Register | Sign In


Understanding through Discussion


EvC Forum active members: 52 (9178 total)
2 online now:
Newest Member: Anig
Upcoming Birthdays: Theodoric
Post Volume: Total: 918,102 Year: 5,359/9,624 Month: 384/323 Week: 24/204 Day: 24/21 Hour: 0/0


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   Evolving the Musculoskeletal System
Dr Jack
Member
Posts: 3514
From: Immigrant in the land of Deutsch
Joined: 07-14-2003


Message 100 of 527 (578005)
08-31-2010 1:22 PM
Reply to: Message 87 by ICdesign
08-30-2010 7:26 PM


For one thing, your blood needs your bones. Do your nerves need blood?...can you live without your bones?...will your nerves survive if you die?
We, of course, can't survive without these things. But they didn't evolve in us, or anything like us. Bones first emerged in fish, probably initially as a means of storing valuable minerals which was only later co-opted as a means of additionally strengthening cartilage. Blood evolved earlier, probably in a worm-like organism. Nerves in some of the most basal animals, but in nothing like the organisation or complexity seen in us.

This message is a reply to:
 Message 87 by ICdesign, posted 08-30-2010 7:26 PM ICdesign has not replied

  
Dr Jack
Member
Posts: 3514
From: Immigrant in the land of Deutsch
Joined: 07-14-2003


Message 111 of 527 (578032)
08-31-2010 3:18 PM
Reply to: Message 109 by Dogmafood
08-31-2010 3:00 PM


People are often born today with six fingers.
I think this is a horrible example, for three reasons:
1. In all the history of all the tetrapods in all the world there has never been a line of tetrapods that reversed the orginal reduction to pentadactyl "hands". Many lineages have reduced that number, none have increased it.
2. Most (not all) six fingered individuals are the result of a development defect not a genetic mutation.
3. It suggests that the primary mode of evolution is through that kind of jump when, in face, there is every reason to think that the primary mode of evolution is vastly more gradual.
Is it really that hard to imagine the first opposable thumb showing up out of the blue?
It may or may not be hard to imagine, but it's not what happened. In fact, primates evolved from tree climbing ancestors who ran along branches, in these ancestors the thumb-to-be spread from the other digits giving a wider running surface, suitable for gripping the top of branches in a small mammal. It was only later that the thumb continued its separation and formed the kind of oppositional arrangement familiar to us.
Thumbs, like nearly any other feature you care to mention, came about by very, very gradual changes not saltational jumps.
Edited by Mr Jack, : No reason given.

This message is a reply to:
 Message 109 by Dogmafood, posted 08-31-2010 3:00 PM Dogmafood has replied

Replies to this message:
 Message 114 by bluegenes, posted 08-31-2010 3:39 PM Dr Jack has replied
 Message 116 by Dogmafood, posted 08-31-2010 3:45 PM Dr Jack has not replied

  
Dr Jack
Member
Posts: 3514
From: Immigrant in the land of Deutsch
Joined: 07-14-2003


Message 115 of 527 (578044)
08-31-2010 3:43 PM
Reply to: Message 114 by bluegenes
08-31-2010 3:39 PM


However, the creationists on the thread are asking for dramatic novelty from mutations, and the rare functional extra digits show that it's possible. The thread starts off with someone listing the number of bones in our body, as if the implication is that mutations can never create extras, so I point out that it can, and still does.
True, but I would argue that Creationists are asking for something that is neither necessary nor particularly illustrative of evolution. By pointing to the tiny number of dramatic mutational changes out there, we simply reinforce the notion that these dramatic changes are a necessary part of Evolutionary theory whereas, of course, they're not.
Better, I think, to keep banging on the central drum of gradual change.

