The sequal to my previous poorly researched thoughts on evolution. I'm not disatisfied by my faliure, it has only increased my intrest. I started a new thread as I feel the title is more reflective of my intention, and that the other thread has become more difficult to follow.
I have learnt that I don't fully understand the thoery. I've taken the time to better research the subject, and rather than speculations, I would like to put foward some questions where the concepts are unclear(to me), difficult to accept(not invalid), and ethical(5).
2. Does the enviroment act on an organism causing them to adapt themselfes each in a particular way? How can external conditions shape and color blossoms? Why would some flowers develop a gay outer rim which there is no honey,designed to attract insects, while the honey-bearing and fertile flower are less showy?
[http://www.christs.cam.ac.uk/darwin200/pages/index.php?page_id=b3]
3. Is excersing a certain organ necessary for its growth? Does the disuse of an organ arrest development altogether? If the excersize of a skill is NOT necessary then what is the alternative to their improvement? Mutation?
[http://www.encyclopedia.com/topic/August_Weismann.aspx]
4. Has the physio-chemical basis being proven the sole explanation of life?
Wouldn't the changing world enviroment which brought about the conditions favourable to the origin of life must, in time, have given rise to other conditions less favourable for its maintenance?
[http://www.1902encyclopedia.com/E/EVO/evolution-02.html]
5. Assuming we have a soul, do you think its mechanism would also be evolutionary? Can we form an idea of the "whole" of life by combining simple ideas that have been left behing by life itself in the course of evolution? And can the finalistic interpretaion of evolution be taken for an anticipation of the future?
I'm loving the discussion of this topic and would very much appreciate your thoughts and evidence.
I would like to put the past behind us and assist you in your endeavour. Even if you are not convinced about evolution (I cannot say I believe it 100% myself), that would be completely acceptable.
I will contribute what I can once I have more time.
I'll respond to this when I have an opportunity to give it the time it deserves. In the meantime, I made a post a while back that gives a brief overview of evolution that may answer some of your questions:
1. There is a field, fairly newly discovered, called Epigenetics, which deals with external alterations of what genes are activated and deactivated. (the old adage "Genes are the Gun, but Environment pulls the trigger" comes to mind.)
This has been attempted applied to such things as inherited obesity, though I'm not sure how well they've supported it yet.
However, it seems clear that the environment can enhance which genes function at a time, and suppress others, (Though it cannot make your body read a genetic recipe it doesn't have, it can make your body skip parts.)
This also seems to be inheritable.
However, most traits are not inherited in this way. Mostly it seems we, as humans, inherit more like tendencies to be good towards some things, and worse at others. (Some are better suited to grow big, showy muscles when subjected to stimuli that requires a muscular adaptation, while others will grow leaner, but stronger from the same stimuli. Some will have genes that compose a body which is particularly good at adapting to tasks like running, while others will easily adapt to abstract thinking. Usually these traits will be passed down from father and mother, but speaking of epigenetics there seems to be some influence from diet at the moment of conception.)
2. Evolution is not directed, it is a shot in the dark, every time.
Picture it more like an arms-race where all participants try to outrace their closest competitors, but where there is no clear direction, and where all any participant is doing is trying to survive.
This will lead to flowers seemingly attempting to attract insects, either through reward, or through imitating those that do deliver reward, which they then use to pollinate others like themselves.
Bees will try to sort away those that do not yield any nectar, and the flowers will try to attract the bees. (now, when we say try, what is meant is that bees that do not find nectar will die, and flowers that do not attract bees will die. This is solely because they will not be able to pass on their DNA, and therefore their particular traits will not be passed on to children. )
Other may bet more on the inherit ability of bees to figure out where the goods are, and thereby learn to go for those instead.
3. The environment will decide which individuals survive.
If your particular field is one that demands keen eyes, like an Eagle, then those with the keenest eyes in a generation will be the ones that gets the most food, raise the most children, and are least likely to die.
In this way specialization will gradually occur. since the circle repeats itself in the next generation. (Remember, it never stops. It will always be the one that is most adapted to its environment that will be most likely to survive and pass it's genes on.)
If the environment changes and an organ is no longer needed, then, since maintaining a useless organ requires more energy, those that invest their energy in something which does not aid their survival will have less energy for raising children and surviving themselves.
Therefore those that have more energy to spare, by letting this particular organ wither (again the individuals have nothing to do with it, but the children with less energy spent on this feature will be more likely to survive.) will be more likely to survive.
Mutation always takes place.
Most of the time it does nothing, so you neither gain nor lose advantage by it, and it doesn't cause you to invest energy into anything particularly wasteful.
4. Not entirely sure what you're asking here, but I'll take a shot.
Every living thing, ( remember, we have defined what "life" means) seems to be composed of Carbon Hydrogen and Oxygen (and Nitrogen). Which is what we refer to as Organic Chemistry.
I haven't heard of living organisms that do not contain these elements, and who aren't based upon them.
There's been plenty speculation about how there maybe could've been Silicon life-forms, where Silicon is replacing Carbon, but since there is so much more Carbon in the universe, Carbon seems to be the safest bet, and therefore the most likely basis for life-forms.
However, we cannot Prove that this is prerequisite for life. Other forms can be possible, but they are far less likely.
There may have been other forms, but because of the chemical bonds these would have been less stable. (I've heard speculations of crystal life-forms that may have existed before organic life-forms, but these would quickly have been broken down and "overpowered"/incorporated by organic life, which is much quicker and more adaptable.)
5. Souls seem to me to be more of a mental construct to explain life in a previous era.
Poetic, but superfluous.
If, however, they would exist they would indeed be subject to natural selection.
Souls that are good at surviving will survive, and those that are bad at it won't. (regardless of what body they were in.)
