|
Register | Sign In |
|
QuickSearch
Thread ▼ Details |
|
Thread Info
|
|
|
Author | Topic: where was the transition within fossil record?? [Stalled: randman] | |||||||||||||||||||||||
nwr Member Posts: 6412 From: Geneva, Illinois Joined: Member Rating: 5.3 |
I want to know if it has EVER been observed or recorded that a certain organism has EVER changed to something of a completely different kind. Such as a dog becoming a cat, or vice versa, or a transition between the two.
I doubt that this has ever been observed. The theory of evolution does not claim that this will ever occur. What it claims is that an early ancestor of cats was also an early ancestor of dogs. But that early ancestor might not have had any distinctive cat features or characteristics, nor any distinctive dog features or characteristics.
|
|||||||||||||||||||||||
nwr Member Posts: 6412 From: Geneva, Illinois Joined: Member Rating: 5.3 |
Are you telling me that evolution doesn't require that one species become another one in order to get all the different species that we observe today?
No, that is not what I am saying. Did you actually read my earlier post, and read it all the way to the end? I'll repeat, with a little more detail. The theory claims that there was an early species which was a predecessor of cats. This early species probably had no cat-like distinguishing features. That early species evolved into different species. Some of the successor species acquired cat features through a number of evolutionary steps. Other successor species acquired dog features. As you can see, I am talking about a species evolving into one or more successor species. But there is no requirement that a cat evolve into a dog.
|
|||||||||||||||||||||||
nwr Member Posts: 6412 From: Geneva, Illinois Joined: Member Rating: 5.3 |
Apparently not, because, as I stated earlier, you would have realized that I was not trying to use an exact example from evolutionary theory, I was simply throwing out CATS & DOGS! I don't really care that cats didn't come from dogs, or vice versa.
The same principle applies. Evolution does not claim that any modern species will evolve into any other highly different species. It claims only that there were common ancestors. I don't expect any of my children or grandchildren to resemble any of your children or grandchildren. But, as far as I can tell, we did both have a common ancestor. And I suspect that even you agree on that.
I want to see a good example as to how we have observed a similar jump to a transitional form.
Rahvin has given you some examples in Message 31.
|
|||||||||||||||||||||||
nwr Member Posts: 6412 From: Geneva, Illinois Joined: Member Rating: 5.3 |
If creation is a scientific theory, it ought to make some predictions. So what predictions does it make, and how will we test those empirically?
|
|||||||||||||||||||||||
nwr Member Posts: 6412 From: Geneva, Illinois Joined: Member Rating: 5.3 |
Hi randman
This has been expained to you before. I'm not sure why you don't get it. Here are some ways that a species can evolve:
mode 1: There is an extended period of gradual change in the environment - could be a climate change, or it could be that a food species goes extinct, some other change. The species adapts. There will be slow change as it adapts, and this will affect the population as a whole. If the population is large, there should be quite a few fossils, and a good set of transitional fossils.
There could be several variations of the second mode. In some cases the parent species might persist, while in other cases it might go extinct over a number of generations. mode 2: A small group within the species tries a new ecological niche. It could be due to a new alternative food source becoming available, or maybe the group was cut off from the main species population due to some event. The group might be only poorly adapted to this new niche, so the population of this group diminishes, and continues to diminish for several generations. There is heavy selection pressure, due to the mismatch between the group and the changed environmental niche. After several generations of this high selection pressure, the successor group that remains is better adapted, but the population is small. It will take many more generations for its population to expand to a significant size. Because the group size is small during the transition, there is a good chance of no fossilization. It is only after the successor group has become well enough adapted, and its population begins to enlarge, that the likelihood of fossilization starts to increase. Although there was slow change over many generations, most of the change happened in a very small group. In the fossil record it is likely to show up as the apparent sudden appearance of the successor species. What you are seeing in the fossil record, is that the second mode of evolution is the more common.
|
|||||||||||||||||||||||
nwr Member Posts: 6412 From: Geneva, Illinois Joined: Member Rating: 5.3 |
randman writes:
Where do I admit that? It seems you are misreading. You admit that at some point even with this type of evolutionary mode that the population will gain a significant size in adaptation. What I actually wrote and you quoted, was:
It is only after the successor group has become well enough adapted, and its population begins to enlarge, that the likelihood of fossilization starts to increase.
