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Author Topic:   Are there evolutionary reasons for reproduction?
MrQ
Member (Idle past 5052 days)
Posts: 116
Joined: 04-04-2010


Message 46 of 136 (554844)
04-10-2010 1:04 PM
Reply to: Message 44 by Blue Jay
04-10-2010 11:39 AM


Since the reason and direction are not actually real, the thing you are interested in discussing doesn't actually exist, except as a metaphor that is a useful way to help new students visualize the process.
Agreed. So survival or dominance is also metaphorical parameter that ultimately created by the system. I don't see anything wrong in naming things as everything in science is like that! Do you really really believe electrons move in orbitals?! Also there is no such a thing as perimeter of an geometric object. Perimeter in real world is just an illusion as well as the whole euclidean geometry which we use everyday.

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MrQ
Member (Idle past 5052 days)
Posts: 116
Joined: 04-04-2010


Message 47 of 136 (554846)
04-10-2010 1:21 PM
Reply to: Message 45 by Taq
04-10-2010 11:46 AM


That would be the genetics of the population as a whole.
True! but to achieve what?! What is the target?
Why doesn't it make sense to include the primary parameter in an equation? It would seem to be required.
Ok ok! Let's add it and see what happens!
Original:
Y= G(t)+R(t)-D(t)+...
We name the second reproduction parameter as g(t) now lets as add it:
Y= G(t)+g(t)+R(t)-D(t)
Now we have T(t)=G(t)+g(t) as the two reproductions are summable so formula becomes:
Y=T(t)+R(t)-D(t)
Do you see really any difference?!! As I said it is already there! You can't add something that is already there!
Survival doesn't mean living the longest. It means having the most grandchildren. It means survival of your genes, and this is dependent on reproduction and the reproductive fitness of your children.
I understand where are you coming from. But I am not after fuzzy description of things. To me there is huge difference between 'having the most grandchildren' and 'survival of genes'. I am looking for scientific definition not just laymen talking. I understand things relate to each other but relation is something, being equal is something else. You can't mix one with another.
Dying before you can reproduce does affect the reproduction rate. On average, the sunlight resistant bacteria will have more offspring than the sunlight sensitive bacteria due to having more offspring.
True! that's why I previously mentioned that all the main primary parameters have a minimum accepted level which should be met. But in this example, I assumed both species are the same in that respect. So only thing that is different is death rate and we assume still that death rate is above the limit that is acceptable. Still you will see that dominant bacteria will be the dark one. Why? because light one die with a higher rate. Simple as that.
There is no target, per se. You might as well claim that rivers in the Western US have the Pacific Ocean as a target. This would be wrong. The unavoidable consequence of gravity is that water will drain to the lowest elevation.
As I said in previous post, these are all metaphorical but in fact it is true. It doesn't matter weather a target is avoidable or unavoidable, the fact is that is the target no matter what is the reasons behind it. So if somebody says the target of the rivers are the oceans then it is not wrong. But if we say rivers consciously looking for oceans then that is wrong!

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Taq
Member
Posts: 9973
Joined: 03-06-2009
Member Rating: 5.7


Message 48 of 136 (554848)
04-10-2010 1:47 PM
Reply to: Message 47 by MrQ
04-10-2010 1:21 PM


True! but to achieve what?! What is the target?
There is no target.
I understand where are you coming from. But I am not after fuzzy description of things. To me there is huge difference between 'having the most grandchildren' and 'survival of genes'.
So what is that difference?
Still you will see that dominant bacteria will be the dark one. Why? because light one die with a higher rate. Simple as that.
The dark bacteria make up the majority of the population because they carry the fitter genes. The gene which is responsible for the dark phenotype results in more descedants with the dark phenotype. What it comes down to is the inheritance of fitter genes through reproduction.
As I said in previous post, these are all metaphorical but in fact it is true. It doesn't matter weather a target is avoidable or unavoidable, the fact is that is the target no matter what is the reasons behind it.
"Target" implies many outcomes, only one of which is aimed for. There is only one possible outcome in evolution, an increase in fitness over time. To use another analogy, the inevitable outcome of pulling the trigger on a gun is a bullet hitting something. Just because a round hits something does not imply that this something was the target. When you go target shooting do you randomly wave a gun around and squeeze off shots hitting random things around you?
Edited by Taq, : No reason given.

