than a shark.

A shark is a non-bony fish.  It is not a mammal like dolphins, porpoises, and whales.  It does not have scales, but neither do catfish.  It does not lay eggs but produces its young through live birth — just like guppies.  It has gills and fins and shares numerous other attributes with bony fish; and that's good enough for me.  

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Re: 1211: "Birds and Dinosaurs"

Postby chenille » Tue May 14, 2013 9:59 pm UTC

Misanthropic Scott wrote:But, no, that is not the idea of evolution. The idea of evolution is to track the lineage, period.

That's the idea of phylogenetics. For evolutionary biology as a whole, it can be very significant that one lineage has diverged dramatically from all its siblings, and it's useful to have language to match that. For all people like to complain about paraphyletic groups, they actually get used all the time even by people who reject them in taxonomy - many who refuse to use "reptiles" in the old sense will still talk about "basal amniotes", so why pretend that's not a good thing to name?

tofudragon7 wrote:If the comic were comparing a Tyrannosaur to a Triceratops [sic] (yes, it should be Torosaurus), I'd have far less to complain about—but this was clearly not a fact-checked comic, and I'm a bit disappointed that nobody has pointed out yet that Tyrannosaurus was in fact clearly more closely related to a Stegosaur.

Not at all. Tyrannosaurus, birds, and other maniraptora all belong to the Saurischian line, and Stegosaurus to the separate Ornithischian line. And the name stays Triceratops, even if it turns out to be the same genus as Torosaurus, because that has priority.

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Re: 1211: "Birds and Dinosaurs"

Postby tigerhawkvok » Tue May 14, 2013 11:18 pm UTC

Diadem wrote:
ahammel wrote:How about "the rules of modern systematics prevent biologists from defining a taxon which includes Stegosaurs and Tryranosaurs but excludes modern birds"?

This is only true if you require every taxon to be a clade. However if you do that, you are begging the question, because that is precisely the point where the disagreement is about.

A taxon is just a group of one or more populations of organisms. While modern biology generally tries to do taxonomy according to evolutionary links, there is no formal requirement for such a link when defining taxons, and there is certainly no requirement for a taxon to be monophyletic. If you're only interested in the evolutionary history of life on earth, then monophylecity is the way to go. But taxonomy is not just about evolutionary distance, it's about describing similarities and differences between species.

Evolution isn't a constant factor that makes all species diverge exactly as fast all the time. Sometimes one species in a group of related species diverges much more rapidly from the others than the others diverge from each other. If you want to do serious taxonomy you have to recognize this, and thus you have to introduce paraphyletic groups.

Taxonomy without paraphyletic groups is not taxonomy at all. It is just describing evolutionary relatedness.

I don't know about birds and dinosaurs. I'm no expert in that particular area. But the idea that birds have to be dinosaurs because otherwise dinosaurs are paraphyletic is just silly.


Patent nonsense. If you don't require every taxon to be a clade, then you can construct taxons on any arbitrary grouping of characteristics (and bear in mind you're implictly arguing here that many, if not all, definitions of taxon, including non-cladistic ones, are valid). This means I can create a taxon with the characteristics "bilaterally symmetrical, no limbs" and you get a "taxon" consisting of worms, caecilians, snakes, eels, polychaetes, etc. This is a simple grouping that by itself demonstrates how *useless* such groupings can be. It includes terrestrial, arboreal, fossorial, and marine animals, with and without backbones, deuterostomes and protostomes. You garner no information whatsoever from that grouping.

The obvious retort is then "OK, sure, we can agree that's a useless group. But that's too broad of a group! No one would define a group like that". But that's not the point. You've constructed a definition of taxon that doesn't prohibit that from being a valid taxon. So, praytell, how do you restrict taxon definitions in a way that is not explicitly evolutionary but doesn't accept obviously bogus "taxons" as valid? I'd love to see it. And until you can produce such a definition, I'll reiterate -- your point is patently silly.