This message is a reply to:
 Message 114 by bluegenes, posted 08-31-2010 3:39 PM bluegenes has seen this message but not replied

  
Dr Jack
Member
Posts: 3514
From: Immigrant in the land of Deutsch
Joined: 07-14-2003


Message 126 of 527 (578202)
09-01-2010 4:24 AM
Reply to: Message 122 by ICdesign
09-01-2010 3:53 AM


I said YOU can't live without bones.
If you want to change goal posts and
talk about worms then start a new thread.
Of course we can't live without bones; how's that relevant to evolution? Evolution does not posit a bone-free human. Bones evolved in fish. The first tetrapods to crawl on land already had bones, the first mammals had bones. Bones and muscle were already well developed by the time you reached humans.

This message is a reply to:
 Message 122 by ICdesign, posted 09-01-2010 3:53 AM ICdesign has not replied

  
Dr Jack
Member
Posts: 3514
From: Immigrant in the land of Deutsch
Joined: 07-14-2003


Message 129 of 527 (578258)
09-01-2010 8:54 AM
Reply to: Message 124 by ICdesign
09-01-2010 4:06 AM


Perfection is relative
State of the art indeed. Saying they gradually progressed from simple beginnings into a state of the art mammalian skeleton does nothing to explain how they ended up in such perfect formation from the skull to the toe.
In what sense is it a perfect formation? What does it to do perfectly? Are we perfectly design for sitting at computers, working away? Or playing football? Does our perfection lie in the aesthetics of the buttocks? Or the ability to climb ladders? There are single celled organisms out there that can only in boiling water, which would kill us, are they more perfect or less?
Perfection cannot be defined without context.
And if I'm perfect, what does that mean for other people who's muscles and skeletons are different from mine? I'm 6' 3", are shorter people therefore slightly defective in the inferior organisation of the mechanical operation of their bodies. What about muscles? I'm not that strong a guy, are all those weightlifters less perfect with all those extra muscles? Is my eight stone girlfriend less perfect since she can't lift as much as me?
You see, the human design can't be perfect because there's too much variation within it. We are all different from one another, and we all change during our lifetime.

This message is a reply to:
 Message 124 by ICdesign, posted 09-01-2010 4:06 AM ICdesign has not replied

  
Dr Jack
Member
Posts: 3514
From: Immigrant in the land of Deutsch
Joined: 07-14-2003


(1)
Message 144 of 527 (578439)
09-01-2010 6:55 PM
Reply to: Message 142 by ICdesign
09-01-2010 6:46 PM


Re: Seeking to understand basis for incredulity
Now. How did the very first worm become fully-formed?
It evolved from an equally 'fully-formed' thing that was not quite a worm. (Or, to be pedantic, since the term "worm" is nothing like well defined and actually describes multiple phyla, multiple things which were not quite worms).
In other words, the exact same answer you will get about how any organism ever came to be: it was born of parents (or a parent) very similar to it, and who were very similar to their parents, but different enough from their great-great-great-(x100)-great-grandparents for those differences to be worth noticing.

This message is a reply to:
 Message 142 by ICdesign, posted 09-01-2010 6:46 PM ICdesign has replied

Replies to this message:
 Message 146 by ICdesign, posted 09-01-2010 7:06 PM Dr Jack has replied

  
Dr Jack
Member
Posts: 3514
From: Immigrant in the land of Deutsch
Joined: 07-14-2003


Message 147 of 527 (578446)
09-01-2010 7:07 PM
Reply to: Message 145 by crashfrog
09-01-2010 7:02 PM


Re: Seeking to understand basis for incredulity
That evolution does not begin in the human species; humans inherited the traits of their skeletons from their ancestors, which were then changed by random mutation and natural selection.
As an adjunct to this, I believe I am correct in saying that there are no new bones, joints, or major nerves that occur in humans but not in chimps. All the differences in body shape are the result of differences in the size and geometry of existing features.

This message is a reply to:
 Message 145 by crashfrog, posted 09-01-2010 7:02 PM crashfrog has not replied

  
Dr Jack
Member
Posts: 3514
From: Immigrant in the land of Deutsch
Joined: 07-14-2003


Message 149 of 527 (578448)
09-01-2010 7:08 PM
Reply to: Message 146 by ICdesign
09-01-2010 7:06 PM


Re: Seeking to understand basis for incredulity
Keep going back to the first one. The very first one. What is you guys don't get about being the very first one?
If the first one burst on the scene fully formed that is called creation not evolution.
You're correct, the very first replicator did not arrive on the scene by evolution. You'd be very hard pressed to claim that has any resemblance to anything that might normally be described as "creation" though.

