h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

A couple of questions that have occupied my mind of recent, and I wondered what the rest of the community thought.

Given that no evidence for the "missing links" of evolutionary theory have ever been found, and that Darwin himself had grave doubts whether this evidence would ever be found, and that only completely formed animal fossils have been found - i.e., no intermediary species in the fossil record, shouldn't it be time that science modifies it's views on evolution? Some would argue that most of the theory of evolution is wrong and that there is no evidence to support it.

They have been searching for the evidence for over a century and so far nothing has been found (although it may be the case that a 100 years isn't very long at all and there are a lot of places to look!). Science has been wrong on many counts when it comes to the prehistoric past. One thing Scientists can't explain is the sudden explosion of life on this planet in a very (geologically) short time.

The other thing is how long has modern man been around? Orthodox science say around 1.5 or 2 million years or so, but archaeologists are constantly finding evidence that shows modern man to have been around at least 40 million years ago but this evidence is either kept locked away in museum basements or has been destroyed (as happened to one unlucky American archaeologist).

Does anyone else have any thoughts on the above?

Depends what you mean by a "missing link" - there have been many 'intermediate' stages found between the early primates and homo sapiens, the other point is that due to the specific conditions required for fossilisation, a minute percentage of living creatures were fossilised, and we've found just a minute percentage of those few creatures...

As to the last paragraph of your posting - I must admit that as I've never heard of this particular phenomenon then it does sound a little like a typical 'conspiracy theory' - do you have any links to back it up? (Not trying to offend you in any way, it's just I've never heard of what you're stating before)

Missing links have been found - archaeopteryx for instance - but that then needs two other fossils to fill in the missing part between lizard/archaeopteryx and the part between archaeopteryx/modern birds, and people who do not, cannot, will not believe in evolution will always point out the missing parts. There are fossils and remains of horses showing the evolution of the hooves from toes as the climate changed their habitats from forests to plains.

The trouble being that fossils are rare - only a tiny, tiny part of any population will end up fossilised (the rest are recylced) - and the transition animals (the best to show evolution) into new habitats are normally only extant in a small period of time before they are replaced by better adapted animals.

So to say that nothing has been found is misleading, plenty has been found, but each time doubters need the next two fossils as the 'missing links'. The sudden explosion of life is hard one. The thoery goes that this occurs after a holocaust activity, when competition is at an all time low - allowing large amounts of the survivors to blossom and then adapt into various different forms.

As for modern man being around for longer than generally supposed, I do not know of any evidence and so will not comment. Hope this helps and that you have not just come out from underneath a bridge Until later...
BCNU - Crescent

bugger, took too long to compose a response Until later...
BCNU - Crescent

i have absolutely nothing to add but like the topic

Modern man older than 40 Million years? No chance.
Modern man is 100,000 years old approx. Given that the average species lifetime is generally thought to be around 3 million years, we are still babies really.

However, the human family tree, going back to the autralopithecus(sp!) and others or further can be traced back to, I believe, 40 million years or even back to the original branch which separated great apes from the monkeys (no, not the band!) which was 54.8 to 33.7 million years ago it is thought.

So no evidence there. But no chance of modern man existing that far back.

As for intermediary fossils, there are several of these. Including ones from when the first animals crawled onto land. Don't forget, also, there are thousands of fossilised bits that are still uncatalogued. Or catalogued incorrectly.

For interest I found this:-

"The Genus Homo appears first around 1,800,000 years ago. The species Homo sapiens appears first around 500,000-300,000 years ago. The subspecies Homo sapiens sapiens appears first around 150,000 years ago. "
here:
http://hypertextbook.com/facts/1997/TroyHolder.shtml
also this
http://www.pbs.org/wgbh/evolution/humans/humankind/o.html
which gives the oldest direct human relative as 6 million years ago.

which is neither evidence for or against but thought I should set the accepted line for the age of various species.

Outside fossils, which as previously said, only form under very particular and in essence unusual conditions, comparative and evolutionary genetics has a lot to add in terms of 'missing links', in the genetic record of evolution, and through examining the genomes of living species, especially in prokaryotes, and single celled organisms, the evolution of such things can be fairly well accounted for, in all its intermediate stages.
One thing to remember, (if I'm remembering correctly), is that 'intermediate stages', or the 'mising links' in evolution are inevitably 'intermediate' stages between, say as an example mentioned, between lizzard/reptile and bird, as intermediate stages in chemical reactions, many such intermediate stages are not themselves long lived as 'species', or 'subspecies', being, in essence, like the intermediates in a chemical reaction 'unstable'. Which I guess in evolutionary terms means that 'intermediate' stages, or 'transition' stages between Non-bird like reptile (using same example), and 'bird like reptile', inevitably don't last long, giving less chance for preservation in the fossil records.
Simularly, there are plenty of examples of 'missing links', in things such as 'systems' of organisms; take the example of the circulatory system, in man, and mammels, a four chambred heart, large division of 'work' within it, specialised tissues and sections in it to achieve this, complicated (relitivly speaking) double circulation off to lungs, and systemic circulation, 'intermediate' stages can be seen in three chambred hearts, and more primitivly two chambred hearts, and the single chambred 'pumping organ'/heart in even more primitive organisms...