Also, have you actually done any taxonomic or phylogenetic work? People don't really study paraphyletic groupings like that in any serious manner. You may study niches ("parasites") with no phylogenetic implications, locales ("mammals of the Sierras"), and even "herpetologist" means "Knows about a bunch of lizards and amphibians, but really, my Ph.D. is on _Crotalus_ or 'Southeast Asian Lizards'". (I say this knowing several Ph.D.s in herpetology, who study _Crotalus_, _Crotophytus_, _Draco_, _Aniella_, Indonesia, Sulawesi, and the Middle East. Note those are either all niches/locales or monophyletic). I can't think of any example where people go "I'm studying non-murid glirans" or "My research is on non-mustelid carnivorans". (Source: I work in a research museum)

Simply absurd. To be fair the issue is muddied with things like plants that hybridize like no other, but that's neither here nor there.

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Re: 1211: "Birds and Dinosaurs"

Postby The Cat » Tue May 14, 2013 11:47 pm UTC

I don't really want to get into this, but sharks have several reproductive strategist. http://en.wikipedia.org/wiki/Shark.
Last edited by The Cat on Tue May 14, 2013 11:51 pm UTC, edited 1 time in total.

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Re: 1211: "Birds and Dinosaurs"

Postby Copper Bezel » Tue May 14, 2013 11:51 pm UTC

tigerhawkvok wrote:Patent nonsense. If you don't require every taxon to be a clade, then you can construct taxons on any arbitrary grouping of characteristics (and bear in mind you're implictly arguing here that many, if not all, definitions of taxon, including non-cladistic ones, are valid). This means I can create a taxon with the characteristics "bilaterally symmetrical, no limbs" and you get a "taxon" consisting of worms, caecilians, snakes, eels, polychaetes, etc. This is a simple grouping that by itself demonstrates how *useless* such groupings can be. It includes terrestrial, arboreal, fossorial, and marine animals, with and without backbones, deuterostomes and protostomes. You garner no information whatsoever from that grouping.


I don't like Diadem's second paragraph there. It doesn't sound like a realistic way to define taxa, because you're right that it opens the door to polyphyletic taxa, which are nonsense. However, I do think that the argument actually in progress, which is about an example a paraphyletic taxon having a useful role to play, is a relatively benign one. chenille's link (pdf) from earlier on makes exactly that argument - that paraphyletic can be good, but polyphyletic is always-always bad. (That's not to say that we don't have terms that group members of many taxa for non-taxonomic purposes, such as when we refer to groups of species by communities, niches, or strategies, like benthos or waders or whatever.)

chenille's comment that paraphyletic taxa are already used (whenever we say "basal X", "non-Y X", and so on) is a valid one. The only thing I'd argue is that again, since it's an artificial grouping, it's sensible to have a reminder of that, right in the term we use for it. Using "reptile" or "dinosaur" paraphyletically doesn't give any reminder that it's an artificial grouping. When we use "fish" or "protozoan," I think we tend to know that we don't mean a natural group, so I don't think those terms have the same hazard, and anyway, there is a fairly big distinction between each of those groups and its outgroup or groups, enough that I think it's fair to forget about the outgroups sometimes.

But of course, that's fuzzy, and as chenille said, a herpetologist can definitely get by without thinking much about birds, as mentioned earlier, while someone interested in taxonomy can get used to "reptile" being as obviously not a clade as "fish." I'm biased by my own interests here.

But I'm defending chenille's position more than Diadem's, and I'd like to hear Diadem chime in on whether or not polyphyletic groups are allowed.
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Re: 1211: "Birds and Dinosaurs"

Postby chenille » Wed May 15, 2013 12:00 am UTC

tigerhawkvok wrote:The obvious retort is then "OK, sure, we can agree that's a useless group. But that's too broad of a group! No one would define a group like that". But that's not the point.

