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HOMO SAPIENS

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samivel
102689.  Fri Oct 13, 2006 3:10 am Reply with quote

Oo-er.

 
Quaintly Ignorant
102784.  Fri Oct 13, 2006 8:04 am Reply with quote

Ameena wrote:
Humans have opposable thumbs, are bipedal, and also (I've been told) have the largest brain in relation to body mass (meaning that although, say, a blue whale's brain is probably kinda bigger than ours, in comparison to the rest of its body it's a pretty small percentage...although I don't know how big a blue whale's brain is :P).


There is perhaps a little more to it:

Species Brain weight (gram) Body weight(tonn) Brain
weight as %
Code:

                                   
                                               

Man     1500            0,07             2,1
Bottlenose
dolphin  1600           0,17            0,94
Dolphin  840             0,11          0,74
Asian
elephant 7500            5,0          0,15
Killer
whale     5620            6,0          0,094
Cow       500              0,5          0,1
Pilot
whale    2670             3,5          0,076
Sperm
whale    7820             37,0        0,021
Fin
whale    6930             90,0      0,008
Mouse   0,4               0,000,012  3,2


What is more unique about us humans is(are?) the density of our neural pathways/connections and our long childhoods to allow more refined development. It appears that a mouse's brain is larger as a ratio to its body but then again we already knew that they were super-intelligent pan-dimensional beings running a massive simulation as an experiment to reveal the answer to the ultimate question. Didn't we?


I could google it I suppose, but are we not also known as Cro-Magnon?

(Yes I'm a software engineer, but if you think that means I can work out the formatting of that table you are clearly wrong)

 
Long Haired Hippy
102832.  Fri Oct 13, 2006 10:01 am Reply with quote

dr.bob wrote:

But, back to the original point:

grizzly wrote:
Homo Sapiens or Humans


Not quite. Modern Humans are, in fact, Homo Sapiens Sapiens and are a sub-species of Homo Sapiens. However, the only other sub-species of Homo Sapiens, Homo Sapiens Idaltu, are now extinct.


Whilst not quite sub species of Homo Sapiens there were other Early hominids which would have been a closely related species. The question is have they perhaps survived and are just in hiding. With the recent discovery of a new species of mouse in Cyprus http://news.bbc.co.uk/1/hi/sci/tech/6043648.stm We are reminded that there are plenty of species that have not yet been discovered or catalogued even on our own doorstep. The search for evidence of yet un-catalogued species or of those thought to be extinct is called crypto zoology and these species they search for are called cryptids. By far the most provocative cryptids are the hominid cryptids.

Take for example the Ebu Gogo a race of three foot high human like creatures from the island of Indonesia. Consigned by many to the realm of myth the search for them was revitalised after the 13,000 year old remains of Homo Floresiensis were discovered on the island of Flores. Some maintain sightings of Ebu Gogo as recently as 100 years ago though most islanders believe that Ebu Gogo disappeared shortly after the arrival of the Portuguese 400 years ago. This is still far more recent that the estimate that Homo Floresiensis died out 12,000 years ago killed off by a volcanic eruption. Homo Sapiens Sapiens were believed to have arrived on the island only 11,000 years ago so if Ebo Gogo is to be associated with a racial memory of Homo Floresiensis then their date of extinction should be revised. See also related Indonesian crytids Orang Pendek Uhang Pandak, Sedapa, Batutut, Umang, Orang Gugu, Orang Letjo, Atoe Pandak, Atoe Rimbo, Ijaoe, Sedabo, and Goegoeh.

Given this possibility perhaps scepticism of Bigfoot and Yeti sightings is a little hasty. Perhaps these are evidence of ancient apes such as Gigantopithecus, Paranthropus or Meganthropus

The agogwe or east Africa also known as the Kakundakari or Kilomba may either be evidence of a surviving population of Gracile australopithecine, another early relative of ours.