Of course there are examples from evolution of animals that were very well adapted for something, but that through random acts of nature, like volcanoes, earth-quakes, lightning, etc. did not survive to pass on their genes.
Someone very talented at music, but born before musical instruments, will never realize the potential, and therefore it is less likely to benefit from this adaptation, (and worse, even more likely to perish because of the energy expended at useless traits.)
A thing about evolution is that it's impossible to guess which paths it might take in the future, but it's pretty clear in retrospect.
This is probably due to the random mutations that the DNA is subject to, and the unpredictability of future environments.
I'm not expert, but I do not think so. there are mutations that could occur later on a parent's life that might be passed on, but I don't think those mutations are the result of altering to match the environment. They're chance mutations like all the rest.
2. Does the enviroment act on an organism causing them to adapt themselfes each in a particular way? How can external conditions shape and color blossoms? Why would some flowers develop a gay outer rim which there is no honey,designed to attract insects, while the honey-bearing and fertile flower are less showy?
[http://www.christs.cam.ac.uk/darwin200/pages/index.php?page_id=b3]
most bodies of animals are designed in such a way that they react to the environment (a rabbit's hair color changes with the seasons, for example), but it does not alter that aspect of them genetically.
I'm no botanist. I cannot explain the evolution of specific flower baring plants. All I know is that flowers attract insects, and the insects get the pollen on them, and then land on another flower and implant it with the clinging pollen. The article you linked to doesn't mention anything about it, though, so I really don't know what you're talking about.
3. Is excersing a certain organ necessary for its growth? Does the disuse of an organ arrest development altogether? If the excersize of a skill is NOT necessary then what is the alternative to their improvement? Mutation?
[http://www.encyclopedia.com/topic/August_Weismann.aspx]
No, organs develop with or without exercise, in the cases I'm aware of. They may become larger and more powerful with exercise, but they will still be there without it.
4. Has the physio-chemical basis being proven the sole explanation of life?
Wouldn't the changing world enviroment which brought about the conditions favourable to the origin of life must, in time, have given rise to other conditions less favourable for its maintenance?
[http://www.1902encyclopedia.com/E/EVO/evolution-02.html]
It's the only testable, verifiable explanation we have, and it makes sense granting the evidence.
5. Assuming we have a soul, do you think its mechanism would also be evolutionary? Can we form an idea of the "whole" of life by combining simple ideas that have been left behing by life itself in the course of evolution? And can the finalistic interpretaion of evolution be taken for an anticipation of the future?
I suppose a soul could be suspect to evolution alongside it's physical body, assuming souls exist in the first place. However, I don't believe the spiritual sort of soul exists, so I really don't feel confident saying what kind of aspects they'd have, granting we could imagine them having any characteristic we want them to have.
I'd say evolution is a natural process with no desires or expectations at all.
I'm loving the discussion of this topic and would very much appreciate your thoughts and evidence.
A retrovirus is an RNA virus that is duplicated in a host cell using the reverse transcriptase enzyme to produce DNA from its RNA genome. The DNA is then incorporated into the host's genome by an integrase enzyme. The virus thereafter replicates as part of the host cell's DNA. Retroviruses are enveloped viruses that belong to the viral family Retroviridae.
When retroviruses have integrated their own genome into the germ line, their genome is passed on to a following generation. These endogenous retroviruses (ERVs), contrasted with exogenous ones, now make up 5-8% of the human genome.
Simply put, a retrovirus is a virus that alters host's DNA to its own in order to use its host to produce more copies of itself.
Although unrelated, another interesting topic is that of mitochondria. They have their own DNA that is completely different from ours, yet they live in our bodies and are responsible for energy creation.
2. Does the enviroment act on an organism causing them to adapt themselfes each in a particular way? How can external conditions shape and color blossoms? Why would some flowers develop a gay outer rim which there is no honey,designed to attract insects, while the honey-bearing and fertile flower are less showy?
[http://www.christs.cam.ac.uk/darwin200/pages/index.php?page_id=b3]
This is most easily observable in bacteria, which have very short life cycles, and hence are able to propagate beneficial genes much faster then other organisms.
Essentially the experiment documents the bacteria's development of a resistance to a bacteriophage by the mechanism of spontaneous mutation. Bacteria that fell to the bacteriophage simply were not able to pass on their genes, leaving only the resistant strains to reproduce.
Owing to the short lifecycle of the bacteria, the experiment was able to be carried out in a relatively short amount of time.
3. Is excersing a certain organ necessary for its growth? Does the disuse of an organ arrest development altogether? If the excersize of a skill is NOT necessary then what is the alternative to their improvement? Mutation?
[http://www.encyclopedia.com/topic/August_Weismann.aspx]
Essential organs theoretically should never atrophy as they are central to the survival of an organism. However in extraordinary cases, the dynamic may change in different ways.
We humans no longer have to develop strong muscles to hunt prey and evade predators, leading to a possible disuse. This could be compounded by disease or injury and could possibly have a genetic component.
4. Has the physio-chemical basis being proven the sole explanation of life?
Wouldn't the changing world enviroment which brought about the conditions favourable to the origin of life must, in time, have given rise to other conditions less favourable for its maintenance?
[http://www.1902encyclopedia.com/E/EVO/evolution-02.html]
But now researchers have discovered a bacterium that appears to have replaced that life-enabling phosphorus with its toxic cousin arsenic, raising new and provocative questions about the origins and nature of life.
As you might know, arsenic is highly toxic to most carbon based life, yet this aresnic based bacterium is undeniably alive.
5. Assuming we have a soul, do you think its mechanism would also be evolutionary? Can we form an idea of the "whole" of life by combining simple ideas that have been left behing by life itself in the course of evolution? And can the finalistic interpretaion of evolution be taken for an anticipation of the future?
