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Author Topic:   Why is evolutions primary mechanism mutation ?
igor_the_hero
Inactive Member


Message 31 of 141 (243422)
09-14-2005 5:18 PM
Reply to: Message 30 by Gary
09-14-2005 5:14 PM


Re: Evolution's primary mechanism
But then there would be only one species per enviorment.
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Replies to this message:
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Chiroptera
Member
Posts: 6617
From: Oklahoma
Joined: 09-28-2003
Member Rating: 4.8


Message 32 of 141 (243423)
09-14-2005 5:23 PM
Reply to: Message 30 by Gary
09-14-2005 5:14 PM


Re: Evolution's primary mechanism
quote:
I think that we should have spent more time on evolution....

I recently (about two years ago) read an introductory college biology text; evolution was the central theme of the book. It began with a chapter on evolution, and everthing else in the rest of the book was tied in one way or another with evolution. The theory of evolution is the central, organizing principle of biologyl; nothing in biology makes sense except in light of evolution (Theodosius Dobzhansky).

The book was about ten to fifteen years old; I had hoped that it was the beginning of a trend, and all biology texts make evolution the central organizing principle, even high school texts.


This message is a reply to:
 Message 30 by Gary, posted 09-14-2005 5:14 PM Gary has responded

Replies to this message:
 Message 34 by igor_the_hero, posted 09-14-2005 5:35 PM Chiroptera has responded
 Message 35 by Gary, posted 09-14-2005 5:36 PM Chiroptera has not yet responded

  
Chiroptera
Member
Posts: 6617
From: Oklahoma
Joined: 09-28-2003
Member Rating: 4.8


Message 33 of 141 (243424)
09-14-2005 5:24 PM
Reply to: Message 31 by igor_the_hero
09-14-2005 5:18 PM


Re: Evolution's primary mechanism
There is no single "environment". Every "environment" has many different niches available, where different organisms may use different methods to make a living.
This message is a reply to:
 Message 31 by igor_the_hero, posted 09-14-2005 5:18 PM igor_the_hero has not yet responded

  
igor_the_hero
Inactive Member


Message 34 of 141 (243431)
09-14-2005 5:35 PM
Reply to: Message 32 by Chiroptera
09-14-2005 5:23 PM


Re: Evolution's primary mechanism
I believe that you have that backwards. Evolution does not make sense unless every part of known laws in the world agree with it.
This message is a reply to:
 Message 32 by Chiroptera, posted 09-14-2005 5:23 PM Chiroptera has responded

Replies to this message:
 Message 36 by Gary, posted 09-14-2005 5:39 PM igor_the_hero has responded
 Message 39 by Chiroptera, posted 09-14-2005 5:50 PM igor_the_hero has not yet responded

  
Gary
Inactive Member


Message 35 of 141 (243432)
09-14-2005 5:36 PM
Reply to: Message 32 by Chiroptera
09-14-2005 5:23 PM


Re: Evolution's primary mechanism
I was in the IB program, so we used Campbell's Biology, which I feel handles evolution extremely well. Evolution is a central theme, as it should be. Those books are expensive though, and schools are underfunded, so we couldn't bring them home, and so not much reading got done. Most of the course was based around what the teacher at the front of the class was talking about, or what the IB guide told us we should be studying. The way the course was set up encouraged us to write a page of BS and then show it to the teacher and then we could just socialize for the rest of the period.

When I got to college, I took Biology 1, and we used the same book, except it was the sixth edition instead of the second, third and fourth. We did much more reading and I learned much more, but I didn't really give evolution a lot of my time until I started reading books like The Blind Watchmaker on my own time.

I'm now majoring in biology, and I agree with Dobzhansky. In a vertebrate anatomy class I'm taking now, evolution explains the anatomy of a given animal far better than any other explanation.

Campbell's Biology isn't meant to be a high school text though. Nowadays, many textbooks are written by teams of editors rather than experts, and these textbooks are meant to sell to as many schools as possible at $50 a pop, instead of conveying useful information. Because of this system, the books are rife with errors and they result in a school system that allows people to graduate high school without being able to read.