It isn't guaranteed that a population will ever grow large enough to have a good chance of leaving fossils. Some species occupy small niches, and never develop large populations. There could be many successive transitions during a period of low population, and later environmental changes are such that the population blooms. Gaps in the fossil record are a problem for those attempting to reconstruct natural history (see Science vs History - a source of equivocation?). It isn't a problem for the theory of evolution. ToE does not predict that there will be fossils. It only predicts that when fossils are found, they will turn out to be consistent with the theory.
The problem is that within the lines of theorized evolution, say of whale evolution, we would expect to see most of the significant new features occuring in fairly large and well-established groups, according to your scenario, but we don't.
Why would we expect this? It isn't obvious to me. Some of the new features might even be exaptions - side effects of the strong selection pressures that a small group went through. The populations of intermediate species might have been quite small, occupying narrow niches.
It is likely we would not see a fine-grained change, but no one is demanding them.
I'm glad to hear that you are not demanding them.
But we should see fossils of every major new features present in the fossil record, and we don't.
But now you are demanding them. It isn't obvious at all as to why we should expect this. The fossil record is not time lapse photography. I'm not a paleontologist. I don't have detailed knowledge of the fossil record for whales and their ancestors, so I can't comment on those kinds of specifics. Perhaps someone else will.
You theorize that small isolated groups evolved leaving no fossils, but even you admit they would eventually grow to larger groups of species.
No, I don't theorize that, as I explained above. In the case of whales, they did eventually grow to a decent population size. But many ancestral species might have remained small. And even if a large group, it isn't certain that there will be many fossils - that would likely depend on the kind of niche that they are in. The question of the history of modern whales is, technically, a question of natural history. If you think that the history has been wrongly constructed, then you should come up with an alternative and see if anybody can punch holes in your alternative history.
|
|||||||||||||||||||||||
nwr Member Posts: 6412 From: Geneva, Illinois Joined: Member Rating: 5.3 |
Gould and Etheridge proposed solutions to the fact the fossil record exhibits:
A lot of what Gould and Eldredge proposed seems to have been absorbed into what people are currently presenting as neo-Darwinism. Or at least that is my impression.
StasisSudden appearance They felt the then current gradualistic explanations did not fit well with the evidence in the fossil record.
|
|||||||||||||||||||||||
nwr Member Posts: 6412 From: Geneva, Illinois Joined: Member Rating: 5.3 |
nwr, you are correct on that, which is more evidence for my point that there were facts on the record, for decades, as far as the fossil record which evos refused to admit to, until Ethridge and Gould used those same facts to help advocate ToE models.
Most evolutionists (in the sense of those who do research in evolutionary biology) are working in genetics, biochemistry, reproductive biology. The theory of evolution is mostly derived from what is observed in these studies. The fossil record was never the basis for the theory. These evolutionists can be excused for not noticing the details of the fossil record until paleontologists pointed it out to them. That they adjusted the theory, by paying more attention to likely environmental conditions for speciation, only shows that they are concerned with evidence.
When facts were used to denigrate ToE, those same facts were denied as being true at all.