This is a metaphysical question, as such, in my opinion, it is beyond the ability of science to tackle as of now. I am afraid that this is a question we all have to face on our own and for ourselves. Everyone faces their own mortality in their own way.
What is a soul? Does that mean an afterlife?
Would it be terrifying to believe that there is no afterlife? Why so?
Is there any way to know? If there isn't, is it fine to simply believe? If simply believing is beneficial to you, then why not?
Would believing in an afterlife make your current life richer? Or would it make it easier to give up and say, hey I'll do it the next time around?
I am still young, so maybe I have not experienced the fear of death yet. I know that my time is limited, whether or not I have a soul, and that is why I strive to make the most of my life here and now.
This was an idea proposed by Jean-Baptiste Lamarck (often called Lamarckism). For the most part, it has been rejected, because any adaptation would have to be passed on through the gametes - changes in the genetics or epigenetics of somatic cells would not pass on to offspring.
But as stated by someone else, there are epigenetic influences that may possibly effect gametes. There is a phenomena called bookmarking, which is known to occur in somatic cells, where promoter genes are chemically marked (eg DNA methylation, histone modifications, silencing/expressing due to RNAs such as piRNAs, siRNAs, miRNAs or other regulatory RNAs) to increase or decrease the expression of certain genes, and these markers can persist through mitosis, so that both daughter cells have the same bookmarks. It's not a stretch to think this could occur in gametes.
There is also a phenomena known as paramutation, which is when two alleles at a locus influence each other during metaphase, making heritable changes between them. An allele at one point heritably affects the other allele epigenetically (eg the bookmarks mentioned above), even if it's not passed on.
2. Does the enviroment act on an organism causing them to adapt themselfes each in a particular way? How can external conditions shape and color blossoms? Why would some flowers develop a gay outer rim which there is no honey,designed to attract insects, while the honey-bearing and fertile flower are less showy?
[http://www.christs.cam.ac.uk/darwin200/pages/index.php?page_id=b3]
More intelligent organisms can pass on learned adaptations via memes. This has been observed in great apes, dolphins and orcas, otters, and several other organisms. Other than this, evolution, as someone else said, is a shot in the dark - it's throwing everything against the wall and seeing what sticks.
Mutations give rise to novelty, and selection pressures (the environment, the climate, other organisms etc) weed out the genetic combinations with the least fitness. A metaphor might be that mutations create branches on the tree of life, and natural selection trims them. The result is that over 99% of all organisms that have ever lived on earth are extinct, most of which did not go extinct during the five major extinction events.
To give a concrete example, African elephants have, in the past two hundred years or so, evolved to grow smaller tusks. The reason for this is because poachers kill the elephants with the largest tusks for the ivory. The elephants never decided at any time to start growing smaller tusks. Before poaching became rampant, there were elephants with tusks of all different sizes, even though large tusks would have been more prominent (due to sexual selection). But, since all of the large tusked elephants were being killed off, the only elephants that survived long enough to breed were the ones with smaller tusks, thereby passing on their smaller tusked genes. Over several generations, elephants have evolved to have smaller tusks. I can't find the primary source for this on the internet, but this article talks about it.
To sum up: elephants had a wide array of tusk sizes (due too genetic diversity throwing everything at the wall); poachers provided a selection pressure against elephants with large tusks, resulting in the mean tusk size of elephants to decrease.
An example like this could be abstracted to other cases, such as the flowers you mentioned (a case I haven't heard of before).
3. Is excersing a certain organ necessary for its growth? Does the disuse of an organ arrest development altogether? If the excersize of a skill is NOT necessary then what is the alternative to their improvement? Mutation?
[http://www.encyclopedia.com/topic/August_Weismann.aspx]
Organs can become atrophied if not used, but this doesn't get passed on in the gametes (unless epigenetic changes occur that can be passed down to other generations).
If you are wondering how organs can become vestigial, or even eventually go away, it would be similar to the example I gave above. If an organism becomes more fit by having smaller, weaker, or less prominent organs, then those offspring that have smaller, weaker, or less prominent organs will be more likely to survive to breeding age and successfully pass on the genes for smaller, weaker, or less prominent organs.
Think about it for the evolution of cetaceans. If the ancestors of modern whales and porpoises are in an environment with a lot of water (eg their main food source is in the water; they can escape predation by being in the water etc), then those organisms with limbs and tails that are more effective for swimming will survive to breeding age and pass on the genes for limbs and tails more conducive for swimming. As the limbs become more and more conducive for swimming, they will, as a result, become "weaker" for the purpose of moving around on land. This wasn't because they stopped using those limbs for terrestrial locomotion, it's because those organisms that had limbs more conducive to different environments and selection pressures were able to successfully reproduce more. In the case of whales, the hind limbs were not necessary for an aquatic environment, so those ancestors that had smaller and smaller hind limbs survived longer and bred more, until the whales hind limbs became nothing but vestigial bones (labeled "c" in this picture).
In this case, the improvements would come about by mutation. As I stated earlier, mutations create branches on the tree of life - in this case, the branches would be front limbs that are more like flippers and smaller hind limbs, and front limbs that are more like legs and larger hind limbs - while selection pressures prune the branches - in this case, those offspring with flipperlike front limbs and smaller hind limbs would catch more prey and do better at avoiding predators, and therefore could more successfully breed and pass on those flipper front limb and small hind limb genes. As a result, we end up with a fossil record that looks like this:
4. Has the physio-chemical basis being proven the sole explanation of life?
Wouldn't the changing world enviroment which brought about the conditions favourable to the origin of life must, in time, have given rise to other conditions less favourable for its maintenance?
[http://www.1902encyclopedia.com/E/EVO/evolution-02.html]
The world environment has changed dramatically. Aside from tectonic shift and climate change, the chemical environment has change dramatically. The early earth (Archean and Proterozoic eons) had little to no oxygen gas. The evolution of photosynthesis (in something similar to cyanobacteria) and the success and prominence of this life form for several billion years produced the oxygen we have in our atmosphere now.
