Shapes of Time 204
| Shapes of Time: the Evolution of Growth and Development | |
| author | Kenneth J. McNamara |
| pages | 342 |
| publisher | John Hopkins University Press |
| rating | 9 |
| reviewer | Danny Yee |
| ISBN | 0801855713 |
| summary | evolutionary changes in the timing of developmental features and in rates of growth |
Many popular books on evolution ignore or downplay the role of growth and development, of ontogeny. But in Shapes of Time Kenneth McNamara's focus is on heterochrony, on evolutionary changes in the timing of developmental features and in rates of growth. As he puts it:
Heterochrony constrains natural selection; it also provides it with raw material, allowing small genetic changes to have big phenotypic effects."evolution is not only about genetics and natural selection. Just as crucial are the changes in the timing and rate of development, with the three, genetics, heterochrony, and natural selection, forming an interdependent evolutionary triumvirate."
Ideas about the relationship between ontogeny and phylogeny (evolutionary history) have changed over the last few centuries, with notions of recapitulation and paedomorphosis going in and out of fashion. McNamara's outline of this covers Ernst Haeckel, Karl Ernst von Baer, and Walter Garstang, ending with Stephen Jay Gould, from whose Ontogeny and Phylogeny he takes the terminology for different kinds of heterochrony. The basic division is into paedomorphosis (less growth) and peramorphosis (more growth). These can each take three forms: paedomorphosis can be the result of progenesis (finishing early), neoteny (slower growth rate), and postdisplacement (starting late), while peramorphosis can result from predisplacement (starting early), acceleration (greater growth rate), and hypermorphosis (finishing late).
That's a lot of technical terms, but don't let them scare you away - the bulk of Shapes of Time consists of lively and engaging examples of heterochrony, taken from across the animal kingdom, from dogs and humans to invertebrates (McNamara is an invertebrate paleontologist), which help both to explain those terms and to fix them in the memory. But first McNamara presents a little bit of developmental biology, covering the stages of neofertilization, differentiation and growth, touching on Hox genes and morphogens, and mechanisms of organ and appendage formation. This is enough background for the higher level (zoological and ecological and paleontological) survey that follows, but may be frustratingly slender for those after more, after a better understanding of the developmental biology behind heterochrony.
McNamara begins his tour of heterochrony with dog varieties - even looking at paedomorphosis in depictions of Snoopy in Peanuts cartoons - and examples from insects and salamanders. Heterochrony is "all-pervasive" in the generation of sexual dimorphism, from simple size differences to extreme cases with males that are little more than "parasitic" sperm sacs. And heterochrony can play a key role in speciation, often combining with environmental gradients to separate populations; examples include Darwin's finches, brachiopods, and bushbucks.
Are some forms of heterochrony more common than others in particular lineages? In some cases paedomorphism seems unusually common, notably among the amphibians (axolotls are paedomorphic salamanders, for example); McNamara also looks at paedomorphism in lungfish, cats, and various invertebrates and at connections with genome and cell size. In other cases peramorphosis seems to dominate: a dramatic example is the combination of hypermorphosis and acceleration that produced increasing size in dinosaur lineages, but Cope's rule suggests that size tends to increase more generally. More common is the mixing of peramorphism and paedomorphism, acting on different features and subject to "trade-offs": examples here come from the evolution of wings (and of flightlessness) and tetrapod limbs, with a brief glance at the origin of turtle shells.
Heterochronic mechanisms enable the adaptation of life cycles to different environments: hypermorphosis and neoteny are more common in stable environments ("K-selected") and progenesis and acceleration in unpredictable ones ("r-selected"). Heterochronic changes can be driven by biological "arms-races", with a clear example in the evolution of sea urchins in response to predation by cassids (marine snails). And heterochrony has played a key role in human evolution, where McNamara highlights peramorphic features against a tradition which has stressed paedomorphism.
McNamara sometimes appears to reduce the significance of ontogeny in evolution to heterochrony, when it is actually considerably broader. There are ontogenetic constraints and processes other than those of timing and rate: biophysical and biochemical limits, ways in which novel proteins or cell types arise, and self-assembly and exploration allowing "adaptive" development, to list just a few. If there is a "triumvirate" that rules evolution it has to be "genetics, ontogeny, and natural selection". Still, there's no doubting that heterochrony is one of the key links between ontogeny and phylogeny - at least not after reading Shapes of Time.
You might like to check out Danny's other evolution, developmental biology, and popular science reviews. You can purchase Shapes of Time from bn.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.
Baah (Score:2, Funny)
Oh and btw. If you got scared please read this [talkorigins.org]afterwards.
Re:OMG that's scary! (Score:1)
But seriously, how scary are these people? Like 666 out of 10! Did you read into that site and see the part about the "Islamic Invasion" of Christianity? Geez, maybe natural selection hasn't taken care of these weak genes yet. My who faith in Science and rational thought has been ripped from cranium.
LOL.
Thanks for the good read!
Re:Baah (Score:2)
It just annoys me to see other christians latch on to ideas that have NO support even within the text they are referencing and try to bludgeon their faulty premise into everyone elses head.
Argh.
Kintanon
Re:Baah (Score:1)
I've heard this before but if you consider the text(Genesis): God seprerates light and darkness (and later goes on to create the sun and the moon to rule over it). If you read this litterally, the text would only make sense if this is done in 6 days, as in 6x24 hours. At least thats how I read it in my translation.
Re:Baah (Score:2)
Kintanon
Nasty Agenda (Score:1)
Time has shape (Score:2, Funny)
And how long will it take to solve? (without taking off and rearranging the stickers?)
Re:Time has shape (Score:1, Interesting)
The rough edges where all the action goes on in the universe. The energy potentials dancing around each other until they equalize. In their wake are impressions left in the universe.
Wintertime is a good time to see this. All the trees without their leaves stand contrasetd against the sky. Elements in the air and sky are no longer sufficiently reactive to induce change when left by themselves. So they formed trees to maintain the steady march downwards towards equilibrium.
This time of year you can literally see this fuzz of entropy that branches out from what is to what is not.