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Gary
Inactive Member


Message 36 of 141 (243434)
09-14-2005 5:39 PM
Reply to: Message 34 by igor_the_hero
09-14-2005 5:35 PM


Re: Evolution's primary mechanism
All the known laws do agree with the theory of evolution.

A very common argument against evolution is that it violates the Second Law of Thermodynamics. This states that entropy (most simply, a measure of chaos) must increase in a closed system. Opponents of evolution either ignore "in a closed system" or they take Earth to be a closed system. It isn't. Earth is an open system, getting energy from the Sun. The Sun puts out a tremendous amount of energy, relative to the amount of biomass in existence. If the Earth was a closed system, everything on it would gradually die out in the cold darkness.


This message is a reply to:
 Message 34 by igor_the_hero, posted 09-14-2005 5:35 PM igor_the_hero has responded

Replies to this message:
 Message 37 by igor_the_hero, posted 09-14-2005 5:42 PM Gary has responded

  
igor_the_hero
Inactive Member


Message 37 of 141 (243436)
09-14-2005 5:42 PM
Reply to: Message 36 by Gary
09-14-2005 5:39 PM


Re: Evolution's primary mechanism
Which will in turn happen. Eventually the sun will die and we will be in cold darkness.
This message is a reply to:
 Message 36 by Gary, posted 09-14-2005 5:39 PM Gary has responded

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Gary
Inactive Member


Message 38 of 141 (243438)
09-14-2005 5:45 PM
Reply to: Message 37 by igor_the_hero
09-14-2005 5:42 PM


Re: Evolution's primary mechanism
igor_the_hero writes:

Which will in turn happen. Eventually the sun will die and we will be in cold darkness.

And then everything on Earth will die.

Either that, or the sun will expand and swallow up the Earth, in which case everything will die.

The Sun hasn't run out of fuel yet, I just checked. It's really bright right now.


This message is a reply to:
 Message 37 by igor_the_hero, posted 09-14-2005 5:42 PM igor_the_hero has not yet responded

  
Chiroptera
Member
Posts: 6617
From: Oklahoma
Joined: 09-28-2003
Member Rating: 4.8


Message 39 of 141 (243441)
09-14-2005 5:50 PM
Reply to: Message 34 by igor_the_hero
09-14-2005 5:35 PM


Re: Evolution's primary mechanism
Hi, igor.

Here is the entire theory of evolution in a nutshell:

1. Fact: Most breeding organisms produce more offspring than is necessary to replace themselves.

2. Fact: The population of most species are not increasing.

3. Conclusion: Most individuals must die before reproducing.

4. Fact: Many of the physical traits of individual organisms are hereditary.

5. Fact: Some traits make an organism more likely to survive and reproduce, while others make an organism less likely to survive and reproduce.

6. Conclusion: From 3, 4, and 5 we can conclude that organisms with the traits that make them more likely to survive and reproduce will produce offspring with those traits, while organisms with traits that make them less likely to survive and reproduce will leave few or no offspring with those traits.

7. Conclusion: A corollary of 6 is that as generations pass, the number of organisms with "good" traits will increase, while the number of organisms with "bad" traits will decrease, until eventually all individuals in the species will have the "good" trait and the "bad" trait will disappear altogether.

8. Fact: New heritable traits, usually subtle, occasionally appear.

9. Fact: These new traits do not appear in any predictable pattern; these traits can appear in any body part or instinctual behavior; furthermore, some of these traits are helpful to an organism's survival, and others are detrimental.

10. Conclusion: From 7, 8 and 9 we can conclude that a species will slowly "improve" with time, as new helpful traits appear and as the organisms with these traits are better able to survive and produce offspring with these traits.

11. Fact: There is no mechanism that is known to prevent these small, incremental changes from adding up, over time, to large changes; furthermore, there very few (if any) physical organs and instinctual behaviors in any species that do not appear in simpler versions in other species.

12. Conclusion: From 10 and 11 we conclude that there is nothing that will prevent very simple, primitive living species from producing the complex species that we see around us.

13. Fact: Occassionally separate populations of a species will become physically isolated from one another and cannot interbreed.

