De-extinction and creating new life

[KerikBalm]

The gut bacteria would likely be similar enough that it would work.

FYI, humans are born basically with a sterile gut, which is then quickly colonized by bacteria. The bacteria living on your skin are not the same as those on someone else's skin. The bacteria on your outer elbow are not the same as the bacteria on your inner elbow.

If you look at how fast and how much bacteria can evolve in the lab when subjected to different conditions, its likely bacteria acquired from the environment would become adapted to a dino digestive system very rapidly. The pH, temperature, food intake, would all be relatively similar to animals still living today.

The biggest problem is simply that DNA doesn't last that long...

And I would not say its the least accurate of the natural sciences. Molecular biology, a subset of microbiology, is very rigorous.

Just because there is a debate over useless terminology, does not make it pseudoscience.

Nobody in the lab I work in concerns themselves with the definition of a species or life. Its quite irrelevant to the studies we're doing.

Of course, to the laypeople, these irrelevant definitions are pretty much all they understand.

[Klingon Admiral]

The problem is that we don't know anything about the physiology of dinosaurs, as fossils can only tell us that much. Our most educated guess at the moment is that their metabolism was somewhere between modern mammals/birds and "reptiles", with sauropods and ankylosaurs possible having the slowest metabolism and maniraptorans having the fastest. The problem is that dinosaurs were a highly heterogenous group, from a few centimetre long insect eaters to maybe 60 metres long herbivores which are only second to the large baleen whales in weight. The large theropods could grow up to 14 to 16 metres long while weighting 10 tons or something, completely dwarfing every terrestrial predator which came before or after them. Dinosaurs must have done something very, very right what no other group of animals has figured out, and it was possible something with their physiology.

And I have never said biology is a pseudoscience. But as long as cladistics is a part of biology I just cannot view biology as a whole as accurate.

[Nibb31]

Why has nobody brought up the maybe biggest pronlem with de-extinction of long extinct species yet?

I did, in post #4 of this thread. But you are forgiven

[Seret]

FYI, humans are born basically with a sterile gut, which is then quickly colonized by bacteria.

Which they receive from other humans.

[CaptainKipard]

I've found that scientists have already attempted to do this. Early days still.

[78stonewobble]

There was a viewpoint mentioned about us humans thriving and extinct animals that just didn't and that therefore we have no responsibility. For either animals extinct long ago or animals recently and due to our interference.

The first I agree with that there we have no responsibility, any revival should be due to scientific curiosity.

To the 2nd groups I think we have some responsibility, because there is "thriving" and there is "thriving while being an ass about it".

An analogy might be a big corporation bullying a small local provider.

It might be a moral argument, but I stand by it.

Humanity would in no way go extinct or be diminished in any measurable way if we brought back ie. the thylacine in small but viable area of tasmania.

[Comrade Jenkens]

I most promising way I've currently seen for bringing back dinosaur like creatures (they wouldn't actually be dinosaurs) was by switching on and off genes in living birds. Scientists founds that birds have the sets of genes for teeth, tail, scales and arms but they are just unused.

It wouldn't be dinosaur but it sure as hell would look like one.

Apart from that I think that bringing back more recently extinct species would be good for biodiversity and this time around it would be our job to not act so recklessly as to drive them to (re)extinction.

[Klingon Admiral]

As birds are dinosaurs, there is no need to bring dinosaurs back, they never went away.

[Ralathon]

As birds are dinosaurs, there is no need to bring dinosaurs back, they never went away.

A pigeon just doesn't have the same dramatic flair as a T-rex though.

[KerikBalm]

The problem is that we don't know anything about the physiology of dinosaurs, as fossils can only tell us that much.

You are aware that there are cases of fossilized dino mummies, preserving internal organs, right? We also have some amino acid sequences.

We know about their breathing+ air sac aparatus, rather bird like.

Our most educated guess at the moment is that their metabolism was somewhere between modern mammals/birds and "reptiles"

No. Seeing as how birds are dinosaurs, that is just asinine to say that birds metabolism is less than birds metabolism. Fuzy dinos were cold blooded eh? Also, given ample evidence that the ancestral archosaur was warm blooded, and that crocodiles are secondarily cold blooded, this cold blooded vs warm blooded debate is long over.

The problem is that dinosaurs were a highly heterogenous group, from a few centimetre long insect eaters to maybe 60 metres long herbivores which are only second to the large baleen whales in weight.