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AZPaul3
Member
Posts: 8513
From: Phoenix
Joined: 11-06-2006
Member Rating: 5.3


Message 49 of 136 (554890)
04-10-2010 6:55 PM
Reply to: Message 40 by MrQ
04-10-2010 6:35 AM


This doesn't make sense at all. I don't know why everybody is so focused on reproduction. I can easily break your theory by saying what if variation didn't change the reproduction at all but dropped the death rate? for example by better resistance against an illness. This will only lengthen the life span of that specie and cause them to be a dominant specie
The longer life span WILL NOT cause them to become the dominant species outside your idealization. Differential reproduction causes dominance in the real world.
In your example, X develops a variation conferring protection from disease but retains the same reproduction rate as all other individuals. X lives longer but is no more productive than any other. In an idealized mathematical case the offspring of X will eventually dominate. However, evolution does not follow any idealized mathematical case. Evolution works in the real world.
First there is the case to be made that longer lived individuals of limited reproduction potential sap scarce resources from the species ecological niche thus endangering the species evolutionary future as a whole. Second, any other variation that arises that gives more reproductive success, regardless of longevity, WILL come to domination. These are facts of the world in which we live.
Mathematical models are useful if they model the real world. Yours do not appear to do so.

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DC85
Member (Idle past 380 days)
Posts: 876
From: Richmond, Virginia USA
Joined: 05-06-2003


Message 50 of 136 (554909)
04-10-2010 8:14 PM
Reply to: Message 47 by MrQ
04-10-2010 1:21 PM


True! but to achieve what?! What is the target?
Why would natural processes have a target or a purpose? Why can't people understand that outside of what humans build or create nothing in the natural world has a target or goal?
If an asteroid impacts earth was that it's goal or target?
If a star goes Nova was that it's goal or target?
There are reasons these things happen but they certainly don't have this goal....
Imperfect organisms reproduce and produce more imperfect organisms who also reproduce. The populations of imperfect organisms evolve because they were imperfectly replicated. What more do you need?
Edited by DC85, : No reason given.

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bluescat48
Member (Idle past 4190 days)
Posts: 2347
From: United States
Joined: 10-06-2007


Message 51 of 136 (554938)
04-10-2010 10:45 PM
Reply to: Message 47 by MrQ
04-10-2010 1:21 PM


Why?
True! but to achieve what?! What is the target?
Why is it that people seam to demand that everything does things with a particular purpose? I have never been able to understand this.

There is no better love between 2 people than mutual respect for each other WT Young, 2002
Who gave anyone the authority to call me an authority on anything. WT Young, 1969
Since Evolution is only ~90% correct it should be thrown out and replaced by Creation which has even a lower % of correctness. W T Young, 2008

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DC85
Member (Idle past 380 days)
Posts: 876
From: Richmond, Virginia USA
Joined: 05-06-2003


Message 52 of 136 (554943)
04-10-2010 10:52 PM
Reply to: Message 51 by bluescat48
04-10-2010 10:45 PM


Re: Why?
Why is it that people seam to demand that everything does things with a particular purpose? I have never been able to understand this.
I think it goes back to the fact in our world humans build and create things for a purpose and for some reason many have a hard time not applying that to natural processes. I think this is the reason many creationists also have a hard time understanding evolution. They want order and a goal attached to something that doesn't have one

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Jon
Inactive Member


Message 53 of 136 (554959)
04-11-2010 1:17 AM
Reply to: Message 1 by MrQ
04-04-2010 6:18 PM


... reproduction is a key driving force in the evolution process.
It is evolution.
But nobody actually said why is that the case?!
See above.
I mean, reproduction is very energy consuming process.
Also a very fun one.
What I think is that whist reproduction can increase the density of the molecule in a solution but also soon the resources will finish and the process ends there. Much like when a fire starts. It extends as far as it has fuel and air to burn and then stops. I don't understand what is the advantage here?!
Yawn... Just a poorly attempted variation of the old 2LoT argument; too bad we actually don't live in a closed system.
Jon
ABE: I should have known joining three pages in that others would have beat me to all this... oh well... more fuel for the fire I guess...
Edited by Jon, : ABE

