|
Register | Sign In |
|
QuickSearch
EvC Forum active members: 61 (9209 total) |
| |
The Rutificador chile | |
Total: 919,503 Year: 6,760/9,624 Month: 100/238 Week: 17/83 Day: 8/9 Hour: 0/0 |
Thread ▼ Details |
Junior Member (Idle past 3725 days) Posts: 13 From: mississippi Joined: |
|
Thread Info
|
|
|
Author | Topic: If evolution is true, where did flying creatures come from? | |||||||||||||||||||||||||||||||||||
Admin Director Posts: 13108 From: EvC Forum Joined: |
Faith writes: Evolution doesn't come to an end for lack of genetic material, it comes to an end because the processes that bring it about require the reduction of genetic material. It's becoming clear now that this is what you want to discuss in this thread. I'll continue reading this thread to the end, but I'm pretty sure I'm going to rule that there should be a new thread proposal to discuss the idea that diversity was greatest when life first began, that no new and advantageous genetic material has been created since, and that each new species has had less genetic variation than any of its ancestor species. If you'd like to continue the discussion then you (or someone) might want to begin preparing an opening post now. An alternative to a new thread might be to look through old threads and see if you can find one where this was the topic.
|
|||||||||||||||||||||||||||||||||||
Admin Director Posts: 13108 From: EvC Forum Joined: |
Denisova writes: And I didn't meant "do your homework" to denigrate you, I just asked "do your homework", which, as a non-native speaker of English, I thought it is also to be understood just as a saying "May I recommend that you cut to the chase and present your argument for this now" (which were YOUR words). Just for future reference, that's not an interpretation of "do your homework" that I think most English speakers would agree with. It has a couple possible contexts. There's a positive one, as in "It was apparent in her presentation that she had done her homework." But in the way you used it it means something closer to "You're uninformed" or "You're wrong" or both, and it *is* a put down.
|
|||||||||||||||||||||||||||||||||||
Admin Director Posts: 13108 From: EvC Forum Joined: |
Denisova writes: 2. the fact that after the split into two genetically isolated genomes, both of those sub-genomes take away only a subset of the original, total genome DOES NOT detract ANYTHING of the simple fact that there was an initial gain in genetic diversity BEFORE the split, which is what evolution theory ACTUALLY requires.... The OBJECT of evolution theory is to explain speciation. When speciation occurs, there MUST be an initial gain in genetic diversity. Concerning a gain in genetic diversity for speciation, characterizations of "requires" and "must" might be a bit too strong. You're describing the typical or common way for speciation to occur, but there's a richness in possibility that this ignores. One of the difficulties encountered in discussing this topic with Faith in the past is that a reduction in genetic diversity with no associated prior increase *is* a possible path to speciation. Where Faith differs with everyone else is in believing it is the only possible path to speciation.
|
|||||||||||||||||||||||||||||||||||
Admin Director Posts: 13108 From: EvC Forum Joined: |
Hi Everyone,
Thanks for the recent discussion, but I'm going to rule it off-topic. Someone should propose a new thread to discuss this over at Proposed New Topics. I think I characterized Faith's position pretty well a couple messages ago:
Diversity was greatest when life first began, no new and advantageous genetic material has been created since, and each new species has had less genetic variation than any of its ancestor species. Anyone who would like to discuss the evolution of flight, please carry on. AbE: A good candidate thread for resuming discussion of Faith's topic is Evolution Requires Reduction in Genetic Diversity. Some discussion has already picked up there. Edited by Admin, : AbE.
|
|||||||||||||||||||||||||||||||||||
Denisova Member (Idle past 3473 days) Posts: 96 From: The Earth Clod.... Joined: |
Denisova writes: As soon as speciation happened, we will now have 2 species with different and separated genomes. And evidently each genome inevitably will be a *subset* of the original combined genome of the ancestral species.
I'd like to make sure that your meaning is clear for everyone. Here you say that the genome of each new species will be a subset of the parent species, but your previous paragraph talks about genetic change (alleles and genes will be both created and lost in each subpopulation), so in the end each subpopulation's genome will actually be both a subset and a superset of the parent species. Is that what you meant? Thanks for lending me your sharp eyes! I already tried to clarify this point in my post #163, especially by the example in the second part of it. The creation or loss of alleles and genes, responsible for the genetic isolation of the subpopulations and therefore the cause of the split or the ancestral genome, happened BEFORE the split. At the very moment of the split, two specialised species emerged."Specialisation" means by definition that NONE of the newly emerged species has "taken away" ALL of the genes and alleles which were present in the combined ancestral genome at the moment of the split. Species A most likely resembles the initial genetic diversity of the original ancestral species before even any divergence occurred (part from the usual "portion" of genetic drift) - because it continued to live in the old environment and didn't have much or any reason to change. But the genome of species A DIFFERS from the combined ancestral genome at the moment of split. So genome A is a subset of the combined, ancestral genome at the moment of the split. Species B "takes away" (most of the) the genetic change since the start of the divergence. Because this species consist of the original subpopulation of the ancestral species that actually underwent the environmental changes which gave rise to the genetic change. Species B also has a genome that differs from the combined ancestral genome at the moment of the split. This implies that the genome of species B is a subset of the combined ancestral genome at the moment of split.
