Thread: Chronological order of human anatomical evolution?

I am looking for the biological version of this: Graphical timeline of the Big Bang - Wikipedia, the free encyclopedia. Hoping anyone could provide any information that would assist me in chronologically plotting the evolutionary start points of human organs and organ systems throughout time and taxonomy, all the way from domain to species:

Eukaryota -> Animalia -> Chordata -> Mammalia -> Primata -> Hominidae -> Homo -> Sapiens.

I want to establish a very simplified big picture of the chronological order of human anatomical evolution. Which of the systems evolved first from where we currently draw the line at "inorganic material" and which of the systems evolved last. For example, just as the five natural senses present in us today have evolved throughout time (the earliest organisms could not see, hear, smell...) and this evolution can be chronologically graphed throughout homo sapien ancestry... likewise today's homo sapien organ systems were not present in the earliest organisms and I am hoping to establish a simplified chronological graph of that evolutionary process. (For example: a respiratory organ system was not present in the earliest single celled organisms because nutrients and gases could diffuse directly across the cell membrane, and a reproductive organ system was not present seeing as these organisms produced asexually.) I am aware that there is no generally accepted consensus as to the number of human organs and organ systems, so for the sake of this discussion let us assume the below 13 organ systems from wiki to be acceptably accurate, and forgive me for any innaccuracies above, you get the drift...

•Circulatory system
•Digestive System
•Endocannabinoid system
•Endocrine system
•Integumentary system
•Immune system
•Lymphatic system
•Musculoskeletal system
•Nervous system
•Reproductive system
•Respiratory system
•Urinary system
•Vestibular system

anatomically, humans didn't evolve that much.

from apes up to now, all we got, were slimmer lighter bone structure, longer legs, feet formed to stumps, and increased brain capacity.. Not much of an evolution if you compare it to the first fish who got up on land, and had to come up with a new way to absorb oxygen..

You've missed Luke's point. He wishes to know, for example, where in our line of ancestry did the digestive system first appear. Without doing any actual literature search it seems to me that practically all of these would have emerged at or around the time of the Cambrian explosion, since they are all basic to the more complex metazoans which appeared in detectable numbers around that time.

Originally Posted by John Galt

You've missed Luke's point. He wishes to know, for example, where in our line of ancestry did the digestive system first appear. Without doing any actual literature search it seems to me that practically all of these would have emerged at or around the time of the Cambrian explosion, since they are all basic to the more complex metazoans which appeared in detectable numbers around that time.

Pretty much what I was going to say.

Part of the problem, also, is defining when these things appear. They evolve out of earlier structures. So at what point do you say some particular organ exists rather than a more primitive precursor. The basis for most of these goes all the way back to the appearance of triploblastoc animals and the appearance of the coelem in the Ediacarn era.

Also, some things, such as the evolution of the immune system cannot be observed directly as they leave no fossil remains. Some information could be gathered from genetic analysis, I suppose.

This sounds like it would require a large amount of research in many different areas. And for no real benefit that I can see.

A large amount of research indeed, that's why I am hoping there are some people out there who have already gathered information and participated in this study, perhaps for their university or career, or maybe there are some type of publishings I could find on the internet or in a library. Any information that anyone might be aware of on this topic would be greatly appreciated. Thanks.

Hehe, indeed, i didn't get it.. But lately i'm a little lazy and not reading everything someone posts.. Maybe i should.. Though in our ancestry, the digestive system was already incorporated while we were single cellular. As still seen today in amoeba, as they already have a digestive system.

Or did you mean the digestive system similar to what we have, then... it's probably just us, as ones digestive system is extremely adaptable and one of the first things to slightly change over the years. I'm pretty sure that in the 40.000 years people had to evolve independently, our digestive system adapted to the food most abundant to that specific location. Our commensal bacteria even evolve to the food we eat in several days, months or years.

I'll look for some information though :-)

http://www.jstor.org/stable/10.2307/2744104

This is a piece about evolution about digestive/brain system. I hope it's helpfull.. though i must admit, i didn't read it yet..

I'm not completely convinced by the theory of common decent.

How would the ability to sense just develop at some point? like some ancient organism with no sight, no eyes, just gave birth to somethin with the ability to detect light, then those organs give the organism an advantage and it goes on to survive and strive and give birth to all the other organisms that have eyes in the future.

Ok, it's one theory, it's possible.

Going back in time and finding all this info on when the first ears occured etc will be impossible is my geuss.

