PDA

View Full Version : how the very first man came on earth



suntrack2
2005-Aug-21, 05:06 PM
this is somewhat different topic than "life in space", but we are ofcourse the part of the space.

as it was taught in the schools and colleges that man came on earth through the different stages, man is a just shadow of monkey like make, later due to improvements man came in existence. or first man came from the universe? the destination don't know? or we have no clear evidence when the first man came on earth? the physical life of a man started through a asteroid like object fall on earth and later the existence of a man started from that point? or the first man was in only the shape of a single cell?

or what? what do you think? then can we assume "how the life may be start on the different sorts of planets" as it was happend on the earth. !

GOURDHEAD
2005-Aug-21, 06:08 PM
My crack at answering your question is covered here (http://www.universetoday.com/forum/index.php?showtopic=1697&st=0&hl=consciousness). This process by gradual change eventually produced humans who currently host the most developed technical competence skills that we know of.

cran
2005-Aug-22, 01:07 AM
Once again, suntrack2, you have summarised a question that has plagued philosophers through the ages... :D

And once again, Gourdy, you have conducted a sterling effort at addressing the question... :D

For 'grey matter' exercise, UT is such great fun! :lol:

... notice how I neatly avoided the actual question... <_<

j0seph
2005-Aug-22, 12:46 PM
I&#39;m just waiting for time travel.... then we can watch our evolution with binoculars :P

suntrack2
2005-Aug-23, 04:16 PM
thanks gourjosephcran for your reply. may be one cay say that monkey first or man? and if the true enjoyment or comedy being resolves through this topic then this is some what added advantage of the topic. but the same question i asked to many to the biologists, anthropologist and many students and teachers about" is there any sort of story related with this topic," they just looked at me with their oval jaw and raised eyebrows the answer i could not found through their face readings.

who will assist to search for a real answer for the above topic.

i am very much curious, and then we will be turn towards the possibilities that how the process can be start on the other planets that "how life begins" there.
also i am expecting replies from starlab/jimmy/piersdad and team, ofcourse from damien too.


sunil

cran
2005-Aug-23, 06:07 PM
The reason you get blank stares when you ask the question, Sunil, is that we don&#39;t have a solid answer yet ... :huh:
We have theories; we have myths and legends; we have entire branches of science devoted to aspects of that very question "Where did we come from, and why?" :unsure:
We have philosophies, religions, and cultures pondering ... but solid answers? not yet. :(

As a species, the geological evidence suggests that modern humans emerged from in or very near to the East Rift Valley in Africa ... and recent evidence has come to light that we did not descend from Neanderthal Man (as was previously thought), but we co-existed for a period of time... modern humans (homo sapiens sapiens - or &#39;homo saps&#39;) seem to have emerged during the last major ice age ... and spread from East Africa as a period of global warming/glacial retreat began...

BBC News online have just recently published an article relating to this here ( http://news.bbc.co.uk/2/hi/science/nature/4164022.stm) ... I&#39;ve mucked up the link, but it should still get you there...

Some earlier study seems to suggest that the exodus from the Rift Valley was not so much a matter of choice, but of fear and necessity ... as the temperatures rose into the high 20&#39;s C, it encouraged some plague viruses to flourish - that would explain why the first homo saps chose to head north out of Africa... to follow the retreating cold climate... and boy&#33; doesn&#39;t that have overtones of being forced out of the Garden of Eden...? :blink:

Evolutionary biologists have been redrawing the &#39;tree of life&#39;... and it was not as simple Darwin had conceived... studies of DNA and other evidence show that while we can consider ourselves related to chimpanzees and other simian primates, it is far less likely that we evolved directly from them... rather it seems that we share a common ancestor that evolved into many new forms (a speciation event, I have ideas about that... but that&#39;s another story), many of which have died out and only left a fossil record ... we just haven&#39;t found that common ancestor yet ... the earliest evidence of homo saps is a roughly 2 million year old near complete skeleton called "Lucy" found by ....>damn&#33; what&#39;s his name? His family continued with the work... he&#39;s got places named after him... rotten memory&#33; :angry: <... a really famous palaeontologist... :P

Maybe others here have more information for you, Sunil...

