Talk:Timeline of evolution

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[edit] 100ka Skin Color

"100ka: Mutation causes skin color changes in order to absorb optimal UV light for different geographical latitudes. Modern "race" formation begins."

Is there any study or evidence for this? As opposed to skin, hair, and other changes coming about from interbreeding with the other lines of hominid who were already in Europe and Asia? If so, a reference would be good.

[edit] Lungs from swimbladders?

I thought the general consensus was that swim bladders evolved from lungs, or at least that a generic swim-bladder-lung is ancestral to both?

See e.g. Wikipedia swim bladder article and [http://www.britannica.com/eb/article?eu=120748 "Fish." Encyclopædia Britannica. 2004. Encyclopædia Britannica Premium Service. 27 Aug. 2004]

[edit] kYA instead of TYA ?

I'd like to change the notation slightly to be more in line with SI standards. In particular, I'd like to use kYA instead of TYA.

Are there any objections?

Works for me, do it! -Vsmith 16:41, 22 Nov 2004 (UTC)

[edit] Magic

There's this statement: Neanderthal man (Homo neanderthalensis) makes magic, bury the dead and care for the sick.

Burying the dead is deducible from finding graves, care for the sick is deducible from the bones of injured individuals who couldn't have survived unaided. But where does the statement they practiced magic come from? (There's nothing about this on the Neanderthal page) I suppose burial itself might be considered a magical act, but that's not what we today generally call magic.

Burial in modern times are associated with religion and rituals. The magic here probably refers to such rituals and a belief in after-life, precursors to modern religion.

Also, in one neander grave they found remnants of a hat and a rabbit skeleton. (j/k)

[edit] 60 kYA ?

What about the events 60kYA and 150kYA ? Is it a joke or something ?

Not jokes, but actual scientific results obtained by comparing the genetic material of a wide selection of modern humans. The numbers come from biological measures of inbreeding.
Since female humans have no Y chromosome (except in a few rare instances which I'll ignore), Y's are only inherited from men, and there's no (or very little?) mixing of genetic material. If you have a Y, you got it from your dad. The only way to change the Y is to have a mutation. Since mutations occur at a known, (approximately) constant rate counting up the number of mutations necessary to cover all modern variants of the Y chromosome gives the amount of time which has passed since the life of the last male ancestor of all living human males. See [1] and Y-chromosomal Adam.
You can do something similar to calculate the age of the last female ancestor of all living humans. The mitochondria in your cells has a different set of genetic material from the cells / cell nuclei themselves. Your mitochondria come only from your mother since a sperm carries its mitochondria at the base of its tail - which is shed at fertilization. The zygote thus retains mitochondria only from the ovum. Analyze a large sample of mitochondria extracted from the cells of many different people of different ethnic groups to get an estimate of the number of mutations that have occurred and you can calculate the age of everyone's great-great-great-...-great-grandmother. See [2] and Mitochondrial Eve.
Scientists have named the two individuals described above as Adam & Eve, although there were older humans and the two people didn't coexist. Incidentally, you could probably do something similar to determine the age of the last common ancestor of humans & chimpanzees, humans & new world monkeys, humans & dogs, etc. You'd run into trouble at some point, though, since the mechanisms of reproduction vary somewhat between species and I'm not sure how much you have to assume about the age at which reproduction happens. SMesser 17:54, 7 Jan 2005 (UTC)
Y-chromosomal Adam was not "the last male ancestor of all humans alive today." He was the last male-line-only ancestor of all humans alive today. They are two different concepts.
For example, the last male ancestor of me and my cousin Aaron is our maternal grandfather. (His mother is my mother's sister). But I am not closely related to his father, nor he to mine, so our last male-line-only (Y-chromosomal) ancestor, tracing back through our fathers and our father's fathers etc., lived much further back in time. --Cam 15:36, Apr 16, 2005 (UTC)

[edit] self-reproducing RNA molecules?

Is there an evidence for that? I mean, do we have the kind of evidence on this as we have on -for example- the first lifeforms found on earth? If there is, it's not mentioned in the RNA world hypothesis article, which I find very strange. If wikipedia does indeed maintain a NPOV, this should really not be in the article. It does, however say that this theory -at least in it's present state- is very improbable.

The evidence is admittedly scant. But then, the first lifeforms on earth to leave fossils were fairly complex. Bacteria, viruses, prions are all fairly simple critters, but don't generally leave fossils the way things with hard shells / bones do. The first lifeforms were probably even smaller and simpler. Talk.Origins[3] has a nice, detailed discussion of the stages between no life and life as we know it, as well as a set of technical links to many of the stages, including the RNA world hypothesis. That Wikipedia article also has several external links supporting the hypothesis.
In the interest of brevity, I'd rather not have external links at every stage of the Timeline of evolution page. For this entry, I think links to RNA world hypothesis and Origin of life are sufficient. Since it is a hypothesis (rather than a leading theory) with only scant evidence, I think the word "possibly" is essential. I've also deleted the word "first" since the boundary between auto-catalyzing (or mutually-catalyzing) chemical reactions and actual life is vague, and the RNA world might have been one of the later stages of abiogenesis.
If you'd rather replace the RNA world entry on Timeline of Evolution with something else, I'll be satisfied as long as the new entry reflects an intermediate stage of abiogenesis the mainstream science community considers somewhat plausible.SMesser 17:41, 24 Mar 2005 (UTC)
My only concern is -even though the article does say "probably"- that the scientific community only accepts abiogenesis as a basis for a lack of better explanation. Now, I might sound like a creationist nut for saying this, but I don't think we should accept this as a valid standpoint. If we do, however, we should provide links to all theories about the origins of life (even non-scientific ones, since at this stage, science simply cannot provide a good answer to that question), or -preferably- none at all. My point is, that right now this is a matter of belief (in the non-religious meaning of the word).
I'm really hoping that this suggestion won't start a creationist-abiogenesist flamewar.
AndrasGerlits 11:06, 26 Mar 2005 (UTC)
First things first - you can use a sequence of four tildes (~) to sign your posts. Added benefits include a nifty timestamp and a link to your talk page (where you can get & respond to messages that might not be interesting to the broader community). It also helps readability when multiple people are discussing something.
Second, evolution is a scientific term and theory, so Timeline of evolution should emphasize the scientific standpoint. As a scientist (Ph.D. in plasma physics), I am personally biased in favor of giving the scientific POV as much screen space as possible. I'll try not to let that get in the way of writing NPOV articles.
There are several points of view which may not be scientific, but which are completely valid from a religious / philosophical point of view. I'd put creationism & intelligent design in that category. Science is as much a philosophy and a problem-solving / technology-building tool as anything else. Maintaining NPOV probably means we should make at least passing reference to those on anything as contentious as the origin of life.
Getting back to the specific topic, I'd rather not list all the different ideas floating around about how life got here. Crossing the "genes-first" and "metabolism-first" models with the four location models (ocean, clay surfaces, deep subterranean, and extraterrestial), we get eightvery broad scientific hypotheses, each with its own proponents, weaknesses, sub-categories, etc. We shouldn't spend the time to outline each of them here. That's what the link to origin of life is for. The various creationist models show a similar variety in the level of divine intervention, the age of the universe, and the way in which creation happened. Creation vs. evolution debate outlines a number of additional ideas which don't fit neatly into either of the above categories.
I'm horrible at brevity.
I'd also argue that the scientific community has more to support their ideas of abiogenesis than a lack of a better explanation.
Anyway, what do you think of the following entry:
4000 MYA | Life appears, probably in some form much simpler than any modern cell. See origin of life. The atmosphere doesn't contain any free oxygen
If absolutely necessary, we could put some link to creation vs. evolution debate at the top, although I think the contextual link to evolution and the links on origin of life are sufficient. Timeline of evolution isn't a stand-alone page, so we don't need to link in as much stuff directly.SMesser 22:46, 25 Mar 2005 (UTC)
I'm very much impressed by your constructive approach to my suggestion. Yes, I do think that the sentence you're proposing is a step in the right direction, and would be glad to see those changes. However, I think you're confusing science with materialism, a misconcept shared by many. I still believe that the scientific approach (which is the only true NPOV) would be not to mention even abiogenesis (note, I'm not saying we should give any explanation to the origins of life on earth), since that's a materialist dogma (since it's a philosophy, not a methodology) and not a scientific fact. AndrasGerlits 11:06, 26 Mar 2005 (UTC)

What's wrong with the use of materialism in science? I thought this is the ONLY way to do science?