"Can we say the chair on the cat, for example? Or the basket in the person? No, we can't..." - Harriet J. Ottenheimer

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MrQ
Member (Idle past 5052 days)
Posts: 116
Joined: 04-04-2010


Message 54 of 136 (554964)
04-11-2010 5:20 AM
Reply to: Message 50 by DC85
04-10-2010 8:14 PM


Why would natural processes have a target or a purpose? Why can't people understand that outside of what humans build or create nothing in the natural world has a target or goal?
If an asteroid impacts earth was that it's goal or target?
If a star goes Nova was that it's goal or target?
I don't really understand why people here are reacting like this. Asteroid doesn't hit the earth not because it chooses to hit the earth. But everything in universe has reason behind it. The reason for asteroid hitting the earth is gravity. You remove that and no asteroid will even bother coming this way! Also, Nova is created the same way by gravity. So if you have the mass of the star, you can calculate when it is going to use up all the fuel and when it is going to collapse. If we can calculate everything of a star just by having two or three basic parameters, then I don't see why we can't calculate the mechanics of evolution like that. I am sure somebody actually have done this. The problem is I have engineering background and don't know that much of biology. But I know there are many evolution simulation programs out there. I don't know to what details they went but you can't do very much if don't have a proper mathematical modeling of what is happening in the evolution. And in mathematics you always have a function that has a target like that is maximizing or minimizing or get close to something. The same is true in thermodynamics as total entropy of the system always increases. So THIS IS THE TARGET that I am talking about! You might say entropy is a natural process of particles randomly move about. In reality then there is no entropy. Entropy is a MAN MADE phenomena and it is an illusion but it is a TARGET for everything happening in the universe. It is a illusional target but nobody seems to complain about it!
Edited by MrQ, : Spell

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MrQ
Member (Idle past 5052 days)
Posts: 116
Joined: 04-04-2010


Message 55 of 136 (554965)
04-11-2010 5:44 AM
Reply to: Message 49 by AZPaul3
04-10-2010 6:55 PM


In your example, X develops a variation conferring protection from disease but retains the same reproduction rate as all other individuals. X lives longer but is no more productive than any other. In an idealized mathematical case the offspring of X will eventually dominate. However, evolution does not follow any idealized mathematical case. Evolution works in the real world.
That's interesting. But what I understand from development of physics is that in many many occasions we did the calculation first and these calculations resulted some predictions that only long time after it we realized that they are true. If the actual model really doesn't reflect the reality then that means that we don't understand reality properly yet. What I said is a logical behavior of a random system like evolution. If we don't have at least one event in nature that correspond to it then we are missing something here. But with my poor biology, I can count you at least one event like this. In Africa we have highest number of cases of a genetically disease known as sickle cell. In this disease, the blood cells bend like sickle and can absorb less oxygen. Therefore, people with this condition constantly suffer from it and can't do much physical activity. Also their average life span comes dramatically down to 40 years. The reason this disease is prevalent there is because of Malaria. Malaria bug can't live on sickle shaped cells therefore they have immunity against it. These kind of individual have many key characteristics of evolution lower than normal people. They live less, reproduce less and have less physical activity which means they would become good prey. But still Malaria protection was so powerful force which kept the trait survive till now.
I don't know if this phenomena can be explained by Differential Reproduction. If yes, then I guess we just have a misnomer here. It could be we are talking about the same thing. I think best name for it would be 'survival of traits' or 'differential traits' or 'trait dominance'. The key is that the main factor here is the trait and not reproduction.

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DC85
Member (Idle past 380 days)
Posts: 876
From: Richmond, Virginia USA
Joined: 05-06-2003


Message 56 of 136 (554978)
04-11-2010 8:25 AM
Reply to: Message 54 by MrQ
04-11-2010 5:20 AM


If we can calculate everything of a star just by having two or three basic parameters, then I don't see why we can't calculate the mechanics of evolution like that.
you're looking for a way to predict evolution? If we take samples of the population perhaps we could predict which genetics will be selected.
It happens because imperfect things replicate imperfectly. If we ever had an organism that perfectly replicated itself it would not be selected. Without mutations it would not evolve .
Things reproduce + Mutations + time = Evolution
But everything in universe has reason behind it. The reason for asteroid hitting the earth is gravity
So the target of the asteroid is Gravity?

