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Post by malikc6 on Jan 30, 2015 11:40:39 GMT 5
Mutation again. Some cells happened to develop a light receptor protein, and this protein turned out to be a huge advantage. Euglena is an example of such an organism. In the case of metazoans, some developed a genetic mutation that led to the development of certain cells that had light receptor proteins. Subsequent mutations led to the development of more complex eyes. So basically yes, it did "just happen", and this random development proved so successful that over billions of years it evolved into more complex forms, and evolved independently for many times. For some reason the eye is sort of a creationist’s favourite, just like the banana. But just that it’s complex and an example of great engineering doesn’t mean evolution doesn’t explain it. In fact, nothing can explain it as well as evolution does, because evolution of the eye happened over enourmous spans of time during which its structure could be adapted, optimised and diversifed. Animals that don’t have eyes don’t have them because they provide no evolutionary advantage. Obviously, if there’s no light in their environment, a light receptor is useless. But if there is, it is apparently tremendously useful. I think a better question would be how did the brain evolve? |
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Post by theropod on Jan 30, 2015 14:54:11 GMT 5
Mutation again. Some cells happened to develop a light receptor protein, and this protein turned out to be a huge advantage. Euglena is an example of such an organism. In the case of metazoans, some developed a genetic mutation that led to the development of certain cells that had light receptor proteins. Subsequent mutations led to the development of more complex eyes. So basically yes, it did "just happen", and this random development proved so successful that over billions of years it evolved into more complex forms, and evolved independently for many times. For some reason the eye is sort of a creationist’s favourite, just like the banana. But just that it’s complex and an example of great engineering doesn’t mean evolution doesn’t explain it. In fact, nothing can explain it as well as evolution does, because evolution of the eye happened over enourmous spans of time during which its structure could be adapted, optimised and diversifed. Animals that don’t have eyes don’t have them because they provide no evolutionary advantage. Obviously, if there’s no light in their environment, a light receptor is useless. But if there is, it is apparently tremendously useful. I think a better question would be how did the brain evolve? Well, the answer to that is fundameentally the same, but obviously it started in multi-celled organisms, and with the evolution of a cell type that was capable of transmitting a chemoelectrical system by altering its concentration of potassium ions. Since that is pretty much a prerequisite for a metazoan to be able to move in coordinated fashion, I guess the advantage is obvious. I'm not a neurologist, and the brain is very complex, but it seems to work like a computer that never shuts down, with neurons instead of transistors. |
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Post by malikc6 on Jan 30, 2015 15:32:40 GMT 5
We also don't really know how the brain generates consciousness, if it even does. I've read articles that suggests that consciousness and the brain are actually separate.
You know, I know that this took eons to happen, but it seems like a species is connected to itself. It's as if DNA is alive and is slowly changing for the survival of a species, but it is random. It just completely blows my mind on how current complex life forms are theorized to have started from something so basic from random chance, mutations, environment, etc.
And here is another thing I've been thinking about since I was 12. Dinosaurs were here MUCH longer than humans. If anything, I feel that they should have been the ones running the world similar to how humans are doing today. They had several eons to do it, but it seems like human beings evolved the fastest and the best out of every living organism of today. I also find it crazy how one species evolved to rule the world. Weren't they also in similar conditions that we were in?
My dad has a similar issue with this to, and him being a creationist, he said in the scriptures that the bible itself says that humans were created last. That the bible itself tells of other life forms before humans.
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Post by theropod on Jan 30, 2015 16:24:09 GMT 5
We also don't really know how the brain generates consciousness, if it even does. I've read articles that suggests that consciousness and the brain are actually separate. You know, I know that this took eons to happen, but it seems like a species is connected to itself. It's as if DNA is alive and is slowly changing for the survival of a species, but it is random. It just completely blows my mind on how current complex life forms are theorized to have started from something so basic from random chance, mutations, environment, etc. And here is another thing I've been thinking about since I was 12. Dinosaurs were here MUCH longer than humans. If anything, I feel that they should have been the ones running the world similar to how humans are doing today. They had several eons to do it, but it seems like human beings evolved the fastest and the best out of every living organism of today. I also find it crazy how one species evolved to rule the world. Weren't they also in similar conditions that we were in? My dad has a similar issue with this to, and him being a creationist, he said in the scriptures that the bible itself says that humans were created last. That the bible itself tells of other life forms before humans. But can you give me a reason why the phenomenon called consciousness should not simply be a necessary consequence of having such a powerful brain? DNA is not alive, but it's a very large organic molecule that is part of every lifeform. It changes because it has to be replicated, and replication can involve errors. These copying errors are the mutations that drive evolution. Dinosaurs have not been around for eons, they only exist since the triassic. I think the fallacy of the creationist worldview is to set humans apart from other animals, when they really only have yet another way of adapting, by an elaborate type of eusocial lifestyles if you will. Mammals have been around for almost as long as dinosaurs, and they just happpened to be in the niches most favourable for evolving the human brain and body shape. Birds, after the cretaceous, were mostly volant. Mammals brought forth small, agile arboreal fructi- and omnivores, a niche favouring relatively large brains and grasping hands, and plate tectonics affecting tthe climate in Neogene Africa did the rest, by forcing them to quickly adapt for terrestrial habits. Evolution is a chain of events, and its results in exactly the shape they took are certainly remarkably complex. But what is there that explains them better? Many random small, simple changes simply sum up to create a complex result over long timespans. |
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Post by malikc6 on Jan 30, 2015 17:18:21 GMT 5
By eons, I meant millions of years. Isn't that the correct term? Yes a lot of creationists (including my father) believe that humans are separate from animals.