14. Conclusion: From 9 and 13 we conclude that these populations will evolve independently; from 12 we conclude that these will become different species.

15. Conclusion: From several interations of 14, we conclude that several species can have a common ancestor.

Everything that I have labelled as a fact is a fact; these facts have been observed and verified. Everything I have labelled as a conclusion seems to me (and to most people) reasonable conclusions based on these facts. What about all of this do you not think makes sense? More to the point, what here violates any known law?

I will end this post with evidence for the plausibility of evolution, and evidence for evolution having actually occurred.

16. Fact: Over the course of human history, animal and plant breeders have produce a huge variety of animal and plant breeds; many of these breeds share of common ancestor, and these breeds are often very, very different from one another as well as from the ancestor.

17. Conclusion: The appearance of random traits coupled with a selection process can result in evolution.

18. Fact: The species can be classified in a hierarchical pattern.

19. Conclusion: 15 and 18 allows us to conclude that all known species have evolved from a very few (perhaps one) ancestral species.


This message is a reply to:
 Message 34 by igor_the_hero, posted 09-14-2005 5:35 PM igor_the_hero has not yet responded

Replies to this message:
 Message 141 by Adminnemooseus, posted 03-08-2006 5:53 PM Chiroptera has not yet responded

  
Gary
Inactive Member


Message 40 of 141 (243444)
09-14-2005 5:52 PM


Imagine an environment in which only one species existed. Wouldn't this environment have many empty niches? For example, if one individual from that lonely species died, his body would have to rot, so bacteria would be there. Also, some other species could scavenge the body, like vultures. Also, what would feed that first species? Maybe it could be carnivorous, in which case it would probably eat herbivores. And those herbivores would in turn have to eat plants.

There could be parasites on everything too. And maybe something that eats the parasites, the way some fish let other fish clean them off. Maybe a carnivorous plant could eat some insects too, taking over a previously empty niche.

What about dung? There could be insects that eat or lay eggs in all the animals' dung.

Humans have E. coli bacteria in their large intestines, and they help us absorb Vitamin K. Maybe the animals we are talking about would have something similar.

You can see where this is going. In what seems like an environment with one species, I expanded that to nine. There is room for plenty of diversity.


  
Wounded King
Member (Idle past 2257 days)
Posts: 4149
From: Edinburgh, Scotland
Joined: 04-09-2003


Message 41 of 141 (243450)
09-14-2005 6:12 PM
Reply to: Message 24 by igor_the_hero
09-14-2005 4:26 PM


Re: Evolution's primary mechanism
You are lucky to get one good mutation every say 1 billion years.

What exactly are you basing this on? It sounds like you have just made this figure up off the top of your head.

And which textbooks have you been reading which give you such completely ludicrous ideas about evolution?

Copying DNA is not 'embryology', it occurs every time a cell divides which can be throughout an organisms life. As Chiroptera has pointed out it is only mutations which occur in the germline cells which can be inherited transgenerationally. Mutations in the somatic cells will only last for the lifetime of the orgnaism in which they occur.

These only apply to multicellular organisms with distinct somatic or germ lineages of course. Unicellular organism such as bacteria make no such distinction, although some genetic elements such as plasmid based genes are also likely to be propagated by horizontal transfer between bacteria as well as through direct inheritance.

TTFN,

WK


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ausar_maat
Member (Idle past 3662 days)
Posts: 136
From: Toronto
Joined: 10-04-2005


Message 42 of 141 (249495)
10-06-2005 11:31 AM
Reply to: Message 30 by Gary
09-14-2005 5:14 PM


Re: Evolution's primary mechanism
quote:
Mutations occur more or less randomly. They occur all the time. It isn't a rare thing at all. They are simply products of an imperfect copying system. All the errors lead to variation within a population. As time goes on, some individuals end up with the ability to produce more viable offspring than others. These individuals are said to be more "fit". They pass on their mutations and eventually the whole population is full of these "fit" genes.

But you guys don't seem to have set the ground rules on "mutation". Because you are both referring to different aspects of mutation as it pertains to the subject.

This is an interesting discussion, but set ground rules on "mutation". Agree on set parameters of mutation as it pertains directly to the subject.


