If You Could Change History

[GAROVORKIN]

2 hours ago, Robin Of House Hill said:

I'd prevent the extinction of dinosaurs.That ought to be sufficient to keep humans from overwhelming the world.

Indications are that the Dinosaurs were in decline before the asteroid hit.  

[TrueMetis]

There are 10000 species of dinosaur alive today, sure that's a decline compared to their heyday but that kicks the shit out of how many most groups has. Sure as hell beats us with the pathetic little 300 monkeys that makes up our group.

[GAROVORKIN]

14 minutes ago, TrueMetis said:

There are 10000 species of dinosaur alive today, sure that's a decline compared to their heyday but that kicks the shit out of how many most groups has. Sure as hell beats us with the pathetic little 300 monkeys that makes up our group.

Indeed , I should have said non avian Dinosaurs were on the decline .

[TrueMetis]

1 minute ago, GAROVORKIN said:

Indeed , I should have said non avian Dinosaurs were on the decline .

Oh yeah, sucks to be a sauropod.

[GAROVORKIN]

18 minutes ago, TrueMetis said:

Oh yeah, sucks to be a sauropod.

 

If the sauropods  had only had wings they would have survived. 

 

 

[Yukle]

11 hours ago, TrueMetis said:

There are 10000 species of dinosaur alive today, sure that's a decline compared to their heyday but that kicks the shit out of how many most groups has. Sure as hell beats us with the pathetic little 300 monkeys that makes up our group.

That's not a fair comparison, since that's comparing two different levels of magnitude.

You'd need to compare avians to mammals.

And the number of species is one way of looking at it, but another way of looking at it is the overall range of their species on earth. You can find mammals literally everywhere that's habitable on earth. It's not the same for birds, since they're not living in the oceans.

Mammals have adapted for more environments than avians have, and tend to outcompete birds (not always, but more often than not). Think of how many species of mammals live full time underwater compared to birds. As impressive as a penguin is, whales are incredible.

[TrueMetis]

4 hours ago, Yukle said:

That's not a fair comparison, since that's comparing two different levels of magnitude.

You'd need to compare avians to mammals.

I disagree, comparing avians to mammals wouldn't be accurate. Avians are a subgroup of dinosaurs who are themselves a sub group of archosaurs, who are a sub group of reptiles. Monkey's are a subgroup of primates who are a subgroup of mammals. If anything I'm being overly generous to monkeys who really should be compared to dinosaurs.

Avians and mammals aren't remotely on the same level of magnitude. Mammals would be better compared to reptiles or archosaurs.

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And the number of species is one way of looking at it, but another way of looking at it is the overall range of their species on earth. You can find mammals literally everywhere that's habitable on earth. It's not the same for birds, since they're not living in the oceans.

Mammals have adapted for more environments than avians have, and tend to outcompete birds (not always, but more often than not). Think of how many species of mammals live full time underwater compared to birds. As impressive as a penguin is, whales are incredible.

Sure, but I don't accept that the comparison should be mammals to birds. And reptiles and archosaurs both have fully aquatic members.

[Yukle]

15 hours ago, TrueMetis said:

Avians and mammals aren't remotely on the same level of magnitude. Mammals would be better compared to reptiles or archosaurs.

This isn't a matter of debate, as taxonomy is a science. They're on exactly the same level.

Classification is done like this:

Domain > Kingdom > Phylum > Class > Order > Family > Genus > Species

Each split, as far as is known, is done to represent the moments when distinct organism groups diverge into different kinds.

Mammals and birds are both a Class, diverging at the same point.

Birds:

Eukaryote > Animalia > Chordata > Aves

Mammals:

Eukaryote > Animalia >  Chordata > Mammalia

Here's an episode of Community where Pierce provides a mnemonic device that is a variation of one more commonly used.

 

 

[TrueMetis]

10 hours ago, Yukle said:

This isn't a matter of debate, as taxonomy is a science. They're on exactly the same level.

Classification is done like this:

Domain > Kingdom > Phylum > Class > Order > Family > Genus > Species

Each split, as far as is known, is done to represent the moments when distinct organism groups diverge into different kinds.

Mammals and birds are both a Class, diverging at the same point.