It's also known that on the early earth, the moon was closer, so because of invariance, the days would also have been much shorter (a day-night period would have occurred in as little as eight hours). The sun would also have been one third dimmer. However, temperature maintained due to more greenhouse gases and lower albedo, so this wouldn't have had too much affect on the evolution of early life. This means that the decrease in greenhouse gases (due to photosynthesis occurring) would not have altered the climate too drastically.
Firstly, @oblivious; I appreciate your contribution (we got of on the wrong foot lol). And @agentintellect; you always manage to say something that suprises me. Your arguments are clear, and I find it easy to follow your logic.
Now, I'm not trying to change anyones mind, but I'll not pretend to be fully satified with the theory. Reason and Logic will be valued over all other factors. Hopefully we both acquire a better understanding.
1. I agree that only existing characteristics have been brought out. In other words, heridity limits the range of variation, and limits it more narrowly as evolution advances, but natural selection cannot go without variation.
Now, it follows that; it can only combine variation, it doesn't originate them. So what is the origin of variation? I cannot seriously consider the idea of epeginisis(which maintains Weismann's preformation) that one cell can contain the whole futere animal. MY question is concerned with the AQUIRED characteristics(i.e increased power obtained by training being transmitted to the next generation),are improvements of existing characters by specialising passed on?
2. I'll give an example to elaborate on my question. The hard thorny plant so common in the desert is well adapted, has it adapted to its surrounding(i.e retrovirus), or has their enviroment given them their characters (i.e in the case of the elephant trunks)? I have less understanding of the retrovirus, but to oppose the concept that its aided by external condition; The fruits of many plants are admirably suited to attract birds who eat them and scatter the seeds far and wide so that the species extends its range, the strawberry is splendidly adapted to that part of its enviroment which we call the black bird; yet it cannot have been influenced by the requirement of the palate to which it appeals so forcibly.
To further illustaret my Questions with further examples; Why have not the insects constant stimulation caused the center of the daisy for example to sprout into startling forms? Why in the wild guelder rose are the outer baren flourets, which insects do not visit large and showy, while those in the center, thier hunting ground, are small and inconspicious?
I want an explanation that will explain both color and form.
3. The voice for example will become much stronger if constantly used in the proper way. For good and intelligible reasons growth has become associated with constant exersise. In some breeds of domestic ducks that have given up
the habit of flying(i.e humerus, radius), the wing development is no doubt less than it would be with more active habits. Without engaging in any definite speculation, how can you exersise what does not exist?
If the disuse of the muscles will also lead to atrophy, then why does men still posses muscles for moving his ears forward when he has altogether lost the use for them? In the early stages where disuse is incomplete we may have expected the reduction to be slow, but when the muscles has become so small that exersise was out of the question, wouldn't we expect that all traces would disappear rapidly? If it is urged that all vestiges gradually go away, the answer is that in many cases the organ has reached the vestigial state and still they linger on. For ages the horse's forefoot has borne only one toe, yet there still remains the so called splint bones, that once carried a toe on either side.
As for mutation, I beleive this article presents its problems adecquatly;[http://www.cs.unc.edu/~plaisted/ce/problem.html]
4. I am defining life as the manifest activity resulting from the interaction. The organism is a mechanism for storage and transformation of energy, but the source of its energy is the world about it. We seem to agree that the whole history of the world is one of changing climate and geological events. But according to our ideas of evolution the complex population of the modern world has evolved from a simple primordium. Given the complexity that we have arrived at, the possibility of surviving all those stages, in my perpective, just seems astounding.
5. For this question, I would like to accept this qoute; "I am afraid that this is a question we all have to face on our own and for ourselves. Everyone faces their own mortality in their own way." But I thought it was interesting from a philosophical perspective.
1. I agree that only existing characteristics have been brought out. In other words, heridity limits the range of variation, and limits it more narrowly as evolution advances, but natural selection cannot go without variation.
Now, it follows that; it can only combine variation, it doesn't originate them. So what is the origin of variation? I cannot seriously consider the idea of epeginisis(which maintains Weismann's preformation) that one cell can contain the whole futere animal. MY question is concerned with the AQUIRED characteristics(i.e increased power obtained by training being transmitted to the next generation),are improvements of existing characters by specialising passed on?
Variation comes from mutation. Something you may not know about mutations are that they're common. Each individual human is born with over a hundred minor mutations, which neither of their parents have. Most of these mutations have either no effect or a very insignificant effect. However, that's all that's necessary. With new mutations at random locations due to imperfect copying, plus with attrition, the next generation is different than the first. The third generation is more different, yet. However, this continues indefinitely. Every generation is more different from that first one.
And, still, no. If a weakling spends his entire life exercising and becomes physically powerful, offspring will not acquire his strength. However, they will acquire enough of his biology that they, too, would regain muscle after it gets torn during exercise, as that's part of all animals structure, so far as I'm aware.
2. I'll give an example to elaborate on my question. The hard thorny plant so common in the desert is well adapted, has it adapted to its surrounding(i.e retrovirus), or has their enviroment given them their characters (i.e in the case of the elephant trunks)? I have less understanding of the retrovirus, but to oppose the concept that its aided by external condition; The fruits of many plants are admirably suited to attract birds who eat them and scatter the seeds far and wide so that the species extends its range, the strawberry is splendidly adapted to that part of its enviroment which we call the black bird; yet it cannot have been influenced by the requirement of the palate to which it appeals so forcibly.
To further illustaret my Questions with further examples; Why have not the insects constant stimulation caused the center of the daisy for example to sprout into startling forms? Why in the wild guelder rose are the outer baren flourets, which insects do not visit large and showy, while those in the center, thier hunting ground, are small and inconspicious?
