Skull of Homo erectus throws story of human evolution into disarray

First topic message reminder :

The spectacular fossilised skull of an ancient human ancestor that died nearly two million years ago in central Asia has forced scientists to rethink the story of early human evolution. Anthropologists unearthed the skull at a site in Dmanisi, a small town in southern Georgia, where other remains of human ancestors, simple stone tools and long-extinct animals have been dated to 1.8m years old.

Experts believe the skull is one of the most important fossil finds to date, but it has proved as controversial as it is stunning. Analysis of the skull and other remains at Dmanisi suggests that scientists have been too ready to name separate species of human ancestors in Africa. Many of those species may now have to be wiped from the textbooks.

http://www.theguardian.com/science/2013/oct/17/skull-homo-erectus-human-evolution?CMP=twt_gu

Tess wrote:I'd say, or hope, that if they were advanced enough to visit us, they'd be more civilized than that.  Could be they're keeping an eye on things at the moment - if they are they must be shaking their heads in despair!

That is the view I have Tess, but you never know I guess, and to me are waiting until we reach a higher level of understanding, of which in my view the world is way off from achieving this yet

Transfer of Hereditary Information, the Error Threshold, and Eigen's Paradox
Inheritance Requires Information Transfer
Evolution is essentially a process of trial and error. Within a population of organisms, variations can occur between the characteristics of different organisms. When a variation occurs that is beneficial to an organism in some way, it will tend to have more offspring than organisms without the variation. The variation is inherited by the organism's offspring, which will also tend to have more offspring themselves. As a result of this process of natural selection, the variation can soon become prevalent in the population.
In order for this process to work, it is essential that child organisms should inherit their parents' characteristics. Otherwise any beneficial characteristic 'discovered' by the process of trial and error would be lost when the organism in which the characteristic manifested itself died.
Inheritance of characteristics from one generation to the next involves information transfer; a parent must pass information about its characteristics to its children in order for those characteristics to be inherited. The information received by the child must be accurate, otherwise characteristics will not be properly inherited, and the characteristics of offspring will 'drift away' from those of their parents, with the effect that beneficial characteristics will be lost.
The Error Threshold
In contemporary organisms, most of the information transferred between generations in relation to inherited characteristics is carried by DNA and RNA molecules.
These organisms use sophisticated error correction mechanisms involving multiple enzymes to ensure that information is transferred accurately when replication occurs. The effectiveness of these correction mechanisms is such that in the E. coli bacterium, the mutation rate is in the region of 5 x 10^-10 mutations per base per replication. That is to say, when E. coli replicates, the probability that a particular base mutates is about one in 2 billion. Since the size of the E. coli genome is about 4.7 x 10⁶ base pairs, the chance that even a single base mutates when an E. coli replicates is very low.
Under the Genetic View of the origin of life, it is thought that early lifeforms were template replicators. These replicators would have been 'naked genes', meaning that they did not affect their environment or control a metabolism in the way that modern genes do. RNA has often been thought of as a candidate material from which naked genes could have been constructed.
RNA based naked genes would not have had the sopisticated error correction mechanisms available to contemporary organisms. It has been estimated that without error correcting mechanisms the mutation rate for an RNA based naked gene could not be less than 0.01 mutations per base per replication . For a genome consisting of N bases, the probability that there are no errors when replication takes place is:-
This means that in the case of a 100 base (RNA) naked gene, the likelihood that a replication event occurs with no errors is 0.37. For an RNA naked gene with 300 bases, the corresponding figure is 0.049. The significance of this is that without sophisticated error correction mechanisms, the size of an RNA based naked gene could not be substantially more than 100 base pairs. For larger (RNA) naked genes the effect of mutations would be that any beneficial base sequences 'discovered' by evolution would soon be 'forgotten'.
The only way to counter this 'forgetting' effect would be for the naked gene to produce a very large number of offspring, and for natural selection to weed out the majority of the mutations before they could replicate, so that the small number of correctly replicated offspring would not be swamped. Given that these naked genes are envisaged as simple replicators, rather than the carriers of information specifying and controlling a metabolism on which their survival depends, it is not plausible that a single mutation could make a large enough difference to the ability of a naked gene to replicate.
We must therefore conclude that the size of a naked gene is limited by its mutation rate. This limit is known as the Error Threshold; in the case of RNA the error threshold is about 100 bases.
The Error Threshold was first highlighted by Manfred Eigen and Peter Schuster in the 1970s. They constructed detailed models of evolution among replicating molecules such as DNA or RNA which were competing with one another and subject to fixed mutation rates per nucleotide base.
Eigen's Paradox
The error correction mechanisms that exist in contemporary organisms are extremely complex. These organisms include as part of their genomes the instructions for construction of the error correction machinery. Any such set of instructions, even for a very simple error correction mechanism, would require far more than 100 base pairs. We are thus faced with the following situation:-