Shape of time? (Score:2)
Missing human mind with Science (Score:4, Insightful)
There is something very dangerous on using and fixing the attention to certain terms that are simply used as metaphoras. We have an example right here, where we already see two "triumvirates" fighting each other. Frankly I believe that the original author was sincerly remarking the importance of his ideas in the frame of three important conditions for Evolution. However the reviewer made a serious mistake on catching up with this. Whatever happens in Evolution, surely is not a triumvirate and we may be quite far from it. I think that the idea of the book is utterly incomplete, but I have to read the book to be sure for that. The reviewer sincerly makes a bigger mistake on remarking three important factors of Evolution and forgetting that this is too overclassical and artificial from the very start. One cannot simply put three simple conditions to explain all the complexity of the evolutionary process. While it is important to simplify the fundamental conditions of Evolution, I think that we cannot hold up to "Three conditions". That also sounds to much as an revival of the traditionalist "Three Laws" of Physics. This sounds too human to be scientific and too subjective to accept.
Ontogeny (Score:3, Informative)
> evolution it has to be "genetics, ontogeny,
> and natural selection"
On the other hand, ontogeny is also genetic. Even the development constrained (or encouraged) by environmental conditions are responses that pushes the organism down an existing genetic pathway. Heterochrony is an important aspect of evolution, but it is an aspect of genetic adaptation, and cannot stand alone (although I agree that it can be singled out for purposes of study).
Natural selection acting on genetic (or, better yet, phenotypic) variation is the whole of evolution (and here I'm considering the neutral network stuff to also be phenotypic as it is a product of the genome's position in a topoloical structure).
Sigh, not more dialectical things, I hope? (Score:2, Informative)
To see where the reviewer, and most modern criticism against evolutionary biology, comes from -- see The Dialectical Biologist [dannyreviews.com].
I stopped reading the popular criticism after coming to the opinion that there are two different religions that have dogmatic problems with evolution -- Xians/Muslims and Marxists.
I think I understand why the Xians have problems accepting that some (tendencies to) behavior are built into humans. I never read up enough on Marxism to understand their problem. I leave that to people with more religious needs.
Re:Sigh, not more dialectical things, I hope? (Score:2, Interesting)
Marxists believe that cooperation is more efficient than competition in the long term and that Darwinistic tendancies like those above lead to more wasted energy and in turn there is less energy in the system to profit from. The Marxists don't question the evidence or case for evolution in the same manner as the religious fanatics. They just don't believe evolution by competition is the better way to achieve goals.
Re:Sigh, not more dialectical things, I hope? (Score:3, Informative)
Danny.
Gould? (Score:1)
Well, it seems few (non-marxist) evolutionary biologists consider Gould's writing on alternatives in evolution to be interesting. And neither are the psychological researchers impressed by his work in that area; in fact, the criticism from them seem similar. (Somewhere between dishonest and Gould being the Newton of straw man attacks.)
The majority of the world's evol biologists and intelligence researchers might be idiots (or in a conspiracy), of course...
Or Gould might have been an idealist with a finished answer about some things, looking to get them confirmed. The only thing we know about the world is that we don't know what we will find -- and as a corollary, it won't be what we expected or wanted. There are so many more ways to be wrong than to be right, so if you have the answer ready before looking, you are certain to be wrong.
Re:Gould? (Score:2)
That's just completely false. Shapes of Time is one counter-example, as is Patterns and Processes in Vertebrate Evolution [dannyreviews.com], but there are thousands of other non-marxist biologists who have used Gould's ideas on evolution. Check the citation record for Ontogeny and Phylogeny sometime!
Danny.
Re:Gould? (Score:2)
Danny.
Re:No answer? (Score:2)
Do the critics of Gould's popular writing really include Mayr, Maynard Smith, George Williams, Hamilton, Wilson, Trives, etc?
There's been lots of criticism of Gould, sure. Some of it has been very uninteresting or demonstrably wrong, but a lot of it has been quite solid. Some of Gould's responses have been weak, but sometime's he's revised his ideas and come back stronger than before. And both "sides" have on occasion resorted to "playing the man" instead of the ideas. But this is how debate works...
Frankly, I never understood the fuss. I can read Dawkins and Wilson - I'm just reading The Ants now, it's an incredible achievement - and Gould and Lewontin, and find them all well worthwhile. And when what they say is incompatible... well, we can't expect everything to be handed to us on a platter!
And Wilson certainly has cred when it comes to ants, but frankly Sociobiology has aged less well than Ontogeny and Phylogeny and while I haven't read Consilience, reports suggest it isn't entirely convincing. And if you want to know how Gould is considered by palaeontologists, Carroll's highly regarded Patterns and Processes of Vertebrate Evolution is quite critical - but definitely not dismissive. If this is "Gouldism"... well, then Gouldism has totally permeated palaeontology.
For my information, is it really true that Gould really dropped all references about brain size from the first and second edition of "mismeasured"?
There's plenty of discussion of brain size in the 2nd editon of Mismeasured... And someone borrowed my 1st edition and never returned it, so I can't compare.
OK, Gould claims (in his popular writing) that evolutionary biologists ignore alternatives to selection for changing gene frequency. Despite genetic drift being accepted for decades.
It's possible for something to be neglected while still being known... and neutral theory had to fight for a place. In any event, there's no doubt at all that the range of approaches to evolution - in terms of levels of selection, understanding of developmental constraints, etc. - is much broader now than it was fifty years ago.
Dawkins is not a myopic as some critics have suggested, but some of his attacks misrepresent people woefully too. I can't remember the Dawkins article in the Langton volume - and my copy of that isn't where it ought to be on my shelf, so I can't comment on that directly - but there's a difference between evolvability and levels of selection.
If I have learned anything yet in life, it is that idealists lie.
Idealists?? I think you must be using a different sense of that word to the rest of the philosophical community. And accusations that people are "lying" always remind me of creationists, who have to fall back on accusing biologists of lying because they have no other response to what they are saying...
Danny.
Re:The popular writing! (Score:2)
I'm not sure what "emotional pathos" is, or why trying to change the view of where one's "pathos" is is such a sin... (?) But "idealism" is a technical term in philosophy which should be used with caution. As for politicisation... almost everybody writes from some "political" stance, and the history of science is intertwined with politics. But this is rather more complex than "but Dawkins votes Labour and Gould is a Marxist".
Danny.
Re:The popular writing! (Score:2)
I just don't see Gould as being particularly unusual here - and certainly not to the point where you can rule out his ideas on extra-scientific grounds, which is what you seem to be trying to do. Every single one of your criticisms (presumably taken from others) has been "playing the man" rather than his ideas. What does that suggest about the sources you're using?