 
Flash
103528.  Mon Oct 16, 2006 4:19 am Reply with quote

If intelligence confers such a huge evolutionary advantage as it evidently does, why haven't other intelligent species evolved over the millennia, eh? Answer me that.

 
grizzly
103542.  Mon Oct 16, 2006 4:59 am Reply with quote

The likelihood is a combination of 2 factors:

1. The significant evolutionary disadvantages of intelligence - humans have huge heads. The result of this is that childbirth is a far riskier event than it would otherwise be. If the benefit in terms of survivability is outweighed by a larger cost to survival because of the risks involved in childbirth then "intelligence genes" will disappear due to natural selection.

This isn't the only example. The fact that the nuturing period for children is so long, and it places such huge demands upon parents and social groupings, can be perceived to be a significant disadvantage.

2. Circumstance - we have only evolved our intelligence at a tremendous rate in the last couple of million years because circumstances have been in our favour. We are a species that live in small (and now increasingly large) social groups. Hence, whilst some of the disadvantages of becoming more intelligent would have prevented other species from doing so, these disadvantages have been minimized in our species. For example, other members of the group can care for a child whilst it is growing up, reducing the burdon on the mother.

Other circumstances have been important. Climate has played a significant role in our evolution over the last 2 million years with the number of ice ages and inter-glacial periods.


In addition, the premise of your question is wrong. Other intelligent species, may have evolved over the hundreds of millions of years. However, you don't recognise this because you are not measuring intelligence in the correct method.

I assume that you are measuring our intelligence by the fact that we can have such a huge influence on our environments, shaping them to suit our own needs. However, our own intelligence is not the only factor that is necessary for us to do this. Indeed the job would be nearly impossible without opposable thumbs and the ability to stand on 2 legs. ANimals may exist (such as the dolphin) or others in the past that are as equally as intelligent as our own or more so. They simply haven't been capable of fullfiling your measure of intelligence (making sophisticated buildings or creating a written language etc) because of other reasons (e.g. they have flippers instead of hands).

 
Flash
103574.  Mon Oct 16, 2006 6:45 am Reply with quote

OK, that's good stuff. Here's something else: would it be possible for there to be two intelligent species (intelligent in the sense that the word applies to humans) co-existing on the same planet, do we think?

 
grizzly
103584.  Mon Oct 16, 2006 7:14 am Reply with quote

Flash wrote:
OK, that's good stuff. Here's something else: would it be possible for there to be two intelligent species (intelligent in the sense that the word applies to humans) co-existing on the same planet, do we think?


You should watch some episodes of star trek every once in a while.

The answer to the questions is a "it depends" one.

It is quite conceivable that different species could co-exist, particularly if they have a common ancestor. Of course in our case the Neaderthals were not able to coexist (despite research suggesting that they were just as intelligent). They were unable to compete and adapt in the changing world after the end of the last ice age. There are also those that believe they disappeared because they interbred with Homo Sapiens (Sapiens) (although they were a different species, the dividing line between 2 species isn't so distinct as S Fry suggested).

Perhaps one of the interesting concepts is what would have happened to Home Sapiens over the next few hundred thousand years had changes occured (such as in the climate) that would have prevented our ancestors from beginning to develop ways of travelling around the world. Perhaps a rather distasteful concept for some is that European, Asian, African and North/South American humans would have evolved into seperate and distinct species (obviously with the history of racism and such this is a highly charged and contentious issue).

 
Sergei
170981.  Mon Apr 30, 2007 2:18 pm Reply with quote

Interesting idea. Once we had spread around the world though, it's hard to imaging what circumstances would prevent us - any of us - continuing to do so.

Incidentally, isn't there some argument that Neanderthals could more properly be seen as a subspecies of modern humans - homo sapiens neanderthalis - rather than a separate species?

 
ali
171009.  Mon Apr 30, 2007 3:09 pm Reply with quote

The Lagar Velho Boy is taken by some researchers to be evidence of interbreeding between H. sapiens sapiens and H. sapiens neanderthalensis based on the fact that the skeleton has similarities to both. This is still a subject of much debate.

 
suze
171015.  Mon Apr 30, 2007 3:36 pm Reply with quote

Just a little, yes.

In my day we were told categorically that H. sapiens sapiens and H. sapiens neanderthalensis were not able to interbreed. That was probably inappropriately dogmatic, but all the same it seems probably to be the case.

