Evolution and Increased Diversity

How could this viewed in an evolutionary context? Are you going to tell me that a single that doesn't evolve is engaged in evolution?”HM

If the allele frequencies in the population changed then it would be evolving, but if it remained as one species, then there was not an increase in biodiversity.I've come to understand biodiviersity to mean, in this thread at lease, the number of species present.Certainly, you could argue that if the allele frequency changed, then that one species would be more biodiverse. But that would be conflating definitions.From another angle:If you look at what I wrote:

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It could thrive and not evolve and not go extinct.

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That should answer your question.But if I look again at what I was replying too: Its ambiguous as what you mean by doing things evolutionarily.My reply might be "out of bounds" because it could be assuming that the species is not evolving when you have assumed that it is.But things can evolve without speciating, and bidiversity is the number of species, so as long as the bateria doesn't speciate while its allele frequency changes, it could be said to be evolving without diversifying and without going extinct.Make sense?

Well...yes...if you say so. Why can't it be numbers of genera or families? Paraphrasing what RAZD already said: 'To a single species, there's nothing less diverse than no species at all.' Sure, so long as you agree that if a species neither evolves nor goes extinct has not been engaged in that biological process we call evolution. If this doesn't make sense then I must goin' nuts!”HM

But it doesn't mean they lived in different niches either. Ambulocetus should have evolved in estuaries. Doesn't many crocodiles species also live in estuaries? Or do you suppose that crocodiles which survived K/T extinction were gentlemans and didn't filled all emptied niches (estuaries) for which they were pre-adapted? Dinosaurus were unable to hold sway in conditions which were very favourable for them. Warm-blooded mammals developed before KT extinction and probably would have won "struggle for life" with dinos regardless of empty niches, meteorites etc... I have already discussed it here. Make some research on your own if you like. Evolution is over. No new mammalian order has arisen since Eocene (except pinnipedia). I have discussed the issue in the thread "Is evolution of mammals finished?". Have a look at my introducing post if you like:http://EvC Forum: Is evolution of mammals finished? -->EvC Forum: Is evolution of mammals finished?

This has been an interesting discussion of what effects diversity.You are not welcome to jump in and start mudding the waters.If you are tired of the mimicry thread then I suggest you start another one to play in.If you mess up other threads you will get suspended for it.Edited by AdminNosy, : fix author

An increase in the number of genera or families is also an increase in the number of species, however, an increase in the number of species is not necessarily an increase in the number of genera or families. Agreed.You've basically said that if a species isn't evolving then it isn't evolving. Quite tautological.But.... heh, there's always a but I don't think its possible for a species to not be engaged in that biological process we call evolution. Imperfect replication of DNA demands that genetic mutations arrise, thereby changing the frequency of alleles, thus evolution. If the environment lacks the selective pressure for those mutations to "stick", then the species will be in stasis and could be descibed as not evolving. It sounds like I'm contradicting myself but it really boils down to the way people use the word "evolve".

I looked through the first five pages of the thread you provided the think to, and didn't find any references supporting the idea that there was a point in deep time when mammalian species diversity was higher than today, which is what: you wrote in message #51 indicates.Moreover, these papers, by John Alroy alone, just one author:Alroy, J. 2000. Successive approximations of diversity curves: ten more years in the library. Geology 28(11):1023-1026.Alroy, J. 1999. The fossil record of North American mammals: Evidence for a Paleocene evolutionary radiation. Systematic Biology 48(1):107-118.seem to flatly contradict the statement and this paper seems to indirectly suggest that the statement is false:Alroy, J. 1998. Cope's rule and the dynamics of body mass evolution in North American mammals. Science 280:731-734.Now, mammalian diversity is a long way from what I do and I could be wrong, so again, please provide substantive evidence that mammalian species diversity has been higher at points in deep time than now. We're talking about species here, not higher taxonomic ranks (which cannot be directly compared). I never said it did. You said it was obvious that they lived in the same niche based on morphological similarity and I opined that this was bull and gave my reasoning. Again, show me some actual data back up this assertion.

I suppose I adressed the issue sufficently in the introducing post of the mentioned thread. Fossils record in John Day Formation seems to support my idea.Being reprimanded I will not continue in discussion in this thread.

Actually, the .pdf you linked to in that opening post refuted that point...it didn't support it.