• Without error correction machinery, the maximum size of a naked gene replicator is about 100 bases
  
  
  
• In order for a genome to specify an error correction machinery, it must be substantially larger than 100 bases.
  
  
  

We therefore have what appears to be a chicken and egg problem. A genome cannot be larger than 100 bases without an error correction mechanism, but in order to specify an error correction mechanism it must be substantially larger than 100 bases. This is Eigen's Paradox.

http://www.simsoup.info/Origin_Issues_XFer_Hereditary_Info.html

Never believe in science and discoveries until the facts are all in.  Scientists once said the world was flat and could prove it, in the dark ages when you ran and then touched metal it gave you magical jolt, demons were at work....nobody knew about static electricity.

Even modern day scientific findings are open to scrutiny, history shows us this.

What would be so terrible about human life springing up at virtually the same time in different places and either some dying out or merging with others?
As for alien life they would need to be more adavanced technologically but that doesn't mean they would be more altruistic, they may just be looking for resources and don't particulary care how advanced we are, we may not even register on their scale of adavanced civilisation, even insects can build communities, they may not even care how advanceda planets civilisation is provided it isn't anywhere near enough to them to give them too much trouble and what if their exploration machines are robotic and are just there to seek out resources and return it to the home world regardless of who might already own it?

Did all life originate in Africa animal and human? If it did why did various animals develop into different species and why didn't humans do the same, if it didn't and various anumals developed in various environments to fit those environments why didn't the human animal develop
in different places at similar times?

Ulrich von Liechtenstein wrote:Never believe in science and discoveries until the facts are all in.  Scientists once said the world was flat and could prove it, in the dark ages when you ran and then touched metal it gave you magical jolt, demons were at work....nobody knew about static electricity.

Even modern day scientific findings are open to scrutiny, history shows us this.

'Scientists' didn't say the world was flat; human ignorance (in the literacy sense not as a derogatory term) led to that being the assumption till what we now call science came along and proved otherwise. And yes many scientific findings are open to scrutiny, no one ever said otherwise.

Flix wrote:What would be so terrible about human life springing up at virtually the same time in different places and either some dying out or merging with others?
As for alien life they would need to be more adavanced technologically but that doesn't mean they would be more altruistic, they may just be looking for resources and don't particulary care how advanced we are, we may not even register on their scale of adavanced civilisation, even insects can build communities, they may not even care how advanceda planets civilisation is provided it isn't anywhere near enough to them to give them too much trouble and what if their exploration machines are robotic and are just there to seek out resources and return it to the home world regardless of who might already own it?

Nothing would be terrible about that, it just probably wasn't the case. Why on earth would anyone think it terrible (have I missed something)?

As for aliens, there a doubtless thousands or more inhabited planets in the Universe; some will be much more primitive than us, many more advanced; some will be altruistic, some not so much.

Flix wrote:Did all life originate in Africa animal and human? If it did why did various animals develop into different species and why didn't humans do the same, if it didn't and various anumals developed in various environments to fit those environments why didn't the human animal develop
in different places at similar times?

No all life did not originate in Africa as I am aware. Dinosaurs for instance roamed when the geography of Earth was much different and did bacteria which began life not come from the sea? Various animals did develop in different places and of course 'Neanderthal' men (not a part of the chain of evolution which led to Homo sapiens as is often misconceived) existed in Europe I think before 'we' (as in Homo sapien) arrived and wiped them out.