Blows the mind. I watched a program about a few organisms that havve survived completely unchanged for estimated 40 billion years... 40 billion years unchanged! they didn't even grow any bigger or smaller... they were happy in there niche for that long! An other species, nay families, nay kingdoms are supposed to have evolved and produce many new organisms! How can this make sense? it boggles my poor little mind.

How do they know a rock is forty million years old anyway? what did they use to calibrate the carbon dater? How can it be claimed that a stretch of mud in japan has not changed in 40 billion years? The thing that annoys me is that countless scientists make these claims... yet none of them really give any detailed evidence of the claims.

just becuase darwin spotted adaptions it follows that we all evolved from the same organism 'billions' of years ago does it? great may i see some evidence please? if there is no solid evidence can we stop assuming this is the absolute truth please? I know theres an agender to get rid of 'creationists' and power of religions... but please stick to the facts and prove what you claim mr media Scientists! Thank you very much.

Please hear me brian cox, david attenborough, the mad one with the monacle, patrick moor! If you share your theories that you beleive in, give us the evidence instead of expecting us to beleive what you say (though most probably will beleive you with out evidence, but they are not scientific minds). That's all I ask.

Rant over, thank you.

i doubt this 40 billion years.. as the age of the universe is about 13,75 billion years... soo..... it were organisms found from before the big bang..?¿?..

Originally Posted by Zwolver

i doubt this 40 billion years.. as the age of the universe is about 13,75 billion years... soo..... it were organisms found from before the big bang..?¿?..

It must have been 40 million. Thank you. I wish i remembered the name.

I doubt the 40 million, it sounds like a typical tv program oversimplification to make it sensational sounding. There are groups that have undergone little change over the eons, but they are not "the same" over that whole time.

Originally Posted by Paleoichneum

I doubt the 40 million, it sounds like a typical tv program oversimplification to make it sensational sounding. There are groups that have undergone little change over the eons, but they are not "the same" over that whole time.

I also tend to doubt any claim about 40 millions years ago... I doubt what was supposed to have happened 4000 yrs ago, let alone 40 million.

But remember this is bbc 4 we'r dealing with, not fox news!

Give it a look, it might be interesting: BBC iPlayer - Survivors: Nature's Indestructible Creatures: The Great Dying

The creature include a lanclet which is supposed to be our oldest know ancestor (BS!) excuse me... the old terrents syndrom. And also horse shoe crabs.

At 38 minutes he digs up a 'lingula anatina' which he claims he is used to seeing fossilised in rocks that are 400 MILLION yrs old... completely unchanged! Shocker.

(wild guess du jour)
digestion first
followed closely by reproductive

then we had to go multi cell before any of the others mattered
then circulation and communication would help the different cells specialize
(as/re communication, i suspect that chemical preceeded electric preceeded electro-chemical)

as to the rest, wow, I ain't got a clue, but I'll think about it.
I suspect that we carry dormant genetic code(stored in a dna reference library---currently refered to as "junk dna") from most of our ancestors, all the way back to single cell organisms. Some junk we haul around with us no matter where we go(double entendre intended) but most of our baggage has valuable uses when needed.

Interesting comments sig.


RE: my previous comments... I do beleive it's called torretts syndrome or something, not terrents.

Originally Posted by question for you

Interesting comments sig.


RE: my previous comments... I do beleive it's called torretts syndrome or something, not terrents.

One helluva non sequitor?
Or, did I miss something important?

As each system evolved, in conjunction and in context with the others, feedback created selection pressure on everything else.

I very much doubt any major subsytsem of the human body predates, in its present form, all the rest of them.

Originally Posted by question for you

I'm not completely convinced by the theory of common decent.

I assume that is because you don't know much about it? The only alternative is some sort of religious bias (and I don't think that applies). It would seem impossible to consider the evidence with an open mind and not be convinced.

How would the ability to sense just develop at some point? like some ancient organism with no sight, no eyes, just gave birth to somethin with the ability to detect light, then those organs give the organism an advantage and it goes on to survive and strive and give birth to all the other organisms that have eyes in the future.

Even the most primitive organisms would have been sensitive to their environment in some ways: it's warmer this way, or there is more nutrient this way, or whatever.

Developing a cell which is sensitive to light wouldn't be too surprising. Many chemical reactions are enabled or changed by the presence of light (look at photosynthesis). Once an organism is able to sense light and dark better than its competitors (or its prey, or its predators) then it has a survival advantage. In the continuous arms race that is life, this is very valuable. A survival advantage means more offspring. Those offspring will carry the same advantage. At some point some of them will develop better light sensing organs; perhaps able to see more than just light and dark, but also vague shapes, etc. Survival advantage! More offspring! etc.