Science does not equal materialism. Science is a methodology designed to use our senses when analysing our environment, any scientific theory must adhere to the scientific_methods, some of which abiogenetic theories clearly do not. For example, they cannot be falsified. Materialism on the other hand, is a philosophy, a certain belief in the way the universe works, when certain thing are assumed without needing any proof. Nothing is taken for granted in the natural sciences. AndrasGerlits 11:52, 30 Mar 2005 (UTC)

Then what is material science?

You're joking with me, right? Also, what's that new stuff about the self-replicating molecules? This section is getting worse by the minute. We should just get rid of the whole thing. AndrasGerlits 08:57, 2 Apr 2005 (UTC)
I'm sorry, but I was under the impression that self catalytic RNA wasn't exactly controversial, rather *some* people dispute whether this was enough to qualify as biological reproduction, you can after all test for catalytic activity without too much effort--Bah' 00:22, 7 October 2005 (UTC)
You're wrong. I gather you're one of the wishful thinkers on this matter, so I'd like to draw your attention to one of the very fine books by Hubert P. Yockey covering this very issue. It might be very mathematical, but than again, we're talking about mathematical models.
This section should be removed altogether. Talking about self-reproducing RNA in this context is just lazy.


An RNA World where certain RNA sequences tend to be more common than others in an "RNA soup" is fine. Where they start evolving, spewing out lipids and DNA, and spawning Life As We Know It, is (bad) science fiction. Its inclusion here undermines the credibility of an otherwise fine article. Why not change it to something like the following?

Self-organizing RNA molecules may have existed, providing potential building-blocks for the subsequent emergence of life.

And I see no reason why a scientific article needs any links to creationism pages. However, please consider that secular theories without a firm basis in evidence are just as out-of-place in a scientific article as purely religious treatments of the matter. 68.81.105.126 02:07, 23 September 2006 (UTC)

[edit] Tunguska event

I added the Tunguska event just to remind our human readers that collision with Near Earth Objects have always been happening. I have not even included the near-misses discovered in recent years. Flattening 2000 square km of forests to me is quite a significant change to earth and might have caused certain species(though not human) to be extinct. It all depends on your perpectives. It seems that smaller collisions are more frequent than bigger ones , which really change the course of evolution. We ourselves have a real possibility of following the footsteps of the dinosaurs. Such catastrophe really put man's ego in their humble and correct place.

Tunguska event removed from timeline
I removed the Tunguska event from the timeline, because it has absolutely nothing to do with the evolution of life on Earth, nor did it have any significant effect on the Earth itself. 157.181.71.7 06:07, 19 Apr 2005 (UTC)

[edit] Evolution is at best a Theory

It's nice to think about how and why we exist on this planet but at best, these thoughts that we as individuals have, can only be answered with a philosophical answer. Let's face it, we all live with a philosophy of life. Some have bought into this notion that in the THEORY of Evolution, life sprang forth from non-living material, which was given the exact conditions it needed for this to occur.

Before you even begin to entertain this idea, I would ask you to think about this one thing. Where did the information come form in order to have life in any form, exist under any condition?

I would suggest that evolution and the theories thereof, is more closely related to a religion by which great faith must be exercised in order to explain that which is not subject to real science scrutiny of the ideas and theories that are not able to be observed and or duplicated in a laboratory.

So before any further meaningful discussion about evolution can be explored, lets have a moment to examine our motives for wanting to adhere to this theory and in that, present it as such....just another theory to try and bring meaning to our lives. For if all it does is to explanation our being, then what real purpose does it serve in our fragile humanity.

Regards, B.E.

Some have bought into this notion that in the THEORY of Evolution, life sprang forth from non-living material -- it would help if you would actually read the article on which you are commenting, not to mention the millions of words that have been written on science, evolution, information theory, and the various other topics on which you have expounded completely erroneously and fallaciously. -- Jibal 13:56, 11 May 2006 (UTC)
Sigh...click here for a definition of theory in the scientific sense. As Isaac Asimov said, "Creationists make it sound as though a 'theory' is something you dreamt up after being drunk all night." And no, evolution is not a religion. Can you name anyone who thinks evolution "brings meaning to their life"? Look, it's perfectly okay to be religious - but what are you trying to accomplish by making everyone who doesn't agree with your personal beliefs religious? If you want to reject the 150 years of scientific support for evolution, and believe in the literal interpretation of your religion's sacred text, that's fine. Just admit that you do this on faith rather than reason, and that this has no place in a science classroom. Isn't religion supposed to be based on faith, anyway? - 68.33.120.32 00:34, 27 November 2005 (UTC)

What do you mean? You seem to be self-contradicting. You begin by saying that the question of life should best be answered by philosophy and yet when you examine evolutionary theory you advocate the use of labaratory work. What are you trying to say?

Who knows? Who can fathom the psychology of the Creationist? Maybe he's having a crisis of faith. - 68.33.120.32 01:06, 27 November 2005 (UTC)

Qoute, B.E. :"theories that are not able to be observed and or duplicated in a laboratory". Observance of evolution, that is; DNA sequencing and comparing, is one of the most common way of typing and identifying bacteria and other organisms. The small changes in DNA sequences are observed, even between a few generations. If you refute this, you are at best oblivious. Induction of mutations (I.e UV-radiation) has been used since the 1930s to create bacteria with special features. Making mice glow in the dark is another example of how to create "evolution" in a laboratory, though this might not apply to you as more than support for your "Intelligent design". In fact, you are right, Intelligent design has happend, though not before the 20th. Sentury.


.......


Evolution is a theory with powerful evidence behind it, evidence that does not depend upon cultural biases. It explains phenomena lacking any other credible explanation. Darwinian evolution proves consistent with later discoveries in genetics, biochemistry, astronomy, paleontology, archeology, and of course comparative anatomy. Does anyone question the obvious similarities between humans and chimpanzees in physiology? We don't have to see something happening to know that somethig has happened. Just as linguists have been able to demonstrate that languages as diverse in time and distance as Icelandic and Sanskrit derive from the same early speech that has left no recorded evidence, biological evidence leaves overwhelming evidence of processes of agonizing sloth that have allowed evolution of life. Just as one has no need for direct evidence in written records that classical Latin evolved into modern French, Italian, Spanish, Portuguese, and Romanian when nobody was paying attention, one does not have to see evolution at work to know that it has happened.