We've been into the matter before in this forums - post 46046 et seq, for instance.

 
legspin
171053.  Mon Apr 30, 2007 8:02 pm Reply with quote

My wife is convinced that Kerrymen (of which I am one) are actually a sub-species of Homo Neanderthalenis. I'm almost sure she is joking in this but it did lead to an undoubtedly mis-guided but curious question.

I have the feeling that if the interbreeding of Neanderthal and Cro-Magnon would have been latest on the periphery of Europe ie. Ireland, and thus would be most likely to survive out around here. By extention Kerry is as far out on the edge (in many way it must be said) as is possible here. I was struck by some of the probably more co-incidential similarities. Shorter limbs and longer torsos seem to be common-place, as do short but broad hands and feet. (You have no idea how hard it is to get ice skating or roller-blade boots that are designed for Irish feet. These all lend towards squatness and solidity. Broad, open features tend to crop up quite often as well.
I think you can see where this is leading to....
Of course these characterisitics could easily have been bred back in later but I do sometimes wonder.....
In fairness, I am giving myself as the example of the above

 
Sergei
171056.  Mon Apr 30, 2007 8:46 pm Reply with quote

It's argued that Ireland has had relatively little genetic influx since Bronze Age or even Neolithic times, but the Neanderthals are a lot further back than that. In fact there's no evidence of them reaching here at all. The closest they seem to have come is - funnily enough - southern England.

So I think it's more likely that you share genes with the makers of Newgrange and other megalithic machinery. Of course, this may make you a fir bolg instead...


ali wrote:
The Lagar Velho Boy is taken by some researchers to be evidence of interbreeding between H. sapiens sapiens and H. sapiens neanderthalensis based on the fact that the skeleton has similarities to both. This is still a subject of much debate.


I know this debate rages, but the classification was what surprised me. I'd thought Neanderthals were considered a subspecies of modern humans, but people here - and Wikipedia - refer to them as a separate species. Homo neanderthalensis rather than homo sapiens neanderthalensis. Does this reflect new knowledge about them, or simply a change in the way the concept of species is defined (which seems to happen a lot these days)?

 
legspin
171057.  Mon Apr 30, 2007 9:11 pm Reply with quote

[quote="Sergei"] In fact there's no evidence of them reaching here at all. The closest they seem to have come is - funnily enough - southern England.

This was always one of the points where the argument for fell down

 
ali
172120.  Fri May 04, 2007 5:27 pm Reply with quote

Sergei wrote:

ali wrote:
The Lagar Velho Boy is taken by some researchers to be evidence of interbreeding between H. sapiens sapiens and H. sapiens neanderthalensis based on the fact that the skeleton has similarities to both. This is still a subject of much debate.


I know this debate rages, but the classification was what surprised me. I'd thought Neanderthals were considered a subspecies of modern humans, but people here - and Wikipedia - refer to them as a separate species. Homo neanderthalensis rather than homo sapiens neanderthalensis. Does this reflect new knowledge about them, or simply a change in the way the concept of species is defined (which seems to happen a lot these days)?


There doesn't seem to be any consensus on it. In fact it seems quite common to see both forms in the same article. The same is true of H. (sapiens) heidelbergensis, which some researchers do not accept as a valid species, and others believe to be ancestral to both neanderthals and modern humans. The multiregionalist vs. 'out-of-Africa' debate seems to have some bearing on researchers' preferences, but I haven't figured out exactly what yet.

 
feynmanMH42
253203.  Sun Jan 06, 2008 11:38 am Reply with quote

I don't really feel that species and genus names really matter when discussing evolution, only when classifying individuals. I mean, it's not as if a H. heidelbergensis mother gave birth to a H. sapiens child. Or worse, that an Australopithecus gave birth to a Homo. In evolution boundaries are very blurred. I think it's silly discussing the subtle differences between heidelbergensis, Neanderthals and ourselves, and to argue about "Out Of Africa" vs "multiregionalism." Instead we should accept that it doesn't have to be one or the other but elements of both could be true and we should focus on learning the story of human evolution instead of trying to classify every fossil we find.

 

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