I want an explanation that will explain both color and form.
It seems you don't fully understand evolution's explanation for variation, so here's a synopsis. A population of plant lives in the desert. Each plant of this kind in each new generation has very minor differences from their parent generation. When one of these plants has a thicker, harder shell or a pricklier surface, that individual plant is more likely to survive and pass it's mutations on to the next generation. Some of the next generation will die from predation or due to the environment, so the ones more likely to survive are the ones with harder shells and pricklier surfaces yet. These very small, minor changes add up over hundreds or thousands of generations to produce a population of plant well suited to the environment. The changes in the life is the important. The environment doesn't do anything except to provide the attrition necessary for some of the life to die before it passes on it's traits instead of the traits from the ones more suited to living in that environment.
When a plant is bright and colorful, thereby attracting animals and insects, it's because the more colorful a flower was in the past made it more likely to attract the animal or insect which would pass pollen and allow the plant to reproduce. So the more colorful, the more likely it survived, which means every time a plant mutated to make it's flower just a scoshe brighter or more colorful, that particular plant was more likely to reproduce. And birds or insects obviously survive to help make the next generation of their species if they find the food the flower contains and eat, so the ones who ate bright flowers were more likely to survive to reproduce.
3. The voice for example will become much stronger if constantly used in the proper way. For good and intelligible reasons growth has become associated with constant exersise. In some breeds of domestic ducks that have given up
the habit of flying(i.e humerus, radius), the wing development is no doubt less than it would be with more active habits. Without engaging in any definite speculation, how can you exersise what does not exist?
If the disuse of the muscles will also lead to atrophy, then why does men still posses muscles for moving his ears forward when he has altogether lost the use for them? In the early stages where disuse is incomplete we may have expected the reduction to be slow, but when the muscles has become so small that exersise was out of the question, wouldn't we expect that all traces would disappear rapidly? If it is urged that all vestiges gradually go away, the answer is that in many cases the organ has reached the vestigial state and still they linger on. For ages the horse's forefoot has borne only one toe, yet there still remains the so called splint bones, that once carried a toe on either side.
As for mutation, I beleive this article presents its problems adecquatly;[http://www.cs.unc.edu/~plaisted/ce/problem.html]
Muscles don't just dissappear. They might after a very long time of disuse, evolutionarily speaking, but that's only due to chance mutations which reduce them and, since they aren't used, does not effect the individual's ability to survive and so is as likely to go on to the next generation as any other mutation he possesses. If foot size didn't matter to the survival of some species, then after a few hundred generation there was nothing to avoid smaller feet. Though, if they don't need feet at all, big feet may even be a hamper to survival, for it's uinneccesary weight and would make you slightly less likely to survive. Either way, the genetic code for the foot (muscle) is still there. Not using doesn't make it go away. That's why there are such things as vestigial organs.
4. I am defining life as the manifest activity resulting from th
e interaction. The organism is a mechanism for storage and transformation of energy, but the source of its energy is the world about it. We seem to agree that the whole history of the world is one of changing climate and geological events. But according to our ideas of evolution the complex population of the modern world has evolved from a simple primordium. Given the complexity that we have arrived at, the possibility of surviving all those stages, in my perpective, just seems astounding.
Well, you have to consider that, according to abiogenesis, primordiums would have been extremely common back then, as they resulted from a natural process which would produce them. There may have been millions of different kinds of pseudo-life back then... and one of them just happened to spawn enough others to begin producing things which meet the biological definition for life, which then continued reproducing for billions of years. This is the line between evolution and abiogenesis. The first life. Realistically, though, the line would be anything but fine.
5. For this question, I would like to accept this qoute; "I am afraid that this is a question we all have to face on our own and for ourselves. Everyone faces their own mortality in their own way." But I thought it was interesting from a philosophical perspective.
1. I agree that only existing characteristics have been brought out. In other words, heridity limits the range of variation, and limits it more narrowly as evolution advances, but natural selection cannot go without variation.
Now, it follows that; it can only combine variation, it doesn't originate them. So what is the origin of variation?
The expression of genes essentially 'builds' an organism with various phenotypic tools for survival. Those genes that code for phenotypes that are best suited for a particular environment will allow the organism to survive longer and pass on those genes that allowed the organism to survive.
However, the fitness of a genome is not binary. A single allelic difference between two organisms of the same species will not decide whether one breeds and one doesn't, and even large allelic variations between two organisms of the same species will not cause one to be unable to breed and the other to do all the breeding. Fitness is a continuum, whereby those subsets of a population with certain alleles will breed, on average, more often than those subsets that contain alleles with less fitness.
By this I mean that, in populations that are sufficiently large, variation increases faster than natural selection can decrease it. It's when new selection pressures are introduced that large subsets of a population will be eliminated from the gene pool and variation decreases dramatically - such as the case when antibiotics lead to antibiotic resistant strains of diseases, by killing off the 95% of bacteria that are not resistant and allowing the small subset of bacteria with those alleles that give them resistance to proliferate.
This begins to border on a metaphysical discussion - Weismann wouldn't have known what DNA or genetic inheritance even was. It's not that the cell, in-itself, contains any essence of some entity. The cell contains instructions for how daughter cells will differentiate. This can be empirically verified through such techniques as cloning, recombinant DNA, and even synthetically engineering life.
MY question is concerned with the AQUIRED characteristics(i.e increased power obtained by training being transmitted to the next generation),are improvements of existing characters by specialising passed on?
Changes in the phenotype of an organism (eg by training some skill) will not be passed on to the offspring unless it causes some change in the genome of the gametes. As I said in my last post, it's possible that certain epigenetic changes in the genome can be passed on.
But a change in epigenetics is tantamount to changing the font size in a book. The words that are written (the actual genome) are still the same.