Homo sapiens however did evolve in Africa becoming modern humans as we know them only 200,000 years ago (VERY recent in evolutionary timescale) and then migrated first to Asia then Europe and America.

Tess wrote:I think what it does show is that, no matter how self-important and ponderous scientists are, and how they "prove facts", all it is is educated assumptions based on the evidence they have to hand at the time.  After all it wasn't so long ago in the scheme of things that they believed the Earth was flat.  I've always thought the neanderthals got a bad press, they were probably far more intelligent than they've been given credit for.

although this is not an undeniable fact as yet and many scientists still think that the multi species theory is still valid.

what is certain in this field is that nothing is certain.

the only certainty is that the "yuman" race did not evolve in several places but had a common ancestor

Neanderthals and modern humans apparently had a common ancestor which would make Neanderthals an earlier type of human that came out of Africa, they were bigger than Homo Sapiens and had a similar or larger brain case, there is evidence that modern humans outside of Africa have Neanderthal genes 1- 4% but these genes are not found in Africans and that Otzi the iceman found some years ago had a much larger percentage of Neanderthal genes.

Flix wrote:What would be so terrible about human life springing up at virtually the same time in different places and either some dying out or merging with others?
As for alien life they would need to be more adavanced technologically but that doesn't mean they would be more altruistic, they may just be looking for resources and don't particulary care how advanced we are, we may not even register on their scale of adavanced civilisation, even insects can build communities, they may not even care how advanceda planets civilisation is provided it isn't anywhere near enough to them to give them too much trouble and what if their exploration machines are robotic and are just there to seek out resources and return it to the home world regardless of who might already own it?

panspermia is the only way that alien life could be involved.

any species that could travel between the stars would be coming to stay for good as travel times are so large even at a fraction of the speed of light. It took over 40 years for voyager to leave the solar system. It will be 80000 years before it reached the next star.

yes it has been unpowered almost since it left earth. But to gain enough velocity to get to even a small fraction of the speed of light you need to carry fuel. solar sails can accelerate you but outside of a solar system provide little thrust, Ion motors can provide thrust for a long time on small volumes of fuel, but it takes many years of thrust to reach interstellar speeds. So unless they invent a warp drive visiting the stars will always be a one way trip. Whilst folding space is theoretically possible, the energy requirements for doing so make it impractical.
The best chance for reaching distant stars is a generation ship which will have to be vast in size and carry everything that is required for an eco system with it. those that leave will not be the ones that arrive.

Flix wrote:Neanderthals and modern humans apparently had a common ancestor which would make Neanderthals an earlier type of human that came out of Africa, they were bigger than Homo Sapiens and had a similar or larger brain case, there is evidence that modern humans outside of Africa have Neanderthal genes 1- 4% but these genes are not found in Africans and that Otzi the iceman found some years ago had a much larger percentage of Neanderthal genes.

Yes, but the point is Homo sapien, which we are, evolved in, and spread from, Africa.

Flix wrote:Neanderthals and modern humans apparently had a common ancestor which would make Neanderthals an earlier type of human that came out of Africa, they were bigger than Homo Sapiens and had a similar or larger brain case, there is evidence that modern humans outside of Africa have Neanderthal genes 1- 4% but these genes are not found in Africans and that Otzi the iceman found some years ago had a much larger percentage of Neanderthal genes.

different but similar species can mate. lions and tigers are a prime example.
I am sure that HS and Neanderthals did breed together as we coexisted for thousands of years.
but both species will have shared a common ancestor.

Wouldn't having different genes that are identifiable make you a sub species, which I think some schools of thought consider Neanderthals to be, therefore mixing Neanderthals genes with the next influx of humans - Homo Sapiens would make them another sub species distinct in this case from their ancestral roots in Africa who have continued along their distinct evolutionary path?

Flix wrote:Wouldn't having different genes that are identifiable make you a sub species, which I think some schools of thought consider Neanderthals to be, therefore mixing Neanderthals genes with the next influx of humans - Homo Sapiens would make them another sub species distinct in this case from their ancestral roots in Africa who have continued along their distinct evolutionary path?

wouldn't you only be a sub species if you bred true.
after all those different species of finches on the galapagos are all finches and came from a common ancestor but are now recognised as separate species/sub species.
But the point is they breed true when bred together. they evolved different beaks to cope with the different environments.