As for the politics... Gould would be the first to acknowledge that he has ideological motivations - whereas some of his critics pretend that they don't.
You seem to want everything to be black and white, with "good" people and "bad" people. But the world isn't like that...
Danny.
Re:WHICH parts of this is wrong? (Score:2)
There have been lots of criticisms of different parts of Gould's popular works... I'd say that most of Gould's popular writing is solid, both the biology and the history of science - that is, a lot of details may have been improved on (developmental biology in particular has made huge strides in the last thirty years), but it's not fundamentally wrong-headed.
Was Maynard Smith wrong in claiming almost all prominent evol biologists consider Gould to be totally confused?
If he claimed that, then yes, he was wrong. See the books by Carroll or McNamara for examples, but there are plenty more.
Was Mayr wrong in claiming Gould is misrepresenting the position of the foremost evol biol researchers?
I'd say "partly true" - a lot of people in this debate have oversimplified the positions of their opponents and Gould is no exception.
what political positions of the evol biologists influenced the criticisms, as you hinted? (Dawkins for one doesn't seem extreme.)
Dawkins is rabidly anti-religious! Something I sympathise with (I'm an atheist myself), but still something to keep in mind when reading him.
Danny.
Re:WHICH parts of this is wrong? (Score:2)
That's hyperbole if ever I saw any! And it doesn't seem to be talking about popular works, either... so in this case my counterexamples stand. (Even if Gould's popular works were wrong-headed, that would be true of lots of scientists moving into the popular arena - Pauling on vitamin C and Penrose on AI spring to mind - and doesn't mean his other work is bad.)
Dawkins' anti-religious position clearly influences his approach - I have no problem with that, but I don't see why Gould's very tenuous Marxism is somehow totally damning while this is completely irrelevant.
Lots of ill-informed critics have whinged about Gould's Marxism - again, if that's the best they can do, it's pretty feeble. Of course the existence of poor criticism doesn't undermine the more robust criticims, but there has been an awful lot of ad homninem attacks flying around.
But we both seem to have made up our minds on this, so there's not much point arguing it really - you don't have to read Gould (whose style is a bit of an acquired taste even for those who like his content) and I plan to keep on reading The Structure of Evolutionary Theory... you might see a review sometime, then we can restart this discussion!
Danny.
Re:No evol biologists supporting Gould? (Score:2)
Influential, sure. Important... well, that's obviously debatable, but I don't think it's aged that well. (Don't you feel just a bit odd quoting an author's own opinion of his books as evidence of their importance??)
Danny.
Re:No evol biologists supporting Gould? (Score:2)
It all depends how narrowly you define "evolutionary biologist" (palaeontologists are evolutionary biologists!), but check the citation records for e.g. Ontogeny and Phylogeny or the Spandrels paper, and I'm sure you'll find some who meet even narrow criteria. Someone like Elizabeth Vrba is an evolutionary biologist - unless any connection with palaeontology is somehow enough to prevent someone qualifying!
And frankly, if practicising palaeontologists find Gould's evolutionary biology so useful that it informs entire research programmes, that trumps any number of throwaway one line dismissals by theoretical evolutionary biologists.
Danny.
Re:No evol biologists supporting Gould? (Score:2)
But if that kind of award matters to you, what about all of Gould's awards, both for professional and popular work? (American Book Award for Science, Science Book Prize, Macarthur Foundation fellowship, etc.) There does seem to be a bit of a double standard again...
Danny.
Re:No evol biologists supporting Gould? (Score:2)
Can you point to any examples other than Mayr and Maynard Smith? Those two have a personal vendetta against Gould, so I think they should be excluded - certainly that's a more sensible ground for "excluding" people than knowledge of palaeontology or sociology!
Also, you are still switching backwards and forwards between 'public writing' and 'popular writing'. Check the citation records for Gould's academic work, or any of the scores of books and collections just on punctuated equilibrium, for starters.
Gould's popular writing is on the same subjects as his academic work, and presents the same general ideas. And the critics you worship attack both, so I don't see why you have this obsession with his popular writing - except that it allows you to ignore the evidence of Gould's scientific influence and rant about "Gouldism". (By the way, I agree this exists - it's what afflicts people who have read Gould and nothing else in the area - it's similar to "Dawkinsism", which comes from people who have read _The Selfish Gene_ but nothing else about evolution.)
Gould has obvious emotional (and/or ideological) interest in stopping a public impression that there are biological basis for human behaviour.
And his opponents have obvious emotional and ideological biases of their own. I find it totally incredible that some of Gould's critics whinge about his ideological bias and then complain because he tries to highlight the ideological background to their science.
It seems the intelligence research people in psychology has more or less the same opinion about Gould's popular writing in their field ("Mismeasure")
Again, this depends on which side of the debate you pick people from. There are psychologists on both sides. But you probably think The Bell Curve was good science... whereas I think the general consensus was that it was crap.
Danny.
Mayr on Gould (Score:2)
Re:No evol biologists supporting Gould? (Score:2)
But all scientists are biased, and all are influenced by the social context in which they live and work. This isn't rocket science, this is just basic philosophy of science. If you want studies, heaps has been written on evolutionary biology (perhaps even too much, proportionately - personally I think other areas of science deserve more attention from the historians and philosophers).
Danny.
Re:Mayr on Gould (Score:2)
Danny.
Re:Mayr on Gould (Score:2)
Danny.
Re:Mayr on Gould (Score:2)
Danny.
Re:Are you pulling my leg? (Score:2)
Anyway, as I've pointed out before, Dawkins has a very clear ideological axe to grind - he's rabidly anti-religous. But you still trust him...
It's very clear that your criteria for judging whether people are trustworthy (or worth reading) are based on your preconceptions - you agree with Dawkins, etc. therefore any evidence that they might not be 100% reliable can be ignored, you disagree with Gould, so similar evidence gets your full attention.
Danny.
Re:You are pulling my leg (Score:2)
Danny.
Re:This IS testable (Score:2)
There are some people who do do this. Gould is certainly inaccurate if he's applying this universally, but it's not a strawman - there are real "Selfish Geneists" out there. In any event, the fact that evolutionary biologists are (mostly) careful in this area now is at least partly a result of e.g. Gould and Lewontin's Spandrels paper and similar writings...
Danny.