|
|||||||||||||||||||||||||||||||||||
Denisova Member (Idle past 3473 days) Posts: 96 From: The Earth Clod.... Joined: |
Just for future reference, that's not an interpretation of "do your homework" that I think most English speakers would agree with. It has a couple possible contexts. There's a positive one, as in "It was apparent in her presentation that she had done her homework." But in the way you used it it means something closer to "You're uninformed" or "You're wrong" or both, and it *is* a put down. OK, point taken.As I said, it's often a little bit difficult for me to set the correct tone when translating from Dutch to English. Guess I learned a bit of English here....
|
|||||||||||||||||||||||||||||||||||
Denisova Member (Idle past 3473 days) Posts: 96 From: The Earth Clod.... Joined: |
Concerning a gain in genetic diversity for speciation, characterizations of "requires" and "must" might be a bit too strong. You're describing the typical or common way for speciation to occur, but there's a richness in possibility that this ignores. One of the difficulties encountered in discussing this topic with Faith in the past is that a reduction in genetic diversity with no associated prior increase *is* a possible path to speciation. Where Faith differs with everyone else is in believing it is the only possible path to speciation. I fully agree!But I still was following Faith's argumentations - for sake of not complicating the discussion too much. I'm afraid that reduction in genetic diversity with no associated prior increase being a possible path to speciation indeed is not serving Faith's claims well!
|
|||||||||||||||||||||||||||||||||||
Denisova Member (Idle past 3473 days) Posts: 96 From: The Earth Clod.... Joined: |
Thanks for the recent discussion, but I'm going to rule it off-topic. Someone should propose a new thread to discuss this over at Proposed New Topics. I think I characterized Faith's position pretty well a couple messages ago:
Faith writes: Diversity was greatest when life first began, no new and advantageous genetic material has been created since, and each new species has had less genetic variation than any of its ancestor species. Anyone who would like to discuss the evolution of flight, please carry on. AbE: A good candidate thread for resuming discussion of Faith's topic is Evolution Requires Reduction in Genetic Diversity. Some discussion has already picked up there. Indeed I also now notice it's off topic.Actually, i started this line of debate in the "Evolution Requires Reduction in Genetic Diversity" thread but for some strange reason we end up here. Maybe it was my fault or maybe I followed a lead by Faith. So I suggest we just continue where it belongs: in the "Evolution Requires Reduction in Genetic Diversity" thread. I don't think we have to start a new thread. Edited by Admin, : Fix quoted portion.
|
|||||||||||||||||||||||||||||||||||
RAZD Member (Idle past 1661 days) Posts: 20714 From: the other end of the sidewalk Joined:
|
HI Faith,
I have to stop here in your voluminous post. Yes, we both tend to get verbose. If you like we can break it up into multiple posts if length becomes a problem in covering the topics.
Selection certainly applies here as Darwin himself was doing the selecting, at times rather drastically isolating a trait of his choosing and breeding to enhance that trait until the bird was dominated by it to the exclusion of other characteristics. If there was some reason in nature for the development of the same trait you would see Natural Selection at work to the same end. Agreed, but I would also note that the result of natural selection are individuals within a species that are adapted to survive and breed in their ecology, while human selection is for traits that appeal to humans, whether they have any survival or reproductive value, and for that reason a lot of domesticated breeds of pigeon, horses, sows, pigs, dogs and cats have traits that would be disadvantageous in the wild or even lethal without human medical interference. Different purpose → different effect.