jhwegener
2005-Aug-23, 06:25 PM
"We donīt have a solid answer yet". But what kind of "solid answer", as opposed to "theories" could we expect?Scientists continue to find new fossil of human ancestors or "relatives"(as late as yesterday this was published about "new" discoveries in the Republic of Georgia of 1.7 million year fossil skull: http://www.livescience.com/history/ap_0508...old_skull.html) (http://www.livescience.com/history/ap_050822_old_skull.html)). I think no one could expect to find a complete tree of ancestors. In fact many of us do not know before a few generations (beside there is the question specially about who is "real fathers"&#33;). So, for all who do not know all their ancestors, say 200 years ago: how do you expect to know them say 200.000 years ago?

suntrack2
2005-Aug-24, 04:32 PM
thanks cran and jhwegner, for your reply, i am just giving you a week or so to find out a correct navigation road or path to search that when the first life begins to live on earth. even if don&#39;t know that how many ancesters were there. thanks for the links too.

cran
2005-Aug-24, 07:06 PM
i am just giving you a week or so to find out a correct navigation road or path to search that when the first life begins to live on earth.
"a week or so"? :huh: That&#39;s... er... generous of you, Sunil :(

&#39;First life&#39; on Earth... that&#39;s a very different story (or stories...) because then we are back to asking "when does chemistry become biology?"

Basic conditions for life (fluid water, available energy/food) seem to have been available on Earth from at least 4.41Ga BP ... based on isotopic analysis of zircon crystals dated to that age...

Chemical evidence consistent with biogenic signatures have been found in the some of the oldest rocks so far examined and isotopically dated to more than 4Ga BP ... but was it life? or some form of &#39;proto-life&#39;? or a non-biogenic residue which just happens to mimic life? Even the best experts can&#39;t answer that... yet. :huh:

There is more confidence in some samples dated to ~2.6Ga BP which include not only the &#39;biogenic&#39; chemical signatures, but also microscopic inclusions consistent with known viruses... of similar age are structures thought to be early stromatolites (colonies of microscopic algae which form rock like structures by trapping fine sediments and growing through and over them - over time they form layered structures of varying shapes - some have survived to modern times, and these exist in a wide range of shallow water environments from mildy brackish estuaries to marine embayments to hypersaline lakes... and that&#39;s just in Western Australia&#33;)

Fossil evidence of macroscopic life (life you don&#39;t need a microscope to see) have been identified from the beginning of the recently announced period called the Ediacaran which immediately precedes the Cambrian (~545Ma BP - million years before present era) and extends at least to ~600Ma BP... which is shortly after a very extended Cold Period including two large glacial peaks (ice ages), sometimes called &#39;Snowball Earths&#39;.

For up to date and detailed information about earliest life on Earth, a simple Google search will turn up literally hundreds of research papers and announcements from universities all around the world... Sunil, it would be smarter for you to search, rather than for others to recommend one or two sites, because only you will know how much detail you want; how specialised the reports or the language in the reports will suit you; and whether you want to follow a particular evolutionary trail, or something more general... :unsure:

suntrack2
2005-Aug-27, 12:22 PM
oh &#33; thanks cran for the reply and the information.

my goal in asking that any planet like earth must have to gone to these sorts of stages, that how life developed on earth through the different stages, and that sorts of stages must or may be applicable for the other planet too.

google search is a different thing to apply, that&#39;s not i am searching for.

only we have to see during the discussion that whether the other planets where the life formation is possible or whether the life was existed thereon very previously or not? and if so then how the stages developed or their (other planets) system is different or was different or may be different than our stages?

where the life existed on a xyz(where the propspects are to see for a new life)the man of that planet is walking like reptiles &#33;

cran
2005-Aug-27, 08:35 PM
Originally posted by suntrack2@Aug 27 2005, 08:22 PM
... that any planet like earth must have to gone to these sorts of stages, that how life developed on earth through the different stages, and that sorts of stages must or may be applicable for the other planet too...
...only we have to see during the discussion that whether the other planets where the life formation is possible or whether the life was existed thereon very previously or not? and if so then how the stages developed or their (other planets) system is different or was different or may be different than our stages?

where the life existed on a xyz(where the propspects are to see for a new life)the man of that planet is walking like reptiles &#33;
Yes, Sunil ... your thinking seems to be along the right track... :)

One of the points on which Seth (Shostak of SETI) and disagree is whether homo saps might be considered the "new kids on the galactic block" - Seth&#39;s (and others&#39;) view is that &#39;civilised&#39;* life such as ours has had time to evolve three times over; based purely on the time that the universe has existed (ie, the unverse is about 13.7Ga; the Earth is about 4.5Ga... ergo, the Earth could have evolved 3 times over since the beginning of the universe...)