2. I'll give an example to elaborate on my question. The hard thorny plant so common in the desert is well adapted, has it adapted to its surrounding(i.e retrovirus), or has their enviroment given them their characters (i.e in the case of the elephant trunks)?
A plant will not evolve to the surroundings. A population of plants will pass on variation to offspring, and selection pressures (the environment, the climate, other organisms etc) will create a situation in which certain variations are better suited and others not as well suited (fitness).
The thing to keep in mind is that selection occurs on an individual level, but evolution occurs at the population level. Individuals in a population are naturally selected via their ability to survive in a given environment. Because certain variations live and breed, while others do not, the population as a whole will be altered over time as selection pressures shift and new variations arise that are even better at surviving than current variations.
I wouldn't worry about endogenous retroviruses. That is a source of new genetic material, which can potentially be a source of variation, but it's not an incredibly significant source. I think people read about this at some point and found it interesting, so they decided to point it out in this thread.
but to oppose the concept that its aided by external condition; The fruits of many plants are admirably suited to attract birds who eat them and scatter the seeds far and wide so that the species extends its range, the strawberry is splendidly adapted to that part of its enviroment which we call the black bird; yet it cannot have been influenced by the requirement of the palate to which it appeals so forcibly.
There are variations of fruit that have different sizes, shapes, textures, colors, and tastes. Certain variations would have been more appealing to other organisms in the environment (birds, bats, rodents etc). These other organisms would have chosen those fruits they found more appealing. This would allow those more appealing fruits to have their seeds spread, and therefore propagate those genes that code for fruits that are more appealing to those organisms.
Using fruits that humans grow and sell at markets would be a bad analog, because humans artificially manipulate the genes of the fruits we eat.
To further illustaret my Questions with further examples; Why have not the insects constant stimulation caused the center of the daisy for example to sprout into startling forms? Why in the wild guelder rose are the outer baren flourets, which insects do not visit large and showy, while those in the center, thier hunting ground, are small and inconspicious?
I want an explanation that will explain both color and form.
I don't know much about the evolution of these, so I could only speculate.
It's difficult to pinpoint exactly what selection pressures in an organisms evolutionary past caused it to come upon it's present form. Humans are good at artificially selecting certain traits on organisms that they desire (eg on food fruits and vegetables, on lab rats, on pets like cats and dogs etc) but we can't very well ask a pollinator why it chooses flowers of certain shapes and colors. However, we can empirically observe the tendency of pollinators to choose certain flowers.
While I can't really give any specifics on the examples you provided, I can name a few general "rules" in the flower-pollinator relationship that seems to act as selection pressures:
1. Smell is important. Sweet smelling flowers tend to attract bees, butterflies and hummingbirds, whereas carrion smelling flowers attract flies as pollinators. So we can conclude that the type of pollinator in an environment would select certain types of flowers.
2. Exposure to pollen is important. Flowers will evolve to be shaped in such a way that the pollinator, on it's way to obtaining nectar, will have to get pollen on itself.
3. Some flowers have shapes that resemble something else - for example, Rotheca myricoides which looks like a butterfly in order to attract other butterflies.
4. Pollination syndrome.
3. The voice for example will become much stronger if constantly used in the proper way. For good and intelligible reasons growth has become associated with constant exersise. In some breeds of domestic ducks that have given up
the habit of flying(i.e humerus, radius), the wing development is no doubt less than it would be with more active habits. Without engaging in any definite speculation, how can you exersise what does not exist?
If understand what you're asking, you seem to be trying to explain evolution on an individual organism basis again. Different ducks will have variations on the size and strength of wings, and those that are better suited to survive will pass on the genes for their wing size and shape more often, and therefore become more prominent in the population.
Why would a duck with smaller/weaker wings be better suited, you may ask? Evolution is a 'game' of economics. I'm going to copy/paste this from my Brief Overview of Evolution post:
To think about this on a more abstract level, one has to remember that a beneficial trait has to have a cost/benefit analysis (by means of natural selection). Thinking about humans, the reason we do not have supercomputer brains is because it would not be economical on in an evolutionary sense. We would require bigger heads to fit bigger brains which a) would be more difficult to fit through the birth canal, b) would require more neck strength and skull protection (more 'recourses' would need to go towards making the bones and muscles in the head and neck stronger) and c) the brains we have are already energy black holes (just our brain uses about 20%~ of the total energy we consume).
So, essentially, natural selection has to do the equation:
Beneficial trait - Cost to body = Total overall benefit.
If the energy cost of having a larger brain outweighed the benefit of having a larger brain, it would make the trait ultimately less beneficial; the person with the smaller brain would actually survive better if, perhaps, there was a food shortage. The person with the large brain would require a lot more food to support the energy needs of the larger brain and the nutrients required for the stronger skull and neck muscles/bones. The selection pressure of a food shortage, or a disease (which would be taxing on the bodies energy), or one had to escape other dangers (being faster or stronger also requires energy), and the limiting factor of the birth canal size all prevent larger brains from becoming a predominant trait.
This can apply to other organisms, as well. Elephants do not become perpetually larger, even though their size make them better able to survive predation from lions. The increase in size would come with an increased need for food as well as oxygen.
In short, natural selection makes sure that organisms stay at a tenuous 'balance' by forcing populations to continually adapt to selection pressures, while at the same time remaining efficient.
If the disuse of the muscles will also lead to atrophy, then why does men still posses muscles for moving his ears forward when he has altogether lost the use for them? In the early stages where disuse is incomplete we may have expected the reduction to be slow, but when the muscles has become so small that exersise was out of the question, wouldn't we expect that all traces would disappear rapidly? If it is urged that all vestiges gradually go away, the answer is that in many cases the organ has reached the vestigial state and still they linger on. For ages the horse's forefoot has borne only one toe, yet there still remains the so called splint bones, that once carried a toe on either side.