Why isn't that the point? That's how taxa started out, it's all that the ICZN and ICN mandate, and for that matter, it's how definitions work in every other part of science. You can categorize particles or minerals or astronomical objects on whatever properties you like, but if it doesn't turn out to be useful nobody will bother with your scheme.

In the case of biological classification, everyone generally accepts it's useful to stick to taxa with a single evolutionary origin where possible*, simply because it turns out to be much more useful for discussing evolution. But not everyone accepts the same about requiring clades; I posted a link to an example arguing it makes it harder to discuss. Certainly I notice most people use non-clades at least informally, some just insist on saying them as two words, like "basal angiosperms" or "non-avian dinosaurs". And yet here you see the claim that even outside taxonomy, terms like fish or reptile need to be abolished.

That's crazy. The point of taxonomy, not just in biology but in general, is to make it easy to order to the world around us in a useful fashion. It's valuable to adopt some rules to keep order when there are millions of species under consideration, but not simply out of fear that someone might make a useless group otherwise. When that happens, and it has happened many times, people just ignore it and move on their way.

Compare "bryophytes" and "cryptogams"; people find it practical to consider mosses and liverworts together, less often mosses and lichens, and so the first endures and the second fades. Is that really so bad?

* Some people do deliberately use groups based only on general similarity, for instance in classification of some odd microfossils, because until you understand what evolution took place they are clearly more useful than nothing.

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Re: 1211: "Birds and Dinosaurs"

Postby tigerhawkvok » Wed May 15, 2013 12:16 am UTC

chenille wrote:
tigerhawkvok wrote:The obvious retort is then "OK, sure, we can agree that's a useless group. But that's too broad of a group! No one would define a group like that". But that's not the point.

Why isn't that the point? That's how taxa started out, it's all that the ICZN and ICN mandate, and for that matter, it's how definitions work in every other part of science. You can categorize particles or minerals or astronomical objects on whatever properties you like, but if it doesn't turn out to be useful nobody will bother with your scheme.

Err, because these things aren't evolutionarily related? There is no descent with modification? So bucketing them by characters is already descriptive and predictive? It doesn't work with organisms because *organisms evolve* and *organisms are related to each other by differential selection and descent*. A 5 micron silicate dust grain is a 5 micron silicate dust grain no matter where it comes from in the universe. _Dermophis mexicanus_ ( https://en.wikipedia.org/wiki/Dermophis_mexicanus ) and _Eryx johnii_ ( https://en.wikipedia.org/wiki/Eryx_johnii ) are not the same regardless of similar shape, size, and (broadly) behaviour.
In the case of biological classification, everyone generally accepts it's useful to stick to taxa with a single evolutionary origin where possible, simply because it turns out to be much more useful for discussing evolution. But not everyone accepts the same about requiring clades; I posted a link to an example arguing it makes it harder to discuss. Certainly I notice most people use non-clades at least informally, some just insist on saying them as two words, like "basal angiosperms" or "non-avian dinosaurs". And yet here you see the claim that even outside taxonomy, terms like fish or reptile need to be abolished.

Why in the world would they need to be abolished? There are easy fixes. "Reptile" = "Sauropsida". Blam-o. The term that people were using paraphyletically to describe "reptile" that you object to already has a term without historical baggage -- "amniote".

I'm leaving the fish/shark/lamprey argument alone here, because it seems like everyone on this board got a different education on the matter from everyone else, though I daresay that actinopterygia=fish, chondrichthyes="sharks, skates, rays" (because lay people don't really group them anyway), and agnatha="who talks about something without a bloody *jaw* as a fish anyway!?!" is good enough.

If you need to refer to the non-clades for whatever reason, the two-word solution is elegant insofar as it makes it *explicitly and abundantly clear* that it is an artificial grouping and you shouldn't assume characters are synapomorphies, they could very well be homoplasies, without either rattling off that sentence every time or assuming who you're talking to is familiar with all the organisms' evolutionary relationships.