This message is a reply to:
 Message 146 by ICdesign, posted 09-01-2010 7:06 PM ICdesign has not replied

  
Dr Jack
Member
Posts: 3514
From: Immigrant in the land of Deutsch
Joined: 07-14-2003


Message 173 of 527 (578669)
09-02-2010 8:55 AM
Reply to: Message 168 by Meldinoor
09-02-2010 6:02 AM


Just to add to this
It started off where it was useful of course. If it were somewhere obtrusive and un-useful, it would not have lasted "many generations". It probably wouldn't last one generation. Probably it began as a very gradual stiffening around the "spine" and "head".
Indeed. But even here, the addition of cartilage was likely not the first stiffening of the "spine" of an animal. The notochord (which is the "spine" in the most primitive chordates and which emerges briefly during development even in humans) consists of fluid filled vesicles surrounded by connective tissue. It is the hydrostatic pressure of this fluid that stiffens the body of these chordates. It is likely that the development of a more conventional skeleton began with a thickening and merging of this connective tissue to form a primitive cartilage "spine".
As I said, the first "bones" would have been cartilaginous. Cartilage is made up of fiber and collagen proteins which are fairly ubiquitous throughout the animal kingdom. For instance, it makes up the tip of your nose.
In fact the proteins involved in forming the extracellular matrix, and later skeletons, arose before animals and before multi-cellular eukaryotes. Very similar proteins are found in single celled organisms such Choanoflagellates where they act as anchoring proteins to bind these organisms to rocky surfaces, and these anchoring proteins are themselves related to proteins that are involved in forming the cytoskeleton internal to the cell itself.

This message is a reply to:
 Message 168 by Meldinoor, posted 09-02-2010 6:02 AM Meldinoor has not replied

  
Dr Jack
Member
Posts: 3514
From: Immigrant in the land of Deutsch
Joined: 07-14-2003


(1)
Message 185 of 527 (578936)
09-03-2010 4:47 AM
Reply to: Message 179 by ICANT
09-02-2010 1:45 PM


Punctuated Equilibrium is wrong and misrepresented
The fossil record does not support evolution by mutation and natural sellection.
The observation of the fossil record supports that species are amazingly conservative and stasis for long periods of time.
Since this is a fact some scientist developed the Theory of Punctuated Equilibria.
Eldredge, N. and Tattersall, I. (1982) in "The Myths of Human" Evolution Columbia University Press, p. 48 says: "The record is there, and the record speaks for tremendous anatomical conservatism. Change in the manner Darwin expected is just not found in the fossil record."
Gould, S.J. (1977) in "Evolution's Erratic Pace" Natural History, vol. 86, May says:
"The history of most fossil species include two features particularly inconsistent with gradualism:
1) Stasis - most species exhibit no directional change during their tenure on earth. They appear in the fossil record looking much the same as when they disappear; morphological change is usually limited and directionless;
2) Sudden appearance - in any local area, a species does not arise gradually by the steady transformation of its ancestors; it appears all at once and 'fully formed'."
A species appearing fully formed all at once supports creation, not evolution.
Firstly, Gould and Edlredge were wrong. Punctuated Equilibrium as a theory is discredited*. He were wrong that mophological change occurs only at speciation, he were wrong that statis followed by sudden change is the dominant pattern of the fossil record and they were wrong in asserting that where observed it represents an accurate picture of the rate and pattern of actual change in the organisms (in the same way that someone looking at a series of images of people walking from a camera taking photos only once every 10 seconds would be wrong to conclude that the people were moving suddenly from place to place rather than smoothly between points).
Secondly, your interpretation about what Gould is saying is wrong. Gould is not saying that dramatically different organisms spring forth suddenly in the fossil record. The thing you must realise is that species are generally very similar. Many species can only be easily distinguished by experts. Gould is not talking about an organism suddenly sprouting wings (say), he's talking about a shell acquiring a new ridge in a geological blink of an eye.
Thirdly, you've again stumbled over the fully-formed canard. Evolution does not predict half-formed creatures! It predicts that all species that have ever survived for any length of time are well adapted to their environment and successfully reproducing in it.
* - Punctuated equilibrium has brought some ideas into evolutionary theory. In particular, it's now widely recognised that evolutionary change is very variable in rate and can be very fast (something that would not have surprised Darwin), and there has been a considerable amount of investigation into stasis. But Gould and Eldredge's overblown claims for the idea are simply not supported by the evidence.
Edited by Mr Jack, : Forgot footnote.

