tag:blogger.com,1999:blog-37148773.post735894748415014282..comments2024-03-27T14:50:47.345-04:00Comments on <center>Sandwalk</center>: The Many Faces of Sal CordovaLarry Moranhttp://www.blogger.com/profile/05756598746605455848noreply@blogger.comBlogger52125tag:blogger.com,1999:blog-37148773.post-60790638911512764812013-07-24T14:33:20.418-04:002013-07-24T14:33:20.418-04:00I don't really understand the confusion. If yo...I don't really understand the confusion. If you have sisters, doesn't that require that you also had parents? Even if your parents are extinct or unknown?John Harshmanhttps://www.blogger.com/profile/06705501480675917237noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-35073836194587766332013-07-23T22:46:36.618-04:002013-07-23T22:46:36.618-04:00The stupid is acutely painful, but I can bear enou...The stupid is acutely painful, but I can bear enough for this point: if the morphology is just a hunch and the DNA is just a hunch, why are they both (for the most part) giving us the same hunch? How weird is that?John Harshmanhttps://www.blogger.com/profile/06705501480675917237noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-32240840352018630072013-07-23T22:32:59.566-04:002013-07-23T22:32:59.566-04:00Its not crazy but a re examination of presumptions...Its not crazy but a re examination of presumptions. This has overturned science conclusions before.<br />There has never been a reason to lump "mammals" together or "reptiles" together.<br />They did this too quickly based on shared traits.<br />Yet missed the option that shared traits was simply from shared needs and unrelated to biological relationship.<br />Moles having fur like tigers is just a coincidence. <br />There is no reason to think it shows common ancestry. Even if true it would be just extrapolation. <br />Yet from a common blueprint from the creator of physics it would also be this way.<br />Thats what i would do!<br /><br />Joining creatures together in descent trees has all been a grand hunch.<br />The DNA stuff is just more hunching it up.<br />There is another option that just by existing places the stress on the first options to show they are the product of scientific investigation and not just lack of imagination and first impressions. Robert Byershttps://www.blogger.com/profile/05631863870635096770noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-56178783235043887582013-07-23T10:47:03.153-04:002013-07-23T10:47:03.153-04:00@Mikkel Rumraket Rasmussen: very well-argued and v...@Mikkel Rumraket Rasmussen: very well-argued and very convincing, in my opinion. JimVhttps://www.blogger.com/profile/10198704789965278981noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-31895163881699478372013-07-23T05:33:16.115-04:002013-07-23T05:33:16.115-04:00And of course, another possibility is intervention...<b>And of course, another possibility is intervention, a form of genetic engineering to produce a radical re-design. And not in one 'poof', but incrementally as the timeline plays out.</b><br />But why believe in an unobserved entity. And not just an unobserved entity(like, another collection of matter), but some mysterious and unfathomably intelligent being that has apparently existed for billions of years, can reach in through physical matter and structures and manipulate the genomes of living organisms creating entire genes and new structures, on oganisms everywhere on the planet (truly on a global scale), over geological eons, with planning and foresight and so on? Isn't <b>that</b> the motherloadly most grotesque of all extrapolations? <br /><br />Especially when compared with evolution, which simply takes the observed and multiplies it over longer timescales. Mutations and genetic recombination happens, they're observed facts. The phenotypical variation which results from mutations and recombination samples environmental niches(has adaptive impact), it's an observed fact. Environmens change over time due to geological and atmospheric processes, it's an observed fact. And so on and so forth, evolutionary theory, macroevolutionary change and transitions and common descent simply take observed facts and multiply them over the available time on our planet. <br /><br />In every concievable way, evolution wins hands down as the most plausible and simplest hypothesis, and consequently the only one we're justified believing. It works only with the observed, doesn't postulate unobserved mechanisms that possibly violate the laws of physics. In fact, many of the properties of evolution (like some selective pressures) are logically entailed by our extant knowledge of physics. Take water, all objects submerged in a body of water are subject to hydrodynamic drag. This is, has always been, and will