Re:Are you serious!? (Score:2)
Gould's criticisms of pan-adaptationism are not (I think) as important or as extensive in reach as he makes them out to be - but neither are they unimportant or mis-aimed as his critics suggest.
Danny.
Marx stole the concept of the dialectic (Score:4, Insightful)
For Hegel, the dialectic [pfeiffer.edu] was the observeable process of societal change to a more complex state, which Marx misrepresented as a controllable process with a finite goal: the Worker's Paradise. Of course, if you are trying to get folks to follow you, it's best to promise them a better world will result from drinking your koolaid.
Which maybe is why Marxists don't like Evolution, since like Hegel's dialectic, Evolution is an ongoing process without an ideal ending, rather a road to Paradise.
PS, try reading the Manifesto and then reading Revelations sometime, the two are eerily similar...
Re:Marx stole the concept of the dialectic (Score:2)
Well, don't forget that the synthesis becomes the new thesis, and the wheel turns on. But I think it applies more to how cultural ideals evolve than simply how one reachs a conclusion.
There is really no 'antithesis' in evolution, thus you couldn't use the dialectical method in evolution.
Right, well I was really pointing out that the dialectic can be a useful tool to understand and even predict how human ideas will evolove, not so much natural systems. I agree that it is usually a bad idea to use anthropomorphic metaphors when trying to describe evolution (or other complex scientific theories). A dialectical methodology is useful only when there is interaction between the two ideals or features. So it might be a useful way to look at predator prey relationships, or sexual selection, for instance, but not so useful for speciation due to land bridges or other external (to the system) natural events.
However, the term is perhaps perpetually tainted by Marx's pseudo-religious movement, such that to even mention it one is called a Marxist rather than a Hegelist, as most people actually seem to believe Marx's claims that his ideas were an extension and refinement of Hegel's rather than a corruption.
Who is John Hopkins? (Score:1)
Biggest problem with macroevolution... (Score:1)
The issue here is that, like many complex physical systems, you require initial conditions to define the evolutionary starting point which macroevolution doesn't consider. It is, however, adept at describing the physical system itself. I believe that the nature of this must be metaphysical in nature. What mechanism is unknown, but again, just MHO.
Re:Biggest problem with macroevolution... (Score:3, Interesting)
Two problems with this contentin that I can see right off the bat:
Re:Biggest problem with macroevolution... (Score:2)
What on earth are you gibbering about? Can macroevolution , in your confused view, decribe the initial non-living conditions or not?
Anyway, what is metaphical about the emergent properties of matter? Go read this [everything2.com] for some real evolutionary metaphics.
Biggest problem with astronomy... (Score:2)
Re:Biggest problem with astronomy... (Score:1)
I second the motion. To such a succinct retort, I will only add that 'metaphysics' (nice ten-dollar word, huh?) is a poor relation to its vastly superior successor: a materialist understanding of 'emergent behavior' -- something Dennett [everything2.com] does indeed excel at teasing out of empirical facts.
Initial conditions don't really matter (Score:2)
If you read Wolfram's "A new kind of science" you'll see that behaviour of systems like this is typically independent of initial conditions. It's the rule that counts. Of couse when a lot of rules are competing in parallel then the most efficient will win, so presumably DNA has itself evolved so that typical mutations are viable.
Re:Initial conditions don't really matter (Score:2)
Re:Biggest problem with macroevolution... (Score:1)
the term "macroevolution" was initially invented by fundamentalists for their own reasons, but eventually became used even by biologists as a convenient shorthand for "evolution at or above the species level", that is, more or less, "speciation". insofar as the term "macroevolution" means anything at all, that's pretty much it. and when you're talking of that, then you're presupposing an initial (population of a) species which changes or diverges (evolves, for short) into one or more different species.
perhaps you meant to refer to abiogenesis and the fact that the conditions of the very early earth are not very well known. but if so, you used the wrong terminology; "macroevolution" - like any kind of biological evolution - really has nothing much to do with that.
sigh .. there is no such thing as "macroevolution" (Score:4, Interesting)
If I stand on one side of my living room and walk heel-to-toe, I will eventually end up at the other side of my living room. If I stand in San Francisco and walk heel-to-toe in an easterly direction, I will eventually end up in New York. Fundamentalists would call the former activity "microwalking" and the latter "macrowalking", but it should be perfectly obvious that the process in both cases is exactly the same; the difference is in the scale of magnitude.
"Macroevolution" is a fictional concept invented by fundamentalists who have discovered (to their chagrin) that biological evolution cannot be honestly denied, but cannot be allowed to be the explanation for the biodiversity on life on Earth. It's just too bad for the fundamentalists that their basic premise (that evolution is incompatible with religion) is one of the most outlandish and potentially destructive lies ever told.
Re:sigh .. there is no such thing as "macroevoluti (Score:5, Insightful)
You seem to have a narrow view of evolution derived from the classical genetics viewpoint circa 1930. As someone who has written papers on molecular evolution, I could equally claim that "changes in the gene pool" is a fictious concept because from the molecular viewpoint it is obviously just DNA mutations. And a chemist looking at the situation could say "no, it is just chemical reactions" and the physicist could say "no, it is just subatomic interactions". Science works on many different levels. Like the story of the blind men and the elephant, the true story can only be put together from integrating the various viewpoints.
Re:sigh .. there is no such thing as "macroevoluti (Score:4, Informative)
For example, there's the idea Dawkins called "evolution of evolvability" - certain body plans might be more adaptable than others, allowing some phyla to radiate more rapidly (e.g. insects). That's not part of classical natural selection, but it's probably an important process.
Also, long term trends might be influenced by catastrophes. A sudden environmental change might alter the rules of selection overnight. You might see pruning of groups which can't survive meteor impacts.
That's not to say that natural selection isn't the most important part of evolution. It's the only way that complex adaptations can evolve.
Re:sigh .. there is no such thing as "macroevoluti (Score:1)
Re:sigh .. there is no such thing as "macroevoluti (Score:2)
Re:sigh .. there is no such thing as "macroevoluti (Score:1)
On an unrelated note I'm really getting tired of the 'fundamentalist' title being thrown around here, it's basically name calling and no better than the good old days of calling your neighbor a commie to get your way.
Re:sigh .. there is no such thing as "macroevoluti (Score:1)
Even though the fossil record and DNA analysis provide excellent evidence that the species are related.