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Replies to this message:
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Xeriar
Inactive Member


Message 43 of 141 (249547)
10-06-2005 1:35 PM
Reply to: Message 42 by ausar_maat
10-06-2005 11:31 AM


Re: Evolution's primary mechanism
But you guys don't seem to have set the ground rules on "mutation". Because you are both referring to different aspects of mutation as it pertains to the subject.

This is an interesting discussion, but set ground rules on "mutation". Agree on set parameters of mutation as it pertains directly to the subject.

This is a bit of a puzzling request... What is a ground rule? I think it's easy enough to say that there is a lot involved here.

There are several kinds of mutations. Ignoring duplications, truncations, reversals, and other things that don't -immediately- cause a change in the organism's real genetic information, point mutations are by far the most common survivable mutations.

Shift mutations also occur, but in the case of mammals, result in a dead sperm, useless ovum, etc.

Transcriptions might also swap out parts of genes, say, replacing a part of one of mommy's chromosome's with the matching part of one of daddy's, but this wouldn't always be considered a mutation, though it is a factor in evolution.

By far the most common, survivable mutations are point mutations. While 'random', some parts of the genetic structure are more susceptible to mutation than others. Thus the overall rate (~100 per generation in humans) might change from species to species like the 'real' rate (~1 per generation in humans) does.

Alright, so you have 100 or so genetic errors that make you different from your parents. Likely, 1 or 2 of these has caused a real change - the other 98 causing no change in an actual protein being coded.

Is this mutation you have beneficial, harmful, or neutral? Well, since you are alive, it is most likely somewhere between 'slightly harmful' and 'quite beneficial'. If it were 'very harmful' you would probably have been miscarried in your mother's womb, as 70% of pregnancies end.

So yes, it's true that most real mutations are in fact harmful. For every human alive today, at least two more died in the womb. Those were the most harmful of them (some do survive to birth, but tend not to live to maturity).


This message is a reply to:
 Message 42 by ausar_maat, posted 10-06-2005 11:31 AM ausar_maat has responded

Replies to this message:
 Message 44 by Chiroptera, posted 10-06-2005 2:05 PM Xeriar has not yet responded
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Chiroptera
Member
Posts: 6617
From: Oklahoma
Joined: 09-28-2003
Member Rating: 4.8


Message 44 of 141 (249553)
10-06-2005 2:05 PM
Reply to: Message 43 by Xeriar
10-06-2005 1:35 PM


Re: Evolution's primary mechanism
quote:
But you guys don't seem to have set the ground rules on "mutation".

This is a bit of a puzzling request... What is a ground rule?


ausar_maat has also asked for

how can I find out more about the biochemical origins of "survival" in living organism, as a purely scientific process though.

whatever that means. Ask Yaro -- she seems to understand what he is asking.


"Intellectually, scientifically, even artistically, fundamentalism -- biblical literalism -- is a road to nowhere, because it insists on fidelity to revealed truths that are not true." -- Katha Pollitt
This message is a reply to:
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ausar_maat
Member (Idle past 3662 days)
Posts: 136
From: Toronto
Joined: 10-04-2005


Message 45 of 141 (249557)
10-06-2005 2:27 PM
Reply to: Message 43 by Xeriar
10-06-2005 1:35 PM


Re: Evolution's primary mechanism
thanx,

oh and I didn't mention this but, mutations are contributing factors to evolution though, not a primary mechanism.

However, the only concrete link between the actual fossils found and number of factors determined to influence NS, ie: the biochemical processes, environemental factors, isolation factors, etc, seem to be of a quasi philosophical nature. It seems like a collage of things that would make sense. This is what I think provides fuel for creationists. On the other hand, creationists are so motivated by proving the Bible that any of their worthwhile observations become contaminated by their agenda and motives for pointing them out. Unfortunately, it forfeits any significant contributions some of it's scientists could make. Because it is ok to question evolution, and sometimes when you do, your treated like religous people treat heretics and non-believers, who view Darwin in the way some christians view Jesus, where no one can question anything..Meanwhile, many serious questions about Evolution need considerable revision. From the method to the conclusions.


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