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Questions Regarding Evolution

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intaglio

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I have just read a fascinating article in Nexus about problems faced by evolutionary theory. I cannot post the article yet, they have not yet put it on their website, so selected highlights will have to do. I do not necessarily agree where the author, Lloyd Pye, is going but the questions he asks do need to be addressed.

The biggest query he throws up is the frequently quoted similarity between Chimp and Gorilla DNA to Human - 1% for Chimps, 2% for gorillas. Firstly this figure has been around since before Genome Mapping. Secondly Chimps and Gorilla DNA is arranged into 24 chromosome pairs, Human is on 23. To gloss this it is like saying that Shaw and Shakespear used the same sorts of words in their plays apart from a couple of per cent so Shaw and Shakespear are related.

Then there is the difficulty of cultivated grains. we eat grains that are larger, easier to harvest and more amenable to processing. these 3 differences are very difficult to achieve. Chromosome numbers have been increased dramatically, the stalks that hold the seeds to the stem have been strengthened, husks have been weakened. All this from grains that in the wild state are largely imossible for humans to handle.

Domestication of beasts also presents difficulties. How, for example do you tame the first aurochs? a notably vicious herbivore. Similarly wild boar.

There is a lot more and Mr pye makes a good case.

Editted in later. the original article with thanks to Itzpapalotl
 
Domestication of beasts also presents difficulties. How, for example do you tame the first aurochs?
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Ask the Masai. And what kind of bulls did they dance with at Knossos?

Similarily, ask rottweiler and jack russel breeders. Dutch tulip kwekers and rose growers. Very short periods of intensive selective breeding. Quite enough to greatly accelerate the evolutionary process.

I'm a modified Lamarkian, me.
 
It's probably worth giving this old thread a plug here.

It attacks such crucial questions as "Who first drank cows's milk" and similar vital issues!

Human ingenuity is fascinating, and given the time-scale it's had to operate in I don't find its achievements improbable. I agree with Androman about selective breeding - it doesn't take long to make big changes under artificial selection.

As for shared genes, we share half our genes with a banana! We're all on the same planet, and probably derive from a single early reproducing cell. The first one to manage this trick would quickly overwhelm any late starters - unless the late starters were superior in some significant way, and perhaps came from elsewhere, such as deep space. (I'm talking spores, viruses, etc, here, not aliens in flying saucers - but wouldn't it be somehow ironic if all life on earth had evolved from alien snot on a tissue discarded by some interstellar traveller 4 billion years ago!)
 
In response to the 'biggest query'
The difference between humans and chimps is in the DNA sequence. The differences in the chromosome numbers are caused by rearrangements of chromosomes so it is possible to have exactly the same genes but for example one less chromosome caused by two chromosomes fusing together or one extra chromosome caused by a chromosome break.
The figure of 1% was arrived at before DNA mapping by DNA hybridisation using the phenomenon that similar DNA sequences bind more strongly and so the temperature at which a mixture of two DNA samples 'melts' gives a good idea of the sequence similarity. Looking at the references for these claims would have revealed how the estimates were obtained although i suppose if the author couldn't be bothered to do this would still remain a question.
Many experiments have been conducted that show which parts of ape chromosome align with human chromosomes and the history of the rearrangements of the chromosomes in the great apes has been worked out in detail. For example it has been proved that human chromosome 2 derives from the fusion of two ape chromosomes (in the chimpanzee chromosomes 12 and 13).
To quote one paper "The karyotypes (the appearance of the chromosomes) of man and of the closely related Pongidae--chimpanzee, gorilla, and orangutan--differ by a small number of well known rearrangements, mainly pericentric inversions and one fusion which reduced the chromosome number from 48 in the Pongidae to 46 in man"
Even looking at stained chromosomes down a microscope shows that the banding patterns of human and ape chromosomes are the same for large regions. Chromosomal rearrangements of many different types are very common and would be expected to occur in two species that had diverged at some point in the past. In fact anyone who has investigated this area would have discovered this which would raise two possibilities either the author had not researched the area in any detail or knew the answers and was deliberately misleading his readers.
No one has glossed over this as the differences between apes and humans in their chromosomes has been studied in detail and the conclusions reached have been based on many experiments and detailed mapping of the chromosomes and genes. Referring back to Lloyd Pye's analogy if shaw and shakespeare for example had thousands of the same words in the same order (as in the case of many of the genes of chimps and humans) then they would be related. So in effect Pye has proved evolution!.

I dont know if it is the same article but it seems to make many of the same points:
http://www.newageuniversity.org/lloyd_essay.htm
If you want to read a paper on the history of human chromosomes 7, 16, and 19 heres a link:
http://www.genome.org/cgi/content/full/10/5/644
and human chromosome 3
http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=10618396
The paper qoted was De Grouchy J. Chromosome phylogenies of man, great apes, and Old World monkeys.
Genetica 1987 Aug 31;73(1-2):37-52
 
Thanks for the links. The Lloyd (Pye) one is indeed the Nexus article.