always be a fact. In this respect, natural selection for reduction of hydrodynamic drag for purely physical and energetic reasons will have been in operation on all aquatic forms of life for the entire history of life. It is no surprise that aquatic life finds itself having largely all found similar adaptive solutions to reduce drag. Most fish look roughly alike in body shape: Long and slim. <br /><br />Time and again, evolution is the simplest explanation which doesn't postulate onobserved entitites or hitherto inexplicable mechanisms to explain the observed diversity and quality of life on our planet. Mikkel Rumraket Rasmussenhttps://www.blogger.com/profile/07670550711237457368noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-59993462338490883842013-07-23T04:27:07.623-04:002013-07-23T04:27:07.623-04:00"In this respect we don't even need to wa...<b><i>"In this respect we don't even need to wait for mutations. This is why sex is so important for the evolution of large multicellular species like plants and animals."</i><br />True, and yes, sexual bimorphism is essential for evolutionary progressions (sorry unicellulars), but (1) is that all that is/was required to build novelty and complexity, and (2)how did diploid bisexual phyla originate?</b><br />At the earliest stage, probably through some form of single-celled eukaryotic conjugation or similar type of sharing of genetic material. That's of course a very interesting subject in it's own right and has a pretty substantial litterature devoted to it. I'm sure you can find something recent on the origin and evolution of sexual reproduction online. <br />I recommend starting here for a short primer: <br />https://en.wikipedia.org/wiki/Evolution_of_sexual_reproduction<br />But nothing beats the specialist litterature of course, and I'm not a specialist in the field. <br /><br /><b>Me: "Selective to females" might well confer a selective advantage. But again, what is available to manually select and breed does not necessarily equate with other traits that may develop long term.</b><br />Of course not, there are no guarantees in evolution. Over 99.9% of all species that ever lived have gone extinct. But life overs pretty much the entire surface of our planet and in many places goes up to a few kilometers into the ground. All environments on the planet are constantly sampled by variation generated by mutation and recombination. <br />Evolution simply retains "something, anything that works". That one species in one environment (say, in a north-american forest or river) evolved in the wrong direction and is heading for extinction just means that another one will eventually take it's place and adapt for the niche it failed to, given time. Of course, sometimes environmental changes are too fast and happen on a global scale, and that's where we get mass-extinctions. Nonetheless, global-scale environmental sampling of generated variants goes on and when conditions settle down again, diversification explodes. This makes intuitive sense and is confirmed in the fossil record.Mikkel Rumraket Rasmussenhttps://www.blogger.com/profile/07670550711237457368noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-17441829767624146302013-07-23T04:13:38.421-04:002013-07-23T04:13:38.421-04:00"In fact, the primary source of variation wit...<b><i>"In fact, the primary source of variation within sexually reproducing species is genetic recombination. Huge amounts of variation that doesn't even exist as part of the standing variation in populations, can be generated through recombinatorial events alone."</i><br />Yes, but with no 'look ahead' function for building incrementally non-functional, but functional at a later time constructs</b><br />There is no requirement for "look ahead function" in order for genetic recombination to result in neutral-but-later-adaptive change. It seems you've invented a problem it isn't even clear exists. <br />It is often the case that environment determines functionality, so what might in one environment prove detrimental to the host organism, can in another turn out to be selectively beneficial. The Betta double-tail variant is a good example of such recombination-generated variation that has selective effects that depends on environment. <br /><br /><b>the amount of change, however generated, does not explain certain complexities and novelties.