One of the things that genetics and dna studies also shows is the vast amount of similarity between the various species. The one that always gets me as being astoundingly odd is that most plants have the genes to code for haemoglobin. But haemoglobin is only of use in us red blooded animals, plants have no use for it, so how come they have the genes to code for it?

There has been some transitory fossils found. But as mentioned, the problem is then people just want a fossil between those two. And if one is found, they want a fossil between that and the middle fossil. There's no pleasing some people.

As for evidence of Man being older than a few million years, there are a few oddities yes. But some of them are hoaxes as well, like the Paluxy River prints. Or misinterpretation. I don't think there is enough to prove that Man is older that he's supposed to be.

I must agree that there are some things that I don't quite see howthe current theories of evolution can explain, but at the same time it seems obvious that whatever has happened it must be something very similar to evolution.

what function does haemoglobin carry out in our blood?

sorry, but i'm not too up on biology

I don't have any links to evidence. I shall explain - I have been doing a lot of reading recent, due to being off work, most archaeological works.

There was a site in the USA - a northern state (I'm at work and the info is at home), that a very respected American archaeologist was excavating. He came across some anomalies - tools and human bones in a section of rock he dated at something like 2 millions years ago. Naturally he thought that this cannot be correct, but over some time he had over 100 geologists come and date the rock - they all dated it to over 2 million years old and yet the bones and artifacts he found belonged to modern man - homo sapiens. He still couldn't figure out what these artifacts and bones were doing in that strata. Anyway when he tried to publish his findings he couldn't find anyone who would - except one museum director. The archaeologist's career was destroyed, his work rubbished and buried (so to speak) and the site was allowed to be built over. And the museum director lost his job.

I shall have to find out the names and dates, etc., at home and let you know.

I'm not into conspiracy theories - believing 99% of them to be rubbish or coincidences at best. But science has got things drastically wrong before and it wouldn't surprise me if they got it wrong again with this?

I do find it an interesting area but what the truth is - only time will tell.

*preview before posting.....
Continueing.... With the say example of the heart, 'intermediates', or 'missing links', would be, I guess most people would pressume, to find fossils, or examples of organisms, with 1.5 chambred hearts, 2.5 chambred hearts etc.... Obviously no such things ever existed, I'd hazzard a guess, that a plausible way in which a organism could move from a 1 chambred heart/pumping organ, to a 2 chambred heart might be duplication of teh gene encoding production/growth of the muscle of the chambre/organ, so it wouldn't happen in 'gradual' change from 1 to 2 chambres, through 'intermediate' stages, as there can't be intermediate stages, this doesn't go against the idea of evolution, it supports natural selection, as organisms with the 'mutation' that would result in a 2 chambred heart would have selective advantages of 'fitness' against its 1 chambred heart peers. Darwin himself had to 'dum down' 'Origion of the species' when he published the book; the population at the time were not read to accept 'rapid' change, so hence the 'gradual change' and all that..... In some respects it is gradual change; when looking at over 'evolutionary periods', which are pretty long in the main but the actual points at which a species changes/evolves, are typically over short periods within this longer evolutionary period; just look at the much-quoted 'peppered moth', or whateve the stupid damn thing is called...... You know, the one which was mainly light coloured, then the industrial revolution resulted in lots of soot, dark buildings/trees covered in soot, the light colour made it visable to preditors, so it was eaten up, yum, yum, beats McD I guess... Anyhow, as within any population, there were mutations, resulting in a darker coloured version, which thrived better in teh new conditions created by the industrial revolution, within a relitivly short period, this phenotype of darker colouration came to predominate, as it had a selective advantage against its lighter coloured comrads... Previously of course, when there weren't no big industrial factorys kicking out soot, it was at a disadvantage, on the clean, non-darkened-by-soot environment, and the lighter species predominated as it possed the selective advantage.....
However, what with the clean air act and such like, the situeation eventually changed, and the soot wasn't so much a problem, then the lighter coloured species had the selective advantage and came to predominate and teh darker coloured phenotype bit the dust so to speak.... I really should dig out some of my genetics books if I've still got them

Wulfric, there is a HUGE amount of evidence for evolution. The examples listed above are just a small fraction of the total. Among mammals there is fossil evidence for the evolution of antelopes, bovines (cattle to you and me), cats n dogs and many more. Whales, for example, have a very clear sequence of fossils showing the transition from land-based to water-based living. The theory of punctuated equilibrium states that evolution does not happen at a constant, slow rate in geological terms, but tends to stay still and then move geologically rather quickly so it is very unlikely we will find any 'intermediate' species at all. Anyway talking about intermediate species; Archeopteryx is basically a dinosaur with wings! How more intermediate can you get between dinosaurs and birds. Another point is, how would we know if a species which lived millions of years ago was an intermediate between two longer lived species which are either undiscovered or only known from fossils in a different time or location?
Secondly, given the moral outrage the theory of evolution causes among the religious right in the US, don't you think if they had any scientific evidence to refute evolution they would use it and publish it. I think most scientists are honest enough to accept strong evidence which contradicts current theories. Unfortunately, the 'evidence' which contradicts evolution is usually from a source which has an agenda against the view of Earth's history which evolution forces us to acknowledge.

