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Xin Yu
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Emeryville, CA, USA
Jan 1970
time: 21:28
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I love forum discussion! Topics are always changed after several pages. Now where are we?
Evolution in microscopic manner has no problem with me. That's the way we survive. For example, germs develop resistence pretty quickly and new variations emerge after being attacked by antibiotics.
However evoluting from one species to another is in question.
First there is lack of evidence for such an evolution. There are thousands of species being observed constantly, why haven't we seen an example of one species morphing into another? You may argue that evolution takes several generations to be accomplished, but for some species, one generation is just several hours to several days, so that is not an excuse.
Second, the evolution theory does not consider the side effect of a gene change -- deficits (i.e., mental retardness, lack of ability to bear children, etc.). Do you expect a clear cut change from one type of gene to another? That may not happen in real world. Deficits will appear. And what happens when a child is born with deficits? It will be abandoned or killed and never get a chance to retain its new gene.
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Immortal Wombat
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in perpetuity
Dec 2000
time: 05:28
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quote:
Originally posted by Xin Yu
First there is lack of evidence for such an evolution. There are thousands of species being observed constantly, why haven't we seen an example of one species morphing into another? You may argue that evolution takes several generations to be accomplished, but for some species, one generation is just several hours to several days, so that is not an excuse. |
Firstly: species don't "morph" into another, they usually diverge into two or more species by whatever means, and the change is very slow. Secondly: "several" can mean hundreds, thousands. Even thousands of fly generations is a considerable amount of time, and when under observation, there is seldom a strong selective pressure acting - people generally want their objects of study to stay alive as they are.
It is likely that organisms with shorter generations have more conserved genes, since selective pressure from predators operates on a much less immediate level. Example: If it takes 5 years for a generation of aarvark to come up with a more efficient way of eating ants, there isn't any reason for ants to be selected for avoiding the new technique. There won't be any change in the ant gene pool until the new aarvark gene becomes widespread.
I can't offhand think of many animal species we have seen diverge before our eyes - there are certainly bacteria that have changed (although the species definition doesn't really work for bacteria), there are probably insects or fish. Plant species frequently arise from polyploidy events, though again the exact defintion of 'species' is looser. It would be a fun experiment to try to produce two different species of some insect. Anything bigger than an insect and time becomes a very very good excuse as to why we haven't seen a precise speciation event.
quote:
Second, the evolution theory does not consider the side effect of a gene change -- deficits (i.e., mental retardness, lack of ability to bear children, etc.). Do you expect a clear cut change from one type of gene to another? That may not happen in real world. Deficits will appear. And what happens when a child is born with deficits? It will be abandoned or killed and never get a chance to retain its new gene. |
That's the entire point of natural selection  Individuals with disadvantageous mutations die out before reproducing, individuals with advantageous mutations survive to reproduce better.
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Boris Godunov
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Portland, OR
Aug 2001
time: 00:28
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quote:
Originally posted by Xin Yu
Evolution in microscopic manner has no problem with me. That's the way we survive. For example, germs develop resistence pretty quickly and new variations emerge after being attacked by antibiotics. |
If you accept such "microevolution," then you have no logical grounds on which to reject "macroevolution." The difference is of scale, nothing more:
http://www.talkorigins.org/faqs/macroevolution.html
"There is no difference between micro- and macroevolution except that genes between species usually diverge, while genes within species usually combine. The same processes that cause within-species evolution are responsible for above-species evolution, except that the processes that cause speciation include things that cannot happen to lesser groups, such as the evolution of different sexual apparatus (because, by definition, once organisms cannot interbreed, they are different species).