The same can be said of mammals, where is the problem?

The large theropods could grow up to 14 to 16 metres long while weighting 10 tons or something, completely dwarfing every terrestrial predator which came before or after them. Dinosaurs must have done something very, very right what no other group of animals has figured out, and it was possible something with their physiology.

Umm, so you subscribe to bigger= better? btw, those mass estimates have come down quite a bit. More modern T rex estimates are between 6-7 tons.

In comparison, a polar bear may reach 2 tons.

But as long as cladistics is a part of biology I just cannot view biology as a whole as accurate.

What is your problem with cladistics?

Its a whole lot better than the old taxonomy, your statement is somewhat like saying as long as astonomy (do oyu consider that a subset of physics? I'd say it certainly is, its advanced physics with studies of high energy processes, singularities, CBR, etc) has a stellar and planetary classification system you just cannot view physics as a whole as accurate.

They can't even make up their minds about what a planet is! Why is ceres not a planet? oh, it hasn't cleared its orbit? but what's this? earth crossing asteroids? (not that I disagree with this classification, classifications are human made constructs, and as long as it is useful and works, go with it, just don't pretend its some innate quality)

You seem to be confusing philisophical debates that deal with biology, with biology.

One can study adenovirus, modifying its promoter sequences, characterizing how microRNAs transcribed from viral DNA affect host cell gene expression, etc - You could describe exactly what it is, and what it does. Yet, that would not answer the philisophical question "is it alive?"

I'll leave the questions of what is life and what is not life to the philosophers.

Is a self replicating RNA molecule alive? I don't know, but I know it has biological activity, that there is hereditary descent with modification, that it evolves, etc.

Likewise, I'm not overly concerned with what is a species, genus, subspecies, race, etc...

If I want to study mRNA expression in mitochondria, its not even enough that two samples are from the same species... I want them to come from the same clonal cell line, wouldn't want results complicated by interspecies variation.

After you get that down, then you stat useing these classifications as simply tools to direct your search...

If you look at classification as anything more than a tool, you are doing it wrong.

[RuBisCO]

Imagine soon we can kill everything off without guilt, because we will retain a genetic ark of every species, so we can repopulate them at our leisure... nothing morally awkward about that, nope.

[Kryten]

Which they receive from other humans.

Don't conflate us being dependent on them with them being dependent on us. All common GI tract microbiota organisms have non-human hosts (and usually non animal habitats), except H. Pylori, and H Pylori isn't a commensual.

[Klingon Admiral]

No. Seeing as how birds are dinosaurs, that is just asinine to say that birds metabolism is less than birds metabolism. Fuzy dinos were cold blooded eh? Also, given ample evidence that the ancestral archosaur was warm blooded, and that crocodiles are secondarily cold blooded, this cold blooded vs warm blooded debate is long over.

Warmblooded can mean a lot of different things. And the metabolism rate can vary extremely even between homoiothermic animals, just compare the metabolism of a shrew with the metabolism of a diving sperm whale or a hibernating bear. Day and night. The general scientific consensus is that the metabolism of dinosaurs was homoiothermic, but slow, with a increase in metabolism rate the closer one gets to modern birds. And "fuzzy dinos"? New discoveries indicate that all dinosaurs were fuzzy (probably with secondary intergument loss with sauropods). There is a feathered siberian neoornithischian awaiting description, and ceratopsians posessed brittle-like structures on their skin.

Umm, so you subscribe to bigger= better? btw, those mass estimates have come down quite a bit. More modern T rex estimates are between 6-7 tons.

In comparison, a polar bear may reach 2 tons.

T. rex was more likely 6 tons than 7 tons, at least the Sue specimen, although there are some partial remains of even larger specimens. But Spinosaurus aegyptiacus was quite a bit larger than T. rex, and some estimates put it's weight at 20 metric tons (which I find kind of unlikely, though). T. rex may have been the most efficient killer of all large dinosaurs (hard to argue against that biteforce), but it was quite lightweight. Coelurosaur stays Coelurosaur, after all. And when it comes to being bigger, dinosaurs where just better than every other group of terrestial animal.

What is your problem with cladistics?

Since crocdiles where classified as reptiles in my biology book during my years leading up to the final exams, I have a burning hatred against cladistics.

[Crocodiles are birds!]