As for consciousness, I have no idea. There are many people saying that it is separate from the brain.
Question, do you think free will even exists?
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Post by theropod on Jan 30, 2015 18:43:05 GMT 5
Eons are high-rank measures of times, in the order of Ga or several hundred Ma long. For example, the current eon (the phanerozoic) comprises the Palaeozoic, Mesozoic and Cenozoic eras.
I know many people think that there is, but that doesn’t make it true. Theres no reason for any non-material consciousness to exist, it’s irrational.
The answer depends on your definition of the term. If, like some, you define free will as some higher form of sould or spirit that is acting independent of the physical body and of neurological processes, then no, it doesn’t exist. I would however rather define "free will" as the enourmous complexity involved in decision-making processes of the brain, which makes them unique and impossible to control or predict. Every decision we make depends on our neurophysiology, which in turn has been influenced by our genetics, behaviour and experiences.
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Post by creature386 on Jan 30, 2015 18:54:25 GMT 5
I know that feeling. There are few of my posts that are older than a year and that I like to read. Not in my case. I actually refuse to read some old threads from back in 2011-12 because I physically cringe at how bad my posts used to be. What I meant to say is that there are few old posts that I like to read which means I don't like the majority of them. |
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Post by malikc6 on Jan 31, 2015 0:48:49 GMT 5
I'm going to type this fast since I have to go soon. So if I'm correct about this, evolution only gives us what we need? Past posts you said. "No light = no need for eyes." But evolution is random. There are blind animal species with eyes that just do not work.
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Post by theropod on Jan 31, 2015 15:38:06 GMT 5
Evolution itself is not random. It TENDS to just give us what is advantageous, but of course an individual with a disadvantageous mutation can also survive in some cases, for example if the animal’s social structure or living conditions permit it, and/or if it has other mutations or acquired behavioural adaptions that provide it with an advantage. That’s why evolution happens over large time scales.
Since all of it bases on random mutation, there are no 100% certainties, just very high probabilities.
The example with the eyes is different. Completely losing a feature like eyes takes very long, especially if the pressure is not that high. This is not about a feature that represents a functional advantage, but about the loss of a feature that represents a slight energetic benefit. So the evolutionary pressure to lose these eyes and the degree to which individuals with reduced or absent eyes are favoured is very slight, ergo the process of losing them takes a very long time. Think of it in a similar way to diffusion gradients, the greater the advantage it brings, the more likely a mutation is to be passed on, the quicker the evolutionary process takes place (given an equal likelyhood of the mutation).
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Post by malikc6 on Feb 1, 2015 3:05:15 GMT 5
Are we currently viewing evolution in any animal species today?
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Post by coherentsheaf on Feb 1, 2015 4:18:03 GMT 5
Are we currently viewing evolution in any animal species today? Yes. Many cases we are seeing changes under laboratory settings, e.g. long term genetic studies of Drosophila. However you have to keep in mind that evolution is a relatively slow process and you will find the largest changes in massive populations under strong selection with very low generation lengths. Therefore when studying active evolution you often want to look at bacteria. One of the more famous such exaples is Lensky's long term experiment: en.wikipedia.org/wiki/E._coli_long-term_evolution_experimentBacteria therein evolved a powerful new enzyme capable of breaking down citrate not found in the ancestral strand. |
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Post by theropod on Feb 1, 2015 4:46:53 GMT 5
Evolution happens all the time, but it is usually too slow for humans to notice. But you can definitely observe the principles involved (mutation and natural and sexual selection) on a regular basis, and then there are cases like the ones coherentsheaf listed.
Another such example would be bacteria that are resistant to antibiotics. That (among other things) is also why we shouldn’t use antibiotics when they are not necessary, because doing so will increase the evolutionary pressure on bacteria to evolve into resistant forms (more antibiotics→resistant mutants have a bigger advantage→their genes will be more widely spread→more resistant diseases).
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Post by coherentsheaf on Feb 1, 2015 4:56:30 GMT 5
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Post by malikc6 on Feb 1, 2015 8:49:06 GMT 5
Evolution happens all the time, but it is usually too slow for humans to notice. But you can definitely observe the principles involved (mutation and natural and sexual selection) on a regular basis, and then there are cases like the ones coherentsheaf listed. Another such example would be bacteria that are resistant to antibiotics. That (among other things) is also why we shouldn’t use antibiotics when they are not necessary, because doing so will increase the evolutionary pressure on bacteria to evolve into resistant forms (more antibiotics→resistant mutants have a bigger advantage→their genes will be more widely spread→more resistant diseases). So THAT'S why that strain got resistant! It makes total sense! The more medicines we use, the stronger the disease will get because it will eventually develop an immunity or resistance to it! It's like a vaccine for the bacteria in a sense. |
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Post by Vodmeister on Feb 1, 2015 10:02:10 GMT 5
Individual specimens don't undergo evolutions, species do.
Say we have species X, and some specimens of this species have something called trait A, it is a very rare trait and only 2% of the entire species has it. We use an antibiotic to kill off a disease caused by species X. 98% of all the members of species X dies. The 2% that are left are the ones who had trait A, which for one unbeknown reason or another, makes an individual specimen immune to the antibiotics that we used to kill 98% of its population. Now, 100% of all members of species X will have trait A, because only the individuals with trait X will be able to survive long enough to reproduce.
Because of this, now the species as a whole has developed a resistance towards the antibiotic, rather than a miniscule minority of the overall population.
This is why we shouldn't overuse antibiotics.
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