The idea that the origin of higher taxa, such as genera (canines versus felines, for example), requires something special is based on the misunderstanding of the way in which new phyla (lineages) arise. The two species that are the origin of canines and felines probably differed very little from their common ancestral species and each other. But once they were reproductively isolated from each other, they evolved more and more differences that they shared but the other lineages didn't. This is true of all lineages back to the first eukaryotic (nuclear) cell. Even the changes in the Cambrian explosion are of this kind, although some (eg, Gould 1989) think that the genomes (gene structures) of these early animals were not as tightly regulated as modern animals, and therefore had more freedom to change."
quote:
First there is lack of evidence for such an evolution. There are thousands of species being observed constantly, why haven't we seen an example of one species morphing into another? You may argue that evolution takes several generations to be accomplished, but for some species, one generation is just several hours to several days, so that is not an excuse. |
It is amazing to me that Creationists routinely assert things which are blatantly not true. We have indeed observed speciation:
http://www.talkorigins.org/faqs/comdesc/
http://www.talkorigins.org/faqs/faq-speciation.html
http://www.talkorigins.org/faqs/speciation.html
quote:
Second, the evolution theory does not consider the side effect of a gene change -- deficits (i.e., mental retardness, lack of ability to bear children, etc.). Do you expect a clear cut change from one type of gene to another? That may not happen in real world. Deficits will appear. And what happens when a child is born with deficits? It will be abandoned or killed and never get a chance to retain its new gene. |
Evolution certainly does consider such things. You again make sweeping claims when, in fact, you don't know what you're talking about.
http://www.talkorigins.org/faqs/mutations.html
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germanos
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behind a firm ****, Rotterdam, NL
Apr 2002
time: 06:28
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quote:
Originally posted by Xin Yu
If Darwin's evolution theory was correct, then we should have already used the full potential of our brains and bodies.
However there are theories saying that we only used 10% of our brains. Examples of people releasing brain and body power under emergency were not rare.
One of the two theories must be wrong.
I think darwin was wrong and we were created, what do you think? |
I think the theory on the 10% use of our brain is wrong. It's more likely the scientists have not been able to detect/determine what the other 90% does.
Likewise: why would God create an 90% disfunctionate brain?
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trev
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Adelaide, Australia
Feb 2003
time: 14:58
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quote:
God has never sanctioned vilence as a means for spreading his gospel and crushing opposition. If you wish to oppose my statement, use genuine examples only please. |
Once again despite my pleas that genuine examples be used, only those that do not fit my statement are used as 'counterexamples'. The gospel is the good news that is preached about Jesus life, death and resurrection, and the availability of forgiveness offered by God, this relates to times since the death of Jesus Christ only, not the examples people are giving from the Old Testament. God has never sanctioned the use of force to spread Christianity or to defend it.
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Mordoch
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Denver, Colorado
Jan 2002
time: 05:28
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quote:
Originally posted by Xin Yu
Second, the evolution theory does not consider the side effect of a gene change -- deficits (i.e., mental retardness, lack of ability to bear children, etc.). Do you expect a clear cut change from one type of gene to another? That may not happen in real world. Deficits will appear. And what happens when a child is born with deficits? It will be abandoned or killed and never get a chance to retain its new gene. |
The reality is you don't understand how evolution works. Obviously there are cases where mutations make an animal sterile, but these are fairly rare. Mutations frequently are not advantagious, and are therefore generally not passed on. What happens is there are rare mutations which are simply outright advantagious and provide and evolutionary advantage and get passed on, or a change to the animal's natural enviroment makes a mutation or trait that would previously be a disadvantage is suddenly an advantage.
An example of this phenomenon occuring is with the red-bellied black snake of Australia.
quote:
The toxic cane toad has placed evolutionary pressure on snakes to adapt their body shape, Australian researchers say.
Evolutionary biologist Ben Phillips and PhD supervisor Professor Richard Shine of the University of Sydney say some snakes have grown longer, an adaptation that makes them better able to survive their toxic meal.
The changes in body length, which have arisen in the past 70 or so years since the cane toad was introduced to Australia, were reported today online ahead of print publication in the journal Proceedings of the National Academy of Sciences.
"I'm particularly interested in evolutionary biology and from that perspective, cane toads represent a really strong selective force," Phillips told ABC Science Online.
Cane toads (Bufo marinus) were first introduced to Australia in 1935 to eat sugar cane beetles.