The evolution-creation debate largely hinges not so much religion versus amoral godlessness as it does upon the interpretation of one specific tradition of religious reality versus everything else. It is possible for some evolutionists to accept the necessity of a supernatural power in establishing the ultimate laws of reality in physics, mathematics, and logical structure and exercising the daring choice of letting things go as they did. Some reality exists that no intelligent life can ever know (think of the uncertainty principle) and one can define such unknowable truth as the realm of a supernatural entity.

Creationism is scientifically indefensible. The Biblical chronology makes no sense unless someone wishes to accept that God created a universe about 6000 years ago that appears to be older by a magnitude of over one million -- a view that establishes God as a devious forger of evidence that contradicts His Plan. If one wants to make sense out of the veritable divinity of ethical standards that determine how a few tribes of shepherds and farmers could adapt to early civilization could maintain some cohesion even as the world changed around them, then so be it. Nobody can prove with science alone that human life is precious, that the application of force or fraud to take what someone else worked for or received as charity is wrong, that integrity in ordinary trade and in testimony before judgments is necessary, and that reckless sexuality that leaves children confused about their place in society is unconscionable.

Evolution cannot tell people moral right from wrong any more than can mathematics. But it is useful in explaining things and improving life. We can test medicines and treatments upon animals that have certain similarities to us. Many human medicines are first tested in veterinary medicine which would be inapplicable to us if we were so different from dogs that we had nothing in common with them. Dogs aren't particularly close relatives to us among the mammals.

Evolution is at best a theory -- but so is creationism. Evolution is more reliable and has more utility. If it can't tell us right from wrong, then neither does mathematics or physics, neither of which is rejected. If we want to study right and wrong, then we might as well study religion and jurisprudence such are to be found in the Torah and English common law, or at least the philosophical specialty of ethics. A Creationist framework is never going to offer us a cure for cancer other than prayer; an evolutionary framework might allow medicine to find a flu-like virus that selectively kills cancer cells. A virus that kills cancer cells but leaves the rest of us alone will give people far more cause to praise God than will some proof that the Earth is 6000 years old.--Paul from Michigan 15:43, 12 March 2007 (UTC)

[edit] Lemurs and Fossas

In the timeline Lemurs seem to have moved from Africa into Madagascar 64MYA and 40someting MYA. Was it a long crossing or did they do it twice, or is one crossing to be removed?

The fossa (Cryptoprocta feroxis), a close cousin of the mongoose and a member of the viverrid family, is the largest carnivore on the island of Madagascar. The viverrid family is an ancient line of carnivores that are thought to pre-date wolves, cats, hyenas, and other lineages of meat-eaters — none of which are natives of Madagascar (http://news.nationalgeographic.com/news/2004/06/0602_040602_fossa.html). Granted that Madagascar does have a very unique and unusual collection of 200,000 or more plants and animals, including "35 species of lemur found nowhere else on Earth," and yes, the ancestral fossa and other early carnivores and primates may have "drifted ashore on rafts of vegetation" 21 million years ago; however, I do not think that these events are worldy enough in significant to be on a timeline of evolution on Earth. These are cases of allopatric adaptive radiation on one island. We have no mention of Darwin's finches here? The reference to the migration of early carnivores to Madagascar is a refernce to evolution that took place on one island. It fails to cite a reference, and for the above stated reasons, I am removing it. Perhaps Wiki should have a separate article on the Evolution of Carnivores on Madagascar. Valich 17:33, 12 February 2007 (UTC)

[edit] Anthropoids

An anon just added this:

Anthropoids : Bugtipithecus inexpectans, Phileosimias kamali and Phileosimias brahuiorum similar to today's lemurs , lived in rainforests on Bugti Hills of central Pakistan

"Bugtipithecus inexpectans" and "Phileosimias brahuiorum" each only get one google hit, to the same page from a non-English website, [4]. "Phileosimias kamali" gets me no hits at all. Can anyone confirm this info. func(talk) 06:42, 1 Jun 2005 (UTC)

[edit] 1. Ice Age/isthmus 2. Homo chokepoint

1) Neither here, nor Wiki entries on the ice age I found, discuss the idea that the raising of the Isthmus of Panama [mentioned here] is the ultimate beginning of the global thermohaline circulation, which in turn led to the ice ages. Many think adaptation to the resultant chaotic climate is what drove human evolution over that tiime period. Worth a mention?

2) Toba volcanic eruption at 74 KYA. I've seen the human "chokepoint" population mentioned in several places at circa 10,000, nothing close to 2,000. Consider using a range.

It's great to see all this timeline in one digestable piece!

Skookum172.193.251.124 17:55, 3 Jun 2005 (UTC)

[edit] Eukaryotes

Isn't the emergence of eucaryotes as early as 2100 MYA debated? --EnSamulili 06:21, 28 July 2005 (UTC)

Also, isn't the claim that the origin of life at 4 billion years still being debated? Scanning through some recent news articles, I get the impression that there isn't direct evidence of life past 2.8 billion years. I think it'd be more accurate to put a range of years for this or some other indication of the uncertainty. -- KarlHallowell 20:03, 5 September 2006 (UTC)

[edit] Human brains are modern by 40KYA

From achaeological and cultural remains, we know that the human brain has evolved to its modern cognitive powers by 40KYA. Some recent achaeological studies have pushed that to an even earlier date. (evidence in Zaire etc) Hence 40KYA is also refered to as the Great Leap Forward by Jared Diamond in his book "Guns, Germs and Steel". This intelligent humans rise up to the top of the food chain and become the masters in the animal kingdom. Hence it follows that the reason why Africans do poorly while Eurasians did so well has nothing to do with IQ (they all have the same IQ ) but rather to do with geography. At 10KYA, those people that happen to live near fertile places with many animals for domestication get to start farming and agriculture, which beings about societal differentiation, sohistication and size. However , anatomically , humans have reached the modern state by 200KYA from studies of OMO1, OMO2 and Herto in Ethiopia. As to why this Great Leap Forward happen is still a mystery. One recently proposed theory is that the Toba volanic eruption at 70KYA has selected only those more intelligent humans who are able to survive the calamity.

[edit] Old World Primates in Africa before Collision with Asia?

"New World Monkeys have prehensile tails and migrate to South America. Catarrhines stay in Africa as the two continents drifted apart." This is a very confusing statement for 30MYA. Don't the primates evolve in Laurasia 55MYA. Old World group moves into Africa 20MYA after Africa collides with Asia. There should only be lemur-type prosimians in Africa 30MYA. New World monkeys move into South America from North America 5MYA when those two continents are joined. The classic Old-New World primate split occurred in Laurasia not Gondwana.

Please note my comments about primate contradictions on talk:timeline of human evolution. - UtherSRG (talk) 19:54, 25 October 2005 (UTC)

[edit] Human history

While this is rightly a broadly geologic outline rather than an anthropological one, I wanted to suggest three things to slightly fill out the last six or seven points .

  • Moving the beginning of recorded history back 1200 years to keep it in-line with the invention of writing in Sumeria (3200 B.C.).
  • Mention the industrial revolution, one of the "big two" revolutions alongside agricultural.
  • Mention nuclear weapons and the possibility of our destroying all higher lifeforms. Sensible? Marskell 15:41, 13 October 2005 (UTC)

Good suggestion. Why don't you add it in yourself? I don't think you need any permission, as long as you put down your justification. As long as there is no contradiction with the rest of the timeline, it should be ok.

.......

I have chosen to add four technologies because of their significance in changing human behavior. All have discrete times in which they came into existence and clear moments of introduction.