[Comrade Jenkens]

Since crocdiles where classified as reptiles in my biology book during my years leading up to the final exams, I have a burning hatred against cladistics.

[Crocodiles are birds!]

Erm... Having branched off way before dinosaurs and being only loosely related to them, crocodiles are clearly reptiles.

[Klingon Admiral]

Erm... Having branched off way before dinosaurs and being only loosely related to them, crocodiles are clearly reptiles.

The closest relatives of crocdiles are birds, then turtles, then lizards, according to modern molecular research. Crocdiles are archosaurs, turtles are not and lizards are absolutely not.

[KerikBalm]

The general scientific consensus is that the metabolism of dinosaurs was homoiothermic, but slow, with a increase in metabolism rate the closer one gets to modern birds.

No, that is not the general consensus.

And "fuzzy dinos"? New discoveries indicate that all dinosaurs were fuzzy (probably with secondary intergument loss with sauropods).

That is not the consensus either. There is only good evidence of structures homologous to feathers in tetanura.

It is true that there are bristles on ornithiscians (such as Heterodontosaurus), and the presence of pycnofibers in closely related pterosaurs implies that there may be a "dinofuzz" like covering basal to ornithodira, that is far from settled. Plausible yes, but probable based on the evidence? no.

There's no evidence that the bristles on non theropod ornithodirans is any more homologous to feathers than the dorsal "bristles" on iguanas...

There is a feathered siberian neoornithischian awaiting description, and ceratopsians posessed brittle-like structures on their skin.

But Spinosaurus aegyptiacus was quite a bit larger than T. rex, and some estimates put it's weight at 20 metric tons (which I find kind of unlikely, though).

Yes, quite unlikely. And it was at least semi aquatic. Can we start looking at carnivorus pinnipeds now?

Since crocdiles where classified as reptiles in my biology book during my years leading up to the final exams, I have a burning hatred against cladistics.

[Crocodiles are birds!]

You're begining to sound like a "BANDit" subscriber to that nutjob Martin.

Crocodiles are reptiles.

Birds are reptiles (according to cladistics, and common sense + sufficient information).

Crocodiles are not Birds.

Crocodiles are archosaurs.

Birds are Archosaurs.

Dinosaurs are archosaurs.

Birds are dinosaurs.

Dinosaurs are reptiles.

Crocodiles are not Dinosaurs.

Anything else I need to clarify for you?

[Klingon Admiral]

The problem with reptiles is, that the classification for reptile does not hold up to modern phylogenetical standards.

The closest living relative of any amphibian is a amphibian. The closest living relative of every living bird is a bird. The closest living relative of every living mammel is a mammal. But there are cases where the closest living relative of a reptile is not another reptile, but a bird. The point where a bird is considered a bird and a reptile considered a reptile is absolutely arbitrary and comes from a time where the sciences were quite a bit less exact than today. If it is possible to replace an arbitrary boundary with a boundary well footed in science, than it must be replaced.

[KerikBalm]

By modern phylogenetic standards, a bird is a reptile.

Your argument is a strawman.

The whole point of cladistics is to do away with that sort of crud that you bring up (which was a problem with the old Linnaean taxonomy).

Edited March 27, 2014 by KerikBalm

[Klingon Admiral]

I'd be totally fine with the abolition of the class aves and the inclusion of the clade avialae into reptilia. However, not all cladiograms do that.

[KerikBalm]

even the use of "class A" and "order B" that is stupid IMO. Its much simpler to just refere to clade A and clade B.

A proper cladogram doesn't make any note of rank in the old linnaean taxonomy (although it may still use the same names for clades, it may be clade reptillia, but it will not say order reptillia).

I would challenge you to find a cladogram that does not show that birds are reptiles.

Any textbook which says otherwise is either (a) old or ( written by negligent people whom should not be producing textbooks.

You seem to be making (mostly valid) criticisms of the old linnaean taxonomy, but attributing those criticisms to modern cladistics (aka phylogenetic systematics - the name may make it more clear how important it is that clades be monophyletic, you can't construct a reptile clade without including birds).

I encourage you to visit this website for a (mostly) up to date set of cladograms.

http://tolweb.org/tree/

http://tolweb.org/Terrestrial_Vertebrates/14952

http://tolweb.org/Amniota/14990

Note how birds are grouped with the diapsids, within clade reptilia

http://tolweb.org/Diapsida/14866