Birds:

Eukaryote > Animalia > Chordata > Aves

Mammals:

Eukaryote > Animalia >  Chordata > Mammalia

Here's an episode of Community where Pierce provides a mnemonic device that is a variation of one more commonly used.

 

 

linnaean taxonomy is arbitrary outdated crap.

It's not at all

Eukaryote > Animalia > Chordata > Aves

It's

Eukaryote > Animalia > Chordata > Reptilla > Archosauria > Dinosauria > Aves

Bird cannot be a class as birds are a sub group of reptiles.

I do not appreciate being talked down to on this subject.

ETA: Monkeys would be

Eukaryote > Animalia >  Chordata > Mammalia > Pimates > Haplorhini > Simiiformes

Though one could make an argument that there should actually be more subgroups between birds and reptiles as there are several potential sub groups of dinosaurs. I would personally add at least one, the avian dinosaurs.

[Yukle]

10 hours ago, TrueMetis said:

...

I do not appreciate being talked down to on this subject.

...

Though one could make an argument that there should actually be more subgroups between birds and reptiles as there are several potential sub groups of dinosaurs. I would personally add at least one, the avian dinosaurs.

I'm not aiming to talk down, sorry if that's impression.

That's okay to argue you would personally change the classification system, except it's not the consensus science view, so I'm not at all convinced by your thinking just because you personally disagree.

In part, because the extra classifications you've added are sub-groups; extra classification is used to help to filter so many species. Clades sit between Phylum and Class, for instance, sub-Family is below family, sub-species is below species; there are lots of further divisions that are made because of the huge variety of species. Adding extra detail doesn't change what these levels represent.

Each point in the classification level is an estimation of where the common ancestor diverged.

Taxonomy is extremely well-supported by evolutionary biology. Certainly, lots of species have been reclassified as genetics have been discovered. Once upon a time, we had to guess based on appearance, so animals like the red panda and giant panda have similar names but they're not closely related.

Another reason that I'm not at all convinced is that birds are not a sub-group of reptiles. That doesn't make sense, any more than it does to call mammals a sub-group of reptiles. Evolution is not a linear process, it's a divergent process. Reptiles predate both Classes, sure, but they didn't morph into birds and mammals. At some point a member of them diverged in response to environmental pressures, grew feathers, developed four-chambered hearts and many of them began to fly. A different group diverged, also developed these adaptations and started developing pouches or placentas, as well as milk, to nurture their young.

While that was going on, though, reptiles themselves continued to exist, evolve and adapt as they always had, as a separate branch of the Animalia Kingdom. The classification of Birds, Reptiles and Animals into separate classes indicates that this moment was the last period of time when these Classes shared a common ancestor. This is going 125 million years back for birds, perhaps 80 million for mammals, so it's not going to be very precise, but it's a pretty good estimate. It makes sense, given there is a lot of convergent evolutionary traits between birds and mammals (like four-chambered hearts, warm-blooded, fur/feathers for warmth), that they'd arrive at a similar time (in evolution terms), probably responding to the same changes.

[TrueMetis]

1 hour ago, Yukle said:

I'm not aiming to talk down, sorry if that's impression.

That's okay to argue you would personally change the classification system, except it's not the consensus science view, so I'm not at all convinced by your thinking just because you personally disagree.

If the consensus view is that bird and reptiles are both classes than that consensus is obviously wrong. Fortunately it actually isn't the consensus, since the consensus has been rapidly changing with the introduction of Cladistics which is overturning linnaean taxonomy. And in that view bird are reptiles. You cannot have two sister groups when one evolved from the other. And birds indisputably (except for those band idiots) evolved from reptiles.

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In part, because the extra classifications you've added are sub-groups; extra classification is used to help to filter so many species. Clades sit between Phylum and Class, for instance, sub-Family is below family, sub-species is below species; there are lots of further divisions that are made because of the huge variety of species. Adding extra detail doesn't change what these levels represent.

Clades are just groupings of organisms descended from a common ancestor. Genus homo is a clade. Kingdom Animalia is also a clade. At least so long as you keep them monophyletic.

I wasn't actually using the kingdom to species classification method, just naming clades. Because trying to fit all the animals into the traditional eight layer system is an exercise in futility, as the existence of Magn, Super, Grand, Miro, Sub, Infra, and Parv groupings show.