The printing press reshaped the way in which people store and disseminate information. Cheap books and pamphlets allowed political changes to spread rapidly; cheap maps made travel for any purpose far easier. Inexpensive printing allowed knowledge to be stored long beyond the time of the discoverer and in far more places. People no longer had to travel far to read a specific book; they could have a book travel to them. The difference between the failure of Jan Huss to challenge corruption within the Catholic Church and the success of Martin Luther was that Huss had to rely upon word-of-mouth and that Luther could rely upon printed documents reaching multitudes. Besides, printing became the basis of some of the first true capitalist enterprises not tied closely to land ownership and agricultural production.

Three others (telephone, recorded sound, and electric light) came into existence at roughly the same time and changed how people communicated, stored data, and lived. Like the printing press, they had clear moments of introduction, and even if they are supplanted by such other innovations as computers, laser disks, and LEDs, they shaped the way people did things with such later innovations. The telephone is the first medium of instant messaging accessible to non-experts. Recorded sound (also relevant to data storage and retrieval)allowed non-musicians to have first-rate music in their homes (that is, I don't need to have two violinists, a violist, and a cello player nearby to listen to a Mozart string quartet, and I can listen to Glenn Miller's Big Band performances long after his death). Incandescent lights blurred some of the ancient distinction between day and night for multitudes and even allowed people to travel, transact business, study, and perform surgery at night. These date from a period of fewer than five years and stimulated a modern capitalism that depended upon the workers as a market. It may be my opinion, but the changes that these inventions wrought upon the way in which people live are likely to outlast the effects of the automobile, an innovation that I cannot so clearly associate with a specific time.

I consider these three inventions more significant than the automobile because even if fuels disappear and people must return to wind-powered, steam-powered, horse-drawn, or pedal-powered travel, they might still have portable computers with LED monitors that would be impossible without electric lights and data storage, and unlinkable without some successor of the telephone (or radio). That people read from computers recognizes a pattern that began when Gutenberg printed the Bible. The desire for information and entertainment seem even more powerful than Wanderlust.

Reaping machines certainly allowed human populations to explode -- not that overpopulation is progress, so those are good candidates for inclusion. As for the atom bomb -- to date, more people have been killed in warfare through incendiaries, ammunition, and conventional explosives delivered by aircraft to a war zone that extends far beyond the frontline of battle. I could also add radio, which set the pattern for satellite communications. But fuel consumption that makes motor vehicles expensive to operate will likely make air travel a rarity as well should the motor fuels get scarce.

What the heck? I will add wireless telegraphy (obvious predecessor of radio and television, let alone satellite broadcasting) and the aircraft, two inventions that have remade the world. Like the telephone, recorded music, and electric light I can bunch those two in a short time. --Paul from Michigan 17:39, 12 March 2007 (UTC)

[edit] Extinctions

Might I suggest Timeline of exctinctions? If we start adding them here, there will be no end to it. Extinction events, OK. Marskell 11:25, 25 October 2005 (UTC)

I think extinction is central to the theme of evolution of life , where the tree of life is being pruned and re-trimmed. Without extinction, there would be not much evolution! On the other hand, I do not know what is the use of putting the nuclear bomb( which just killed a tiny fraction of people compared to guns) in. Do you want to put that in the timeline of weapons invention? This is about evolution of life in its grandest scale on earth, not human technology. Most experts say we are in the midst of another mass extinction. In conclusion, I do not understand why people here just removed things without discussing it first. There is really no basic courtesy. Since this is an encyclopedia , I will rather err on the side of more than enough and abundant info as long as it is true than the lack of it due to the censorship of some bias person, who is just one minute little fraction of this global population. As a wikipedian, I am disappointed. It takes a lot of effort to add new information, but just a few keystrokes to remove it.

The information is still there in the history and can be redacted elsewhere. My thought is the "if this then why not that" problem. I realize there are some important prehistoric extinctions listed here but if we go for extinctions in the modern era how do we decide how many is too many and which should be included? The bomb makes sense because it can destroy all higher life on the planet. — Some bias person, er, Marskell 10:02, 27 October 2005 (UTC)
In thinking this through some more, what do people think of the following:
  • Moving all key human landmarks from 10kya onward to Timeline of human evolution and leaving (or adding where missing) broad ecosphere, evolutionary changes. Obviously humans would still get mentioned but it would re-focus things. For instance, remove climbing Everest but add cloning the first animal.
  • Start the Timeline of extinctions and move what I removed there. Marskell 13:19, 27 October 2005 (UTC)
I noticed an inconsistency regarding the number of major extinctions. The first extinction flags itself as the first of seven. I could find only six listed. On the Timeline of Extinction, five is said to be the agreed upon number of major extinctions. 67.86.40.120 16:53, 15 December 2005 (UTC)Brett D.

[edit] Homo-Sapiens and Homo-Floresiensis

Forgive, what you may call, my ignorance. I am a Catholic mother who is trying find information which is not only palatable to my admittedly creationist sensibilities, but that will also provide my children with an intelligent and sensible source of education regarding the history of the world from it's creation.

Since scientific theory and religious theory are NOT mutually exclusive, and, since modern science has repeatedly confirmed biblical historical points rather than refuting them, I feel no reason not to teach evolution to my children as a theory.

However; when I reach 27 kYA on your timeline I become stumped. While you mention the extinction of all of the other "homo" species, you leave us with the impression that there still exists two specific humanoid races; homo-sapien and homo-floresiensis. Following the timeline to it's current point, you never mention the extinction of either species. Is it your theory, then, that there are two distinctly different species of humanoids that now populate the earth? If so, how do I explain this to my children? And how do we tell the difference between who is homo-sapien and who is homo-floresiensis? MOMK9875 01:28, 10 November 2005 (UTC)

Thanks for your question. Homo floresiensis is presumed to be extinct; all humans today are Homo sapiens. H. floresiensis is thought to have become extinct around 12,000 years ago (see Homo floresiensis#Recent survival); after that, Homo sapiens was left as the only surviving human species. Were any to be alive today, you would have no difficulty in differentiating them, as the height of Homo floresiensis is around three feet (one meter). — Knowledge Seeker দ 02:49, 27 November 2005 (UTC)

[edit] Does it matter what the creationists think?

Does it matter what the creationists think? I think reference to that in the first para should be removed. I don't see a scientific disclaimer in the book of Genesis either.

Strongly agreed. This article is about a timeline supported by contemporary scientific wisdom. It would be an entirely different matter if there were any evidence at all in favour of young earth Creationism, but there really really isn't. Their objection is purely religious and has nothing to do with fact or the interpretation of fact. Radix 12:17, 29 November 2005 (UTC)

Has the reference been removed already? If so excellent, SqueakBox 14:47, 29 November 2005 (UTC)

Yes, it has, and I agree with its removal as well. — Knowledge Seeker দ 19:45, 29 November 2005 (UTC)

Argh, I was about to suggest this...you beat me to it. Seriously..."potentially incorrect theories"? - 68.33.120.32 01:59, 30 November 2005 (UTC)

[edit] Some work with the External Links

I added an external link to an evolutionary timeline that's a bit more compact. I also noticed that one of the external links (Palaeos) isn't working so I put it to the bottom. Made some minor edits, including internal linking to monsoon. Kaimiddleton 21:32, 13 December 2005 (UTC)

[edit] The timeline exceeds 32K

Well, I've done a bunch of edits tonight, mostly making links, so that mammoth is instead mammoth, etc. And I received a warning that the article, at 40K, exceeds the recommended maximum 32K length.

