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Everything posted by FreeThinker

  1. http://www.qis.net/~truth/ Sorry, couldn't resist
  2. I don’t think that the moment of birth carries any significance when it comes to the moral issue of taking the life of the fetus/infant. Compare the new born infant to the unborn a day before birth. Is it morally justifiable, no matter which stand we take, to differentiate between the two?
  3. A better question: would life be worth living if we knew everything?
  4. I don’t think its necessarily a "black" thing. I think its more of a media thing. For example, Eminem is white but your kids could have easily caught the "black" slang of him. This imitating phenomena has always been happening. Pictures of my father dressed like a hippy back in the 70s is a good example. It was just portrayed to be cool to do that back in those days. Same can be said of "black talk" currently. I don’t doubt that it originated in African-American communities; however its current form has diverged significantly from its roots. To illustrate by example, here in Australia it is considered ‘cool’ to imitate people of the Lebanese background. Teenagers from all sorts of backgrounds (including Asians, Anglo-Saxons, Europeans…) imitate the Australian-Lebanese slang. Next time you go to Sydney and hear a white Anglo-Saxon kid saying “SHO HABIB” you will know what I mean.
  5. I am currently in the second year of my Bachelors degree. Every semester its the usual pattern; things start of great and you have so much will to search the journals, towards the middle of the semester things start piling up and you are forced to look for shortcuts (E.g. Wiki) and just before exam time its just crazy and time is of the essence (back to the net)! I do think that the amount of assessment greatly reduces ones ability to learn or, more importantly, enjoy learning! I often find myself at Uni day-dreaming about getting a few free days to read some science books. The most frustrating things is that the subject content is fascinating, but the assessment and the expectations can be overwhelming.
  6. Hey all, I have been thinking about the evolutionary accumulation of introns. Firstly, they used to be referred to as "junk-DNA" but now we know that this is not exactly true. For example, intron splicing is responsible for the K+ channels in our ears that enable us to hear different frequencies. However, could they still have accumulated as junk and only later been shaped by natural selection for specific purporses? If they were once just junk, why are there no introns in prokaryotes? They seem as good DNA carries as eukaryotes. It seems logical to suppose that the advance transcription machinery in eukaryotes requires introns, while the prokaryotes do not. This once again leads to an evolutionary selection but this would have had to be a slow accumulation with selection at every step. What would be the benefit of carring extra DNA in your genome? It does not seem economical. Have there been any other roles, besides splicing, discovered for introns? Fascinating things, they are. Thoughts please.
  7. 1) Could be an unavoidable side effect of having such a complex neural network? 2) I heard this as well. Not sure if its true though. 3) Highly unlikley. Just because we have dreams, there is no reason to suppose that they have some direct connection to the future or the past. Maybe in an indirect sence where they prepare us for the everyday challanges. This would make sense from an evolutionary point of view and the fact that most dreams are about sex or predators would further support the notion that they are indeed an evolutionary adaptation.
  8. Penetrance is an important factor in gene expression. For example, the disease polyactyl causes the expression of extra digits in certain individuals. However, it other individuals the level of expression varies according to other genes in the genome. Now, imagine inserting the bear muscle cells into a human. Firstly, it would be impossible to predict how the gene would actually behave. If it was expressed, I am guessing that there would be extra requirements for food consumption which would wear out the digestive system quicker. In short, I think such changes are largely unrealistic, not to speak of laser eyes and such. But then again, who would have imagined that we could insert the glowing protein from certain fish into mice? Science never fails to amaze me....
  9. Well, no. For example, DNA and RNA are nucleic acids composed of nucleotides which have a totally different chemical makeup compared to amino acids. Cell membranes are composed of phospholipids which are, once again, very different from amino acids. Also, other structures of the cells such as carbohydrates are also not made up of amino acids. In short, the answer is no.