This message is a reply to:
 Message 179 by ICANT, posted 09-02-2010 1:45 PM ICANT has not replied

  
Dr Jack
Member
Posts: 3514
From: Immigrant in the land of Deutsch
Joined: 07-14-2003


Message 199 of 527 (579365)
09-04-2010 11:16 AM
Reply to: Message 198 by ICdesign
09-04-2010 10:47 AM


Re: Seeking to understand basis for incredulity
Its no secret I am no biology major but I think its fair to say I can hold my own in the common sense department.
I'm not sure why you think common sense is a useful substitute for knowledge when it comes to biology. I'm about eight weeks off finishing a degree in biology and let me tell you, even outside of Evolution, common sense is a rubbish guide to understanding how biological systems work.

This message is a reply to:
 Message 198 by ICdesign, posted 09-04-2010 10:47 AM ICdesign has replied

Replies to this message:
 Message 201 by ICdesign, posted 09-04-2010 11:43 AM Dr Jack has replied

  
Dr Jack
Member
Posts: 3514
From: Immigrant in the land of Deutsch
Joined: 07-14-2003


Message 216 of 527 (579404)
09-04-2010 1:20 PM
Reply to: Message 201 by ICdesign
09-04-2010 11:43 AM


Re: Seeking to understand basis for incredulity
ToE fails miserably with many common sense tests.
I am again left wondering why you think "common sense" is such a powerful guide in understand the world? Do you find Einstein's Theory of Relativity to be "common sense"? Quantum mechanics? Does common sense guide you to the correct answer to Monty Haul problem?
Do you think common sense will guide you correctly about the inner workings of the cell? Let me ask you a simple question about cell biology: in order to perform their correct function, proteins must reach specific places. It is not enough for a protein simply to be synthesized, it must be transported from where it is synthesized to where it performs its function. Proteins which are to be exported from cells are indicated by particular amino acid sequences at their N-terminus, proteins that are to be bound to the surface of the cell by different sequences at their N-terminus, proteins that are to function in the Nucleus by another sequence, proteins for the Golgi by another. So, given that all these targets are specified by sequences of amino acids at their N-terminus, tell me - using your common sense - how are proteins that are to be targetted to the lysosome specified?
Its all about coming to the right conclusions with the knowledge you have. I think all of you are missing the boat. That's my opinion.
It is indeed about coming to the right conclusions with the knowledge you have. But you don't have knowledge. You don't know how genes function, you don't know how the skeleton develops, you're ignorant of the fossil record, you don't understand how mutation occurs, you know nothing of the vast literature of experiments performed on evolutionary theory, or the mathematical underpinings of the field. How, with so little knowledge, do you think you can possibly be better at reaching the right conclusions than the people who do know these things?
Do you simply think that knowledge is meaningless? Do you think that a detective who has a hunch in the car is as equipped to correctly discern the killer as the detective who has interview the suspects, got the lab work done and reviewed all the salient CCTV footage?
I'll tell you, the thing I have learnt most from studying biology for the last few years is the depth of my own ignorance. Until you start to understand a subject you don't even begin to know what you don't know.