Personally I like a lot of information on one page. E.g., if I'm reading an FAQ I much prefer to have a multi-hundred KB document because I can page through it quickly with the browser. That's my natural bias. But also, I think this timeline is not easily limited in size. It is natural to expand it with new information as it comes out (e.g. homo floresiensis).

One thing that the Wikipedia:Article_size guidelines suggest is to break the article into sections. I don't know if sections would work in a table. I might try it out to see. If I read it right, then, so long as each section is under 20K we're good. And it wouldn't be hard to make arbitrary sections based on some MYA or kYA number; e.g. we could use these sections: >= 1000MYA, 500-1000MYA, 250-500MYA, 65-250MYA, 30-65MYA, 5-30MYA, 1-5MYA, 100kYA-1MYA, 30-100kYA, 0-30kYA, present. I haven't thought about these numbers much.

What do folks think?

Kaimiddleton 07:56, 17 December 2005 (UTC)

Update: putting sections into the table doesn't work (using double equals around 4600MYA, for example). It seems the table would have to be broken up into smaller tables. In which case it would be good to be more formal about the numbers probably. Or maybe wikipedia just bothers you every now and then about the article size and you can just ignore it.

Kaimiddleton 08:06, 17 December 2005 (UTC)

Also, in the external links section I'd already added a link to another timeline of evolution that is much more compact. I have to say I prefer the long timeline.

Kaimiddleton 08:21, 17 December 2005 (UTC)

Important: The 32k warning is a data relic from earlier versions of MediaWiki. There are no hard and fast rules regarding article length of Wikipedia articles; just use common sense. For example, many featured articles are two or three times over the "limit" (History of Poland (1945–1989) is 73kb, Hugo Chávez is 99kb), but because they're no longer than their subject merits and are already in summary format, it is unnecessary to trim them down further. In fact, almost all featured articles break this arbitrary limit; it's hard to have a good article without going in depth enough to do so. So, don't sweat it—worry about the quality of the article itself, not about blind archaic-rules-following. -Silence 12:02, 17 December 2005 (UTC)
Thanks for the feedback! I agree that an emphasis on quality should come first and have been doing a lot of polishing work, in addition to my minor adds here and there.-Kaimiddleton 01:01, 18 December 2005 (UTC)
I have absolutely no problem with keeping the timeline on one page, but I still think a split into section should be discussed. The earlier mentioned intervals (>= 1000MYA, 500-1000MYA, 250-500MYA, 65-250MYA, 30-65MYA, 5-30MYA, 1-5MYA, 100kYA-1MYA, 30-100kYA, 0-30kYA, present) could be used as section headers (enclosed by ==), while using the current left-side table cells as subsection headers (enclosed by ===). Yes, that would mean we'd drop the table entirely :-) What do you think? --Fred Bradstadt 13:05, 24 February 2006 (UTC)

[edit] Y-chromosomal Man before after Modern "race" formation?

The following seems like an error to me:

100 kYA Modern "race" formation begins
60 kYA Y-chromosomal Adam lives in Africa. He is the last male human from whom all current human Y chromosomes are descended.

How do you get racial diversity when everyone is geneticaly related 40,000 years later? 12.20.127.229 17:48, 22 December 2005 (UTC)

The Y-Chromosome has changed in 40000 years, giving genetical diversity, though its ORIGIN is the same. And genitical diversity also, and in a much larger scale, comes from the other 45 chromosomes we have.

Good point. Can anyone from the academic community comment on this? Kaimiddleton 00:13, 23 December 2005 (UTC)

Anyone want to object to my removal of the line:

100 kYA Modern "race" formation begins

? -12.20.127.229 19:06, 6 January 2006 (UTC)

Hmmm: I wouldn't object, per se, but if you remove the sentence "Modern "race" formation begins." then what about the rest: "African populations remain more 'diverse' in their genetic makeup than all other humans, since only a subset of their population (and therefore only a subset of their diversity) leaving Africa. For example, mtDNA shows that an individual with English ancestors is more similar genetically to an individual with Japanese ancestors than are two individuals drawn from two African populations."

I like the reference at 60 kYA because it wiki-links to Y-chromosomal Adam, even though that wikipedia entry describes the time as 60-90 kYA so that 60 kYA is a lower bound.

I don't have a very strong opinion whether to delete or not, but I would suggest a better solution would be to reconcile the entries a bit more thoughtfully. Kaimiddleton 21:02, 6 January 2006 (UTC)

I concur, I think it might be better listed as:

100 kYA - The first anatomically modern humans (Homo sapiens) appear in Africa by this time or earlier; they derive from Homo heidelbergensis. Homo sapiens (humans) live in South Africa (Klasies River Mouth) and Israel (Qafzeh and Skhul), probably alongside Neanderthals. Modern humans enter Asia via two routes: one North through the Middle East, and another further South from Ethiopia, via the Red Sea and southern Arabia. (See: Single-origin hypothesis).
90kYA~60kYA - Mutations causes modern genetic differentation begins. African populations remain more 'diverse' in their genetic makeup than all other humans, since only a subset of their population (and therefore only a subset of their diversity) leaving Africa.

Opinions? I removed 'race' since it is a poor choice of terms, all of the races blend where they overlap making it at best an outdated term. The last sentance was redundant as well, if someone that has read this entire timeline cant figure out what it means for a genetic subset to leave an area and needs an example then they most likely do not understand this article. 12.20.127.229 21:20, 6 January 2006 (UTC)

I think that looks pretty good in terms of an overall approach. Two details: first a minor grammar point: "leaving Africa" should be "leaves Africa". Secondly, if you use a tilde as in "90kYA~60kYA". you're introducting a new notation that hasn't been used in the timeline before. My suggestion would be to use 75 kYA and then note the range of uncertainty in the explanation. I reason that using precise numbers in the left column is legit as they're all approximate anyhow, and over time a better number might be placed there as new archeological results are published. Then if you cover the uncertainty with some comment in the explanatory text you should be fine. Kaimiddleton 23:10, 6 January 2006 (UTC)

I like the idea of a range symbol (~), but it would never work on this timeline after some thought, because 99% of these dates are aproximations, and where would any of the dates get located on the timeline. Are you infavor of the shortining of the one and the splitting of the entry if so I might do that tonight when I get home from work.-12.20.127.229 17:11, 9 January 2006 (UTC)

Sounds fine to me. Thanks for the great work! Kaimiddleton 17:49, 9 January 2006 (UTC)

[edit] First footprints 530 MYA, animals invade the land 450 MYA?

I just added an item to the timeline about fossil footprints discovered at 530 MYA in 2002. Yet the timeline has animals 'invading' the land at 450 MYA. That's quite a few MYs in between, there. Can anyone comment on this, especially as we're going on 4 years with this discovery? Kaimiddleton 00:17, 23 December 2005 (UTC)

'Ancient sandstone is notoriously difficult to date.'

That quote from the margin might help explaine. I'd think that the info added might be better left out till it is concrete and less speculative. 12.20.127.229 19:41, 23 December 2005 (UTC)

[edit] Explanation for arrival of carnivores on Madagascar

21 MYA: A mongoose-like creature floats to Madagascar from Africa on a raft of vegetation. Becomes ancestor of all carnivorous mammals there.

That's just silly. Someone do something.

And if you know about this subject, please also address this line:
64 MYA Lemurs cross the ocean into Madagascar from Africa mainland.
Kaimiddleton 21:43, 26 December 2005 (UTC)

[edit] North America meets South America

Here's another request for someone to make a fix: when does this event occur? The timeline has two entries: 5 MYA: Volcanoes erupt and create the small area of land that joins North and South America 3 MYA: North and South America become joined, allowing migration of animals. Which is it? Can someone work this through? Kaimiddleton 22:06, 26 December 2005 (UTC)

[edit] AD 1000 Humans reach New Zealand from where?