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Re: 1211: "Birds and Dinosaurs"

Postby tigerhawkvok » Wed May 15, 2013 12:34 am UTC

tofudragon7 wrote:My problem with this comic:

Eebster the Great wrote:I don't think there is any doubt, however, that T. Rex is more closely related to the sparrow than to Stegosaurus, which is all the cladogram shows. What specifically are you objecting to here?


Actually, there is plenty of doubt! Maniraptora (birds and raptors) and Tyrannosauroidea most likely diverged between 160 and 170 mya, to the best of my knowledge (with the first proper bird ancestors appearing in the late Jurassic). Putting Tyrannosaurus at 65 mya, Stegosaurus at 150, and the Saurischian-Ornithischian split around 230, this gives us 255-275 mya of distance between Tyrannosaurus and a sparrow, with only 245 mya of distance between Tyrannosaurus and Stegosaurus.

When you add in the fact that the T. rex - bird split contains more (and slightly more significant) extinction events and thus likely more adaptive radiation, Tyrannosaurus is almost certainly more similar to Stegosaurus than to birds!

If the comic were comparing a Tyrannosaur to a Triceratops [sic] (yes, it should be Torosaurus), I'd have far less to complain about—but this was clearly not a fact-checked comic, and I'm a bit disappointed that nobody has pointed out yet that Tyrannosaurus was in fact clearly more closely related to a Stegosaur.


Relatedness in biology is based on "shared derived characteristics" (changes), or "synapomorphies". During that period from 230mya -> 150ish mya, the saurischian/theropod lineage accumulated a bunch of changes that *all of them share* that were never accumulated in the ornithischian lineage.

The temporal problem becomes clear when you realize that the distance from us to Compsognathus (us->basal amniotes = +340 MY, basal amniote -> Chasmatosuchus, basal psuedosuchian = +90 MY = ~430 MY) is about the same temporal distance from us to Dimetrodon, also a synapsid like us ( ~ 380 MY temporal distance), which is clearly false. You can artificially inflate this by picking an even more basal sauropsid -- such as https://en.wikipedia.org/wiki/Paleothyris , which has a temporal distance from us of about 370 MY. Is it actually closer to us than we are to Dimetrodon? Of course not.

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Re: 1211: "Birds and Dinosaurs"

Postby Pfhorrest » Wed May 15, 2013 12:53 am UTC

tigerhawkvok wrote:Why in the world would they need to be abolished? There are easy fixes. "Reptile" = "Sauropsida". Blam-o.

So birds are reptiles now, not merely dinosaurs? Are they going to be called fish next?

Why do we need to redefine the word "reptile" to mean something no non-specialist uses it to mean, when there is already a perfectly good word ("sauropsid") for specialists to use for that purpose?

I'm arguing the same with regards to "dinosaurs". That's a word already in common usage to describe a group of animals which, as it turns out, is paraphyletic, because birds share the same common ancestor but aren't counted in it. Rather than redefining the common word to mean something no non-specialist would use it to mean, why can't we come up with a new technical term (like "avesaurs") for the monophyletic group, like we have "sauropsida" for the group containing all modern reptiles and birds?

Similarly, it seems everyone is happy to agree that we shouldn't redefine "fish" in a way that would count all vertebrates as fish. But why not? By your line of reasoning shouldn't we?

Or else abolish the problematic terms entirely, and stop talking about fish and reptiles... and dinosaurs too, for consistency. Those are our three options: abolish previously-paraphyletic terms (so there are no dinosaurs or reptiles or fish), redefine them into monophyletic terms against conventional usage (so birds are dinosaurs and reptiles and fish), or coin new monophyletic terms and leave the paraphyletic ones alone. I think the last is the best option, the second will make specialists sound absurd to laypeople, and the first is just not going to happen beyond the specialist circles where it already has.
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