I see from the research papers that chromosome banding is still the primary source of comparisson of Human and great ape genes and, at the moment, only probes aimed a very small areas are being used to compare the accuracy of this banding. Fair enough until there is a more complete genome mapping of the great apes.

Even so the effects of the variation are massive and it is difficult to see a non-catastrophic evolutionary sequence that can account for these changes. Remember any weakness in the evolutionist argument will be leapt on by the opposition. Darwinism is the best we have but it does have weaknesses.
 
Even so the effects of the variation are massive and it is difficult to see a non-catastrophic evolutionary sequence that can account for these changes.
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I'm afraid I have to disagree about the massive effects. The differences are really very minor. The majority of our DNA is there to create proteins to carry out the basic biochemistry inside our cells, hence the 50% DNA share with fruit and vegetables. There is a small variation in DNA to convert a man to a mouse.

The principle change from chimp to human is:
A skull shape change (trivia),
Dentition change (more trivia),
A change of skin colour and reduction of body hair (not worth mentioning),
Significant increase in brain size (no idea how difficult this is but I don't think it is difficult to increase the size of an organ)
A botched pelvis and knee redesign (no idea how difficult this is).

The biochemistry of chimps and people is remarkably similar as we share a common omnivorous diet, this similarity is also why chimps make such good human analogues for pharmaceutical testing (no postings on this please).

The real change from chimp to human is behaviour, increased language and in the technology that we can handle. Physically everything else appears to be superficial. If you take a human away from society, technology and manners and you are basically left with a medium sized primate who is liable to sunburn.
 
you missed out a few things
Complete amendment of oestrus and hence fertility cycle
Change in the biochemistry of the musculature (try arm wrestling a chimp)
The fall of the larynx
Complete redistribution of body fat
Complete change in the method of birth
Huge extension of the juvenile phase
Replacement of fur with hair
Constant growth of hair/nails
Complete amendment of the small bone structure in hands and feet
Amendment of long bone structure
Oh yes and the fusion of 2 chromosome pairs into 1

This last case is hugely important because at that point the humans can no longer breed with the ancestors. It is very difficult to see how gradualism can account for this.

On triviality
The change in the form of the skull is not trivial if it was not changed speech, increased brain size and walking would be nigh on impossible

On Botching
The recasting of pelvis and knee are fair adaptation to upright posture. If you want a 'botched' adaptation look at the panda digestive system.
 
What is the difference between hair and fur? :confused:

I know head hair is usually different from the 'short and curlies', but are neither of the these the same as 'fur'?

I was reading something about kiwis recently (the birds, that is) and one thing it mentioned is that because they are wingless and have a ground based life-style, their feathers have changed to become more like coarse hair - or should that be fur?! :)
 
Complete amendment of oestrus and hence fertility cycle
Change in the biochemistry of the musculature (try arm wrestling a chimp)
The fall of the larynx
Complete redistribution of body fat
Complete change in the method of birth
Huge extension of the juvenile phase
Replacement of fur with hair
Constant growth of hair/nails
Complete amendment of the small bone structure in hands and feet
Amendment of long bone structure
Oh yes and the fusion of 2 chromosome pairs into 1
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I still think there's something in Elaine Morgan's theory that human evolution went through an aquatic, or at least semi-aquatic phase.

She wrote two interesting books, `The Ascent of Woman' and `The Aquatic Ape.'

Certainly would explain adipose fat distribution and semi-hairlessness. Not to forget increased brain size and swimming abilities of very young children.
 
There is also a later book by Elaine Morgan

I too find many aspects of the aquatic ape idea very interesting - it has been debated elsewhere on this board.
 
Hair and fur and water

Fur is different from hair
Fur is limited in length, it grows rapidly to a set length then falls out - hair grows slowly and continually

Fur grows several strands per follicle at the same time

That is what I know to be different, I believe - and you'll have to check me on this - that hair follicles only grow 1 hair - once it falls thats it. Fur regrows once a strand falls out.

The Aquatic ape theory helps explain a lot about how human adaptations make sense I admit. It has a problem in that amongst semi-aquatic species dense fur is more common than lack of it, only in fully aquatic species is the loss of hair characteristic. Aquatic Ape also does not explain the mechanism of change and it's this mechanism that needs examining.

Another point raises is the lack of transitional species in the fossil record. This is not surprising, they must be rare, but the lack of them, or the lack of recognition of such a specimen, for any species is difficult. Not only that but amongst the snapshot of life that we have on this planet now there appear to be no transitional species between 2 related animals.