This statement about AD 1000 doesn't seem right...

AD 1000 Human population 300 million. Humans reach New Zealand (from Fiji).

Where is the evidence that they came from Fiji? Maori people are said to have arrived from eastern Polynesia. In fact, the Maori language has more in common with the languages of Hawaii and Tahiti. Unless someone can provide some reference for this Fiji claim, we should simply state it was from Eastern Polynesia, not Fiji.

--Xagent86 21:11, 27 December 2005 (UTC)

Seems like you know the issue, and I haven't gone digging around for the info. This page isn't updated too frequently so you might as well just do it. Kaimiddleton 21:19, 27 December 2005 (UTC)

It's not really my field, but I did a little bit of research. There is a good section on The direction and timing of settlement on the Te Ara Encyclopaedia of New Zealand site: http://www.teara.govt.nz/

While Fiji might have been part of the migration route, Eastern Polynesia would seem to be the more correct answer. I'm tempted to change it - however there is quite a debate about the date of first settlement, with tradtional theories suggesting 1250 to 1300 AD, but other research on Rat bones and Rat DNA suggesting an earlier date.

I might try to find a little more information before I make the change. Xagent86 22:14, 27 December 2005 (UTC)

Now updated to refer to Eastern Polynesia. I've left the date at 1000 AD due to conflicting evidence.
  • Most researchers agree date between 1250 and 1300
  • footprints recorded in ash erupted ca. 1400 AD from Rangitito Island
  • genealogical dating based on oral tradition suggests around 1325–1400 AD
  • Radiocarbon dating of settlements reliable dates after 1250 AD.
  • Rat bones dated 50–150 AD - rats need humans to travel by sea.
  • Rat DNA - inconclusive(?) so far.
  • Rat gnawed seeds and snails - no evidence before 1250.
Conclusion - although it doesn't appear that there was settlement before 1250, it's possible there might have been visits to New Zealand prior to that date, so leaving at 1000 AD. --Xagent86 04:46, 29 December 2005 (UTC)

I know a little about this issue. Maori oral histories state that the ancestors of the Maori came from "Hawaiki", which isn't all that helpful to us since no-one knows exactly where it is. However they definitely came from the eastern islands of Polynesia, possibly the Cook Islands. I'm certain they did not come from Fiji, which is in Melanesia. As for when... I've read several theories. The earliest possibility seems to have been circa 800 AD, but most put it at a later date, though no later than the thirteenth century. James Belich suggests the mid-eleventh century. Aridd 12:10, 7 June 2006 (UTC)

[edit] Speculations removed in the interest of NPOV

'possibly derived from RNA molecules. These molecules copying/reproducing/replicating required resources like energy, space and smaller building blocks, which soon became limited, resulting in competition. Natural selection favors those molecules which are more efficient at replication. The atmosphere does not contain any free oxygen.'

This is pure speculation. It is very interesting science when done in the lab, but very unscientifical, when presented in this way.

'Cells resembling prokaryotes appear'

The best we know, they were prokaryotes. The original NASA press release didn't say things like 'resembling', they said that they had the same chemical ratios as today's prokaryotes.

'These first organisms'

Again, very unscientific. We just have no idea what the first organisms were like. Also, this part refuted an earlier (also removed) paragraph, in which RNA molecules were the first organisms.

'Later, prokaryotes evolve glycolysis, a set of chemical reactions that free the energy of organic molecules such as glucose. Glycolysis generates ATP molecules as short term energy currency and is used in almost all organisms unchanged to this day. Lifetime of the Last universal ancestor, the split between the bacteria and the archaea occurs.'

Pure speculation. Science does not allow unproven statements like that, we have no idea whatsoever, how the original metabolism of organisms evolved.

Please, stick to presenting the scientific facts, and stop pushing your own agenda.

Above umsigned post by anon 62.68.179.65.

reply :If you are right, we should remove Big Bang theory as well. Science can only offer the best educated guess.

[edit] 250 Myo organism

Quote from the article: "Some spores of bacteria Bacillus strain 2-9-3 (Sali bacillus marismortui) are trapped in salt crystals known as halite in New Mexico. They are re-animated in AD 2000 and have multiplied rapidly. Currently the world oldest living organism" I have read a paper disputing this fact, and I suggest that it is removed. I dont want to do it since I`m not a member yet, though someone read it and make up y`alls minds: http://www.tau.ac.il/~talp/publications/Permian.pdf

[edit] Tierra del Fuego

Tierra del Fuego is described as "the last continental region to be inhabited by humans". But surely it's an island (or an archipelago), rather than a continental region. --OpenToppedBus - Talk to the driver 10:13, 22 February 2006 (UTC)

[edit] Featured list

I have listed this excellent article/list as a featured list candidate. Please let us know what you think via that link. I've personally had nothing to do with the article's development and congratulate those who have. One concern mentioned already is that some events, particularly in the last 5-10000 years are not strictly evolution events. I've removed a couple but would be interested in what others think. -- Ian ≡ talk 12:55, 22 February 2006 (UTC)

The greatest concern is the scope of the article. The lead makes it clear that we are dealing here with evolution from a biological perspective. For instance, the evolutionary impact of humans reaching the South Pole is minimal (or so far ahead in the future that it is impossible to predict, remember Wikipedia is not a crystal ball). Same with most of the items at the end of this list. A timeline of sociocultural evolution, or similar, would be the perfect place for these items, but their inclusion in this list is, at best, debatable. -- Rune Welsh | ταλκ 14:58, 22 February 2006 (UTC)
I agree. I would vote for removing some of the latter entries. For instance, someone recently added the first monkey in space, although I notice now it's gone. I think too many such entries dilute the topic. Since the last few entries are short and streamlined I don't object too much, although I have some qualms; for example, we still have both earth orbit and moon walking as notable evolutionary events. I think one would be nice, to give perspective, but two seems overmuch. Kaimiddleton 17:29, 22 February 2006 (UTC)
I've been bold and removed a few more. -- Ian ≡ talk 02:27, 23 February 2006 (UTC)

I think this is too narrow-minded. Now is history, history is now. This is as much a living document as any, though I agree it should be from an evolutionary biological perspectives. I have always thought removing things is destructive while adding things is good. Human reaching south pole or the moon is just part of the continuing journey of man starting from 200KYA in East Africa - a story worth telling. The moment you finish reading these words, that is history too until the next version comes!

That's some very pretty and noble-sounding bullshit, but Timeline of human evolution is a page specifically created for listing such momentous (but not directly relevant to the evolution of life in general) events. -Silence 09:51, 24 February 2006 (UTC)

Well if that is the case, those deleted sections should be pasted there. The person who deleted them did not do it. Migrations of human beings are not directly relevent to the evolution of life? Yet when mammals returned to the seas to become whales, when arthropods , fishes and tetrapods went to the land to live, these moments are considered relevant to the evolution of life. This is very strange logic to me.