</b><br />This is news to the worlds evolutionary biologists. Also an unsupported blind assertion. Mikkel Rumraket Rasmussenhttps://www.blogger.com/profile/07670550711237457368noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-66811619575151360332013-07-23T04:03:07.306-04:002013-07-23T04:03:07.306-04:00Really, your denial here has the same quality of f...Really, your denial here has the same quality of failure as the idea that adding steps can't ever lead to a staircase, or that adding pennies never leads to a million dollars(or whatever arbitrary large amount). What mechanism prevents the accumulation of change? <br /><br />Why should we not take all the evidence from our observations together and find it reasonable that evolution did and does happens to greater extends than we have observed within our lifetimes, simply given even more time? <br /><br />I'm sorry, but no matter how I try to view at this, all we're being offered by the creationist side is stubborn denial. Mikkel Rumraket Rasmussenhttps://www.blogger.com/profile/07670550711237457368noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-28846512834901202232013-07-23T03:58:55.244-04:002013-07-23T03:58:55.244-04:00@Lee Bowman
What I had meant was that equating lon...@Lee Bowman<br /><b>What I had meant was that equating long term evolutionary change to what we do by selective breeding in the short term is to my mind, an unfounded extrapolation (forget the steroids). ;~)</b><br />But <i>why</i> is it an unfounded extrapolation? It's not like we're doing this in a vacuum. The relationships are already implied by phylogenetics and morphology, and it is so unbelievably simple an extrapolation. We observe small amounts of change within human lifetimes, why can't this change simply multiply proportionally over longer timescales? Why? What prevents the accumulation here?<br /><br />We have all he observations we could hope for within human lifetimes, if it really was the case that small-scale changes could accumulate over longer timescales. We have fossil transitions and their chronologies that support it. We have the phylogenetic relationships that are congruent with the morphologically inferred ones. We see mutations accumulate slowly in human lifetimes. We observe that mutations and genetic recombination affect morphology. We observe that natural(and artificial) selection retains adaptive variants. <br /><br />Why, then, is the extrapolation that this happens over longer timescales, an unreasonable extrapolation to you? What can you offer here other than stubborn incredulity or blanket denial? <br /><br />Can you offer <b>a mechanism</b> that blocks the accumulations of change? One that isn't just an ad-hoc rationalization? What is it that compels you to object to the inference? Any observations of this mysterious evolution-preventing barrier that your rejection entails?Mikkel Rumraket Rasmussenhttps://www.blogger.com/profile/07670550711237457368noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-18892117422355912892013-07-23T03:29:43.649-04:002013-07-23T03:29:43.649-04:00Astonishing how many people feel qualified to tell...Astonishing how many people feel qualified to tell a phylogeneticist how evolutionary research works. Maybe in turn I should start explaining to my dentist how they should do their job...Alex SLhttps://www.blogger.com/profile/00801894164903608204noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-70903760494276716282013-07-23T02:59:20.638-04:002013-07-23T02:59:20.638-04:00Alex SL
I don't think observing evolution coun...Alex SL<br />I don't think observing evolution counts as biological investigation. A space alien showing us a video of evolution of anything would just be a video. Even though a true account.<br />Biological investigation must be based on biological processes being demonstrated as actual and actually working .<br />Repeatable one might say.<br />There is no complaint in medicine or flying planes about methodology in drawing results. It works repeatedly.<br /><br />Extrapolation is not biological research. its just a line of reasoning standing on the merits of the reasoning. Conclusions not standing on observation, repeatable details, and raw evidence that such and such did happen.<br /><br />I say extrapolation is not science. Evolution is based on extrapolation almost entirely.<br />Process and and true results are not being demonstrated by investigation methods.<br />Evolution is not using the scientific method and because this is not noticed therefore evolution has not been corrected for its errors by scientific methodology.<br />One can't correct extrapolation. True or not its an abstract and has nothing to do with scientific investigation.Robert Byershttps://www.blogger.com/profile/05631863870635096770noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-3354329780975288012013-07-23T02:33:56.870-04:002013-07-23T02:33:56.870-04:00Robert Schenck