There are still alot of BIG hurdles to get over before we can even prove that it's biologically possible for all species to have evoloved from a common ancestor(s).
Well, nothing is ever *proven* in science - just given overwhelming support. And no, there are no big hurdles about it being biologically possible for all species to have evolved from a common ancestor. Again, the fossil record and DNA do a very nice job.
Just because someone has a non-scientific opinion, does not mean they are ignorant, let alone a fundamentalist.
But if they try to claim that their non-scientific opinion is scientific, then they are either ignorant or lying. And as far as fundamentalists go, if you ever would read the usenet newsgroup talk.origins, you would see that those who object to evolution are overwhelmingly people who identify themselves as fundamentalists.
-MDL
Re:sigh .. there is no such thing as "macroevoluti (Score:1)
Re:Questions evolutionists don't want to answer (Score:1)
The fossil record also shows that at a given time; a certain type of animal existed; and at a later point in time, a similar but different type of animal existed. As an example, look at the evolution of the horse. [talkorigins.org]. As far as DNA goes, one could argue that two animals that have similar physical characteristics should have similar DNA without having common descent. But their having similar "JUNK" DNA makes it near impossible to refute common descent.
The combined evidence of DNA and the fossil record in NO WAY contradict a belief in a world created as Genesis literally describes.
Well, if you take Genesis literally, not only does it contradict biological evolution, but astronomy, geology, physics, and even itself.
I agree alot of people on talk-origins push this as a scientific belief, which it of course is not. That doesn't mean however that the belief is contrary to scientific evidence.
If you take the bible literally, it contradicts scientific evidence in many disiplines. But there are many mainstream Christian denominations that have no problem with evolution and the theory of evolution.
Re:Questions evolutionists don't want to answer (Score:1)
Which does not contradict a world where a set of animals was intially created by God, and then evolved over time from that starting point. The difference is only in seeing it as common descent or as descent from a number of common ancestors.
As far as DNA goes, one could argue that two animals that have similar physical characteristics should have similar DNA without having common descent. But their having similar "JUNK" DNA makes it near impossible to refute common descent.
Two ways to go here, first and most important our understanding of DNA is still in it's early stages and it's probably a little premature to declare what parts of "DNA" are insignificant and which simply haven't had their purpose found yet. Secondly, if an intial set of creatures where created and then evolved to create a much larger diversity, insignificant parts of their DNA would remain similar. But again, untill we understand what is significant and what isn't in DNA alot better, it's far too premature to say what needs to be there and what doesn't.
Well, if you take Genesis literally, not only does it contradict biological evolution, but astronomy, geology, physics, and even itself.
If you take the bible literally, it contradicts scientific evidence in many disiplines
Then show me a single example which works when Genesis is assumed true. All the "contradictions" I've seen people claim fall apart unless you already assume Genesis is false. Or in other words, the contradictions are easily explained if Genesis is both interpreted literally AND taken as truth.
Re:sigh .. there is no such thing as "macroevoluti (Score:1)
Re:sigh .. there is no such thing as "macroevoluti (Score:1)
Re:sigh .. there is no such thing as "macroevoluti (Score:2, Interesting)
Humans determine when a "macroevoltuionary" event has occured in hindsight. Nature does not care whether we deem it a "micro" or "macro" evolution. As far as the physical process is concerned, there is nothing but microevolitionary changes or, in your analogy "footsteps".
There are no oceans seperating a mutated child from it's parent. The only way oceans occur is after the fact, when ancestors of the new orgamism die out.
Re:sigh .. there is no such thing as "macroevoluti (Score:1)
Re:sigh .. there is no such thing as "macroevoluti (Score:2, Interesting)
Re:sigh .. there is no such thing as "macroevoluti (Score:2, Insightful)
You can claim that some gaps were never filled, but until you come up with evidence that it was not filled or an alternate theory that is actually *evidenced*, evolution simply has no competition.
Intelligent designers never provide a scintilla of evidence that any creator/guider exists. They just complain that the (literal) mountains of evidence that scientists have unearthed which favors evolution is not enough. They are nothing but a peanut gallery.
Re:sigh .. there is no such thing as "macroevoluti (Score:1)
Re:sigh .. there is no such thing as "macroevoluti (Score:1)
To turn that around, until you come up with evidence that it was filled...
From a scientific stand point though I agree, evolution has no competition. But that does not mean there aren't other interpretations of scientific evidence that simply don't meet the testability, or simplicity criteria which science demands.
Intelligent designers never provide a scintilla of evidence that any creator/guider exists
Actually, all evidence proposed for evolution is in keeping with the theory of intelligent design, the difference is how the evidence is interpreted. There are two ways unscientific can be taken, to be contrary to scientific evidence, or to the scientific process. Although ID is contrary to the process, it is in keeping with the evidence. Any arguments against it generally wind down to arguing philosophy with a bit of probability thrown. Oh yeah, and a lot of personal opinion and experience thrown in to make it a tough issue to debate calmly
Re:sigh .. there is no such thing as "macroevoluti (Score:1)
Please state one of these reasons for supporting the conclusions of ID, keeping in mind that argument from incredulity is illogical.
Re:sigh .. there is no such thing as "macroevoluti (Score:1)
Re:sigh .. there is no such thing as "macroevoluti (Score:1)
I've stated a couple of times in my posts that evolution/common descent is a good scientific explanation for a lot of the evidence. What I'm also trying to state is that that doesn't make it the only rational explanation. To answer your question about Archy, why wouldn't a God create such a creature? That it proves evolution over creation has an element of philosophy. Sure a particular example can fit better with one explanation over another. But looking at the big picture any explanation is going to have some tough hurdles, Abiogenesis is evolutions. Yes, evolution is independent of how the original ancestor came about. But if a person is putting together a belief for the origin of everything from beggining to end, maybe it is less improbable that God exists than a working cell with DNA came about via natural processes. It's not such an irrational conclusion to reach.
Re:sigh .. there is no such thing as "macroevoluti (Score:1)
Unless we have a time machine, there never will be direct irrefutable evidence for how abiogenesis occurred on Earth, so it's easy to say that any theory is not out of keeping with current evidence, mainly because there is none.
Suppose that a complete path from inorganic materials (water, methane and rocks for example) to a primitive self-replicator is mapped out by science. You can then say that your designer is responsible for the fact that the inorganic materials are so useful for life. I.E, it 'designed' matter itself.