OK. Here evolutionary theory can make a prediction. Sight (of almost any sort) seems to provide such a huge advantage, we would expect it to arise multiple times in different branches of the animal kingdom.

Hey, and guess what?

Ok, it's one theory, it's possible.

Its a very good theory. It is almost certain. There is certainly no contradictory evidence at present.

Going back in time and finding all this info on when the first ears occured etc will be impossible is my geuss.

Funnily enough, not impossible at all. Of course, ears are relatively easy as they have solid structure. Finding when something that leaves no remains developed is trickier. But a lot can be learnt from the analysis of DNA.

Blows the mind. I watched a program about a few organisms that havve survived completely unchanged for estimated 40 billion years... 40 billion years unchanged! they didn't even grow any bigger or smaller... they were happy in there niche for that long!

If they fit their niche and the niche doesn't change and competition doesn't change too much then evolution will tend to keep them generally the same (they will have changed over that time, but their major features may still be very similar to the original; they could be genetically quite different in some ways). This is, of course, another prediction from evolution theory confirmed!

How do they know a rock is forty million years old anyway? what did they use to calibrate the carbon dater? How can it be claimed that a stretch of mud in japan has not changed in 40 billion years? The thing that annoys me is that countless scientists make these claims... yet none of them really give any detailed evidence of the claims.

Dating is done using a whole slew of different techniques which are used to cross-check and calibrate one another. Many use radioactivity, others are quite direct (e.g. counting years in tree rings).

It is not scientists whoe are failing to give detailed evidence. They constantly provide that. It is the news media. Even the best science reporting trivialises research to a level where you either have to know a lot of the background already or you have to take it on trust.

if you are not willing to take it on trust, then the only alternative is to study enough science so that you can read the actual scientific research and see the evidence for yourself.

just becuase darwin spotted adaptions it follows that we all evolved from the same organism 'billions' of years ago does it?

There is a lot more to it than that.

great may i see some evidence please?

Yes you can.

if there is no solid evidence can we stop assuming this is the absolute truth please?

There is masses of evidence. The fact that you are not aware of it is not a problem with the theory of common descent or evolution more generally.

Originally Posted by iceaura

As each system evolved, in conjunction and in context with the others, feedback created selection pressure on everything else.

I very much doubt any major subsytsem of the human body predates, in its present form, all the rest of them.

Sure, they evolve off of each other. I'm not talking about present form though. All these systems surely had their origins in much earlier eras. I am trying to chronologically number these systems, from the earliest to become evident to the latest, creating a "phylogenetic tree of life" if you will. Imagine a tree with 13 final branches at the top (homo sapien as we know it), if the trunk at the bottom is the homo sapien's earliest ancestor in which none of the 13 systems are isolatedly evident, what are the first branches to sprout from the trunk (the first biological systems to find precedent outside the singularity). Now perhaps, as Galt said above, all 13 might have emerged nearly simultaneously from the Cambrian explosion, I don't know, but this tree-like evolution is what science has shown us, and this is what I'm trying to identify... the hierarchy of these biological systems (thickness of each of the 13 branches) in relation to the dimension of time only.

Originally Posted by sculptor

Originally Posted by question for you

Interesting comments sig.


RE: my previous comments... I do beleive it's called torretts syndrome or something, not terrents.

One helluva non sequitor?
Or, did I miss something important?

I beg your pardon sculptor... I seem to have called you sig.

Interesting comment sculptor!

Originally Posted by question for you

Originally Posted by Paleoichneum

I doubt the 40 million, it sounds like a typical tv program oversimplification to make it sensational sounding. There are groups that have undergone little change over the eons, but they are not "the same" over that whole time.

I also tend to doubt any claim about 40 millions years ago... I doubt what was supposed to have happened 4000 yrs ago, let alone 40 million.

But remember this is bbc 4 we'r dealing with, not fox news!

Give it a look, it might be interesting: BBC iPlayer - Survivors: Nature's Indestructible Creatures: The Great Dying

The creature include a lanclet which is supposed to be our oldest know ancestor (BS!) excuse me... the old terrents syndrom. And also horse shoe crabs.

At 38 minutes he digs up a 'lingula anatina' which he claims he is used to seeing fossilised in rocks that are 400 MILLION yrs old... completely unchanged! Shocker.

It doesnt matter if its BBC or The Nature channel or National Geographic. They are first and foremost going to try to make money. Lay media is notorious for getting information wrong or for oversimplifying things.

Why is the Lancelet as ancestral to vertebrates bs?