His insight was that the selection process occurred naturally, where animals that survived and bred passed their genes (that enabled them to survive and be selected by mates for breeding) to the next generation. Yes, this was his insight but he didn't have the knowledge that would tell him that the changes that occur through selection, natural or artificial, are limited by the fact that selection eliminates alleles in the process of developing new phenotypes. Eventually the new breed or type may be quite strikingly different from others of its kind but it will of necessity have much less genetic ability for any further evolution. ... You've been told and shown and shown and told that this is not true, this belief of yours that no new alleles are produced. There are some examples in other replies to you. Curiously I think Zatara had a good new example in Message 61:
Anyone who has raised identical twins has observed the dramatic effects of mutation in just one generation. Their twins may have started out with identical DNA, having come from the same zygote; however, in just nine months in utero the mutations have yielded differences noticeable to all but a casual observer. Their DNA came from the same original single celled zygote, but during fetal development the process of cell division and duplication and selection for which aspects of their DNA is expressed becomes different as different mutations are incorporated into the development of the individual fetuses -- where did those differences come from if not mutation Faith? Greenish warblers again ... When a trait is selected its genotype is also selected, and alleles for other expressions of the same trait are soon eliminated from the population of birds from which the trait is being bred. If the selection continues generation after generation a point may be reached where ONLY the alleles for the chosen trait are present, all others having been left behind in the original population. if this goes on long enough in nature it is easy enough to see how a subpopulation could develop inability to interbreed with other populations of the same Species, from sheer genetic mismatch ... Curiously we can actually examine this claim in more detail with the Asian greenish warblers (Phylloscopus trochiloides):: different traits in each subpopulation, traits that govern plumage variations and mating and call song variations:
quote: Note that it is hypothesized that the original parent population that these varietals all descended from was "once confined to the southern portion of their range" ... SO: if your hypothesis were true (that varietals only arise by the loss of alleles in the descendant populations) that they would KNOW that one population was the source of the others as it would still have ALL the alleles of ALL the varietals. Sadly (for you), the genetic evidence tells us that no one population has more alleles than the others, to say nothing of combining all of them: there isn't one population that has all the alleles of all the variants. Further note that none of the populations are completely isolated from the others, that there are small overlapping zones between them:
So there isn't complete genetic isolation and gene flow is possible from one end to the other. This gene flow is limited by the distance the individual birds will travel from where there were born to where they nest and mate and rear young during their lives, so gene flow from one end to the other could take several generations. Now I would expect a corollary of your hypothesis (that divergence from a parent population results in loss of alleles) to be that when the populations converge in an overlap zone and interbreed that the alleles would be recombined in the hybrid zones and tend to restore the number of alleles from the original parent population in the hybrid population. Your problem is that there are four such zones -- (1st) between viridanus and ludlowi, (2nd) between ludlowi and trochiloides, (3rd) between trochiloides and obscuratus and (4th) between obscuratus and plumbeitarsus. Which of these is your parent population with the more complete set of alleles? Additionally, with gene flow from each of these hybrid zones to each neighboring varietal zone, we would expect (from your hypothesis) that the intermediate varietals would be hybrids between each of their end (hybrid) zones, ie that ludlowi would be a hybrid between the 1st and 2nd zones, that trochiloides would be a hybrid between the 2nd and 3rd zones, and that obscuratus would be a hybrid between the 3rd and 4th zones, and continuing this reasoning we should see trochiloides as a hybrid between ludlowi and obscuratus, that even if trochiloides was not the original parent population posited in your hypothesis that it should, via convergence of the populations, have characteristics more like this posited parent population that the other varietals. That we do NOT see the hybridizing restoring the full allele distribution to one of these populations means one of two things:
Can you explain how this evidence does not invalidate your hypothesis? Evolution with mutations and natural selection explains these population variations without the problems your hypothesis has. Pelycodus again Now I want you to look at the bottom line in this graph, below where it says P.ralstoni:
Under the "P" there is a thicker line, and this designates where more of the population is found, with the thinner lines to each side designating the variation in the population to each extreme right and left. You will note that these thicker lines stagger back and forth a fair bit as you go up in the diagram to younger populations. If I draw a vertical line from the right end of the bottom population (below "P.ralstoni) ...
