"Scientists have at last uncovered the closest living relative of the mighty Tyrannosaurus rex, the most feared and famous of all the dinosaurs. For the first time, researchers have managed to sequence proteins from the long-extinct creature, leading them to the discovery that many of the molecules show a remarkable similarity to those of the humble chicken."

Wait, so that means the last remaining T-rexs have (theoratically) evolved into the chicken? Wait, T-rex was huge, so I guess it possibly turned tiny, a chicken. Does that mean, back then... Earth had more oxygen then it has now? Well, I have been searching the internet and I came across some people saying that the more oxygen on earth here, the bigger the insects and the more powerful we are...

So basically my theory suggests: Millions of years ago, there was more CO2 (oxygen) then there was today...

If someone is smart enough to calculate and also correct me if I might be right, I'd be pleasured!

Quote from MoonJaspers

So basically my theory suggests: Millions of years ago, there was more CO2 (oxygen) then there was today...

Did you just say CO2 = Oxygen???

lmao. Think he meant O2. Or at least I hope.

I would give an insight. But honestly I don't have a clue.

http://www.globalchange.umich.edu/globalchange1/current/lectures/Perry_Samson_lectures/evolution_atm/

Today's oxygen level is ~21%. Between 360 million, and 250 million years ago oxygen levels rose to a high of 35% and then dropped to a low of 15%. That's what is known as the Giant-Fucking-Insects period of earth's history. Tyrannosauruses were roughly 65 million years ago (??), which is long after the most recent significant atmospheric change if the article is anything to go by. Some of the earliest dinosaurs may have had slightly lower levels of oxygen than they would today, but as far as I can see the tyrannosauruses would probably have had about the same as we do.

I learned in school 2 decades ago that at the very beginning there were special forms of bacteria that could digest chemical gases, and one of the by-products of that process was oxygen. This was one of the reasons that the earth was able to keep up with the rising oxygen needs of it's carbon based lifeforms.

The correlation between size and the amount of oxygen doesn't necessarily affect some lines of evolution as you may think. I think Zed is correct (I'll have to double check later on), but the amount of oxygen that reptiles like dinosaurs had were not too far off from what we have today, while millions of years before that, the concentration of oxygen was high enough so life forms such as arthropods and vascular plants (ferns) were massive. Having a large size sometimes wasn't too advantageous when it came to surviving, especially in the harsh environments way back then.
Plus, there are other ways that Tyrannosaurus genes could have been found in chickens, which include (but not excluding) gene flow and the bottleneck effect. It's hard to trace back evolutionary lines due to the dinosaur incident that started adaptive radiation.

Quote from Raptor

The correlation between size and the amount of oxygen doesn't necessarily affect some lines of evolution as you may think.

that's because the correlation isn't "more atmospheric oxygen = larger organisms"

most arthropods and amphibians lack a developed respiratory system, instead they depend on absorbing oxygen through the surface of their skin which gets diffused throughout the rest of their bodies.

as they increase in size, their larger surface area means they can absorb more oxygen, but their overall volume increases by a much larger ratio. that places an upper limit on how large they can get, because at a certain point their skin can't absorb enough oxygen for the rest of their body.

that limit doesn't apply to organisms with developed respiratory systems.

Quote from MoonJaspers

Wait, so that means the last remaining T-rexs have (theoratically) evolved into the chicken?

you're a living relative of your great-great-grandfather, does that mean he evolved into you? no. the t-rex and the chicken are related in the same manner, except instead of 3 generations it's several million. they're very, very distantly related and the chicken only shares a small part of the t-rex's genetics.

Quote from Raptor

Plus, there are other ways that Tyrannosaurus genes could have been found in chickens, which include (but not excluding) gene flow and the bottleneck effect. It's hard to trace back evolutionary lines due to the dinosaur incident that started adaptive radiation.

gene flow occurs between separate populations that can breed with each other. since modern chickens aren't interbreeding with t-rex's it's safe to say that's not a factor. and a population bottleneck reduces genetic variation within a population, that's not an explanation for a very distant genetic relationship between two distinct species.