Eilzel wrote:'Scientists' didn't say the world was flat; human ignorance (in the literacy sense not as a derogatory term) led to that being the assumption till what we now call science came along and proved otherwise. And yes many scientific findings are open to scrutiny, no one ever said otherwise.

They did, maps were made at the time with corners.

Just like the scientists which said taking Thalidomide was perfectly safe.

Just like science said that the ink used on certain food cartons is safe....oh wait a minuendo....it causes cancer.

Let's have a looksee at the gospel of Science, five things which science got wrong:

1: The Circulatory System
You don't have to be a doctor to know how important the heart is…but back in ancient Greece, you could be a doctor and STILL have no idea how important the heart is. Back then, doctors like second-century Greek physician Galen believed (no kidding) that the liver (not the heart) circulated blood (along with some bile and phlegm), while the heart (really) circulated "vital spirit"(whatever that is).
How could they be so wrong? It gets worse. Galen hypothesized that the blood moved in a back-and-forth motion and was consumed by the organs as fuel. What's more, these ideas stuck around for a very long time. How long? It wasn't until 1628 that English physician William Harvey let us in on our heart's big secret. His "An Anatomical Study of the Motion of the Heart and of the Blood in Animals" took a while to catch on, but a few hundred years later, it seems beyond common sense -- perhaps the ultimate compliment for a scientific idea.

2: The Earth Is the Center of the Universe
Chalk it up to humanity's collectively huge ego. Second-century astronomer Ptolemy's (blatantly wrong) Earth-centered model of the solar system didn't just stay in vogue for 20 or 30 years; it stuck around for a millennium and then some.
It wasn't until almost 1,400 years later that Copernicus published his heliocentric (sun-centered) model in 1543. Copernicus wasn't the first to suggest that the we orbited the sun, but his theory was the first to gain traction.
Ninety years after its publication, the Catholic Church was still clinging to the idea that we were at the center of it all and duking it out with Galileo over his defense of the Copernican view. Old habits die hard.

3: Germs in Surgery
Laugh or cry (take your pick), but up until the late 19th century, doctors didn't really see the need to wash their hands before picking up a scalpel.
The result? A lot of gangrene. Most early-19th century doctors tended to attribute contagion to "bad air" and blamed disease on imbalances of the "four humors" (that's blood, phlegm, yellow bile and black bile, in case you weren't familiar).
"Germ theory" (the revolutionary idea that germs cause disease) had been around for a while, but it wasn't till Louis Pasteur got behind it in the 1860s that people started listening. It took a while, but doctors like Joseph Lister eventually connected the dots and realized that hospitals and doctors had the potential to pass on life-threatening germs to patients.
Lister went on to pioneer the idea of actually cleaning wounds and using disinfectant. Remember him next time you reach for the Purell.


4: DNA: Not So Important
DNA was discovered in 1869, but for a long time, it was kind of the unappreciated assistant: doing all the work with none of the credit, always overshadowed by its flashier protein counterparts.
Even after experiments in the middle part of the 20th century offered proof that DNA was indeed the genetic material, many scientists held firmly that proteins, not DNA, were the key to heredity. DNA, they thought, was just too simple to carry so much information.
It wasn't until Watson and Crick published their all-important double-helical model of the structure of DNA in 1953 that biologists finally started to understand how such a simple molecule could do so much. Perhaps they were confusing simplicity with elegance.

5: The Atom Is the Smallest Particle in Existence
Believe it or not, we weren't actually all that stupid in ancient times. The idea that matter was composed of smaller, individual units (atoms) has been around for thousands of years -- but the idea that there was something smaller than that was a bit harder to come by.
It wasn't until the early 20th century, when physicists like J.J. Thompson, Ernest Rutherford, James Chadwick and Neils Bohr came along, that we started to sort out the basics of particle physics: protons, neutrons and electrons and how they make an atom what it is. Since then, we've come a long way: on to charmed quarks and Higgs bosons, anti-electrons and muon neutrinos. Let's hope it doesn't get too much more complicated than that.