Remember that the overlaps from level to level, showing more than 50% of these populations have identical traits, is an indication that they represent the same species/clade breeding population changing over time and adapting to the ecology. Next, If I draw a vertical line from the right end of P.trigonodus I can repeat my questions:
This latter group is now twice removed from the base population that we started with: how do you explain their traits with your hypothesis? Further, if I now draw a vertical line from the left end of P.jarrovii down, then according to your hypothesis that alleles are lost, then ALL the alleles expressed in the base population to the left of this line are now apparently lost in this descendant population, but extending that line up we see traits similar to the original traits returning to the point where N.nunienus seems to recapture most the original traits. Note that the traits involved here are size related traits (size of bones, teeth, body mass, etc), and other traits (coloration, vocalization, etc) are not included so that younger populations would still not appear like the base population even though they now share size related traits. How can you explain this with your hypothesis? Can you explain how this evidence does not invalidate your hypothesis? Note that if you posit that traits can become hidden and then re-expressed later when conditions suit (as you have posited hidden traits that become expressed, as I expect you to claim for traits to the right of my lines - and as you have claimed for the foxes - that this invalidates your claim that the traits are lost and thus results in a death spiral of lost traits). Evolution with mutations and natural selection easily explains these population variations without the multiple contradiction problems your hypothesis has. Foxes again You say nothing about artificially induced mutations here, and there is absolutely no need for them. This change was possible because the genetic material for the chosen traits was already present in the fox genome and could be selected over several generations. This is how all breeds of animals were originally developed, by selection of the traits desired by the breeder, selection meaning basically reproductive isolation of the individuals with those traits. ... Not quite correct Faith -- the ONLY trait selected was tameness, and this was done specifically to make the foxes easier to handle on the fox farms where they are raised for their desired black lush fur. That white spots developed is contrary to what the desired result was. The reason is that tameness is related to adrenalin levels and adrenalin is a hormone that affects fetal development paths, including fur color, ear and tail characteristics. This is about mutations that occur during fetal development because of the different hormonal environment for the fetus. Mutations that affect the timing of development. and Bacteria again Bacteria don't function genetically or reproductively the way sexually reproducing animals do ... Actually the point of bacteria is that cell division and multiplication during fetal development is the same process that bacteria use to reproduce. Thus bacteria developing new traits and fetal development changing to develop new traits (the fox fur, ears and tail traits) are the same process - adaptation to a different chemical environment with new mutations. denial is not evidence ... and I refuse to accept such "evidence." But of course that's the best you can do to answer my obvious points, isn't it? Curiously I think I (and others) have done more than answer your "obvious points" and raised (again) legitimate points that you have yet to answer. Sadly I expect your "answer" to be more denial rather than confronting the evidence. There is a lot more evidence that supports evolution, evidence of mutation providing new alleles, evidence of selection and drift causing an accumulation of new traits in species over time. There is no evidence that traits are only lost and never gained, but there is evidence of traits being gained. Enjoy Moved to Evolution Requires Reduction in Genetic Diversity Message 413 to keep this thread topic on evolution of flight Edited by RAZD, : moved post to more appropriate threaduse peek to see or go to link above Edited by RAZD, : sp in hidden textby our ability to understand Rebel☮American☆Zen☯Deist ... to learn ... to think ... to live ... to laugh ... to share. Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)
|
|||||||||||||||||||||||||||||||||||
RAZD Member (Idle past 1661 days) Posts: 20714 From: the other end of the sidewalk Joined: |
Just caught up. Been a tad sick and so dosed up on meds and sleepy.
I see lots of ground covered since my previous post, and yes it is off topic: do you want me to move my post to the other thread? Thanksby our ability to understand Rebel☮American☆Zen☯Deist ... to learn ... to think ... to live ... to laugh ... to share. Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)
|
|||||||||||||||||||||||||||||||||||
Admin Director Posts: 13108 From: EvC Forum Joined: |
Whatever you'd like to do is fine. You can post a copy over there, or just let Faith know you posted a reply here, though in that case Faith should still reply over there.
|
|||||||||||||||||||||||||||||||||||
NoNukes Inactive Member |
As I said, it's often a little bit difficult for me to set the correct tone when translating from Dutch to English It is difficult for native English speakers. Telling someone politely that they haven't really made an argument when they think they have isn't going to come across as a compliment.Je Suis Charlie Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846) If there is no struggle, there is no progress. Those who profess to favor freedom, and deprecate agitation, are men who want crops without plowing up the ground, they want rain without thunder and lightning. Frederick Douglass
|
|||||||||||||||||||||||||||||||||||
Faith  Suspended Member (Idle past 1700 days) Posts: 35298 From: Nevada, USA Joined: |
I overused my eyes yesterday, have a horrible eyestrain headache and have to be off the internet at least until tomorrow, hope not longer. I'm curious to find out if Denisova ever said anything coherent, and I'll try to deal with the rest of RAZD's post.
|
|||||||||||||||||||||||||||||||||||
Denisova Member (Idle past 3473 days) Posts: 96 From: The Earth Clod.... Joined:
|
I overused my eyes yesterday, have a horrible eyestrain headache and have to be off the internet at least until tomorrow, hope not longer. I'm curious to find out if Denisova ever said anything coherent, and I'll try to deal with the rest of RAZD's post. Take you time!Your health is more important than the evcforum! Edited by Denisova, : No reason given.
|
|||||||||||||||||||||||||||||||||||
Denisova Member (Idle past 3473 days) Posts: 96 From: The Earth Clod.... Joined: |
Percy,
Is there also a way to move a post to another thread altogether, so not mere copying it but actually replacing? I guess, if not, you better use the Edit box when copying, in order to retrieve and incorporate the dbCodes. Thanks in advance!
|
|
|
Do Nothing Button
Copyright 2001-2023 by EvC Forum, All Rights Reserved
Version 4.2
Innovative software from Qwixotic © 2024