If you look at things which were once attributed to divine origin (or design by non-human intelligence in ID-speak) you can see this trend. The sun, moon, stars, weather, lightning, fire and of course the Earth itself, including rivers, mountains, oceans, volcanos. Everything basically.
Don't worry though, there's a nice safe hiding place behind the big bang for your designer to lurk in for quite a while yet.
Re:sigh .. there is no such thing as "macroevoluti (Score:2)
But can we observe speciation or massive shifts from one type of organism to another? No. We know how you you could walk from SF to NY, but exactly how does a dinosaur become a bird or a monkey become a man? There are vague and general theories, but the case is far from closed. Evolutionists respond that we shouldn't expect to see this happening because of the vast amounts of time required, when pressed on this issue.
Now, I may have given away my bias, but I'm trying to be objective here. On the one hand, we understand the process very well, we can observe it in nature, and reproduce it in the lab. On the other hand, we have some "what if's", "maybe's", and such. Nothing observable. I think that warrants some special care to distinguish between the two. Economics on any scale uses concepts such as supply and demand, the rationality of individual choice, etc. but I had to take a microeconomics class as well as a macroeconomics clss. Apparently, it is still important to know the difference between the two.
Re:sigh .. there is no such thing as "macroevoluti (Score:2)
Yes. Read this [talkorigins.org] and this [talkorigins.org].
Re:sigh .. there is no such thing as "macroevoluti (Score:2)
We observe speciation quite regularly, even in mammals (ie, Fenroe Island house rats).
As for monkey to man, well, take a chimpanzee, strip the duplicate of chromosome 2, and change the ~2,000,000 genetic variables that matter (give or take half a million) (only 3-5% of our genes matter).
Obviously, such things are not that simple, at with only ~100 mutations occurring in any given generation, well, that's a lot of time to get things straight, as it were - humans and chimpanzees are about a quarter million generations apart (About 3 billion base pairs, a 1.8% difference between the two, for about 50 million base pairs different (ignoring the duplicated second chromosome in the chimpanzee), they are diverging, ie, split in two, they only need half the generational diference, at 100 mutations a generation, leaves you with a quarter million generations).
I think the problem most antievolutionists have is that they can't wrap their heads around the (admittingly) mind-boggling timescales involved. They certainly are very humbling, to say the least.
Re:sigh .. there is no such thing as "macroevoluti (Score:1)
The vast majority of mutations do not kill an organism, or stop it from reproducing (which is more important in evolutionary terms.) The susceptibility of different genes to mutation is quite variable, and those genes which are 'core' to the viability of an organism (say, genes coding for DNA transcription itself) have developed to be very well protected against change.
A more restrictive definition of "good mutation" might be one which gives the organism and its own offspring a competitive boost. Unfortunately this depends on the very specific selective pressures the organism finds itself under at its own time and place in the ecosystem as a whole. Observation in the lab would be a very artificial ecosystem indeed, and in the field it would be very difficult to observe measurable effects.
Mutation is certainly the result of replication failing to produce an absolutely faithful copy of the original DNA strands, however whether you call that deterioration or not is rather subjective! A certain rate of "transcription errors" is built in (by natural selection) because it allows for the generation of genetic diversity that natural selection can work with.
Re:sigh .. there is no such thing as "macroevoluti (Score:2)
No, you will eventually end up somewhere on the east coast of the United States. The channelling and constraints of the road system make it more likely that you will follow certain paths than others (going due east continuously is not an option!) and also make it likely that you will reach the east coast in an urban centre or road junction, rather than a random point.
Danny.
Yeah, too bad we can't prove Macro-Gravity either (Score:2, Funny)
While one can test microgravity by dropping an apple from a suitably leaning tower, science only draws it's conclusions about macrogravity from observation and forensic evidence, just like Macroevolution. But all good Xians know that this "evidence" the anti-religion scientists put forth is really put there by the dark one to fool us!
We must stop these anti-religious scientists from teaching our children to distrust the invisible hand of Christ and so commit all sorts of immoral acts I can't even begin to type, with their subversive theory of MacroGravity!
Re:Yeah, too bad we can't prove Macro-Gravity eith (Score:2)
Kintanon
Re:Once again.... (Score:2)
I remember when the standard was the bombadier beetle. Now it's the angler fish. Evolution in action!
I can't tell you *how* it evolved, because I, personally, wasn't sitting around watching it. However, you ought to be able to come up with a scenario of how it *could* have happened.
Re:Once again.... (Score:2)
Re:Once again.... (Score:2)
The toast you had for breakfast started out life as a series of wheat plants growing on a farm somewhere. It was then subjected to a variety of processes that ultimately ended up in the toast on your plate.
I can describe these processes in the general, but would find it very difficult to reconstruct those processes in reverse, finally ending up on the plot of land where the wheat once grew that constituted your breakfast.
Instead, it is far easier to generalize somewhat, describing the processes in the chain from wheat to toast in a less specific manner - and you must take it "on faith" that these general processes map to your specific piece of toast.
That inability to provide specific evidence with regards to your breakfast does not mean that the generalization of how toast is made is de facto invalid.
So with regard to your angler fish, the underlying mechanisms and processes - natural selection, random and inheritable mutation, and so on and so forth - can suffice to show how the species _could_ have evolved, without needing to present you with the preserved corpses (and all their contained genetic information) of each successive generation of "angler fish" back to some earlier ancestor.
If you want to see examples of the mechanisms of evolution at work, where you _can_ track change through successive generations, you have to work forward - and there's lots and lots of examples done with fruit flies (whose gestation period is sufficiently short to permit experimentation) and realize - call it an act of "faith" if you must - that the same mechanisms apply to all known DNA-based organisms.
DG
Re:Once again.... (Score:2)
Are you implying that the aluminum your hammer was made of exists because of divine intervention?
As far as your archer fish is concerned, there are evolutionary process analogues to turning, milling, drilling and so on. Some of those processes can be demonstrated in the lab, much the same way that you demonstrated "machining" on scrap metal that was "not your hammer" but was sufficiantly "like your hammer" to demonstrate the validity of the process as applied to "hammers"
So while nobody is going to start with some sort of proto-archerfish and "evolve" it into a bona fide archerfish in front of you, they can demonstrate the mechanisms by which proto-archerfish could develop into bona fide archerfish, and this should be sufficiant to prove the point.
You could call that "faith" if you really wanted to, but to do so is to miss the point.