I cant access the BBC online version of hte program, what is his exact wording regarding Lingula anatina (note the caps on the genus and the italics; proper binomal form). That species is very similar to the fossil forms of hte genus that have been found as far back as the Cambrian, but I find no peer reviewed papers in google Scholar that discuss fossils of the species itself.

See... kind of like this thread we got going here. Where as once we were one (the trunk of the tree), now a branch has found precedent outside the original topic of discussion... and will forever sprout away. This would be considered the first biological system to evolve. In this case we would refer to it as the "urinary system" for it is starting to piss me off...

Ok, I will make this the last comment on this thread as the branch I have created is not desired by the plant itself... I think what luke wants here is more of a cane than a tree. Which is fair enough.

Strange: you're right, it's becuase I haven't seen enough evidence.

Pal: Firstly, I don't know how much you know about the BBC, but it makes some good documentaries... yes they are for the layman. They are in it to teach what they want to teach... it's not so much about money with the bbc as with other broadcasters. They still might be selective with the info they release. The actual words, as far as I can remember were: after diggin a lingula out of the wet mud "this is a lingula, i'm more used to seeing this creature fossilised in rock thats over 400 million years old, in biology class" said by the host of the show who clearly has a passion for science rather than a passion for presenting t.v shows and being famous. (Though I beleive I did see richard hammond, from top gear, doing a nature program following the retirement of david attenborough... this was truely disturbing for me.)

Originally Posted by LukeElevenNine

See... kind of like this thread we got going here. Where as once we were one (the trunk of the tree), now a branch has found precedent outside the original topic of discussion... and will forever sprout away. This would be considered the first biological system to evolve. In this case we would refer to it as the "urinary system" for it is starting to piss me off...

In my youth I was exposed to an old saying "Better to be pissed off than pissed on"

That being said: 2 things
1) hell man, you could write a doctoral dissertation on the evolution of a neuron. And follow it with a series of post doc books and articles.

And, it might not be a bad concept to assume the acquisition of knowledge in a group setting as a neuron. The dendrites acquire knowledge from dozens of sources, send them down the dendritic trees to the soma which coalates and sorts the informational inputs for applicability to the axional connections. Having chosen the appropriate information, and sorted it into priorities, it then sends the information out through the axion to communicate it's choices to the next neuron whose dendrites are also qathering information from dozens of sources, most of which is inapropriate to its axional connections ... and on to the next ...
Which obviously begs the question of how, exactly does the soma know what information to send on, and which to discard?
Are the feedback loops constant, or only extant in the formative stage of the neuron? Does it know which synaptic molecules it the axion has at it's disposal, can it influence the evolution of it's chemical communicational supply? (kinda like fiber-optics in this country, it was one thing to build the backbone, but another more tedious thing to "go the last mile" and connect to everyone's computers---by which time, cable had rebuilt their amplifiers to allow for 2-way traffic)

It seems obvious to me that sight evolved by a rogue dendrite being sensitive to certain external energy sources, and confusing the hell out of it's soma?
Or, that the excitation of a cell by light, led to the evolution of the nerve cell(less likely as per my previous)

Luke, somewhere in your mind, you have a direction and goal for the information you are seeking.
True?
The soma of these forums don't know what axional goal your mind has, so we will flood your dendrites with our own information. Like they say at A.A. take what you need from the meeting, and leave the rest.

2)
Perhaps, a more direct route would be for you to organize your systems in the order in which you currently think the most likely for their sequences of evolution. Provide copious reasoning for the choices, with less ingrained(certain) concepts voiced as such
Then, we could pick at the hypothesis, trashing certain parts, and reinforcing others.
Such is the nature of collaberative evolution of knowledge.

.....
the ball is in your court babe

Originally Posted by sculptor

Perhaps, a more direct route would be for you to organize your systems in the order in which you currently think the most likely for their sequences of evolution. Provide copious reasoning for the choices, with less ingrained(certain) concepts voiced as such
Then, we could pick at the hypothesis, trashing certain parts, and reinforcing others.
Such is the nature of collaberative evolution of knowledge.

Alright... I will resurrect the thread when my guess is educated.




Rather than just hock a loogie...

I am trying to chronologically number these systems, from the earliest to become evident to the latest,

I doubt there is any such sequence to be numbered - if, as seems likely, all the systems of the human body evolved from precursors of various kinds in feedback steps involving each other as well as a common environment otherwise, your chronological order would be a set of more or less arbitrary decisions as to when whatever you have decided is a system becomes whatever you have decided is "evident".

Also a lot of where things get placend on such a hypothetical list will depend greatly on when you choose to classify each system as "modern" or "current".