Morphology comparisons and DNA are ...Robert Schenck<br />Morphology comparisons and DNA are not biological investigation of the relationships between creatures. They are themselves just speculations of how creatures are related.<br />Yet there is no actual biological research going on.<br />Just connecting dots.<br />Just lines of reasoning.<br />So finding OTHER lines of reasoning for relationships by morpholoy and DNA nullify's the first lines.<br />So a common blueprint EQUALLY would predict these relationships by DNA/morphology.<br />Therefore these things are not independently standing on the merits of biological investigation.<br />No biology is going on here and so error can have a option of having entered through a crack in the wall. Robert Byershttps://www.blogger.com/profile/05631863870635096770noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-89443634743584071242013-07-23T01:42:37.193-04:002013-07-23T01:42:37.193-04:00Bowman hypothesizes "non-evolvable complexity...Bowman hypothesizes "non-evolvable complexity", but that only proves that IDers use strictly negative argumentation. Besides the obvious fact that in living organisms there ISN'T any non-evolvable complexity-- the defining feature of life, as opposed to human designed technology, is that life is complex WITHOUT non-evolvable complexity-- it's also ridiculous to have an alleged "theory" based on what scientists allegedly can't explain. It's like when vitalists said "Chemistry can't explain this or that action of an organism, that's positive evidence that the Vital Force did it." Creationists used to be vitalists. Get a real theory-- the kind that makes testable predictions.<br /><br /> Bowman's examples of non-evolvable complexity are the same creationist arguments we've seen for 120 years. "Transitions are impossible." Every concrete example cited by creationists for 120 years has been OBSERVATIONALLY refuted by finding transitional fossils, living intermediates, or living juvenile forms with the EXACT properties creationists called "impossible"!<br /><br /> Creationists were adamant, ADAMANT that the half-whale, the half-bat, the half-flatfish, the half-amphibian, the half-eye, the half-warm blooded mammal, the half-turtle, the half-giraffe, the half-bird and even the half-feather were all IMPOSSIBLE and could NEVER exist and if they ever did they would KILL the animal DEAD. But we found every one of them and more.<br /><br />The creationists have a demonstrated track record, more than a century long, of saying they can prove an intermediate is IMPOSSIBLE and then looking like total assholes when it appears in the fossil record, in living species or juvenile forms.<br />Diogeneshttps://www.blogger.com/profile/15551943619872944637noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-31287154853499097972013-07-23T00:58:27.983-04:002013-07-23T00:58:27.983-04:00Regarding IC/NEC, Behe's irreducible complexit...Regarding IC/NEC, Behe's irreducible complexity and my non-evolvable complexity. Both have some commonality; one looking backward, the other bottom up (simple to complex).<br /><br />NEC is discerned where<br /> <br /> • multiple or co-dependent systems would have no reproductive advantage (or function for that matter) if evolved separately<br /><br /> • where intermediates would similarly have no usable function, sans the infrequent exaptation examples, and thus have to reproductive or survival advantage, and<br /><br /> • where certain intermediates would be disruptive to extant functions.<br /><br />These premises are subject to further confirmation or falsification, but are clearly on the table as investigative science. Maybe it's high time to table the 'religion' canard. <br />Lee Bowmanhttps://www.blogger.com/profile/11032697992689736055noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-60415731898117263402013-07-23T00:42:58.829-04:002013-07-23T00:42:58.829-04:00"No idea what IC/NEC is but above I pointed o...<i><b>"No idea what IC/NEC is but above I pointed out where the circularity lies. You cannot conclude that there is a creator merely by assuming that things must have been created, nor vice versa. To break the circularity, you need some outside information that makes it appear plausible that there is a creator." </b></i><br /><br />ID does not propose a singular creator per se, a religious concept; just verification of design inferences, where evident. The design source could be an intelligent mechanism, multiple alien entities, surrogates acting under a higher authority, or other unknown inteligencia. If natural causation fails as causative (unguided), then guided (interventionary) is a logical alternative. If not, feel free to propose another.