I think there are some good points on both sides of this discussion. For instance, here are two removed items: the birth of the oldest living tree 4000+ years ago (I put that one up originally), and the first monkey in space (put up recently by someone else). Neither of these is really momentous for the history of life on earth. I put the tree one up in order to give the reader a sense of time scale. I thought the monkey one was silly, personally. On the other hand I liked the one about the moon landing as that was a rather amazing migration for any kind of life on earth. So maybe the monkey entry wasn't too silly? There are a lot of shades of gray here.
Another argument is that humans have had a huge impact on the evolution of life on earth so some human migrations are in fact important. Or notices about human populations (e.g. reaching one billion). I'm going to give a whack at adding a few recent entries (recovered from the article history). I'm only going to to it once so if someone changes it I won't object.
Kaimiddleton 23:54, 26 February 2006 (UTC)
Lots of shades of grey, agreed. Agree some items which are not strictly evolutionary can be useful to give a sense of scale, but cannot see the argument for iron age tools and walk on the moon. To the anonymous editor above: - every single event in life could be argued as a progression in the evolutionary ladder, but we cannot list everything. We should only list events which demonstrate milestones in biological evolution, else where do you stop? -- Ian ≡ talk 01:27, 27 February 2006 (UTC)

Since all these are just shades of grey, shouldn't we err on the side of more details rather than less? We are trying to build a complete encyclopedia, not a nursery book on evolution.

Could you please sign your posts with 4 tildes (~~~~) so readers can keep track of who says what. -- Ian ≡ talk 14:05, 27 February 2006 (UTC)
Personally, up to this point I have been opting for inclusion over exclusion. E.g. when I saw the "first monkey in space" bit I just tried to wiki-link it nicely even though I didn't find it to my taste. However, since over time there has been a certain amount of discussion about removing some of these items maybe it's a good idea. Kaimiddleton 05:00, 27 February 2006 (UTC)

Including only "recent" entries seem to imply that evolution has already stopped. Please also note the quote:

"We are the product of 4.5 billion years of fortuitous, slow biological evolution. There is no reason to think that the evolutionary process has stopped. Man is a transitional animal. He is not the climax of creation."

Carl Sagan, astronomer

Hi sorry; I don't understand your point vis-a-vie what you might be proposing. You're saying evolution is a continuing process, therefore ....
Kaimiddleton 19:48, 28 February 2006 (UTC)
Part of the problem, perhaps, is the title. While most of the major events in Earth's history are related to evolution, there are several which are not. For instance, I'd consider the formation of the Earth, the formation of the moon, some of the major continent formations, the development of agriculture, the first time a species develops space travel, and so on important to Earth's history, although they are not directly related to evolution. Perhaps the title of this article should be changed to Chronology of Earth's history or Chronology of Earth or something like that, or a new article be written at that title. The soope of such an article could be a bit wider than than one focusing solely on evolution. I have been working on a somewhat similar idea at History of Earth. Just a thought. — Knowledge Seeker দ 04:27, 1 March 2006 (UTC)
I think you have an interesting idea, but I like the idea of a timeline of evolution, something showing how life on earth has changed, that gives a sense of when events were happening, and something that either directly or indirectly indicates some of how those changes happened. Thus continent movements are relevant because they cause speciation. If you open up the subject to Chronology of Earth then to me it would be a very different article. See also some of my comments immediately below Kaimiddleton 16:55, 1 March 2006 (UTC)

Moon landing: As I mentioned above I took a whack at the recent events in the timeline. I actually think this would be better:

  • 3 kYA Humans start using iron tools.
  • AD 1 Human population 150 million.
  • AD 1835 Human population reaches 1 billion during the Industrial Revolution.

This omits the moon landing and puts in the industrial revolution. I liked the idea of the moon landing because the reader might infer a correlation with "530 MYA First footprints on land [8]" and also see the rapid evolution (if you will) from "using iron tools" to "humans walk on the moon". However, I think that it's not necessarily clear to draw these inferences, and that the moon landing is not quite thematic with a "timeline of evolution". I think the idea of putting in the industrial revolution to show a) the correlation with using iron tools 5000 years ago, and with the advance of population draws the inference much more nicely. I also mentioned above that I would only touch the recent entries once. So if someone else wants to make this change please do so. Kaimiddleton 16:55, 1 March 2006 (UTC)

It is extremely naive to think that evolution can happen in a vacuum. Any geological event can potentially change the physical environment and thus the direction of evolution. If an organism does change, it is perfectly naturally to ask "Why?". Hence all forms of information, (if correct) are useful for providing the clues and answers, and should not be removed from the timeline. It is strange that anybody can separate the story of life FROM the story of Earth.

One reason why I dislike the Book Of Genesis is the lack of details. Lacking details will only make this document look like another Creation story.

The significance of the landing of Homo sapiens on the moon lies in the possibility that this may be the very first time that the Earth's biosphere extends to another heavenly body 1 light-second away, carrying with it not just the first primates but also the first bacteria and viruses.

[edit] Reliability of information

I'm a bit worried about the reliability of some of the information in here. For example, it talks about the extinction of Homo floresiensis, a species discovered only a few years ago. I'm not arguing that the estimated extinction is wrong (that'd be original research), but should something that is still at the bleeding edge of science be included in a timeline like this? Andjam 03:52, 3 March 2006 (UTC)

The date of extinction of H. floresiensis is unknown and probably always will be disputed. Ebu Gogo indicates it may have survived until quite recently. -- Ian ≡ talk 05:30, 3 March 2006 (UTC)

One of the basic tenets( also its strength) of science is that : it is falsifiable. We must be prepared that we are all wrong if new evidence is available. For eg, we are not even completely sure that the creature described is a Homo sapien, Australopithecus or a Homo erectus. We just have to take our safest bet.

[edit] Primordial tide pool = primordial sea/ocean?

I found the first term in a book and the second in a footnote of this article. Do they refer to the same thing, the ancient water mass from where (they say) all forms of life started, or are they different? Adam78 19:26, 5 March 2006 (UTC)

[edit] Origin of seed reference?

The timeline states 360 Ma as an estimate for when seeds evolved. Does anyone have a citation for this or know where this figure came from? I'd like to use it for History of Earth. Thanks! — Knowledge Seeker দ 05:40, 7 April 2006 (UTC)

Took a quick look at K.J. Willis and J.C. McElwain, The evolution of plants. Oxford: OUP, 2002. Their chart on p. 93, and text, shows seeds present in the geological record from the Carboniferous period onwards, i.e. 354 Ma onwards. The earliest seed plants were the seed ferns (Palaeozoic pteridosperms). So 360 Ma seems an acceptable figure, given that something like a seedcoat was evolving in the Late Devonian (370-354 Ma). Mark Nesbitt 07:20, 7 April 2006 (UTC)
That is extremely helpful. Thanks! — Knowledge Seeker দ 07:14, 8 April 2006 (UTC)

[edit] Common Ancestor of Mice & Men

"Humans and mice diverged about 75 million years ago, too little time for many evolutionary differences to accumulate."

Yea, it's what i thought all along. WE ain't that different from mice:) Even seen a few mice that looked like people i knew:)

[edit] Title discussion: why not "timeline of life"?