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AZPaul3
Member
Posts: 8513
From: Phoenix
Joined: 11-06-2006
Member Rating: 5.3


Message 57 of 136 (555000)
04-11-2010 1:30 PM
Reply to: Message 55 by MrQ
04-11-2010 5:44 AM


But what I understand from development of physics is that in many many occasions we did the calculation first and these calculations resulted some predictions that only long time after it we realized that they are true. If the actual model really doesn't reflect the reality then that means that we don't understand reality properly yet. What I said is a logical behavior of a random system like evolution.
What you missed in this example is that the starting equations had already accurately modeled reality. In true scientific fashion the models made predictions which, sooner or later, could be tested.
You also miss those instances, of which there are many, where the equation did not accurately model reality. Again, in true scientific fashion the model made predictions which, sooner or later, were falsified. The equation had to be modified or scrapped.
We already know from the facts we have in the real world your attempted model does not accurately reflect reality.
They live less, reproduce less and have less physical activity which means they would become good prey. But still Malaria protection was so powerful force which kept the trait survive till now.
Sickle Cell is an excellent example of just what we a talking about.
The HbS hemoglobin allele has a single-point mutation from the HbA allele.
We receive one hemoglobin allele from mom and one from dad.
If one and only one of those alleles is HbS then the person has a great protection from malaria. They live a normal life with no symptoms of Sickle Cell Disease and reproduce as normal.
If neither inherited allele is HbS there is no protection from malaria and that portion of the population suffers reduced reproduction potential due to contraction of malaria.
If both alleles are HbS then there is protection from malaria but also Sickle Cell Disease which also limits reproductive potential.
I'll not go into all the combinations and permutations of the various mating possibilities. What is shown in the HbS trait example is that it was not the trait itself but the reproductive differential conveyed by the trait that makes the HbS allele remain in those affected populations.
I don't know if this phenomena can be explained by Differential Reproduction.
Indeed it can and has been shown so.
If yes, then I guess we just have a misnomer here. It could be we are talking about the same thing.
No, MrQ, this is not a misnomer, but a lack of understanding (or appreciation) of the facts.
The key is that the main factor here is the trait and not reproduction.
No, MrQ. The key factor, indeed the only factor, is the reproductive differential that causes the entire suite of traits we know from an individual's genome to grow or decrease in a population through natural selection.
Edited by AZPaul3, : No reason given.
Edited by AZPaul3, : correction
Edited by AZPaul3, : another correction

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MrQ
Member (Idle past 5052 days)
Posts: 116
Joined: 04-04-2010


Message 58 of 136 (555007)
04-11-2010 2:47 PM
Reply to: Message 57 by AZPaul3
04-11-2010 1:30 PM


ok I kind of got where are you coming from. I checked wikipedia for differential reproduction:
"Natural variation occurs among the individuals of any population of organisms. Many of these differences do not affect survival (such as differences in eye color in humans), but some differences may #improve the chances of survival of a particular individual#. A rabbit that runs faster than others may be more likely to escape from predators, and algae that are more efficient at extracting energy from sunlight will grow faster. #Individuals that have better odds for survival also have better odds for reproduction#.
#If the traits that give these individuals a reproductive advantage are also heritable#, that is, passed from parent to child, then there will be a slightly higher proportion of fast rabbits or efficient algae in the next generation. #This is known as differential reproduction#. Even if the reproductive advantage is very slight, over many generations any heritable advantage will become dominant in the population, due to exponential growth. In this way the natural environment of an organism "selects" for traits that confer a reproductive advantage, causing gradual changes or evolution of life. This effect was first described and named by Charles Darwin."
Basically what is mentioned here is that(check between #s):
1- First we should have a variation
2- That variation should bring a better chance of survival for an individual organism
3- The variation should be hereditary
4- Better survival means higher chance of reproduction
5- Gradually over time the variation will have dominance.
now back to drawing board:
reproduction -> variations ~> better adaptation ~> longer existence(survival)
Variation is mentioned here. Statement 2 also means better adaptation and better adaptation means better survival which is also mentioned above. The only thing missing here is the recursive loop which that longer survived individual should reproduce again. Which means basically following:
reproduction -> variations ~> better adaptation ~> longer existence(survival) -> higher reproduction
But in the sickle cell example that I gave, can we really say the sick people had better reproduction or it is better to say normal people died faster and earlier by Malaria so these sick individual had better chance to live and reproduce. But this reproduction is far less than what normal people could do. It only become valuable because normal people died faster and now these guys got better chance with their minimal reproduction. I guess the complexity comes from the fact that several forces and filtering stages are involved at the same time. I presume the better name for this would be 'differential existence' or better even 'differential population growth'. As you can clearly see here 'reproduction' is not a key factor here but 'death' of the competitor is. The word 'reproduction' doesn't include a key aspect in this balance of power which is 'death'. That said I agree that these sick individual must be able to reproduce at a minimum level. But I wouldn't call that higher reproduction as it is nothing close to it. Please comment on this.
Edited by MrQ, : #
Edited by MrQ, : differential existance
Edited by MrQ, : differential population growth