As for mutation, I beleive this article presents its problems adecquatly;[http://www.cs.unc.edu/~plaisted/ce/problem.html]
Vestigiality are evolutionary leftovers the remain in the genome. For many vestigial features, they only exist in small subsets of the population (see human vestigiality - the ear muscle only occurs in about 10% of the population).
What you should remember are two things:
-evolution is blind (it is not goal oriented) and
-evolution can only use existing structures.
By being blind, in evolution, traits will not be added or taken away because it seems reasonable to do so, or because it will be helpful somewhere down the line. Vestigiality will remain, in many cases, because evolution is not a conscious entity that can decide "this organism no longer needs this, so lets just get rid of it." The vestigiality will only be eliminated if certain variations within the species that are better fit are also lacking that vestigiality. If the vestigiality is neutral, it is neither helping nor hindering the fitness of the organism, so there is no survival 'reason' for losing it.
By using only existing structures, evolution cannot "go back to the drawing board" on any particular structure. There is no redesigning the organism except by means of what genes are already present. If organisms with vesgiality continue breeding with other organisms of vestigiality (since vestigiality is generally neutral) there is no mechanism that would redesign the organism not to have that vestigiality. It would only be when the environment changes such that the vestigiality becomes either a hinderance, an advantage, or non-economical that natural selection would select for or against the vestigiality. Any other alteration in the frequency would be due to genetic drift or gene flow.
4. I am defining life as the manifest activity resulting from the interaction. The organism is a mechanism for storage and transformation of energy, but the source of its energy is the world about it. We seem to agree that the whole history of the world is one of changing climate and geological events. But according to our ideas of evolution the complex population of the modern world has evolved from a simple primordium. Given the complexity that we have arrived at, the possibility of surviving all those stages, in my perpective, just seems astounding.
Evolution itself is what would have allowed life to persist through the different environments that have existed on earth. Populations of organisms evolve due to changes in the environment - the organisms that lived during the archean eon or proterozoic eons would have had considerably different biochemistry from life that exists now. Indeed, there are 'extremophiles' that have very different biochemistry from organisms we encounter everyday that still exist right now. Life has a great propensity to evolve to fit an incredible variety of different environments - astrobiologists count on this in order to extrapolate that life must exist on other planets.
5. For this question, I would like to accept this qoute; "I am afraid that this is a question we all have to face on our own and for ourselves. Everyone faces their own mortality in their own way." But I thought it was interesting from a philosophical perspective.
This would all depend on how one defines a soul and what nature one attributes to it. I think by definition a soul would not have come about by natural causes, but perhaps that's just my own definition. I do not believe that souls, by my definition, exist. I do, however, think that emergent downward causation as a result of complex dynamic systems (which could be seen as soul-ish) are naturally evolved.
If you have a bunch of extra time to blow, there is a video series on the website of the Howard Hughes Medical Institute, intended to educate the lay public on the modern theory of evolution. Here it is:
What I just love is what flies in the face of the dogma of evolution. Yes things do evolve most would agree. But the (accepted) idea that man is about 3,000,000 years old and evolved from ape like creatures is far from the whole story. There are verified places on earth where giant foot prints are found..(human footprints) along with dinasaur tracks. Not just one place. Also the foot prints measurment and depth clearly say that this print was made by a 25 foot man in one instance. Now typical when I mention this, I am dissmissed as a crackpot. These anomalies and others fly in the face of traditional science. Anamolies is exactly what mainstream science calls anything they do not understand or do not want to look at. If this were to be Acepted, then most of what we thought we knew would have to be thrwon out! No one likes their beleife destroyed. So all of these things are not studied, or ignored, or ridiculed. Not as much as they once were. There is plenty of evidence of civilization 70,000 years ago. Science would have you think that massive stone blocks cut with incredible precision that master stone workers say could NOT be done today, they would have you think that primitive people did this with copper chisels and crude ropes and logs? In the end when backed into a corner, mainstream science has no explanation and is not even willing to study it. A novice can clearly see more than these guys are willing to admit! There is evidence worldwide that clearly defines very developed civilizations.
What I just love is what flies in the face of the dogma of evolution. Yes things do evolve most would agree. But the (accepted) idea that man is about 3,000,000 years old and evolved from ape like creatures is far from the whole story. There are verified places on earth where giant foot prints are found..(human footprints) along with dinasaur tracks. Not just one place. Also the foot prints measurment and depth clearly say that this print was made by a 25 foot man in one instance. Now typical when I mention this, I am dissmissed as a crackpot. These anomalies and others fly in the face of traditional science. Anamolies is exactly what mainstream science calls anything they do not understand or do not want to look at. If this were to be Acepted, then most of what we thought we knew would have to be thrwon out! No one likes their beleife destroyed. So all of these things are not studied, or ignored, or ridiculed. Not as much as they once were. There is plenty of evidence of civilization 70,000 years ago. Science would have you think that massive stone blocks cut with incredible precision that master stone workers say could NOT be done today, they would have you think that primitive people did this with copper chisels and crude ropes and logs? In the end when backed into a corner, mainstream science has no explanation and is not even willing to study it. A novice can clearly see more than these guys are willing to admit! There is evidence worldwide that clearly defines very developed civilizations.
OK, but you know I would expect that sometimes the novices are simply misled, because sometimes they don't have the background knowledge necessary to decide (or even know about) the most probable explanations for seemingly-strange anomalies. For example, one of the most popular arguments for creationism is the point that the moon has not nearly enough dust to have existed for billions of years. This has convinced a lot of people in the lay community, because they don't know that the argument is based on a measurement of incoming dust from outer space from on top of a mountain on Earth in 1950, getting a very large value that was divided by ten to be fair and account for all the dust in Earth's atmosphere, getting a value that is still far bigger than the actual value recorded in outer space. Lay people don't know that. How would they? They would have to go far out of their way to research it. The debates are of course complicated by the reality that one or two intellectual authorities can be found by an interest group to say almost anything. "Yep, the Moon has not enough space dust. Trust me--I'm a geologist."