What is repeated being brought up by creationists has only a weak evidential basis and does not refute ToE. If creationists come up with solid evidence that is inconsistent with ToE, they will get a lot of attention. Thus far they have only come up with evidence that they don't even understand ToE.
|
|||||||||||||||||||||||
nwr Member Posts: 6412 From: Geneva, Illinois Joined: Member Rating: 5.3 |
randman writes:
I'm not sure what is your point here. Would you prefer that it be identified as an invisible pink unicorn? For example, if you were to look at the features that are supposedly whale-like in Pakicetus, that warranted some evos calling the fully land mammal, Pakicetus a cetacean or whale, what you find is that there were some similarities in teeth and the beginning of an expanded aural cavity. That's it. On that basis, Pakicetus is said to be a whale ancestor. Jaws and teeth have often been used in identifying fossils. Maybe the evidence was scant. The people who attempt to identify fossils have to do the best they can, even when there is only scant evidence available. As more fossils are found, the evidence will increase. That will allow more accurate classification. Perhaps the initial classification will eventually be found wrong. Scientists don't claim to be perfect. They do the best they can with the evidence available.
But let's say cladistic studies indicate a strong connection for a nested heirarchy.
You are missing the main point. This is not the major evidence for ToE. It is supporting evidence for ToE, because it is consistent with the theory. That's about it. That still does nothing to prove ToE. It could just as easily be strong evidence of Intelligent Design, or directed evolution by an Intelligent Agent. There was very strong evidence for ToE before the Pakicetus fossil was found. There is very strong evidence for ToE after the fossil was found. It would seem that the fossil isn't very important (exactly as others have been telling you in the past). The fossil is valuable for reconstructing the natural history of whales. It has little importance with respect to establishing ToE. Sure, it might be taken as evidence of ID among those who do not apply scientific standards. So what?
That's the point you fail to grasp. Your evidence or comprehensive analysis supports ID perhaps more so than ToE.
You are the one failing to grasp. Show me an actual intelligent designer in the process of designing a biological creature, and you will have the beginnings of some evidence of intelligent design. At the present the only evidence for intelligent design is in the imagination of ID proponents. By contrast, evolutionary biological processes are routinely seen. (edit: change subtitle) This message has been edited by nwr, 10-21-2005 04:15 PM
|
|||||||||||||||||||||||
nwr Member Posts: 6412 From: Geneva, Illinois Joined: Member Rating: 5.3 |
randman writes:
Do the analysis. If you can demonstrate extreme inconsistency, you should have no difficulty getting it published.
I consider the fossil evidence extremely inconsistent with ToE and very strong, hard evidence against it. However, if universal common descent were true, it would still not be evidence of ToE since the fossil evidence indicates evo theories of the emergence of species is incorrect. In other words, if common descent is true, the fossil record suggests some sort of other mechanism at work than JUST observed natural mechanisms.
That's hilarious. But I guess you don't see that it is extremely inconsistent.
|
|||||||||||||||||||||||
nwr Member Posts: 6412 From: Geneva, Illinois Joined: Member Rating: 5.3 |
Moreover, the whole nation that similarities automatically involves relatedness via common descent is just a large, and totally unproven assumption.
I don't know of any evolutionist who would disagree with that. That's why similar structures are sometimes credited to parallel evolution, rather than common descent.
|
|||||||||||||||||||||||
nwr Member Posts: 6412 From: Geneva, Illinois Joined: Member Rating: 5.3 |
randman writes:
From that, with a simple application of logic, I can only conclude that
Educated people that reject ToE understand it often far more than evos themselves,either randman does not reject ToE, or
For it is quite obvious that randman has an extremely poor understanding of ToE.randman is not educated. (edit: to change subtitle) This message has been edited by nwr, 10-23-2005 04:08 PM
|
|||||||||||||||||||||||
nwr Member Posts: 6412 From: Geneva, Illinois Joined: Member Rating: 5.3 |
quote:Wow! How could you jump to that conclusion? The spectrum was being used an an analogy. The term "color" is obviously being used here for colors of the spectrum in the analogy, not for skin colors of people. At least that seemed very obvious to me. I don't know how you could possibly see racism there.
|
|
|
Do Nothing Button
Copyright 2001-2023 by EvC Forum, All Rights Reserved
Version 4.2
Innovative software from Qwixotic © 2024