I was just wondering: why not give this article the more broad and simple name of just "timeline of life"? This would help clear up any potential confusing between this article and the "history of evolutionary thought" page, and it would clear up people's misconceptions over the idea that evolution and the history of life are somehow distinct concepts. -Silence 00:41, 20 June 2006 (UTC)

I agree. History of life (currently a redirect) is another alternative, but maybe Timeline is more appropriate given that the article is a list. -- bcasterline • talk 01:09, 20 June 2006 (UTC)
Yes, "Timeline" is fine as-is, since this page is a timeline (and hence a list), not a prose history (unlike History of Earth). So, should I make the move, or should we wait for more feedback? -Silence 00:28, 22 June 2006 (UTC)
Comment: The article seems a timeline of the evolution of life towards us and and some things we care about. Which is fine. People are more interested in lions than in extinct ecosystems and classes. Or even than in all existent insects, or in the plants which dominate our planet. But a timeline format article on life? If it was rewritten as prose, would History of Life be a good title? Maybe. Perhaps a History of when new forms of life showed up? It seems the "evolution" in the title is actually saying something significant about what the article does and doesn't cover. Timeline of life's evolution? I'm not objecting, merely noting reservations. 66.30.119.55 23:13, 9 July 2006 (UTC)
Though if someone wanted to make it more like the history of life, that could be nice. I was just now wishing for more biome information. You can sort of read between the lines ("at N Ma, all the components of a grassland exist, so maybe so does it"). Ie, moving beyond when individual species evolved, to what you would see if you were there. But that might be a different article. And require a lot more work. 66.30.119.55 05:02, 18 July 2006 (UTC)

[edit] Add an overview sentence?

I would have more easily understood the timeline if there was an orienting sentence, a mini-timeline, to help provide context. Rather than having to work one out myself. Eg, Basically, since 4000 Ma, simple cells; since 3000 Ma, photosynthesis; since 2000 Ma, complex cells; and since 1000 Ma, multi-cellular life.. 66.30.119.55 23:30, 9 July 2006 (UTC)

Perhaps also: Since 1000 Ma, algae; since 800 Ma, something; since 600 Ma, sponges; since 400 Ma, insects; since 200 Ma, mammals. 66.30.119.55 23:30, 9 July 2006 (UTC)

Hearing no objection, I've added an overview paragraph. All the numbers are from the body of the article. I considered also doing 100 Ma to present in steps of 10 or 20 Myr, but didn't see a nice narrative. 66.30.119.55 04:40, 18 July 2006 (UTC)

Upon being able to see the big picture, the biggest suprise for me was that mammals had been around for 1/10 the time of multicellular life (and 1/3 the time of animals in general). I had thought of them as more recent. 66.30.119.55 04:40, 18 July 2006 (UTC)

[edit] Add additional links?

Perhaps more of the text should be turned into links? Many of the concepts mentioned now have their own articles. A higher than usual density of linkage might make for more interesting browsing. Hopefully without significantly reducing clarity. 66.30.119.55 05:22, 18 July 2006 (UTC)

  • Do you mean doing more wiki-linking? Sounds like a great idea. That's how I started out editing the page. But do you think it's better to only link the first occurrence of a new word, or all occurrences. E.g., would you want to wiki-link all occurrences of monkey? There might be some guidelines about this somewhere but I don't remember seeing something about that. Kaimiddleton 23:57, 18 July 2006 (UTC)
    • Yes, wiki-linking. Perhaps link one occurrence per time entry (or adjacent set of entries)? Hmm, and, perhaps, it need not be the first occurrence in an entry, if another one would be clearer, as most entries are bite-sized? The motivating story is a user reading some time entry, wants to click on a critter, but it's not a link, so they think "oh drat. was that one of the many many links elsewhere on the page which i've skimmed by? is it linked somewhere else?... who knows. should i page search for it? or search the wiki? do i care enough? ahh... punt.". A timeline seems both more likely to be read non-linearly, and to lack the hierarchical organization which in normal articles provides a way to find the (usually already seen) linked first occurrence when looking at an unlinked one. Timelines may also have to work harder to keep the user interested and engaged, as they look a bit like lists of names, which if linked can be interesting, but if not, can easily become "ok, i've had enough of this now" boring. 66.30.119.55 03:23, 19 July 2006 (UTC)
  • Good stuff from everyone. It is a question that requires some balance. Here's a proposal: make the change all at once (or in two or three steps in the same evening), then ask people what they think. If people don't like it we can revert easily enough, without intertwined changes; otherwise, you've made an improvement. Kaimiddleton 06:45, 19 July 2006 (UTC)

This is an encyclopedia. So this timeline article should be used as a historical reference. For eg, at T=t, what happens to life and its environment everywhere on earth? I should be able to check it out quickly. Whether it is interesting or not is irrelevant.

[edit] Cynodictus

I've added Cynodictus, or dawn dog, the progenitor of modern dogs. But I'm not sure of the correct date. I've seen 40 million years ago, but I've also seen 30 million years ago. If someone could narrow it down that would be great. Kaimiddleton 16:00, 9 August 2006 (UTC)

[edit] needs intro par. overview/summary main strands

I judge an article by 3 criteria. Does it answer my questions? Does it provide me with new info that deepens my understanding? Is it clearly written and well-organised? Yes, on all 3 points. Don't worry about people who want the Olympic Games in Sydney to be on the list. You can't please everyone. You have made good list choices. The non-bilogical stuff, mainly the origin of Solar System is there to frame and give context to what follows. The extinctions are obviously important, so are tectonic plate splitups.

Naturally, we humans we have a specific interest in the geneology of our own species, and few would expect us to organise such a list from the viewpoint of a gerbil. Development of tools is a must inclusion, and landing on the moon is significant as the first step to a wider colonisation of space prefigured by the earlier ones. The later human stuff too gives a reader a good sense of the vast scale of this timeline, events in Western "ancient history" are but seconds in the grand narrative. And that's a perspective that is well-worth presenting clearly. While we think of history in terms of thousands of years rather than millions and thousands of millions, we cannot grasp the nature of evolutionary history. Altogether, a well-considered and wisely chosen selection.Leave it as it is. Certainly, no nukes, no UN, no Black Death.

This would be set off beutifully with a good overview of what follows. Something that points out life has been on Earth for about one quarter of the time that the Earth has existed, and that for most of this time, that life was of the unicellular type. Then a couple of lines on the reign of the dinosaurs and the emergence of mammals etc. Lists can be great lookup devices, but they tend to atomise info. Typically, and most especially for a novice reader, they require some more discursive background material to tie the whole thing together. Put that in and you've got a winner. abzorba 08:07, 1 October 2006 (UTC)

History of Earth may have some of what you are looking for. — Knowledge Seeker দ 08:27, 1 October 2006 (UTC)

[edit] 21Mya

Says that all carnivores derive from a common ancestory. Any sources? thx--sin-man 06:42, 4 December 2006 (UTC)

[edit] Oldest life

I thought the oldest fossilized life was 3.3-3.5 billion years old in Australia and South Africa. I thought the first photosynthetics were about as old. I also thought the moon formed within 30 million of earth's final form.GetAgrippa 21:57, 24 January 2007 (UTC)

[edit] Formation of the Moon

The Hadean eon chart states "4533 Ma The planet Earth and the planet Theia collide, causing rings to form around the young Earth which last for millions of years until they coalesce to form the Moon..."

In a number of articles I've seen recently - including one this year (I think) in Scientific American - there is a growing consensus that the formation of the moon took less than 30 days. Here's a link to one that I googled up quickly (the info is about halfway down):

http://www.dailycamera.com/news/2007/jan/28/cosmic-collisionsx/

And if it's good enough for Robert Redford, its good enough for me! Frunobulax 12:20, 9 March 2007 (UTC)

[edit] KY

what does the unit KY stand for, this should be stated in the intro. —The preceding unsigned comment was added by 82.26.102.42 (talk) 04:04, 18 March 2007 (UTC).

[edit] Date of India/Asia collision

The timeline gives the date of this collision as 22Ma. Previously, the only date I've seen for this event is 50-60 Ma. Thoughts? 140.247.23.113 16:08, 19 March 2007 (UTC)

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