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AZPaul3
Member
Posts: 8513
From: Phoenix
Joined: 11-06-2006
Member Rating: 5.3


Message 59 of 136 (555023)
04-11-2010 7:34 PM
Reply to: Message 58 by MrQ
04-11-2010 2:47 PM


But in the sickle cell example that I gave, can we really say the sick people had better reproduction or it is better to say normal people died faster and earlier by Malaria so these sick individual had better chance to live and reproduce. But this reproduction is far less than what normal people could do. It only become valuable because normal people died faster and now these guys got better chance with their minimal reproduction.
You have totally miss the Sickle Cell example.
There are three (3) populations:
1) Those with 2 HbA alleles.
2) Those with 1 HbA and 1 HbS allele.
3) Those with 2 HbS alleles.
I presume the better name for this would be 'differential existence' or better even 'differential population growth'. As you can clearly see here 'reproduction' is not a key factor here but 'death' of the competitor is. The word 'reproduction' doesn't include a key aspect in this balance of power which is 'death'.
Wiki is a great resource for general knowledge. They cannot, however, give all the details that form that general knowledge in their pages.
Let's go to the old standby example of the Peacock with its display of plumage.
The lesser displayed Cocks have less reproductive success. Not because of any lesser lifetime or early death but solely due to the sexual selection (a form of Natural Selection) by the Peahen. In fact the Cock with greater plumage is at a survival disadvantage. But, the greater displayed Cock has a reproductive advantage.
Over time the grandiose plumage will dominate the population over the lesser plumage because the reproductive differential favors the greater display over longer survival.
The Wiki story of the slightly faster rabbit is a good one since it is easy to understand and helps convey the central theme to those wanting a general knowledge. But, do not continue to mistake survival length as the only, or major, venue for evolution.
Death may or may not confer a reproductive advantage. It depends on whether death comes before or after reproductive age. Other traits may or may not convey reproductive advantage without impacting lifespan. Greater fecundity at an early age out performs lesser fecundity over a longer life.
Lifespan may have an impact but is not the key. Reproductive differential, by whatever means it is achieved, is the key.
Edited by AZPaul3, : correction

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adelpit346
Junior Member (Idle past 5099 days)
Posts: 11
Joined: 04-05-2010


Message 60 of 136 (555052)
04-12-2010 1:08 AM
Reply to: Message 36 by Coyote
04-09-2010 11:53 PM


the measure of your sanity is calculated in this manner
do you use your turn signals each time you change lanes
do you come to an absolute stop at each stop sign
do you alway yield to traffic when you enter the expressway
do you slow to 20 in each school zone
do you observe current traffic flow speeds
do you pay more attention to the traffic that approaches you on the expressway than that which is in front of you
unless you can say that you always keep all the above
then you are massively insane
for were you not then you would keep them for they are excellent to show your love for your fellow man
now i know you have not considerd the need for neither do other men and what they do you also do
so in consideration of your behavior should i take any of your remarks concerning mine to be of value to me
i do not
unless a man sees the impossibility of insane men creating perfect law
law that they have the inability and desire to keep
then that man can not see the possibility of GOd
for GOd loves to work thru insane men and then waits for them to see impossibility of the results
iamnothing0
JESUsISTHeLORd1
a theory called the assembly

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