I'm not saying evolution is wrong, I'm just saying that as we understand it, it has difficulties.
 
Intag said:
Another point raises is the lack of transitional species in the fossil record. This is not surprising, they must be rare, but the lack of them, or the lack of recognition of such a specimen, for any species is difficult. Not only that but amongst the snapshot of life that we have on this planet now there appear to be no transitional species between 2 related animals.
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I thought the whole point of the modern version of evolution ('punctuated equilibrium') is to explain this point. The idea is that generally speaking species stay as they are unless some environmental change provides pressure for natural selection to act in a different direction. The change is supposed to be relatively rapid before a new equilibrium is reached.

The times species are in equilibrium with their environment are thus much longer than the times of change, hence we rarely find 'intermediate' fossils.

Severe environmental change, however, may wipe a species out - it becomes extinct and disappears from the fossil record.

The Aquatic Ape may itself be an example of this. If this change took place during a time of rapidly rising sea-levels (after some ice-age previous to the last one, for example) it may have been only to a relatively small group of hominids who found themselves isolated by rising waters, and who were forced to look for food in the sea as other sources became unavailable.

Most of the intermediate fossils could now be underwater, and there may not have been that many preserved anyway if the group was small. Also the sea is very effective at recycling corpses, so maybe no fossils exist!
 
Also I believe evolution is the best answer so far for how animals emerged.

If you want to breed an animal i certain way all you need do is take a female and a male of the same kind you want and start breeding the characteristics out this may also happen when a species chooses to do this itself.

Take for instance the moth in birmingham their were two types of moth (no not only) a coloured species and a brown speckeled kind in the 17th century (or there abouts) the white was most common when the town became industrial the town became more sooty;)

Birds were able to spot the white moths and the brown ones were able to camouflage themselves the white are now raraer and the brown dominant.

This is fact I learnt it of a degree student doing a degree in animal management.

This is how species tend to evolve by better survival though scientists are still working on increasing discoveries into evolution this is why problems arise.
 
Speckled moth - check that one out I think that it has proved to be a mirage of evolution. Something says that about 95(?) there was a New Scientist article reporting that the dark form pre-existed the industrial age. Either that or it was found that the darker form had an environmental cause :confused:

Thats my problem I've got a wonderful memory but a hellish bad dating system.

Good point about the loss of material but I am talking about the whole of the fossil record - admittedly sparse and the all currently living animals. Punctuated evolution does not remove the need for transitional forms, I think.
 
intaglio said:
Punctuated evolution does not remove the need for transitional forms, I think.
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True, but it does reduce the expectation of finding many.

Some years ago I saw a programme on palaeontology, and someone pointed out that if all the ancient hominid remains were collected together, they'd only fill a cardboard box. [Size unspecified!]

No doubt since then the number of cardboard boxes has increased (2? 5? 10?) but the fact is we still tend to build grandiose theories (or attempt to disprove grandiose theories) on very little real evidence compared to the huge biomass which has existed in the past.
 
Yeah, I too remember reading about methodological problems with the experiments that led to the moth example being in every textbook on evolution - as I recall the guy who did them was later revealed to have been gluing moths to tree trunks, where they don't usually sit, and seeing how many got eaten. But most of the more extreme attacks on the example look to have come from the Christian right, despite scientific posturing; most scientists seem still to accept the moth story in modified form. These links givea mainstream viewpoint.

http://www.pratttribune.com/archives/index.inn?loc=detail&doc=/2000/December/13-653-news92.txt

http://www.wm.edu/biology/melanism.pdf

http://www.millerandlevine.com/km/evol/Moths/moths.html

In general a lot of the more secular and sensible critiques of evolution usually seem convincing while you're reading them, but the alternatives they propose don't. Creationism is utterly bankrupt, ID is just a flashy, jargon-heavy version of the old, discredited Argument from Design, and Lloyd Pye's Zecharia Sitchin-influenced alien theories are hard to swallow to say the least. Many of his examples certainly floor me, but I imagine trained evolutionary biologists might find them laughably simplistic. It often seems these issues are too complex for this kind of layman's argument from common sense to be really interesting. I mean, is Lloyd Pye saying 'evolution can't be true because it doesn't make sense' any more relevant or interesting than me making the same conclusion about, say, quantum mechanics simply because I happened to find it unbelievable and unintuitive? Biologists really do have potential answers to his arguments over the unprovenness/impossibility of macroevolution - answers that he either ignores or caricatures. I find Pye's writings enjoyable and stimulating but I find it hard to imagine him looking like much more than a crackpot dilletante if he actually got into a debate with, say, Richard Dawkins. Could be I'm totally wrong, of course, but I wish he'd actually engage with his targets rather than attacking what amount to straw men.
 