This message is a reply to:
 Message 201 by ICdesign, posted 09-04-2010 11:43 AM ICdesign has not replied

  
Dr Jack
Member
Posts: 3514
From: Immigrant in the land of Deutsch
Joined: 07-14-2003


(1)
Message 226 of 527 (579589)
09-05-2010 5:02 AM
Reply to: Message 220 by ICdesign
09-04-2010 4:14 PM


Re: Seeking to understand basis for incredulity
This is the exact kind of double talk I have been referring to that frankly I am sick of dealing with.
I don't see why you think that what Percy wrote is double talk. It is not a law of biology that genera can't interbreed. And, in fact, it's untrue.
It may surprise you to learn that you regularly eat the product of interbreeding between genera. Bread wheat is the result of crosses between three species, crossing two genera. The wild emmer wheat is itself a cross between Triticum urartu and a wild goatgrass (of unknown species, but closely related to the modern Aegilops speltoides). Later, during domestication this cross-genera hybrid then interbred with yet another species, Aegilops cylindrica, to form the ancestor of the kinds of wheats we now use in breadmaking.
How do we know this? We know this because bread wheats unlike us, and most plants and animals, have not just two copies of their chromosomes but six (are hexaploid, in the parlance), and those six form three distinct pairings. One pairing can be recognised as very similar to T. urartu, one pairing as similar to A. speltoides and one as very similar to A. cylindrica.
Almost the entire Orchid family (Orchidacaeae) can be induced to breed. And it's not just plants, Butterflies are famous for producing viable cross-genera hybrids. Genetic transfer among bacteria can leap even higher categories.
Draw the line wherever the hell you want. If you can't breed one kind of animal with another and that truth is unchangeable then that is a law of biology and a line has been drawn.
Well, yes, a line has been drawn but I'm not sure why you feel its necessarily unchangeable or, indeed, any kind of problem for evolution. Reproductive separation is a very important part of the evolutionary process, without reproductive separation, different species would lose their individual identity and instead form a mix of subspecies.

This message is a reply to:
 Message 220 by ICdesign, posted 09-04-2010 4:14 PM ICdesign has not replied

  
Dr Jack
Member
Posts: 3514
From: Immigrant in the land of Deutsch
Joined: 07-14-2003


Message 296 of 527 (581783)
09-17-2010 1:35 PM
Reply to: Message 285 by ICdesign
09-17-2010 9:42 AM


Re: Round two
Yes I do. I would have a stroke if I ever heard one of you evolutionists admit to being wrong about anything or admitting there is something you don't know.
I doubt I have enough fingers to count the number of times I've admitted that I was wrong on just this forum. Your trouble is that you're so wrong that you get nowhere near the point of reaching where I'm wrong.
I don't know everything. I don't know everything. As I said to you in another thread the thing I've learnt most from doing a degree in Biology is just how little I know. The trouble you have is that you don't even want to spend the time learning what we do know. Do that and you'd get to the stuff we don't know; keep repeating drivel from Creationist lie-sites and you'll keep on frothing up ignorance.

This message is a reply to:
 Message 285 by ICdesign, posted 09-17-2010 9:42 AM ICdesign has not replied

  
Dr Jack
Member
Posts: 3514
From: Immigrant in the land of Deutsch
Joined: 07-14-2003


Message 307 of 527 (581914)
09-18-2010 4:54 AM
Reply to: Message 302 by ICdesign
09-17-2010 6:32 PM


You know what? You want to take your gloves off and gang up on me with all these deep insults over this stupid issue? Go right ahead.
I don't think you're stupid. I think you're ignorant. Ignorance is fixable; you just have to go and learn stuff.
Frankly, any person who can stand there and look at the skeletal system configuration and HONESTLY think it could have formed by way of lucky accidental mutations is in my opinion as dumb as random mutation and natural selection itself.
How many times? We don't think it resulted by way of lucky accidental mutations. We know it resulted by the combination of random mutations and natural selection.

This message is a reply to:
 Message 302 by ICdesign, posted 09-17-2010 6:32 PM ICdesign has not replied

Replies to this message:
 Message 324 by Flatland, posted 10-11-2010 6:47 AM Dr Jack has not replied

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2023 by EvC Forum, All Rights Reserved

™ Version 4.2
Innovative software from Qwixotic © 2024