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Each point in the classification level is an estimation of where the common ancestor diverged.

In Cladisitics yes, not so in Linnaean taxonomy were both para and polyphyletic groups exist. Birds as a class is a linnean classification.

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Taxonomy is extremely well-supported by evolutionary biology. Certainly, lots of species have been reclassified as genetics have been discovered. Once upon a time, we had to guess based on appearance, so animals like the red panda and giant panda have similar names but they're not closely related.

Yes it is, you're just using outdated taxonomy.

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Another reason that I'm not at all convinced is that birds are not a sub-group of reptiles. That doesn't make sense, any more than it does to call mammals a sub-group of reptiles. Evolution is not a linear process, it's a divergent process. Reptiles predate both Classes, sure, but they didn't morph into birds and mammals. At some point a member of them diverged in response to environmental pressures, grew feathers, developed four-chambered hearts and many of them began to fly. A different group diverged, also developed these adaptations and started developing pouches or placentas, as well as milk, to nurture their young.

So, at some point a member of the reptiles diverged from the other reptiles into birds, IE a reptile morphed into a bird. Maybe we're using different definition of diverged but to my understanding diverged just means develop in a different direction. IE humans and chimpanzees diverged from a common ancestor, we're both still apes though. It doesn't mean it stopped being part of it's original group. Birds evolved from reptiles hence birds are reptiles.

Or are you expecting snakes to stop being reptiles one day? In fact do you even consider snake a type of reptile? What exactly is your criteria for when a descendant of a group stops being part of that group?

Mammals incidentally did not evolve from reptiles. We share a common ancestor with them in the amniotes but the definition of reptile was updated because it was paraphyletic. IE including all of the ancestors of mammals and birds but not birds and mammals themselves. The new definition includes birds but no ancestor of mammals.

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While that was going on, though, reptiles themselves continued to exist, evolve and adapt as they always had, as a separate branch of the Animalia Kingdom. The classification of Birds, Reptiles and Animals into separate classes indicates that "Reptiles" was the last period of time when these Classes shared a common ancestor. This is going 125 million years back, so it's not going to be very precise, but it's a pretty good estimate. It makes sense, given there is a lot of convergent evolutionary traits between birds and mammals (like four-chambered hearts, warm-blooded, fur/feathers for warmth), that they'd arrive at a similar time (in evolution terms), probably responding to the same changes.

Again, if you evolved from something you are that thing. Birds are dinosaurs, dinosaurs are archosaurs, archosaurs are reptiles.

Here's another point, Crocodilians, a group of reptiles, are more closely related to birds than any other extant reptile. How is that possible if birds are not also reptiles? Or are Crocodilians not reptiles either?

[Yukle]

34 minutes ago, TrueMetis said:

If the consensus view is that bird and reptiles are both classes than that consensus is obviously wrong. Fortunately it actually isn't the consensus, since the consensus has been rapidly changing with the introduction of Cladistics which is overturning linnaean taxonomy. And in that view bird are reptiles. You cannot have two sister groups when one evolved from the other. And birds indisputably (except for those band idiots) evolved from reptiles.

Hmm... well, I don't think we're going to reconcile views, partly because I don't think that we're discussing the same thing.

Think of the classification systems not as competing but as measuring different things. Clades are intended to determine the time that a species diverged and uses this as a basis of how closely related species are.

Linnaeus' taxonomy uses similarities of genome to determined how closely species are related.

It's stupid to think of one as correct and the other as incorrect, as they're not measuring the same thing; they're competing ways of categorising the same thing.

Even then, those using cladistics don't even agree on whether birds and reptiles are in the same phylum, so I'm still not sure why you're so confident in expressing that. For the most part, that's not even what cladistics is doing; it doesn't profess that everything within a domain is therefore an species of the original kind.

Here's an extract that took me seconds to find:

There are several conceptual and methodological differences between cladistics and taxonomy that cause incongruence. One important conceptual difference is the use of different criteria for grouping: order of branching vs. similarity and difference (clades vs. taxa). Another is the policy regarding paraphyletic groups: to ban them in cladistics but ignore the ban in taxonomy. These two differences automatically lead to some incongruences. One approach is not right and the other wrong; each is operating by its own standards...