*(the term &#39;civilised&#39; used here refers to &#39;tool-making and -using&#39;, &#39;environment-modifying&#39;, and &#39;imaginative&#39; - capable of abstract thought, questions, and concepts beyond experience - and makes no reference to social or ethical implications)

- I have disagreed with this as too simplistic, prefering to consider that for a planet like the Earth to evolve, under the time restrictions given above, the universe (and our galaxy within it) has first had to evolve sufficiently for there to be enough of the right materials in the right ratios, and the development of a substantial &#39;goldilocks&#39; zone (not too much, not too little) ... in short, that homo saps have evolved as fast and as soon as circumstances have allowed... and in other threads, I (and others) have indicated some fortuitous conditions which have provided both protection and encouraged evolution...

"A civilisation analogous to ours requires an environment and evolutionary history analogous to ours, one which forces us not to adapt to it, but to modify it so that it adapts to us; and it must be sufficiently transparent to allow a view beyond the immediate...
"The evolution of life is a response to changes in the environment, and favours those which survive long enough to to breed successors better adapted to the changed environment. Extinctions occur when the change is too drastic and/or too fast for adaptation; for some, it may be a sudden change in climate, or an intense burst of radiation or cataclysmic explosive event; for others, it may be a sudden loss of a basic food supply, or unavoidable competition from a stronger species over a limited supply, or an increase in predation or disease to the point where the death rate exceeds the birth rate..." And a complex &#39;marginal&#39; environment provides further assistance ... "As intelligent as a whale or a dolphin may be, its environment precludes the ability (and necessity) to control fire or other environment-modifying tools..." (2001; "New Kids on the Block?" in &#39;Comparing Time Lines&#39; - essays for Earth Sciences, Flinders University)

So, while life may be possible (even probable) wherever there might be sufficient fluid water and chondritic materials, successful evolution requires a balance of safety and challenge, and the emergence of a &#39;civilised&#39; (as defined earlier) species requires an evolutionary history (including the time requirement) and an environment analogous to ours... if we can find Earth analogs, Sunil, chances are high that it will include analogs to life here, and their ages should be reflected in their evolutionary development ... so we may well find places with species like us (whether they are evolved from mammal-like creatures or reptile-like creatures or even mobile plant-like creatures) but I would expect an evolutionary history at least as long as ours... and much longer if the planet lacks the advantages of our Earth...

jhwegener
2005-Aug-28, 09:35 AM
This discussion, I think, is very little about definite answers, not to say "proofs", more about possibillities and "probabilities", and we should not even quantify the latter, but rather give our opinions and arguments.
And I have a strong suspicion this opinion in many cases have much to do with what one may call "culture" and even our personal history, and sometimes, sometimes not, with "evidense".
One example: We for some time have developed a tendecy to have a more and more "accidental" view of life. Like "It could be like here, but it could equally well be totally different", and intelligent creatures may as well be totally different from us ("who says humans are the peak of it all?"). Has this to do with egallitarian ideals, borrowed maybe from a common view of society("all men are (born?)equal?)
Before moderators delete my post:This is not about propagation of my political or religious views. Rather to say:It may sometimes be hard to separate things completely.
I, as one example, can hardly believe that "anything goes".
It is not accidental how the only "intelligent" (or if you better like it, thinking, toolbased social animal)is. A creature like a reptile or bird, starting its life in an egg outside its mother, would hardly have evolved this way. The egg would have limited its early development, and it would probably miss some social relation.
(of course, this is my view, which may be as biased as anybody elses)

cran
2005-Aug-28, 03:22 PM
Yes... :)

suntrack2
2005-Aug-28, 04:45 PM
then &#33;

cran
2005-Aug-28, 04:56 PM
:lol:

I was responding to jhwegener, Sunil... :D

GOURDHEAD
2005-Aug-28, 07:16 PM
Evidence grows ever dense.

suntrack2
2005-Aug-30, 11:50 AM
was there only the biological evidences of the life on earth when it was grown later, or only the life came through the medium like asteroid fall on the earth ?
or the life was transfered from a very long corner in the universe that the mirror image of this type of life may be there in the existence.

in short the life how it came on earth this is somewhat miraculous.