  10. There is a difference between being a member of the species Homo sapiens and being a person. If we think of a person as a member of Homo sapiens, what does that actually mean? Is it the number of chromosomes? In that case anyone of my cells can be considered a person. Is it intelligence? What about people who are mentally handicapped? Or people with lower IQ, are they less of a person than someone with a higher IQ? I like John Locke’s definition of a person “A thinking intelligent being that has reason and reflection and can consider itself as self, the same thinking thing, in different times and places”. Taking this definition into consideration, I will try and address your categories. Slavery/racism: Clearly any human being with the ability to have future plans and can consider itself as self would be defined as a person. This goes for black, whites or any other race. Abortion: I would not consider a fetus as a ‘person’. It is simply a collection of cells. Until the neurological pathways have been developed , it is nothing but a collection of cells. Animal rights: This is difficult. How can we truly know what sort of an existence a dog experiences ( with its numerous smell detectors) or a bat (with its sonar)? Maybe they experience self in a similar way we do? Genetic engineering: Interesting. Would a chimp/human hybrid be considered a person? Would it have dreams? Do chimps experience some level of consciousness? It is a difficult question. Artificial intelligence: I would say that if A.I was to reach the level of consciousness , it should be considered as a ‘person’. Why should the fact that we contain more carbon (compared to silicon) have anything to do with ethics? Extraterrestrial life: Once again , we can not judge that which we don’t understand. If these beings experienced some level of self awareness, they should be treated just as you and I.
  11. Ribosomes are not proteins, they are made out of RNA (rRNA). RNA has the property where it can act as a catalyst as well as the carrier of information. For example, as Mokele already mentioned, a ribozyme has all the properties of an enzyme. It even requires a substrate (Mg) to be active. This would solve the DNA/Protein problem as RNA can do the job of both! We can imagine a RNA world, where RNA can fold itself into complex shapes and perform the work of enzymes. How did DNA and Proteins come into the picture? It is hard to say. Molecules do not leave fossils. But evidence seems to indicate that RNA arose before DNA. The sugar ribose (In RNA) is quiet easily synthesized in the lab, while deoxyribose (in DNA) requires proteins to be synthesized. What about proteins? I would guess something like the following: natural selection favored the stable RNA molecules. Imagine a scenario where one of these molecules could bond easier with a certain amino acid. Now it would be more stable than its non bonding counter parts. At this time on earth, natural selection would have favored the most stable molecules. As different RNA sequences attracted themselves to different amino acids, some of them begun to merge with one another. This would in turn make them more stable. If, somehow, the amino acids within these merging molecules, managed to bond as well, it would make the molecule more stable still. This could have been the beginning to protein synthesis.
  12. Was I not clear enough in my question or doesnt anyone know the answer?
  13. Hey all, Since RNA polymerase, and a bunch of other enzymes, are needed to translate DNA into proteins, where does the first RNA polymerase of a new organism come from? My guess is that it must be inherited from one of the parents. If so, which single RNA enzyme gets chosen to be passed down to the offspring, or is a new one synthesized from the DNA just before the gamete is made? Are there cases where a defective enzyme has been passed down and no DNA translation took place? My lecturer did not have the answer to these questions and I couldn’t find much on Google (probably because I couldn't phrase it properly in the search).
  14. Hey all, I remember reading one of Richard Dawkins books a long time ago. He was describing animals which are too grotesque to be designed by an omni-benevolent God. One of the organisms he described was a creature which, usually, gives birth to three daughters and one son. Firstly the brother impregnated the sisters. Than, the four of them eat the mother from inside. Once the male breathes in oxygen, he dies. The sisters live on to repeat the cycle. As I recall it was some specie of mice, but I am not convinced it is . Anyone have any ideas?
  15. Homo sapiens are social animals. To fit into a group, and benefit, would require social skills. Favours would be remembered and repaid, and cheaters would be punished as they wouldn’t benefit from interaction with other members of the group. The next questions is; what would make individuals more likely to be cheaters or to follow certain rules (eg. Being good towards others)? The answer is genetic algorithms. Some individuals are genetically more likely to be good (think of it as a strategy) while others are programmed to break the rules. This is a very large simplification. In reality there would probably be multiple genetic algorithms ( eg. Be good to those who are good to you but punish the ones who cheat you, Cheat if you assume the other individual is good and cheat when facing a cheaters...) The Evolutionary Stable strategy would prevail ( I believe it is something in between; we are good when we want to be). Religiously speaking, morality isn’t as simple as it seams. If our sense of right or wrong is set in stone than what is the answer to this questions : Was dropping a bomb on Hiroshima and Nagasaki a good or a bad thing? The answer would depend on the person answering the question. Therefore, what is good or bad is relative, not absolute.