...More generally, the database in a molecular cladogram is, in itself, too narrow to serve as a foundation for an organismic classification. In cases of incongruence, the molecular evidence can be a reliable indicator of taxonomic relationships sometimes, misleading other times, and may afford no clear basis for a systematic decision.

http://www.amjbot.org/content/90/9/1263.full

 

 

[TrueMetis]

2 hours ago, Yukle said:

Hmm... well, I don't think we're going to reconcile views, partly because I don't think that we're discussing the same thing.

Think of the classification systems not as competing but as measuring different things. Clades are intended to determine the time that a species diverged and uses this as a basis of how closely related species are.

Linnaeus' taxonomy uses similarities of genome to determined how closely species are related.

No mate, both are about how closely species are related, which can in turn be used to determine when a split happened. It does not use when a theoretical split happened to determine relation because it would be impossible to determine when a split happened without already knowing how closely related two species are. And both use genetics, as well as many other methods, to determine relations. (Linnean taxonomy was created before DNA was discovered, how could it possible use just the genome to determine relation?) Cladistics is taxonomy just like Linnean taxonomy. The difference is Linnean taxonomy is arbitrary as fuck.

http://www.ucmp.berkeley.edu/clad/clad1.html

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Cladistics is a particular method of hypothesizing relationships among organisms. Like other methods, it has its own set of assumptions, procedures, and limitations. Cladistics is now accepted as the best method available for phylogenetic analysis, for it provides an explicit and testable hypothesis of organismal relationships.

 

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Even then, those using cladistics don't even agree on whether birds and reptiles are in the same phylum, so I'm still not sure why you're so confident in expressing that. For the most part, that's not even what cladistics is doing; it doesn't profess that everything within a domain is therefore an species of the original kind.

What? Fucking everyone agrees birds and reptiles are in the same phylum, both are chordates. And I'm confident in saying birds are in the same clade as reptiles (can't even  guess what you actually meant by phylum) because it's evident that birds are descended from dinosaurs and dinosaurs are descended from reptiles and clades include all descendants of a group by definition. And who the fuck said anything about species? A clade is a group of organisms with a common ancestor. Dinosaurs are a clade. Birds are a clade. Reptiles are a clade. They all include a lot more than just species.

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Here's an extract that took me seconds to find:

There are several conceptual and methodological differences between cladistics and taxonomy that cause incongruence. One important conceptual difference is the use of different criteria for grouping: order of branching vs. similarity and difference (clades vs. taxa). Another is the policy regarding paraphyletic groups: to ban them in cladistics but ignore the ban in taxonomy. These two differences automatically lead to some incongruences. One approach is not right and the other wrong; each is operating by its own standards...

...More generally, the database in a molecular cladogram is, in itself, too narrow to serve as a foundation for an organismic classification. In cases of incongruence, the molecular evidence can be a reliable indicator of taxonomic relationships sometimes, misleading other times, and may afford no clear basis for a systematic decision.

http://www.amjbot.org/content/90/9/1263.full

How does this support your point exactly? As he says paraphyletic groups are banned in cladistics, but not in (presumably linnean) taxonomy. A paraphyletic group is a group that includes an ancestor but not it's descendants. So you can't have a group that says "every member of x except y" in cladistics but you can in linnean taxonomy. Which is exactly what I said, birds are descended from reptiles and therefore a type of reptile according to cladistics.

ETA: Indeed it's stuff like this that's exactly why I called linnean taxonomy outdated, it makes no sense for something to arbitrarily stop being part of it's ancestral group.

[Yukle]

1 hour ago, TrueMetis said:

What? Fucking everyone agrees birds and reptiles are in the same phylum

How does this support your point exactly? As he says paraphyletic groups are banned in cladistics, but not in (presumably linnean) taxonomy. A paraphyletic group is a group that includes an ancestor but not it's descendants. So you can't have a group that says "every member of x except y" in cladistics but you can in linnean taxonomy. Which is exactly what I said, birds are descended from reptiles and therefore a type of reptile according to cladistics.

On the first part, I meant to type Class, not Phylum.