Alcubierre drive

The Alcubierre drive or Alcubierre metric (referring to metric tensor) is a speculative idea based on a solution of Einstein's field equations in general relativity as proposed by theoretical physicist Miguel Alcubierre, by which a spacecraft could achieve faster-than-light travel if negative mass existed. Rather than exceeding the speed of light within its local frame of reference, a spacecraft would traverse distances by contracting space in front of it and expanding space behind it, resulting in effective faster-than-light travel.

ALLAKAKA wrote:
  Yo Nigga.

Yo, homie, wassup?

Morning folks. What we must bear in mind is that science, like everything else, is a learning process using whatever analytical means are available. A prime example is Galileo. 500 years ago he postulated, (or discovered) the Earth went round the sun and we were not the centre of everything. As you know he was placed under house arrest for the remainder of his life. But, let's press on: Science today is using whatever techniques and current knowledge is available, thus we have various speculations as to where we Homo Sapiens originated. Because most of the fossils have been found In Africa, early humanoid and later transitions, thus it is believed that was the home of mankind. A couple of you have mentioned Neanderthals, a prime example for deductions at a given time. Some years ago they were believed to have been a rather brutish species, but it has been proved they were very family and community orientated, even burying their dead. The modern assessment is they were a kind, caring people, not the brutes portrayed by the Victorians. Indeed, as one of you said, we modern humans posses upwards of 3 to 5% of Neanderthal DNA. Because of this it is now believed that we didn't wipe them out aggressively, but by intermingling and mating.
 
The point I'm making is that we only know what we know at any given time, by using whatever means are available at that given time. I hope all that helps to put some of this discussion into perspective.

stardesk wrote:Morning folks. What we must bear in mind is that science, like everything else, is a learning process using whatever analytical means are available. A prime example is Galileo. 500 years ago he postulated, (or discovered) the Earth went round the sun and we were not the centre of everything. As you know he was placed under house arrest for the remainder of his life. But, let's press on: Science today is using whatever techniques and current knowledge is available, thus we have various speculations as to where we Homo Sapiens originated. Because most of the fossils have been found In Africa, early humanoid and later transitions, thus it is believed that was the home of mankind. A couple of you have mentioned Neanderthals, a prime example for deductions at a given time. Some years ago they were believed to have been a rather brutish species, but it has been proved they were very family and community orientated, even burying their dead. The modern assessment is they were a kind, caring people, not the brutes portrayed by the Victorians. Indeed, as one of you said, we modern humans posses upwards of 3 to 5% of Neanderthal DNA. Because of this it is now believed that we didn't wipe them out aggressively, but by intermingling and mating.
 
I hope all that helps to put some of this discussion into perspective.

Exactly.  Science is good...but it is not infallible.  Remember a few years ago when dinosaurs stopped being reptilian and suddenly became the forerunner of birds.

Good morning, Ulrich. I'll answer that in a minute, I'm looking for a picture to post here, of a dinosaur to bird transitional stage. Be back shortly.

Caudipteryx zoui (life-sized reconstruction). Based on fossils from China. Early Cretaceous, 130 - 125 million years ago.
Illustrator:James ReeceRights:© Australian Museum
Additional information
Caudipteryx means 'tail wing', referring to the tail plume that this non-avian dinosaurs may have fanned out for display. The rest of the body was covered in short primitive feathers with longer feathers on its arms and tail.

As you can see, at the ends of the wings/arms there are claws which demonstrate the transition from forelegs legs to wings.

stardesk wrote:
Caudipteryx zoui (life-sized reconstruction). Based on fossils from China. Early Cretaceous, 130 - 125 million years ago.
Illustrator:James ReeceRights:© Australian Museum
Additional information
Caudipteryx means 'tail wing', referring to the tail plume that this non-avian dinosaurs may have fanned out for display. The rest of the body was covered in short primitive feathers with longer feathers on its arms and tail.

As you can see, at the ends of the wings/arms there are claws which demonstrate the transition from forelegs legs to wings.

Wonder what made some dinosaurs morph into birds.  Maybe in a few millenia humans will grow feathers!  Who'd need Ryanair then?  Although I imagine the people of Ireland will grow gills and turn into humanoid fish.