sunil

cran
2005-Aug-30, 12:59 PM
Originally posted by suntrack2@Aug 30 2005, 07:50 PM
was there only the biological evidences of the life on earth when it was grown later, or only the life came through the medium like asteroid fall on the earth ?
or the life was transfered from a very long corner in the universe that the mirror image of this type of life may be there in the existence.

in short the life how it came on earth this is somewhat miraculous.


sunil
Well, Sunil, studies of some meteorites have turned up some complex organic molecules, including some related to, or associated with, life as it is found on Earth...

and there is one famous (or perhaps infamous?) meteorite, which was picked up in Antarctica which microscopic analysis showed some tiny structures that the investigators said looked like fossilised viruses - and some other amorphous silica inclusions (&#39;glass beads&#39;) which contained traces of gases which exactly matched what was thought to be the ancient Martian atmosphere (I forget the name of the meteorite; that&#39;s my rotten memory&#33; but someone will know it)...

the &#39;fossil virus&#39; findings were disputed by two different groups: one group said that the tiny structures were &#39;flaws&#39; or natural formations of the meteoritic material, and this could be clearly seen if more of the microscopic image were visible in the scan;

the other said "yes, they were probably viruses, but they came from Earth" and it seems that the bulk chemistry of the meteorite did seem a close match for that... leading to the conclusion that this piece of rock was the first successful Martian probe (and the viruses must have been the first astronauts) that was lifted off the Earth, travelled to Mars to capture atmospheric samples, and then returned to Earth ... personally, I think it&#39;s a bit of a long shot <_<

A number of laboratory experiments have been conducted by different workers to see if life could spontaneously arise from what was assumed to be the primitive chemistry of the very early Earth... most looked at a liquid water environment, but steamy atmospheres with electric charges (lightning) were also tried ... the results were inconclusive ... but complex building blocks were formed in many of the experiments, the very things needed to combine into simple life ...

There was also some experiments to simulate conditions in space with the raw materials and UV radiation ... these also seemed to be partially successful...

Finally, analyses of chemical spectra of distant nebulae (and even more distant galaxies) have confirmed the presence of organic elements in reasonable abundance, and indications of complex organic molecules in these regions ...

Considering all of these different avenues of investigation, and for the direct experiments under different starting conditions and assumptions, the indications are tantalisingly positive that life has arisen in more than one place in this universe, and that natural processes are sufficient for this to happen... :D

suntrack2
2005-Aug-30, 04:44 PM
thanks cran, one of my friend told me that may be the human being was so short in the height in some few inches later the formation developments the man got height, i laugh over his statement, but if we turn our concentration by looking through this sort of side, we can found some interesting assumptions that the development of life was a very lengthy process on the earth, it gone through the verious transitions.

jhwegener
2005-Aug-30, 06:19 PM
About the Martian meteorites, with remains of "perhaps life": As I remember (I do not guarantee my memory either): They are the only seriously discussed pieces of what may be evidence of life outside earth. But the suspicion that the "fossilised organisms" may be of terrestrial origin do not imply flying to and from Mars a lot of time. They hit the ice in Antarctica long time ago, so the "terrestrials" had time.
Since we have heard little about them lately I suspect the "sceptics" have good arguments(?) Perhaps someone know more about latest discussion?

cran
2005-Aug-31, 01:20 AM
Originally posted by suntrack2@Aug 31 2005, 12:44 AM
thanks cran, one of my friend told me that may be the human being was so short in the height in some few inches later the formation developments the man got height, i laugh over his statement, but if we turn our concentration by looking through this sort of side, we can found some interesting assumptions that the development of life was a very lengthy process on the earth, it gone through the verious transitions.
Indeed, Sunil, a most lengthy process with many variations, and many attempts at improving survival ... not all worked ... and some appeared to have gone &#39;backwards&#39; ... most of all, we must remember that not only do we not have all the answers about what came before us; we must realise that evolution is still going on around us, and that we are a part of it... :)

They hit the ice in Antarctica long time ago, so the "terrestrials" had time. yes, jhwegener, that was one of the ideas suggested... not so much from when it hit the ice in Antarctica (because that was only a few years ago, and if the inclusions are fossil viruses they are hundreds of millions of years old... but they would have had plenty of time to get into the rock if the rock originated on Earth)

