Oldest member of human family found

New-found skull could sink our current ideas about human evolution.

After a decade of digging through the sand dunes of northern Chad, Michel Brunet found a skull 6-7 million years old. He named it Toumaï.
Toumaï is thought to be the oldest fossil from a member of the human family. It's a dispatch from the time when humans and chimpanzee were going their separate evolutionary ways. A thrilling, but confusing dispatch
Sahelanthropus tchadensis - Toumaï's scientific name - was probably one of many similar species living in Africa at that time. "There must have been a group of apes knocking around between 5 and 8 million years ago for which there's a very poor fossil record," says anthropologist Bernard Wood of George Washington University in Washington DC.
Toumaï is the tip of that iceberg - one that could sink our current ideas about human evolution. "Anybody who thinks this isn't going to get more complex isn't learning from history," says Wood.
"When I went to medical school in 1963, human evolution looked like a ladder," he says. The ladder stepped from monkey to man through a progression of intermediates, each slightly less ape-like than the last.
Now human evolution looks like a bush. We have a menagerie of fossil hominids - the group containing everything thought more closely related to humans than chimps. How they are related to each other and which, if any of them, are human forebears is still debated.
Most members of the group are less than three million years old. After Toumaï, the next-oldest hominid is the 6-million-year old Orrorin tugenensis. But Orrorin is known only from a few teeth and bone scraps, and its evolutionary allegiances are controversial.
Our knowledge of Toumaï's period is "at the 1963 stage", says Wood.

"When I first saw the skull I thought: 'Gee, it's a chimp'," says anthropologist Daniel Lieberman of Harvard University. Toumaï's brain, for example, was roughly chimp-sized. A closer look "blew my socks off", he recalls.
Sahelanthropus has many traits that shout 'hominid'. These include smaller canines, and thicker tooth enamel than apes. And the point at the back of skull where neck muscles attach suggests that Toumaï walked upright.
Many of Toumaï's advanced features are missing from later fossils such as Australopithecus, but reappear in still later species that are classified as Homo.

Based on this, we might have to question some species' place in the hominid club. If Australopithecus looks more ape-like than a much older fossil, how can it belong to the human family? "Anything with a more primitive face has to have its membership reviewed," says Wood.
No groups will be expelled on the evidence so far. The real lesson, says Wood, is that appearances are a bad guide to evolutionary relations. Hominid and ape species probably mixed and matched from a set of features, he says, with the same traits evolving independently on multiple lineages.
Toumaï has other features that are just strange. "It's got a massive brow ridge, the size of a large male gorilla, and yet it's just a little hominid," says Lieberman. This heavy brow leads many to believe that Toumaï was male.

Where then does Toumaï fit on the family tree? He could belong on the chimp or hominid lines, or he could be part of a different branch of the family, more distant from both chimps and humans that either is from the other.
Palaeoanthropologist Tim White of the University of California, Berkeley, agrees. He thinks that Toumaï might belong to Ardipithecus, a group defined by fossils dating from about 5.5-4.5 million years ago.

But Wood takes a different view. "My guess is that it's neither a chimp nor a human ancestor - it's a creature that was living at the same time."
To solve the mystery we need more fossils from the same period. Unfortunately our relatives' habits may be against us. The forests favoured by chimps, and apparently by early hominids, are not conducive to fossil formation. Chimps, for example, have no fossil record.
On the bright side, Toumaï's discovery suggests that, even if they were rarely fossilized, ancient apes and hominids roamed right across Africa. "Finding hominids in the Sahara was a bit of a long shot," says Wood. So far, most fossil hominids have turned up in the east, with a few further south.

But desert-bound palaeontologists be warned: "There are brutal field conditions," says Lieberman.


References
1.Brunet, M. et al. A new hominid from the Upper Miocene of Chad, Central Africa. Nature, 418, 145 - 151, (2002).
2.Vignaud, P. et al. Geology and palaeontology of the Upper Miocene Toros-Menalla hominid locality, Chad. Nature, 418, 152 - 155, (2002).

TB... you maybe related to a monkey... but I'm not.

yes you are

Admit it ... we are of two species...

split personality?

why do humans degrade themselves to animal level?
we are a special speices, the only that can think, Allah's precious humans who he put on earth to worship him and make something of this beautiful world.
why can't scientists accept that?

We are special and evolution takes nothing away from this, it is only those who are unable to conceptualise time that would think this way

as an egg and sperm becomes a baby becomes an adult
so we have developed over millions of years from primitive beginnings.

In my eyes it shows how amazing life is and how great God is.

everyone thinks that he is animal , he has the freedom to say that...

i just wonder how come the most developed ape does not have some of human complicated strucureslike amygliod body, the amazng cortex and gyrae, the hypocappos and parahypocampous body...etc,,,
or did these structures just appeared from ape to human in one single generation... like 2 leopard met and produces one cat....
amazing laa.

if humans were evolved from apes, then why aren’t we evolving to something else now?

why aren't the other animals evolving to humans, aliens, etc???

the first human on earth was Adam (pbuh) he was not evolved from anything, he was created by god, which shows us his greatness...

if you believe in evolution, then go and live with monkeys...

Quiet simply we are evolving, we all stand more upright and are taller than we were, but evolution takes millions of years and only happens through necessity (which is the mother of all invention) so when climates change or food becomes scarce or competitors move in to an area or desease hits, only those best able to survive will survive and so, when they mate, those succesfull traits are passed down to the next generation and so on. The best example of this in modern times is the adaptability of rodents/insects and bacteria etc to pesticides and poisons, after only twenty years or so, they have become immune to what once once deadly to them, because only those that, through a minute genetic difference, were naturally immune did survive.
Also the same has happened with dogs, witness all the different breeds and how different they are, from very tiny furry things to massive ugly beast, all caused through specific breeding (in this case deliberatley caused by man) over only 500 years or so, now think of what changes could be made over 1 million years. And then think that this hominid described above, is 5-8 million years old.