haemoglobin is, I believe, the stuff in your blood that carries the oxygen. It latches onto oxygen as it goes through the lungs and then dumps it where needed. However, haemoglobin is not just attracted to oxygen, and this is why carbon monoxide kills so effectivly which is that it also bonds to haemoglobin, but doesn;t unbond. So once you start breathing carbon monoxide and it latches onto your haemoglobin, your ability to take oxygen out of the air decreases thus causing suffocation.
I think anyway.
And apparently it does have a use in certain plants, I don;t fully understand the document i read (all about symbiotic associations between Rhizobium or Frankia and legume or non-legume hosts - which is greek to me!) but it does seem to imply that these plants use haemoglobin to extract nitrogen, although it reckons this is a specialised adaptation. So haemoglobin seems to be a generic gas carrier. Which would point to the origins of haemoglobin being before animals and plants split off frome ach other. it is in other plants too.

Not much to add to what has already been said, but two points worth mentioning.

Firstly, animals and plants didn't split off from each other, but developed separately (as did the fungi) from the eukaryotes (single celled organisms with the nucleus enclosed in a membrane).

Secondly, although there are of course many things still to be explained imagine the situation if evolution was discarded. With no intellectual framework to explain the existence of life as we know it *everything* about life would become unexplained. Evolution won't be discarded unless someone comes up with a better scientific explanation for all the things evolution already explains *and* offers a better a chance of explaining the rest.

Noggin

My understanding is that evolution became by far the most likely mechanism after DNA was discovered in the 1950's. Animals closely related to each other had similar DNA structures, while animals far-removed from each other showed greater differences in DNA. Even so, all living things have many similarities in their DNA sequences. You can't explain this through statistical chance, but you certainly can if you assume that all living things are related. Another interesting thing is that DNA is so full of useless rubbish, which goes against the idea of a designer being involved.

Now with advances genetic engineering, the mechanism of evolution can be seen in front of our eyes, so its funny that there still is such a vehement reaction against it. It's flat-earth stuff, really.

Woodpigeon

Let's see:

"Missing Links" - does anybody seriously use this term? Every fossil found is an "intermediate form" between something and something else.

"only completely formed animal fossils have been found" - What's an incompletely formed animal (other than dead before it gets past the embryo)?

"Some would argue that most of the theory of evolution is wrong and that there is no evidence to support it." - Some would argue that the world is flat and France doesn't exist. Evolutionary theory is constantly be modified in its details -- that's science. It is important to remember that the "theory of evolution" is thousands of years older than Darwin, just as the "theory of a round Earth" is older than Columbus. The only new bit that came with Darwin was the "natural selection" bit. Before Darwin it was commonly held that evolution occurred; there was some mystery about the mechanism, however.

"They have been searching for the evidence for over a century and so far nothing has been found" They have been searching for the evidence for a He11 of a lot longer than a century and the vast body of evidence has convinced a huge proportion of the educated people of each generation for centuries. I'm not sure which books you've been reading, Wulfric, that have told you this lie about the lack of evidence.

"archaeologists are constantly finding evidence that shows modern man to have been around at least 40 million years ago"

Gee, how come these constant finds don't show up in Science or Nature or Scientific American or even in that Disney rag, Discover?

I can well remember when I was very young and came to the sad realization that what seemed to be otherwise intelligent individuals chose to believe absolutely irrational things like "Dinosaurs never existed because they're not in the Bible" or "the World is Flat" or "half an eye has no selective advantage." What is even more disturbing is the fact that there are people with these irrational beliefs who go around telling lies in what pretend to be scientific works in an attempt to convert even more people to their irrationality.

I'd recommend a dose of Richard Dawkins, Wulfric.

I've read Richard Dawkins - fantastic writer.

I don't disbelieve evolution, as it seems to me to be the most reasonable explanation we've had so far. But after spending a couple of weeks off with nothing else to do but read (mainly history and archaeological books) it struck me how science is still split about evolution.

It seems a lot of scientists are looking at quantum and chaos theory to explain the discrepencies in the evolutionary theory - it then went over my head!

I'm not a scientist and will be the first to admit I don't understand a lot of science, although I enjoy reading about it. I wasn't trying to say that evolution is bunk, or that science is rubbish. I was just curious about what people thought about the discrepencies and anomalies that crop up. Can they all really be dismissed or should we be open-minded enough to admit that the theories might need altering?

Theoretical details get changed all the time, but within the broader framework that constitutes the theory of evolution; indeed, one of the reasons evolution is considered so successful is that it has suggested so many new lines of profitable enquiry over the years.

Although there are certainly gaps in our understanding and in parts of the evidence, I'm not sure that there are any discrepancies or anomalies that indicate a need to revamp the essential framework. Did you have anything specific in mind?

Noggin