Decisions can be made by adhering to a method to find the best explanation. Which explanation has the most explanatory power and plausibility?
Explanatory power is the principle that the evidence should be expected by a theory. If you have a footprint in the mud that is 3.75 feet in length, then, OK, that evidence is expected by a 25-foot-tall man that walked about in the mud. But, what other evidence would we expect from a 25-foot-tall man walking about in the mud? Answer: settlements of 25-foot-tall human beings, with enough members to sustain the population of 25-footers, which means graves and 25-footers stuck in mud, tar and ice, with very large skulls, very large femurs, stumps from a tree that was pushed down by a 25-foot-tall man to use as kindling, elephant-crap-sized chunks of human crap, and that kind of thing.
The other criterion is plausibility. Does the existence of a 25-foot-tall man roughly fit what we know about the world? The competing theory, I would expect, is that the footprint is fraudulent. A fake footprint can be carved in the mud, and we know that such fakery has happened many times. But, the hypothesis of a 25-foot-tall man does not fit what we know. It is still a possibility, but, even if they do or did exist, it would take strong evidence for the claim to win against the opposing hypotheses that explain the evidence in terms of what is normal.
Also, this page provides a critical perspective and links to other sources about the alleged set of human footprints (including the giant human footprint) found alongside dinosaur footprints.
Genetics is not the only evolutionary mechanism.
Read about memetics, the evolution of human thought.
I believe there is also a form of animal (or even plant) memetics, since multiple actors(plants or animals or whatever) all do communication (includes competition etc). Any multiple agent pool forms a super-system. A bunch of organisms form a super-organism if there is communication and there always is if they live in the same world, which they do.
These super-organism can influence the evolution of the sub-organisms. There is many layers of evolution.
Not everything can be explained by just looking at one layer (genetics). This is the reason that one-layer-evolution theory comes accross as kind of flawed, since the quantum leaps cannot be explained by just 1 layer. Multiple (intertwined) layers of evolution can however explain it all.
The central way for research psychologists to explain general human behavior is with an ancestral descent of evolution by natural selection, and that book seems to be all about that.
The book contains many very important facts about evolution as a science and how the scientists today are understanding it and using it.
For example, a lot of well-meaning people still seem to think that evolution takes place "for the good of the species." That ain't so.
A lot of people mis-represent evolution by saying things like this: "The bugs that look like leaves developed that trait because it helped them survive in their environment." Again, this is a mis-representation.
It's like asking a 5-year old why it rains. Answer: "To make the flowers grow!"
That's backwards. The bugs in the jungle that look like the leaves look that way because, once upon a time, the bugs in that species that didn't look so much like the leaves were easier prey, and, over time, the population had fewer and fewer members that didn't look like leaves because they were being eaten more frequently and, too often, before having time to reproduce. It's not like the bugs changed themselves, or that they changed on purpose.
Her book is brilliant and helps people "understand evolution," which I why I suggest it in so many threads on evolution.
Furthermore, to get around to the thread which spawned this one directly, if someone believed that what others meant by "evolution" was this weird ability of living things in the wild to sort of "will" themselves to change to adapt to their environment then, yeah, evolution would be bull shit.
I have read some of it, its intresting, and i do see your point about the common misconceptions, regardless, my main concern has to do with the origin of that variation, species can have a weak or iron will, this has minimum affect on the fact that enviroment and inhertance have some deterministic factors that guide evolution.
I am not making judgements, any type of awareness is valid in some sense if applied appropriatly, even if that was the case, such things are better experienced than read, for example, I kinda stopped caring about my personality though I try pay special attention to understanding all other aspect of myself. Natural selection is only a regulating principle, it has 'no control' over evolution other than 'suggeting' a direction for it. That how i feel about this.
Also, no-one should have to wear the collar, its about mutual communication, until I verify evolution is existent myself, don't be upset if your motivation speeches didn't get me moving with the rest of the crowd.
I have read some of it, its intresting, and i do see your point about the common misconceptions, regardless, my main concern has to do with the origin of that variation, species can have a weak or iron will, this has minimum affect on the fact that enviroment and inhertance have some deterministic factors that guide evolution.
I don't understand. A species isn't the kind of thing that has a will. What do you mean?
Natural selection is only a regulating principle, it has 'no control' over evolution other than 'suggeting' a direction for it. That how i feel about this.
That's right. Unfortunately, the word "selection" tends to evoke a sense of intention. Most people, when they select things, select them for some purpose. The phrase "natural selection," in many people's minds, is some idea that nature is some kind of being with intentional states, and that it selects some individuals or species instead of others to survive. That's backwards and incorrect thinking.
Also, no-one should have to wear the collar, its about mutual communication, until I verify evolution is existent myself, don't be upset if your motivation speeches didn't get me moving with the rest of the crowd.
No worries from me. Individuals will still be competing, some surviving, some not, and there will still be statistical analyses of these things, and some people will still be mis-understanding them.
That's right. Unfortunately, the word "selection" tends to evoke a sense of intention. Most people, when they select things, select them for some purpose. The phrase "natural selection," in many people's minds, is some idea that nature is some kind of being with intentional states, and that it selects some individuals or species instead of others to survive. That's backwards and incorrect thinking.
That's not what was suggested, of course, natural selection has no intentional states, what i was emphasing is that it doesn't 'control' how a species evolves, it only eliminates those less fit to survive.
No worries from me. Individuals will still be competing, some surviving, some not, and there will still be statistical analyses of these things, and some people will still be mis-understanding them.
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