But Phillips said little was known about how the toads affected native animals that tried to eat them.
A large gland on the toad's shoulder is packed with potent cardiac toxins and most species of Australian snake die after trying to eat the toad, he said.
In previous research, Phillips sampled snakes from around Australia and found the cane toad toxin did not affect all snakes the same way.
He found that larger snakes were less affected by toad toxin. In particular, the snakes with the larger ratio of body-length to head-size were less affected.
The bigger a snake, the smaller its head is compared to its overall body length. And since the size of a snake's head limits the size of its prey, this means a larger snake is less likely to eat a large enough toad to poison it, said Phillips.
Phillips thought snakes might actually have evolved their body shape in response to exposure to cane toads.
To test his theory he looked at how four species of snake in Queensland changed over time, before and after cane toads were introduced into their area.
He studied 600 preserved specimens dating back to the beginning of the last century from the Queensland Museum.
He predicted that two of the four species, Pseudechis porphyriacus (red-bellied black snake) and Dendrelaphis punctulatus (green tree snake), were highly sensitive to toad toxin.
He thought the other two, Hemiaspis signata (swamp snake) and Tropidonophis mairii (keelback snake), would not be.
Over the 70 odd years since cane toads invaded, Phillips found the sensitive snakes got longer by around 3-5%, while the other two snakes didn't change length.
Phillips said the fact that morphology, such as arm, leg and toe length, is generally inherited, and the finding that only the sensitive snakes got longer, supported his theory.
"It probably means the impact of toads has been slightly reduced through time as a consequence of snakes evolving in response to them."
He said researchers did not often see such rapid evolution.
"I think part of that reason is that there's an idea amongst biologists that evolution takes a long time and so people tend not to look for it in short time-scales," he said.
But he suspected rapid evolutionary changes were more common than scientists thought.
"It may be a force that's ameliorating conservation concern impacts like invasive species."
Phillips said cane toads were still marching across the north of Australia and will have reached the Western Australia border by the end of 2005. |
http://www.abc.net.au/science/news/...ish_1250708.htm
Prior to the appearence of the toxic cane toad on Australia, the snake having a smaller head in relation to its body size was a harmful trait. This means after all the it can't swallow the same size prey that other snakes it size would eat. However when it prevented it from being able to swallow a toxic cane toad that would have killed it, this trait becomes a lifesaver and gets passed on to the next generation while the big mouthed Red-bellied Black Snakes died far more frequently.
Over the longterm, its likely that Red-bellied Black Snakes less sensative to the cane toad poison will evolve since those harmed the least by the poison have a better chance of surviving a reproducing. At this point you will have multiple major differences in the Snake's traits from its ancestors. If you have another population of Red-bellied Black Snakes geographically issolated on another island without toxic cane toads on the island, assuming both group's survival, they will eventually become so genetically different as to become seperate species. The rate the two groups become different will be magnified if additional enviromental factors are different or become different on the two islands.
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molly bloom
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Lundenwic
Oct 2001
time: 15:28
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quote:
Originally posted by Xin Yu
That does not mean I'll be persuaded. Scientific research results published and won the Nobel Price were later proved to be wrong; The world's top intellegence agency claimed that Saddam had WMD and later proved to be wrong. So don't expect me to believe something posted on the web  |
The difference of course is that Linus Pauling, Crick and Watson and Alexander Fleming's 'believers' and 'followers' do not then go about slaying anyone who doesn't 'believe' in the 'true' account of D.N.A. or the efficacy of penicillin. Also these scientific discoveries and theories aren't pulled out of the equivalent of a scientific top hat.
And of course, unlike the Immaculate Conception, transubstantiation, biblical creation and metempsychosis, scientific theories may be tested to destruction.
See, Darwin worked with physical evidence unlike the monks who tried to work out how many angels could fit on the head of a pin, or whether the body of Mary was free from original sin, et cetera, et cetera.
Similarly, geologists don't go to the Bible, like Archbishop Ussher, and add up the dates and years therein to find the age of the earth.
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28-01-2005 21:11
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