Swearing doesn't make your writing any more convincing. I'll scale down to just the part that matters: 

One approach is not right and the other wrong; each is operating by its own standards...

Taxonomy was made before genetics, and has adapted as it's been discovered. I have already accounted for that; it's why species are being reclassified. That's as silly as saying the periodic table was written before atoms were discovered, so it's outdated and wrong. It's just a means of classifying elements, there are others.

That said, you're still incorrect that being a descendant makes you the same. It'd be like saying that since all organisms began as single-celled prokaryotes, then by extension all organisms are prokaryotes. Since all organisms with chitin cell-walls evolved from a common ancestor then fungi are also beetles. Since all land animals came from jellyfish, then all horses are jellyfish.

The time periods are too long for this to make sense; if you're going to classify so loosely, it's not really worth dividing things up at all.

To be honest, I'm wondering about your comment about why I'm mentioning species. In all biological classification, species are usually the discrete quantum that is used, as best as possible, to draw distinctions.The best definition being that species can reproduce with themselves, but not others, and make fertile young. It's not a perfect definition, but it's handy for this. All organisms belong to some species that must have certain characteristics that make them discrete from all others; the less closely species are related, the harder it is to prove how, why and when they've diverged from a common ancestor.

I ask this in a polite way, not a judgemental way, but why are you so confident about this? It's easy for me; as pointed out, I'm quoting the far more common view. As I've quoted, nobody says that one version is superior to the other. You might think so, but biologists seem to use them for different reasons.

[TrueMetis]

24 minutes ago, Yukle said:

On the first part, I meant to type Class, not Phylum.

Swearing doesn't make your writing any more convincing. I'll scale down to just the part that matters: 

One approach is not right and the other wrong; each is operating by its own standards...

Right, in the botanists opinion. Not in mine, because I don't accept that a standard that arbitrarily throws descendant species out of their parent group is equal to one that doesn't.

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Taxonomy was made before genetics, and has adapted as it's been discovered. I have already accounted for that; it's why species are being reclassified. That's as silly as saying the periodic table was written before atoms were discovered, so it's outdated and wrong. It's just a means of classifying elements, there are others.

If the periodic table was as arbitrary as linnean classification I would call it outdated and wrong. If the periodic table was like linnean taxonomy gold and silver wouldn't be in the same family because they are different colours.

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That said, you're still incorrect that being a descendant makes you the same. It'd be like saying that since all organisms began as single-celled prokaryotes, then by extension all organisms are prokaryotes. Since all organisms with chitin cell-walls evolved from a common ancestor then fungi are also beetles. Since all land animals came from jellyfish, then all horses are jellyfish.

It does not make you the same, it makes you part of the same group. Hence if we evolved from prokaryotes we are indeed in the same group as prokaryotes. Beetles and fungi (and humans for that matter) can be placed in a clade that marks us a more related to each other than we are to plants. Similarly horses and jellyfish can be put into a clade that marks them as more closely related to each other than they are to fungi.

And I can't see how you could dispute that, linnean classification already does this to a degree. Jellyfish and horses are both classified as animals. But it doesn't, and cannot with the 8 layer system, recognize the common ancestry of fungi and animal, Cladistics also never takes a species out for changing to much in the arbitrary opinion of whoever is making the classification. Hence horse are and always will be an animal even if they were to lost all of the characteristics of animals.

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The time periods are too long for this to make sense; if you're going to classify so loosely, it's not really worth dividing things up at all

Time periods are irrevelevent. The first prokaryote is 3.5 billion years removed from current prokaryotes. They are still both prokaryotes.

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To be honest, I'm wondering about your comment about why I'm mentioning species. In all biological classification, species are usually the discrete quantum that is used, as best as possible, to draw distinctions.The best definition being that species can reproduce with themselves, but not others, and make fertile young. It's not a perfect definition, but it's handy for this. All organisms belong to some species that must have certain characteristics that make them discrete from all others; the less closely species are related, the harder it is to prove how, why and when they've diverged from a common ancestor.

I commented on it because you seemed to be under the impression that clades meant all of these animals were of the same species. Which isn't true in the slightest. All a clade means is that these organisms are in the same group based on their common ancestors. If you're descended from a bird you're a bird, if your descended from a dinosaur you are a dinosaur, and if your descended from a reptile you are a reptile. Again Linnean classification does the same thing except when it arbitrarily decides something isn't.