I'm here, learning a little about the evolution theories.
But to be honest, there are so many possibilities it doesn't even matter.
Has the speed of light always been the same? Maybe, maybe not.
We know dinosaurs existed a long time ago, who can prove what they evolved into, or if they evolved at all.
And if everything evolves into something else, what evolved into dinosaurs?
Where did dinosaurs come from?
But there is also the difference of Evolution vs. Creation.
(I won't get into that, though)

if I may refute, point-by-point:

Quote from iarentevil

Has the speed of light always been the same? Maybe, maybe not.

as far as we know, yes, is there any evidence suggesting otherwise? what's your point?

Quote from iarentevil

We know dinosaurs existed a long time ago, who can prove what they evolved into, or if they evolved at all.

the fossil record? evolutionary science? what makes you think this hasn't already been proven?

Quote from iarentevil

And if everything evolves into something else, what evolved into dinosaurs?

have you actually tried to learn about this topic? here: http://en.m.wikipedia.org/wiki/Evolution_of_dinosaurs


as far as creationism vs evolution, this isn't the time or place and you clearly don't know enough about evolution to be able to debate it.

Quote from Exilement

if I may refute, point-by-point:



as far as we know, yes, is there any evidence suggesting otherwise? what's your point?



the fossil record? evolutionary science? what makes you think this hasn't already been proven?



have you actually tried to learn about this topic? here: http://en.m.wikipedia.org/wiki/Evolution_of_dinosaurs


as far as creationism vs evolution, this isn't the time or place and you clearly don't know enough about evolution to be able to debate it.

Well;

Quote from iarentevil

I'm here, learning a little about the evolution theories.

And also, there is no evidence proving that the speed of light has differed, but there is none that had proven that it has always been the same, has there?

at the same time; the question is "Could dinosaurs have evolved into a chicken". If the fossil record or evolutionary science has proven this, why is it a question?

Why do you think I said I wouldn't get into it?

Quote from iarentevil

And also, there is no evidence proving that the speed of light has differed, but there is none that had proven that it has always been the same, has there?

it's a fair assumption when every observation consistently leads to the same result. it's a universal physical constant that's part of many other scientific formulas and equations that wouldn't work if it were incorrect.

the question "has the speed of light always been the same?" doesn't have an answer. we haven't always been able to measure it, so we can't say for sure one way or the other, but as long as we've been paying attention it hasn't changed and there's absolutely no evidence to believe it can or ever will. that's the only thing that really matters.

Quote from iarentevil

at the same time; the question is "Could dinosaurs have evolved into a chicken". If the fossil record or evolutionary science has proven this, why is it a question?

it's an accepted fact that evolution occurs, I don't know what kind of proof you're looking for but the evolutionary history of birds isn't exactly a mystery. there's even a Wikipedia article titled "Evolution of birds if you really care enough to look into it.

Quote from Exilement

it's an accepted fact that evolution occurs, I don't know what kind of proof you're looking for but the evolutionary history of birds isn't exactly a mystery. there's even a Wikipedia article titled "Evolution of birds if you really care enough to look into it.

I wasn't talking about evolution as a whole.
Evolution/adaptation happens, it's what keeps animals alive in a hostile environment.
What I was asking "How could we possibly know WHAT the dinosaurs evolved into, or if they went extinct before they could evolve".

EDIT: Okay so I was making food when I posted this and I have NOW looked at that link. What I understood from it was that it was most LIKELY true, but still only a theory.

then look up the definition of scientific theory while you're at it, because the whole "just a theory" bullshit is one of the biggest misconceptions people have about scientific knowledge.

Yes, there was more Oxygen but, that doesn't have too much to do with chickens.

Quote from iarentevil

I wasn't talking about evolution as a whole.
Evolution/adaptation happens, it's what keeps animals alive in a hostile environment.
What I was asking "How could we possibly know WHAT the dinosaurs evolved into, or if they went extinct before they could evolve".

EDIT: Okay so I was making food when I posted this and I have NOW looked at that link. What I understood from it was that it was most LIKELY true, but still only a theory.

http://www.livescience.com/21491-what-is-a-scientific-theory-definition-of-theory.html

I understand that theory is taken as basic scientific fact. Until something else comes along that could possibly prove it wrong.
The problem is that all facts of science are still considered 'theories', such as "gravity exists".
I meant specifically this seemed to be unproven, and not yet a full-fledged theory.