Incidently, people _have_ "developed" atoms before. You can make helium out of hydrogen given enough energy.... it's been done.
DG
you are using some other definition of atom (Score:2)
Negative, moving atomic particles around is not equivalent to making an atom no more than cooking an omelet makes you a chicken.
Atoms are of course made of sub-atomic particles, and are formed by "moving" sub-atomic particles, so this makes no sense. If you move a proton and an electron together, you have made a hydrogen atom. If you add a neutron, you have made a helium atom, refresh your knoledge of atomic theory, please.
You also seem to be building a false dichotomy between theory and fact: fact is, scientific theories describe facts (generally called observations). We see the fact that things fall when you drop them, and derive from that the theory of gravity. We see the fact that species exist and change over time and develop from that the theory of evolution.
Meanwhile predictions are made based on a theory to see if theories do in fact describe facts, if predictive experiments haven't been done, the theory is called a hypothesis.
But you seem to be using the term 'theory' in the way scientists use 'hypothesis', which makes your arguments regarding science rather illogical. We both have to agree something is a hammer before we can discuss hammers, so long as you keep insisting a hammer is a chicken, the process will lead to neither a well driven nail nor to a tasty omelette.
Re:Once again.... (Score:1)
In the case of quantum theory, there's no "proof" that photons or electrons really exist. These are just convinient labels we use to describe our observations. The reason these models are so accepted is because they go a great job explaining observations we had, as well as predicting observations we would make later (in the case of relativity, the bending of light around massive objects, etc).
Re:Once again.... (Score:2)
Evolution is anything but an unsubstantiated theory. This [talkorigins.org] is a good site to start with.
The answer wasn't "Just Believe" it was (Score:2)
Easy enough: start with an ambush predator (on that lies in wait for prey, there are plenty of those), due to a slight mutation one comes along with a lighter or slightly raised patch on it's head, some fish swim in to check it out and are more easily caught, members of the species with the variation tend to catch more, and thus have more offspring. Many of the offspring have the raised patch, some a bit larger some a bit smaller.
The ones with a bit larger catch more and have more offspring, and so on, eventually you have something like an angler fish, no magic hand waving & no faith required, just small changes that confer small advantages that are selected for over millions of years...
Re:Once again.... (Score:2)
No. Consider these two statments:
If I make the first statement, I am asserting that God made the fish and that's that. You must have faith to agree with me.
If I make the second statement, I am only offering a possibility. Agreeing with me in this case only means that you agree that my scenario is *possible*.
Substitute 'car' for 'angler fish. If you point at a car and ask where it came from, I can either say that God made it, or I can say that I know that some cars come from Europe on a boat, and that some come from Detroit on a train, so it might have been one of those two possiblities. Which one requires faith?
If you're trying to convince me
What am I supposed to be convincing you of?
Re:Once again.... (Score:1)
The first problem is your changing the question:
Originaly you are answering the question "How was the fish Made"
Then in your analogy you answer the question "Where did the "fish/car" come from"
Asking where something came from or how it was made are two entirly different things. So if you said the the train or the boat made the car, I would think you were a mad man.
Here's a better anaolgy:
A little parable by this author ('A Tale of Two Fleas', Ex Nihilo 2(3)37-38, July 1979) told of two scientific fleas living in a motor-car, pondering how it came to be. One insisted that, since it was the most logical conclusion from the evidence, the car was not made by processes operating in the car. The other demanded that such religious ideas not be brought into the flea schools, because science could only deal with the sorts of processes observable and operating today. To propose a maker who could not now be seen, and a process of making that was no longer operating, was by definition unscientific in spite of the fact that it happened to be true! This flea was locking the investigation into the belief that the way the world WORKS is also the way it ORIGINATED. He believed that anything else was breaking the rules of science. Hadn't their science developed by means of studying only the present-day, naturally occurring processes in the car? His 'rules', of course, meant that it became impossible for him to deduce logically the correct explanation in the case of the car.
Re:Once again.... (Score:1)
Evolution isn't such a simple process that it can be explained to you in 20 minutes. Neither can the history of one particular species be isolated and explained except in the context of the development of all life.
If it's simple answers you want, well, the creationists have them in spades. If, rather, you're looking for an accurate and predictive model of how the diversity of life on this planet came to be, well, go back to school. It's a complicated theory, like any theory that's useful.
Re:Once again.... (Score:1)
Also, we're learning to predict (as a result of eolutionary theory) which systems are likely to have the balance of simplicity and complexity needed to become emergent.
Maybe those aren't the kind of predictions you were looking for, but those are examples of predictive work being done in evolutionary theory.
Re:I gotta confess... (Score:1, Offtopic)
Re:Something from nothing? (Score:3, Informative)
The problem is with the statement that evolution is the survival of the fittest. This places an emotional constraint in the eyes of people that makes them demand that there is a goal. There isn't. Evolution never set out to create humans, or any other species.
In its most simple terms evolution is life reacting to changes in the environment. Those speices that can adapt to those changes either survive or give rise to new species. Those that can not die.
Evolution doesn't get "new information" for free (this isn't information theory anyway). Life creates the needed inforamtion at great cost. Most mutations are lethal. Many that are not lethal are useless (who needs atwo-headed turtle?) Life is not a closed system by any means. Energy is constantly being pumped in from the sun and the mineral resources in the earth.
Re:Something from nothing? (Score:1)
There is no information inherent to your genome, or mine. If a scientist comes along and maps my genome, he creates information to associate my genes with attributes I display and with attributes displayed by others. If that scientist dies or forgets the information without ever leaving a record of that information, the information is destroyed. If the records are destroyed, and no other copies exist, the information is destroyed. If the records exist, but no other organism is ever able to access or understand them, the information is destroyed.
This all comes back to the tree falling in the forest. It does not make a sound unless you percieve it. It will generate a compression wave in an atmosphere. The compression wave is not sound unless you percieve it. Your genome is not information unless someone maps it.
Researchers don't tread here because they have either (a) come to realize all that I've stated, or more likely than not (b) do not consider defining the consequences of defining a set of facts to be true as important when they are still laboring to prove those facts exist in the first place.
Re:Something from nothing? (Score:2)
Re:Something from nothing? (Score:1)
You've confused "meaning" with "information." Information is a measure of how far removed from random a system is (an objective reality), regardless of whether a mind has perceived it. Meaning is whatever value you place on your perception of it (a subjective reality).