<br /><br />Incremental evolution is a known operative, largely if not totally adaptive, but unknown regarding its mechanisms in toto. Embryogenesis is the creative process, but more likely than not, 'itself' a designed process. Billions of years of algae and prokaryotes may seem odd, but vast time is only a factor to limited time entities like 'us'. Design inteligencia may have varied throughout time, and may or may not be operative at this juncture. ID makes no predictions regarding.<br /><br /><i><b>"And of course there is no scientific evidence whatsoever for a creator, nor has anybody suggested a mechanism for how the process of creation would have proceeded. It's magic! In contrast, evolutionary biology has proposed numerous processes generating biological diversity and structure, and those processes are observable and have been tested."</b></i><br /><br />Sorry, but they have not been empirically verified to form complex structures, just minor adaptations. Extrapolation is the current 'key' to observability.<br /><br /><i><b>"I find creationist claims on this thread insufficiently coherent and elaborated to address them adequately, and that includes you cryptic remark on statistical improbability."</b></i><br /><br />A design theorist is not necessarily a creationist, nor am I. I will go with the evidence wherever it leads.<br /><br /><i><b>"Not only does the vast majority of theoretical and experimental evolutionary biologists disagree with you, there is also all the other evidence to be considered."</b></i><br /><br />And I am open to any and all evidence that presents. But that would refer to efficacious and of course <i>cohesively</i> <b>related</b> evidence only. Bacterial adaptations do not count as either genotypic or phenotypic confirmatory data regarding evolutionary progressions.<br /><br /><i><b>"Phylogenetic structure in non-coding DNA, fossils, biogeography, etc, it all fits into one nice image that looks precisely as one would expect things to look if evolution were true and quite differently from what we expect special creation to look like (unless under a trickster god/Last Thursdayism scenario)." </b></i><br /><br />Correct. According to the data, there was no "special creation", and of course, no "trickster" god. Evolutionary lineages are real.<br /><br /><i><b>"I will assume you do know what the Omphalos hypothesis is and are merely deliberately obtuse." </b></i><br /><br />That would be under philosophy, not science.<br />Lee Bowmanhttps://www.blogger.com/profile/11032697992689736055noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-31448436278427974422013-07-22T23:29:49.718-04:002013-07-22T23:29:49.718-04:00Lee Bowman,
No idea what IC/NEC is but above I po...Lee Bowman,<br /><br />No idea what IC/NEC is but above I pointed out where the circularity lies. You cannot conclude that there is a creator merely by assuming that things must have been created, nor vice versa. To break the circularity, you need some outside information that makes it appear plausible that there is a creator.<br /><br />And of course there is no scientific evidence whatsoever for a creator, nor has anybody suggested a mechanism for how the process of creation would have proceeded. It's magic! In contrast, evolutionary biology has proposed numerous processes generating biological diversity and structure, and those processes are observable and have been tested.<br /><br />I find creationist claims on this thread insufficiently coherent and elaborated to address them adequately, and that includes you cryptic remark on statistical improbability. Not only does the vast majority of theoretical and experimental evolutionary biologists disagree with you, there is also all the other evidence to be considered. Phylogenetic structure in con-coding DNA, fossils, biogeography, etc, it all fits into one nice image that looks precisely as one would expect things to look if evolution were true and quite differently from what we expect special creation to look like (unless under a trickster god/Last Thursdayism scenario).<br /><br />I will assume you do know what the Omphalos hypothesis is and are merely deliberately obtuse.Alex SLhttps://www.blogger.com/profile/00801894164903608204noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-1196211234678892082013-07-22T22:56:31.761-04:002013-07-22T22:56:31.761-04:00Mikkel, I have a question for you-- and I'm go...Mikkel, I have a question for you-- and I'm going to ignore the troll who among other things appears ignorant of the Luria Delbruck experiment, mutation accumulation experiments, Perfeito et al., nylonase bug etc. etc.