Originally posted by FaHaD
everyone thinks that he is animal , he has the freedom to say that...

Thanks. That and the fact that it is the truth.

Originally posted by FaHaD

i just wonder how come the most developed ape does not have some of human complicated strucureslike amygliod body, the amazng cortex and gyrae, the hypocappos and parahypocampous body...etc,,,
or did these structures just appeared from ape to human in one single generation...

Fahad, are you sure about your statement re: unique human brain structures - Amygdala, Hippocampus, Parahippocampus, etc. ? Perhaps a day for you to review and modify your statement is in order.

Originally posted by Kamakazy

if you believe in evolution, then go and live with monkeys...

well said kamkazy,,,
wanderer could u give me the anatomy of ape's brain...
r u should do it by ur own , cmpare it to ur bain anatomy..

Fahad,

Not sure if you are trying to insult me and not entirely sure why you would do such a thing.

I'm just giving you a chance to review your statement regarding certain brain structures being unique to humans. I'm investigating it to see if it's factual. I'm suggesting we both do so.

You should be familiar with the concept of "peer review".

LoooooooooooL... wanderer , pls don't misunderstand me.. sorry if u feel it like an insult..
but i will try to look for it... but i don't have biology books at home and i am in a holiday..
i will try to go to the library to find out the inique structure plus function..

Look simple people:


the point of evolution is that species evolve

they change, some kep some characteristics, others lose them

if we were the same as apes we wouldn't have evolved.

Another NON-CONCLUSIVE discovery that raised questions rather than answers!!!!

Isn't that the point though: to ask questions in order to find the answer

instead of being dumb, unthinking and ignorant

Can u watch ur language TB!! What r u having a hangover?!!
It is so easy to raise questions .... the intellegence comes from answering them ....

I meant 'dumb' as in 'unthinking' not as an insult

but I guess you can be forgiven for thinking otherwise given some of my other posts this happy morning!


I agree, they need answers, but answers are hard to find and one needs to ask more and more questions to even get a hope of getting near the right answer.

I am unclear as to what I really think about evolution, I agree with it to an extent, although I do not follow Darwin's theory completely, I think there is more to it than that.



My point of view is that when God created the universe, he still needed a method to do it by, and that this is evolution. The same as babies need to grow to become adults etc.

I would agree with you that we constantly evolve in the sence that people become more intellegent ..... the bugs run away from you once "Pif-Paf" can enters the room before even getting sprayed.... but turning into a humanbeing from an animal .... I think is like saying an insect would become a bird one day!!

I know it seems strange, but as I said above, think how much can change in a few hundred years, and then think how long 8 million years are (back to this hominid) add another 10 million back to apes and another 3.8 BILLION years plus, back to the first life on Earth

3,8 billion is :

3,800,000,000 years

well great if people believe that human come from apes...
so the next question what is the next species after human ...
what will we call them and how they will look like.. what advantages they will have??

interesting question,

I suppose there are so many factors to consider like desease (AIDS etc) polution, nuclear war.

Also our increases in technology, changes in lifestyle which have already lead to changes in our bodies.

Then there is the terrible factor of genetic engineering that some idiots in the west want to press ahead with.

doesn't look like we're going to get any cleverer!



Many evolutions on nature are caused by things such as climate
for instance imagine if in the wild suddenly all the short plants died, only the tall animals or tree climbers etc would survive, maybe it would be that only the tall horses survived, they would breed and all horses would be tall, but they would eat all the higher up leaves etc, and next time a similar situation happened
all the even taller horses would survive, so on and so on until maybe the giraffe etc. Also anything that ate the small horses would either die, or adapt and so evolve itself.

But our lives seem to be getting easier and it is no longer natural physical ability that ensures survival. Who can say what will be the definnig factors in the event of a catastrophe.

TB are u talking about mutation or evolutions...

They are part of the same process, mutations cause differences, it is then the survival of the fittest, and sometimes those will be the mutations.

u mean major mutation by AIDS , nuclear energy...

so what is the next species ... superman..:gap:

no that's not what I mean

but if aids spreads even further, then onlty those naturaly imune will survive.

Also, imagine if there was a nuclear war and due to winds carrying radiation the only people to survive lived at the tip of argentina or some such, the human race would still continue, but would be changed for ever. No longer would there be black or oriental or european people etc, and we all have very diferent characteristics.

soo not evolution

surely that is part of evolution?

simply put, evolution is the survival of the most suited, sometimes this will just be luck, or be caused by an extreme event.
In this case however we were going to evolve would be rapidly changed. Different factors would come into play. These exaples are actually quite good, because if they happened then man would once again return to being a country dweller and would lose the impact of modern technology/lifestyle.
I cannot say how that would affect us in the long term, maybe when the people from Argentina (the only survivers!) who are adapted to cold climates eventually spread and dispersed back round the world and had other catastropges, other cross-rpads on the way, they would adapt in unforeseen ways. I can guarantee that if this happened a human from 2 thousand years in the future would look very diferent from a human who lived 2000 years without the catastrophe.

Not as different as apes and man, but if you add on another 8 millino years of small changes, occasional famines/deseases/climate change. loss of one food, gain of another etc etc.

Originally posted by Talius Brute

if we were the same as apes we wouldn't have evolved.

?

Apes have evolved too.

We just happen to share a (relatively recent) common ancestor with the Bonobo, Chimp, Gorilla, and Orangutang. But those apes have changed too.