Sorry. Didn't intend to tax your reading ability. You're entitled to an opinion, just like anyone else, including any creationist. But unless you simply make that statement as an article of faith, it would be heplful to the rest of us if you would trouble yourself to back it up with empirical evidence and logical reasoning.
However, if you are unable to do that, I will understand. Another statement of faith. It is clear that "things [have actually been] that way", but that does not logically demonstrate that this observed development was determined, inevitable, and irresistably compelled by any causal force, be that force identified as the OEC's 'divine programming', or your 'natural selection'. To me both are equally 'metaphysical', [i.e., non-scientific], vacuities. Please show how your "NS" causes increased biodiversity, or even how it _might_ cause increased biodiversity. In the late 19th century, and on into the 1930's, it was felt that "NS" could do no such thing, and to compensate for this lacune Fisher and friends invented 'random genetic mutation',["RM"], as the basic cause of viable novel bioforms and behaviours; i.e., increased biodiversity. Evidently you have a more recent opinion, to the effect that "NS" can and does increase/cause biodiversity, and I would like to hear your reasoning for this, and to become acquainted with the empirical observations you use to support your reasoning to that conclusion. Please oblige me. IOW, no. It takes your "random mutation" to do that. [qs]

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can "Random Genetic Mutation" do that?

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No, it provides the opportunity for diversity but you need the selection to actually get the diversity.[qs] I'm afraid you'll have to explain and justify this claim, since on its face it makes no sense. Care to justify this statement of faith? I do not believe so, because if biodiversity is mechanically predetermined, as is widely supposed,
then 'adaptation', 'adaptedness', 'adaptable', and so on, add absolutely nothing to our understanding of it. 'Adaptation' depends upon an implied indeterminism, IMO, as does the whole concept of variety, diversity and difference. I would agree that it is "not stochastic", since there seem to be certain constraints upon biodiversity, and directions wrt its development, but there are many out there who insist that neither adaptation nor "NS" [nor anything else] accounts for biodiversity, but rather they avoid the issue of causation, and scientific explanation, altogether-- by proposing that change, difference, and diversity 'just happen, that's all', and 'what you get is what you get, for no particular reason'. That's what I got from the OP, but the ensuing posts do not seem to address disproving this creationist assumption, nor in demonstrating any scientific alternative. The thread is, in fact, thoroughly muddy and directionless. People are talking at and past each other without coming to grips with the actual issue--a scientific examination of biodiversity, its causes and its constraints, as opposed to the notion of biological diversity as an outcome predestined by 'god'. I would suggest that the notion of biological diversity determined by unspecified 'natural forces', aka "Natural Selection", amounts to the same metaphysical claim as 'predestination', stated in secular rather than theological fashion. If this is true, {How would I know, since you haven't told me why you think it true?}, then at least we can be assured that biodiversity is not mechanically determined. Which doesn't tell us what it is, but only what it is not. Still, if _demonstrably_ true, then at least it is a first step towards understanding. Which would make the entire concept of 'predestined' and 'determined' vacuous and useless. Edited by Elmer, : formatting errors

From Message 77: And from your last post: I'm getting dizzy. I better back off my medicine. Probably true, but hard to prove. What people? Most biologist I know of think that biological evolution is a process of change rather than a process of maintianing the staus quo.Back to RADZ's question. Does biological evolution necessarily lead to biodiversity? I think most biologists would have to say 'no'...at least for microscopic timeframes. But what still bothers me is that interesting increase of marine families since the Permian Extinction, shown in Sepkoski's graph in Message 56. Makes me want to get foolish and conclude that the last 245 million years of evolution on Earth have demonstrated a rather steady increase in biodiversity. Just coincidendal with environmental conditions and nothing more? Or an embedded law of macroevolution?One obvious thuth cannot be ignored: No environmental condition remains unchanged for very long, not in geological timesframes.”HM

Think of it this way: it happened because back then the ecology and the habitability of the planet was such that it could happen, and because it could happen there was a 50-50 chance that it would, meanwhile life muddled along evolving as it went.Enjoy.

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Its ok. Just keep in mind that number of readers of your post is inversely proportional to the difficulty of reading. This thread intends to explain how the process described in Theory of Evolution does not necessarily yield an increase in biodiversity. We are not here to debate if the ToE is, in fact, correct. We are exploring the ramifications of the theory.
I’m just reiterating what the ToE says, not making matter-of-fact statements about what must be true.Or are you saying that the ToE does not say what I said it says? I am able but unwilling. Can you understand that? Like I said, this thread does not intend to logically demonstrate the observed development. What we are doing, is discussing what the Theory of Evolution says about the observations. You don’t even have to believe that the explanations are correct to discuss them.Do you think the ToE necessitates an increase in biodiversity?That is the topic. Equally!? Wow. Hrm. I guess you are entitled to your opinions. But discussing this further is not for this topic. According to the ToE, if the environment is favorable for a trait,
that trait will become more prominent. You need the selective factor for the traits to either “stick” or “fall”. Otherwise it would be stochastic, ie from RM alone. Like I said in previous messages, RM provides the “opportunity” for the variation but it takes NS for the variation to take hold and be passed on. NS alone can’t do it, you need the RM for the source of the variation. Again, the empirical observations are unnecessary. We are just discussing what the ToE says, not if it is really true.I just explained how NS does it. Does that make sense? Any questions? RM doesn’t “do” it. RM provides for the variation, NS determines if the variation gets passed on or not, ie whether the biodiversity increases or not. Are you familiar with how the ToE describes the evolutionary process? My explanation seems pretty straight forward from the ToE to me. What is it that you don’t understand? Umm, how about no. How do they not add anything? I’m not so sure I understand what you are saying here. Could you please expand on it? That indeterminism comes from the randomness of genetic mutation. Can you explain why causation is even necessary? What do we observe that suggests some causative factor?Keep in mind:

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it would be heplful to the rest of us if you would trouble yourself to back it up with empirical evidence and logical reasoning.

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But if that scares you off then just explain to me, in your own words, what makes you think it is causative. This thread is to show that that is not what the ToE postulates. It seems to me that Hoot Man and I were moving forward with our discussion. I think we might have actually came to some grips too. AdminNosy even said the discussion was interesting. The real actual issue is that creationists have claimed that the ToE necessitates an increase in biodiversity. What this thread intends to do is explain how the ToE does not necessitate an increase in biodiversity. What the actual cause of the increase is, is not really the topic. The topic is if the ToE says that the increase must happen, which it does not. How is the claim the same, metaphysically, if it relies on only natural causes? The natural causes explained by the ToE are fairly simple. RM provides for opportunities for variation, and those opportunities are determined to stay or go by NS.If NS allows the opportunity to stick and be passed on favorable, then there will be an increase in the biodiversity. If NS selects against those opportunities, then there will not be an increase. Clearly, the ToE does not require an increase. We can just assume that the ToE is true for the purpose of this discussion. What do you mean by “mechanically determined”? What it is is “just what happens”. You said this avoids the issue of causation, but I don’t see what evidence suggests that there is a causation. Can you show me? And it is, from a scientific point of view. It is only useful for Theology or Philosophy.

RADZ, this is a nice challenge to my early morning brain. I apprerciate it. Let me try to deconstruct your argument, if I actually can do it:1. You are saying that macro-biodiversity is purely a consequence of "the ecology and habitability of the planet." I could hardly disagree with this. If Earth's atmosphere, for example, had been hotter 1000 C and made of nothing but mercury vapors I don't think we'd see much of a record of macro-biodiversity.2. And you are saying that because macro-biodiversity "could happen there was a 50-50 change that it would." Here's where I start having trouble. What enables you to assume that macro-biodiversity has a "50-50 chance" of happening? Why not a 60-40 or 99-1 chance of biodiversity happening. Wouldn't that also depend on inherent factors in the biological populations, such as alleles that can be exapted for bio-diversification? Is there no biological component to your argument that allows for integrated participation with ecology and habitability? Didn't cyanobacteria once radically alter Eath's ecology and habitability in ways that accommodated increasing bio-diversity?3. And you say that "meanwhile life muddled along evolving as it went." Does this automatically mean then that biological evolution could not muddle in the direction of macro-diversification? Or does it mean that such muddling is totally limited by environmental conditions...independed of life itself?RADZ, why couldn't that obvious trend of increasing biodiversity in the last 245 million years be the result of an integrated sort of muddling, wherein the biota and their habitats do not change independently but are instead push and pulled by each other in combination?That's the best I can do for this issue. You and CS may be right about the Post hoc ergo propter hoc falacy, which means "After this therefore because of this'." But I stiil don't see how this negates the obvious trend toward macro-diversification on Earth. Not if biota and their habitats historically evolved together, leaving a chicken-and-egg conundrum impossible to separate using your Post hoc ergo propter hoc argument.Did I score any points at all this morning?”HM

Well, sometimes people use the word "evolution" to meant the Theory of Evolution, and somtimes they use it to just mean change in general. It gets all confusing when we start using different definitions for the same word in the same post. Good questions.The current Theory of Evolution does not have that law embedded in it. It could very well be incomplete and missing that. But right now we do not have enough data/observation to say that the ToE is erroneous in not necessitating an increase in biodiversity.For you to observe the trend, and then conclude the the process of evolving is a cause of that trend is the fallacy we discussed earlier.We need more information to determine if evolving causes the increase.Our current explanation for the evolving does not include a necessity for the increase and we don't have enough info to conclude that the current explanation is missing something.