I did say that the moth did exist before the industrial age.

I also must add with an ever increasing population of humans a certain missing lnk could be under a sky scraper in tokyo, a house in kent or a Mcdonalds in America. And as much as humans think theyve explored the entire planet they haven't.

Most of the antarctic is under deep dense ice, never know whats under there, baron deserts the list of places archeaologists haven't dug is unimaginable.

I must admit i'm not entirely sure what your suggesting, are you under the suspision that evolution is wrong that god created the earth in seven days.

I think evolution and science only deepen god if he had made a universe with a square concrete block a sheet for the sky and a lamp for the sun how boring things would be.
 
And my old problem with evolution is, why do we stil lhave slugs and snails? 8)
 
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rynner2 said:
And my old problem with evolution is, why do we stil lhave slugs and snails?
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Did you know that snails evolved first, and modern slugs are a development from them? (Perhaps to hide in crevices which snails can't exploit?)
 
wembley9 said:
rynner2 said:
And my old problem with evolution is, why do we stil lhave slugs and snails?
Click to expand...

Did you know that snails evolved first, and modern slugs are a development from them? (Perhaps to hide in crevices which snails can't exploit?)
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Obviously, it's all about speed. Slugs discarded their shells so they could outrun...er, hold on....


...SNAILS!! So they could outrun snails.
 
Can slugs move faster than snails?
 
rynner2 said:
And my old problem with evolution is, why do we stil lhave slugs and snails? 8)
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Because, although they seem identical in lifestyle to us, they inhabit slightly different ecological niches, in the same way that although most Americans are descended from Europeans, we still have Europeans.
 
Fluttermoth said:
rynner2 said:
And my old problem with evolution is, why do we stil lhave slugs and snails? 8)
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Because, although they seem identical in lifestyle to us, they inhabit slightly different ecological niches, in the same way that although most Americans are descended from Europeans, we still have Europeans.
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:lol: :lol:
Very good.
 
But Europeans and Americans can still interbreed... 8)
 
OK then Rynner,we still have Chimpanzees, Bonobos and Gorillas; Highland and Lowland.
 
Monstrosa said:
OK then Rynner,we still have Chimpanzees, Bonobos and Gorillas; Highland and Lowland.
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Yes, but they have widely spaced geographic areas. Unlike slugs and snails,which overlap to a high degree, in our gardens!
 
rynner2 said:
Monstrosa said:
OK then Rynner,we still have Chimpanzees, Bonobos and Gorillas; Highland and Lowland.
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Yes, but they have widely spaced geographic areas. Unlike slugs and snails,which overlap to a high degree, in our gardens!
Click to expand...

But the snails can hide in their shells when they see the slugs coming.
 
Here's another puzzle in evolution, from way back when creatures began to colonize the land:

Tetrapod anatomy: Backbone back-to-front in early animals
By Rebecca Morelle, Science reporter, BBC World Service

Textbooks might have to be re-written when it comes to some of the earliest creatures, a study suggests.
Researchers have found that our understanding of the anatomy of the first four-legged animals is wrong.
New 3D models of fossil remains show that previous renderings of the position of the beasts' backbones were actually back-to-front.
The findings, published in the journal Nature, may even change our thinking on how the spine evolved.

The scientists looked at a group of animals called the tetrapods, examining three creatures called Ichthyostega, Acanthostega and Pederpes.
These primitive four-legged animals are of great interest to palaeontologists: they were the first creatures to haul themselves out of the oceans, paving the way for all future vertebrate life on land.
Studying how these animals are put together is key to understanding how they made this transition.

The researchers from the University of Cambridge and the Royal Veterinary College (RVC) used the European Synchrotron Radiation Facility (ESRF) to bombard the 360-million-year old fossils with high energy X-rays.
This enabled them to create detailed computer reconstructions of the prehistoric animals.
RVC's Prof John Hutchinson said: "Their vertebrae are actually structurally completely different from what everyone for the last 150 or so years has pictured. The textbook examples turn out to be wrong."
The scientists found that parts of the spine thought to face the front of the animal, in fact faced the back - and vice versa.
They also discovered the earliest known evidence of a breastbone in Ichthyostega.

Prof Hutchinson said the findings provided more clues about how the early animals physically moved out of the water and on to land.
An earlier paper by the same team suggested that the tetrapods dragged themselves out of the sea, using their front legs to haul the rest of their body along the ground. The new anatomical findings backed this up, Prof Hutchinson said.

The study also shed more light on how the modern backbone evolved.
He explained: "All of that anatomy [from these early land animals ] was handed down to later animals.
"It influenced the future evolution of the spine in everything on land. It tells us about our own development and why our own backbones developed they way they did."

http://www.bbc.co.uk/news/science-environment-20987289
 
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