  16. Since then we have undergone more changes and therefore became more genetically different. Also, the chimpanzees \evolved in another direction. There was probably some geographical split between the species ( our common ancerstor). One side of the split led to us ( with the merged chromosome) and the other led to the chimpanzees. Maybe the merged chromosome enabled survival in another territory ( such as swamplands for example as suggested by the 'aquatic ape' theory). This could have led to the split which resulted in the two species.
  17. Well, I found the way he explained the bat sonnar, for example, amazing. It just showed me another outlook on lilfe, one I did not have before: that complexity is beatifull, but understanding it makes it even more so.
  18. Maybe my story will help you out. I was a good student up to year 10. However, in year 11 and 12 I failed everything. Met the wrong people and did wrong things... Even though I could not enroll into any University ( my enter score was nonexistant) , I did a TAFE course in Network Engineering. First year, I failed every subject. I simply was not interasted. Besides school, everything else in my life was going down the drain. Alchocol, drugs, fights... By the age of 21 I managed to finish first year of TAFE. Than one day I came along 'The Blind Watchmaker' by Richard Dawkins. I dont know why I bought the book. I did not even read anything since year 10. It was propably the best decision in my life. Something changed that day. I went back to Tafe and finished my course with mark in the high 90's. I kept on reading science books throughout the Networking Diploma. At the end of the Diploma I started my own Network consulting bussiness, which is full time now. I just finished my first year at Monash University studying the Bechlor of Science. I was in the top 10% of the entire course. I have an unbelivable passion when it comes to Science. I love going to class. It is NEVER too late, you just have to want it...
  19. Depends on what your doing. If you are downloading torrent for example, you might want to open certain ports on your router firewall.
  20. Hi Martin, I got a page not found error when trying to access the link. Can you repost?
  21. A very quick question. What is the "empty space"* within electron orbitals in an atom? Since most of the atom is "empty space", and our world is made of atoms, than most of the stuff around us is made up of this "empty space". What is it? Does it have any properties that we know of? Is there any research being done to study it?
  22. lucaspa, If we have an individual who is homozygous for a particular allele and another one who is homozygous for the other allele, they can still interbreed. Let assume the same two individuals also are also homozygous for a different allele in another loci. Can these two individuals still interbreed? Yes. Are they difference species? No. My point is simple, just because we have allele selection, it does not mean that we will get a new species emerging. Of course that depends on the definition of specie. For my purpose, specie is formed when it cannot breed with its most recent ancestor. I don’t doubt that shuffling of alleles happens. In fact, I don’t doubt macroevolution happens either. My original post was referring to the mechanisms of both, and whether they are the same. Mokele provided me with some papers indicating the rate of mutations in dogs/mammals. I don’t think we can draw a line between micro evolution and macroevolution, just as we can not draw a line between day and night. The two are obviously different but we cannot definitely point out the time when night turns into day. It is a gradual process which happens without being noticed. Microevolution starts with allele shuffling. A geographic boundary might split the population. This could be labeled as a milestone in the formation of new species. However, gene shuffling would still be going on for some time, and no new species is formed. If an individual from one side managed to cross to the other side, he could still interbreed with the other population. As mutations add up, the species become different. The real question is, how much does the genome have to change in order for the two populations to be different species (not be able to produce fertile offspring). Obviously one mutation wouldn’t equal speciation. Would two, three, four, a hundered? This is equivalent to the day and night metaphor. There is no sharp line, but day and night still remain different. In conclusion, if we look at microevolution as just the shuffling of alleles, it doesn’t equal macroevolution. My original argument was that all dog breeds were just the result of gene shuffling and that no beneficial mutation of a gene has been documented. If this is our definition of microevolution, it is not the same as macroevolution. If we introduce mutations, and we would have to look at the genomes to find them, than the two become the same thing. Edit: When I think about it a bit more, maybe I am wrong. What is the genome of two species other than different alleles? We can transfer a gene from a fly into the mouse and have it function as normal... There is no "different" genes, just "different combinations of genes". Hmmm... now that I think about it, I am wrong.
  23. In that case, everything would make sence. I just need some evidence. Have any mutations been located in the genome of any breed of dog? If yes, could anyone provide a link to the paper/article?
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