<br /><br />Let's talk about sex. I read somewhere, I forget where (Sean Carroll?) about sex producing gains in complexity in one generation-- e.g. a butterfly with let's say a smile pattern on its wings mates with a butterfly with let's say an eye pattern, and the offspring has a smiley face on its wings. That would be a gain in complexity by sex alone. Does that ring any bells?Diogeneshttps://www.blogger.com/profile/15551943619872944637noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-43849803827046536142013-07-22T22:23:39.982-04:002013-07-22T22:23:39.982-04:00Byers opines: "So there is no such thing as m...Byers opines: "So there is no such thing as mammals or reptiles"<br /><br />At the Scopes trial, when WJ Bryan said humans were not mammals, everyone thought it was a joke. It wasn't and it still isn't.Diogeneshttps://www.blogger.com/profile/15551943619872944637noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-46660405851166573372013-07-22T21:30:43.607-04:002013-07-22T21:30:43.607-04:00Ah, Sal "DNA Steganography" Cordova. Y&...Ah, Sal "DNA Steganography" Cordova. Y'know the movie credits where it shows the name of the director? Well one of Sal's theories is that DNA contains hidden messages saying stuff like "Body by God."<br /><br />Next to that, this crap sounds almost tame.judmarchttps://www.blogger.com/profile/03111006189037693272noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-85184527487498562382013-07-22T21:04:18.615-04:002013-07-22T21:04:18.615-04:00"So far I can tick the fields marked circular...<b>"So far I can tick the fields marked circular reasoning, god of the gaps, argument from personal incredulity and Omphalos/Last Thurdsayism."</b><br /><br /> • If my premise is true (IC/NEC), then my conclusion is true (design). Circular only if a false premise is presented.<br /><br /> • I have never posited a monotheistic God, an <i>a priori</i> assumption, and without scientific evidence.<br /><br /> • Personal incredulity? No, statistical improbability. And I will side with the data, when and if reductive exclusivity is confirmed.<br /><br /> • And regarding Omphalos theology, no, what is observable is not a 'charade', just another mind-game fallacy.<br /><br />It's just a little hard to digest, if one is a committed reductionist.<br /><br />And regarding the question of umbilical cord connection points (omphalos, yes or no?), they will always form in placental mammals.<br /><br />Sorry to disappoint ... :)Lee Bowmanhttps://www.blogger.com/profile/11032697992689736055noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-88064544055771982012013-07-22T20:31:46.122-04:002013-07-22T20:31:46.122-04:00We could play some sort of Bingo with this. So far...We could play some sort of Bingo with this. So far I can tick the fields marked circular reasoning, god of the gaps, argument from personal incredulity and Omphalos/Last Thurdsayism.<br /><br />The personal incredulity one is particularly obvious in the thread above. Anybody who argues that gradual changes in allele frequencies are incapable of producing new body plans simply fails to grasp the magnitude of what "hundreds of millions of years" actually means. That is of course understandable to a degree; we are simply ill equipped to intuit about anything more than a human lifetime, which is why intuition is such a poor guide in these matters.Alex SLhttps://www.blogger.com/profile/00801894164903608204noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-44615866186271337332013-07-22T19:25:41.522-04:002013-07-22T19:25:41.522-04:00@Mikkel:
Me: "And again, selective breeding...@Mikkel: <br /><br />Me: <i>"And again, selective breeding does nothing to initiate genetic change short of removing some genetic information in most cases."</i><br /><br />Mikkel: <i><b>"As I just both explained and documented, that is simply false. Gene-shuffling is by definition genetic change, and mere shuffling does not consitute deletions, removal or loss."</b></i><br /><br />Some losses in some cases, but using what is there, rather than by a mutational process.<br /><br /><i><b>"This is of course an irrelevancy for the this discussion. Selective breeding was erected entirely for the purpose of demonstrating that succesive rounds of selection can result in the accumulation of morphological change ... "</b></i><br /><br />I still take umbrage with your statement, however:<br /><br /><i><b>"There simply is no good reason to think that natural selective pressures operating over long time scales can't achieve extensions of what human beings have done in a few thousand years, and sometimes as little as centuries. Add drift, recombination and changing environments on continental scales over geological time, and the whole thing becomes all the more plausible."</b></i><br /><br />Selective breeding responds to the personal 'wants' of the breeder rather than environmental pressures, is limited to available existing genes rather than chance mutations, nor are either equatable in any way to the formation of observed novelty and complexity within the observed domains.