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I ask this in a polite way, not a judgemental way, but why are you so confident about this? It's easy for me; as pointed out, I'm quoting the far more common view. As I've quoted, nobody says that one version is superior to the other. You might think so, but biologists seem to use them for different reasons.

No, one guy says the no version is superior to the other. I'm not stuck in 2002, nor am I going to accept that the classification system that cuts descendant species out of their parent group arbitrarily as being equal to the system that doesn't.

[Yukle]

5 hours ago, TrueMetis said:

[snip]

Since it's not my area, I asked one of my friends, who said you have not correctly described cladistics at all.

In taxonomy, you describe an entire species by its hierarchy. You don't do this in cladistics. Instead, you draw a tree and then certain groups can be circled as being in the same type, on a magnitude that you determine depending on far back you want to go. You don't refer to an entire linear group, since they won't necessarily be grouped by equal hierarchies. Here's an example:

https://en.wikipedia.org/wiki/File:Monophyly,_paraphyly,_polyphyly.png

In short, this was a waste of time. Your descriptions weren’t sensical.

Equally, they said your confidence in genetics was ridiculous because both systems were made before genome sequencing and both systems now use it. Even then, the overwhelming majority of classification is done by anatomy since genetics is expensive.

We have long hijacked the thread anyway, but this was pointless in the end.

[TrueMetis]

On 11/23/2017 at 5:20 AM, Yukle said:

Since it's not my area, I asked one of my friends, who said you have not correctly described cladistics at all.

In taxonomy, you describe an entire species by its hierarchy. You don't do this in cladistics. Instead, you draw a tree and then certain groups can be circled as being in the same type, on a magnitude that you determine depending on far back you want to go. You don't refer to an entire linear group, since they won't necessarily be grouped by equal hierarchies. Here's an example:

https://en.wikipedia.org/wiki/File:Monophyly,_paraphyly,_polyphyly.png

In short, this was a waste of time. Your descriptions weren’t sensical.

I never said that cladistics groups species by hierarchy I said that cladistics groups organisms by common ancestry. Which is exactly what your example shows, except the paraphyly and polyphyly would both be rejected. Though this does naturally lead to a system of hierarchy as you can group clades into further clades. This won't be the traditional 8 layer system, but then the traditional 8 layer system is obviously flawed with how many sub and super groups they needed to put in at every level.

Using the example you provided you could have the clade of humans, which is part of the clade of apes, which is part of the clades of monkeys, or written out more simply Monkeys > Apes > Humans in order of more general to less.

Though traditional taxonomy does not group by hierarchy, because as we've established it remove groups from their ancestral group arbitrarily. How could you possibly call a taxonomic system that place a descendant group on the same level as it's ancestor group a hierarchy?

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Equally, they said your confidence in genetics was ridiculous because both systems were made before genome sequencing and both systems now use it. Even then, the overwhelming majority of classification is done by anatomy since genetics is expensive.

We have long hijacked the thread anyway, but this was pointless in the end.

The only time I've mentioned genetics thus far was pointing out both Linnean taxonomy and cladistics use genetics and that saying " Linnaeus' taxonomy uses similarities of genome to determined how closely species are related." is wrong because Linnean taxonomy predates genetic sequencing and uses a bunch of other stuff besides.

So what the fuck are you talking about?

ETA: For anyone who is interested in a more in depth look at cladistics and systematic classification, and a bit more on the problems of Linnean taxonomy, this is a pretty good series .

[mankytoes]

Holy shit this is like the most technical argument I've ever seen on a forum.

I'd give every king in 15th century Europe a nuke for shits and giggles.

[maarsen]

10 hours ago, mankytoes said:

Holy shit this is like the most technical argument I've ever seen on a forum.

I'd give every king in 15th century Europe a nuke for shits and giggles.

And an oxcart for a delivery system?

[GAROVORKIN]

On 11/23/2017 at 8:01 AM, mankytoes said:

Holy shit this is like the most technical argument I've ever seen on a forum.

I'd give every king in 15th century Europe a nuke for shits and giggles.

Lots the know.