Since we have heard little about them lately I suspect the "sceptics" have good arguments(?) Perhaps someone know more about latest discussion? It appeared the sceptics had some strong arguments and the last decision I&#39;d heard was that all of the evidence made any interpretation &#39;inconclusive&#39; ... I think everyone involved is now waiting on further results from the Martian rovers, and if they are still inconclusive, further investigations are planned on Mars ... so, it seems like a &#39;wait and see&#39; situation. :)

Dave Mitsky
2005-Aug-31, 07:03 AM
The meteorite in question is known as ALH 84001 (Allan Hills 84001). It is an igneous in nature and is classified as a shergottite. It may have fallen on the Antarctic ice sheet some 13,000 years ago. The claim was that ALH 84001 contains evidence of ancient Martian bacterial (or at least bacteria-like) life.

http://www.daviddarling.info/encyclopedia/...A/ALH84001.html (http://www.daviddarling.info/encyclopedia/A/ALH84001.html)

http://calspace.ucsd.edu/marsnow/library/s...eteorites1.html (http://calspace.ucsd.edu/marsnow/library/science/mars_meteorites1.html)

http://en.wikipedia.org/wiki/Martian_meteorite

http://www.lpi.usra.edu/lpi/meteorites/alhnpap.html

http://www2.jpl.nasa.gov/snc/index.html

http://scienceworld.wolfram.com/astronomy/...Meteorites.html (http://scienceworld.wolfram.com/astronomy/SNCMeteorites.html)

Dave Mitsky

jsc248
2005-Aug-31, 10:34 AM
Hi Gang,
This meteorite that Dave Mitsky so rightly describes does bring up the old topic of Panspermia. Along with others the late Fred Hoyle put forward the notion that life was brought from elsewhere by meteorite or comet. Makes you think doesn&#39;t it?
Opinions friends&#33;&#33;&#33;
jsc248

suntrack2
2005-Sep-02, 12:32 PM
thanks dave for the links, dave is a multidimensional personality in my opinion,

i also would like to point out that we were not monkey like in the past, but our appearence and few habbits match with the monkey. think, that today&#39;s monkeys, how they later can be see say in the year 2500 ? during this big transition their habits and looks will be change but they will be only monkey, may be they can use computers in the year 2500 if they get training, may be they can play and watch vedeo games also. may be they can read the novels too, but when will it happen, the number of atempts the monkeys has to practice that.

in short the man came through the stages and that the stages through which he came he was unknown about the boundaries of his world, later after big numbers of years he got the knowledge that further life is there on earth. secondly the man or say monkey can only works in the light, light is very important for them to live, without light they can live betterly, the mock psychology of the monkeys sometime speaks the language that monkeys are having a good understanding power than any other 4 leg animal, ( as chimpanzee do).

the human being is a part of the animal world but due to speaking power the man could develop its brain and the surrounding and other intelectual powers and better thinking of survival finely. all the shadows in the original jean developments of the original peoples of the earth. later we are looking that how the man is improving or enhancing and empowering himself with the many man made tools. but the original question is yet un-answered.

sunil

ZaphodBeeblebrox
2005-Sep-05, 04:09 AM
Hi Gang,
This meteorite that Dave Mitsky so rightly describes does bring up the old topic of Panspermia. Along with others the late Fred Hoyle put forward the notion that life was brought from elsewhere by meteorite or comet. Makes you think doesn't it?
Opinions friends!!!
jsc248

Panspermia Between Systems, is Probably, Nealy Impossible.

HOWEVER, Within a Solar System, Eh, Who Knows ...

Interesting Possibillity, At Any Rate!!!!

:)

Maksutov
2005-Sep-05, 01:37 PM
Panspermia Between Systems, is Probably, Nealy Impossible.[edit]
Quite Right, but It is not Neary Impossible! (http://www.imdb.com/title/tt0075860/) ;)

raju_racelin
2006-Apr-12, 07:09 AM
Hello ,
I Joined In The Group Today . Let Me Use The Site Usefully.....

01101001
2006-Apr-12, 06:28 PM
Hello ,
I Joined In The Group Today . Let Me Use The Site Usefully.....

Welcome to the BAUT Forum.

You just added a comment to an article that sat stagnant since September. That's OK, but you didn't exactly have much to say on the topic. Do you have more to add, or did you just pick this topic to make your introduction?
(If it was jut the introduction, most people do that by using an existing, or starting a new, topic in Off-Topic Babbling (http://www.bautforum.com/forumdisplay.php?f=9).)

Anyway, you've gotten started. Welcome.