<br /><br />Anyway, regarding the liklihood/possibility of a form of genetic engineering at historic points in time, we ourselves are on the cutting edge IMO. Check this out:<br />http://www.scs.illinois.edu/~zhaogrp/publications/HZ45.pdf<br /><br />And of course this:<br />http://en.wikipedia.org/wiki/Genetic_engineering<br />Lee Bowmanhttps://www.blogger.com/profile/11032697992689736055noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-84018160856204585612013-07-22T18:31:24.415-04:002013-07-22T18:31:24.415-04:00@Mikkel: "Now, for another case in point of s...@Mikkel: <i><b>"Now, for another case in point of significant morphological, recombination-generated change, the Betta double-tail "mutation" in the Betta splendens aquarium fish.<br /><br />That is a fish possessing two separate, distinct tail fins, arranged vertically like the barrels of an 'over-under' shotgun, each with its own distinct set of caudal plates in the caudal peduncle, is governed by a single gene exhibiting classic Mendelian single-factor recessive inheritance.</b><br /><br /></i>From the linked page:<i> "Doubletail bettas are expected to differ in several ways from the singletail:"<br /><br />1. Possess two distinct 'tails' or caudal lobes instead of one, with complete separation to the base of the caudal peduncle.<br /><br />2. Possess a wider caudal peduncle to support the double lobes.</i><br /><br />Split or double morphologies sometime occur, and when they do, selective breeding might beget more of them.<br /><br />Mikkel: <i><b>As that page also explains, the double-tail variant is further subject to change once it arises, and selective breeders (or just sexual selection within the aquarium populatipon) can futher facilitate ever more intricate and elaborate tails (they're apparently "impressive" to females)."</b></i><br /><br />Me: "Selective to females" might well confer a selective advantage. But again, what is available to manually select and breed does not necessarily equate with other traits that may develop long term.<br /><br />And of course, another possibility is intervention, a form of genetic engineering to produce a radical re-design. And not in one 'poof', but incrementally as the timeline plays out.<br />Lee Bowmanhttps://www.blogger.com/profile/11032697992689736055noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-36051435636920425282013-07-22T18:11:05.766-04:002013-07-22T18:11:05.766-04:00"Sexual recombination and mutation is what ge...<i><b>"Sexual recombination and mutation is what generates change. Mutations observationally happen and affect morphology and behavior, and sexual recombination even more so."<br /><br /></b></i>Both plus genetic drift are valid operatives<b><i><br /><br />"In fact, the primary source of variation within sexually reproducing species is genetic recombination. Huge amounts of variation that doesn't even exist as part of the standing variation in populations, can be generated through recombinatorial events alone."<br /><br /></i></b>Yes, but with no 'look ahead' function for building incrementally non-functional, but functional at a later time constructs, the amount of change, however generated, does not explain certain complexities and novelties.<i><b><br /><br />"In this respect we don't even need to wait for mutations. This is why sex is so important for the evolution of large multicellular species like plants and animals."</b></i><br /><br />True, and yes, sexual bimorphism is essential for evolutionary progressions (sorry unicellulars), but (1) is that <i>all</i> that is/was required to build novelty and complexity, and (2)how did diploid bisexual phyla originate?Lee Bowmanhttps://www.blogger.com/profile/11032697992689736055noreply@blogger.comtag:blogger.com,1999:blog-37148773.post-71600489289888489752013-07-22T17:43:32.237-04:002013-07-22T17:43:32.237-04:00"Equating manual selection (or for that matte...<i>"Equating manual selection (or for that matter, natural selection) with effectuating a genetic change that has not mutationally occurred, is extrapolation on steroids."<br /><br /><b>"You're apparently very confused. I'm still not saying selection is the source of variation, I'm saying selection is that which retains adaptive variation.</b></i>"<br /><br />Correct, and I had corrected that misstatement as follows:<br /><br /><i>"For clarity, change "with effectuating a genetic change" to "employing an <b>effectuated</b> genetic change"."</i><br /><br />What I had meant was that equating long term evolutionary change to what we do by selective breeding in the short term is to my mind, an unfounded extrapolation (forget the steroids). ;~)Lee Bowmanhttps://www.blogger.com/profile/11032697992689736055noreply@blogger.com