> There is no information inherent to your genome, or mine.
Sorry to disagree, but this is circular reasoning. An ordered system (read: an information-rich objective reality) give birth to you and me. The great question remains: Where does such information originate?
-- BYTEBuG
Researchers tread it all the time, but since they (Score:2)
More==>
The numerical calculation of entropy changes accompanying physical and chemical changes are very well understood and are the basis of the mathematical determination of free energy, emf characteristics of voltaic cells, equilibrium constants, refrigeration cycles, steam turbine operating parameters, and a host of other parameters. The creationist position would necessarily discard the entire mathematical framework of thermodynamics and would provide no basis for the engineering design of turbines, refrigeration units, industrial pumps, etc. It would do away with the well-developed mathematical relationships of physical chemistry, including the effect of temperature and pressure on equilibrium constants and phase changes. [talkorigins.org]
So what you are really asking when talking about thermodynamics is where does the energy needed to reverse entropy come from? The aswer is big, hot, and round, and has often been called a god in the past, but unlike the Xian god can be seen quite easily with the human eye. [nasa.gov]
Meanwhile, the origin of the first cell is interesting (and certainly there are plenty of researchers who aren't afraid of looking into that), but has nothing to do with evolution, since Evolution is the theory of what happened AFTER the first cell formed (which is why Darwin's book is called the Origin of the Species, not the Origin of Life.
Re:Something from nothing? (Score:1)
grep HERE
Re: Something from nothing? (Score:2)
> With every new dissertation on evolution, I find it interesting that no researcher seems to address the fundamental, underlying problem which dogs evolution:
Read a lot of dissertations on evolution, do you?
> Where does new genetic information come from?
Depends on how you define "information". If you use Shannon information, the less predictable an observation is then the more information you get from the observation. From that perspective a mudslide generates more information than a birth with a mutation does.
Evolution deniers have tried their hand at defining genomic information and making a claim that information so defined can't increase spontaneously, but those claims never stand up to the test. The closest thing to rigor was the attempt by Lee Spetner, but a close reading shows that he pulls a bait-n-switch argument when the chips are down. To all appearances, there is no law of nature that says "information can't increase".
> Why is it so important? Because they're saying we're getting something from nothing.
No, we're getting that "something" from evolution.
Scientists are very like creationists when they see something amazing and say "That could never have come about by chance!". The two camps part ways after that observation, with the creationist invoking the "goddidit" mantra and the scientist trying to figure out what actually caused the counterintuitive event. In this case, the explanation is neo-darwinian evolution. But there's nothing special about that; we don't get "something for nothing" when planets form, when hurricanes form, when snowflakes form, or when NaOH + HCl => NaCl + H2O. Science is all about understanding why those things happen rather than some other outcome.
> A system which isn't directed towards any goal teleologically goes nowhere.
Loaded semantics there. Is a mudslide "directed towards a goal"? A hurricane? A supernova?
> And if it is directed, it must have a net positive influx of information. What is that source?
Impossible to say without hearing your definition of "information", but the usual intuitive answer is "from the environment". By intuitive standards, genetic algorithms can "create information" simply by interacting with their environment (i.e., the fitness evaluation). Why can't the "biological algorithm" do the same?
The problem with your argument is that there's no empirical reason to be concerned with it. It's the armchair argument of people who want to show that evolution is wrong for reasons that have nothing to do with information.
Re:Something from nothing? (Score:1)
Seriously, the addition of new genetic information is well documented. It comes from mutations. For instance, certain microorganisms have developed an enzyme which will break down nylon, which IIRC resulted from a phase shift mutation (i.e., an off-by-one error in gene coding).
Mutation, recombination, and selection (Score:2)
A system which isn't directed towards any goal teleologically goes nowhere.
This sentence anthropomorphizes a natural process: think about it, what is the "direction" of plate tectonics? The "direction" of planetary orbits?
Likewise, evolution doesn't have a "goal" and it's not "directed", rather life survives by being flexible, and that flexibility takes new forms. Forms that survive well in the new conditions make lots of copies of themselves, while forms that don't change or change in a way that doesn't work so well don't make lots of copies, and disappear.
By the way, Gould most certainly did "touch on this" in fact devoted a good deal of Wonderful Life [amazon.com] to describing where new genetic information comes from.
not a closed system! (Score:2)
From random mutations.
If you're talking about the classic "evolution violates Newton's third law" argument, the answer is that Newton's third only applies to closed systems (like the universe). The Earth is not a closed system; it happens to be right next to a powerful energy source: our sun. The "something from nothing" is actually "something from solar energy". (And probably geothermal energy.)
A system which isn't directed towards any goal teleologically goes nowhere.
Or everywhere. An expanding system goes in all directions if it's not directed. And evolution isn't directed. However it is constrained by natural selection. Thus harmful mutations are weeded out by the simple fact that those with harmful mutations die (or, more to the point, fail to reproduce).
Nylon eating bacteria (Score:2)
Well, not so good if you like to wear nylon, but good for the bugs who can now eat it...
Huh? Anti Matter Physics? (Score:2)
Huh? Is that -2lot? The 2lot that works in an anti-matter universe? Here, in this universe, releasing energy from a system increases entropy & decreases order (a bush burned to ash), while adding energy to a system tends to decrease entropy and increase order (the growing bush before it burned).
Of course if one system releases so much energy that it overwhelms the ability of another system to absorb that energy, both systems can release their energy and decrease their order (the invisible flame thrower with which might Thor ignited the bush), but in both cases the release of energy accompanies the decrease in entropy and order as the systems burn to a lower energy state (ashes to ashes).
But if you are from an anti-matter universe, I can see how this whole debate would be very confusing to you...
By what cause did "natural selection" arise?
Different issue entirely, but I glad you are starting to see that it has nothing to do with 2lot in the normal matter universe, since yes we are getting a "free lunch" from the god formerly known as Ra. Organic molecules tend to organize themselves in the presence of a steady input of energy [siu.edu], so once we have the free lunch courtesy of the Sun, increasing order is entirely expected.
Of course, non of this speculation is a valid criticism of the theory of evolution, since evolution specifically deals with what happens after the first life has formed...
Once you have the first 2 life forms, small differences between the two lead one to do better in a slightly higher place and the other to do better in a slightly lower place, and so natural selection begins.