reply to TATABox except that you weren't writing about single character evolution. you said, "Mutation is a part of evolution, some people are more suceptible and others aren't. this can be carried through depending who the mates is, mutations are based on many things, DNA duplication, repair mechs (ligase), sunlight etc. Mutations are selected for depending on the environment. For instance, ask the question, what good is six fingers in today's environment, or webbed toes for that matter?"
Reply to paulsamuel For instance, ask the question, what good is six fingers in today's environment, or webbed toes for that matter?" Am I missing something or is this not in reference to a single character evolving, this is the crux of my post.
reply to TATABox you are missing a lot. this is what i was referring to, you said, "Mutation is a part of evolution, some people are more suceptible and others aren't. this can be carried through depending who the mates is, mutations are based on many things, DNA duplication, repair mechs (ligase), sunlight etc. Mutations are selected for depending on the environment."
Birthrate An example of modern evolution could be the disparity between number of children in well-educated/intelligent and not so well educated/stupid people. If we just consider for theory sake that intelligence is to a certain degree heriditary then it would follow if the more stupid people have in general more children than on average we might see the overall intelligence decrease after some time. and considering the current state of the world this effect migth already have started Please Register or Log in to view the hidden image!
with darwins law in mind... we are evolving every second of every day. infact i feel mankind is evolving too fast what with technoligy comming into picuture. a 6th finger? im sure we wont see that for good a while... many bigger brains, better amune systems, better teeth... with every new baby born, we evolve just a lil bit more evoluting is just growing up... cept it takes much longer, then again some people never grow up Please Register or Log in to view the hidden image!
Mutations are a dead end for creating new genetic information.........they kill the process much like changing a letter of a computer program will produce a bug. Micro-evolution, or changes in allele frequency within a species, occurs. Macro-evolution does not occur. If you have evidence supporting macro-evolution, please submit it now.
mutations happen all the time in the genomes of humans, but inspector rightly points out that this doesn't mean automatically that the human species is evolving at the moment. Mutation is just the basis for selection. If there is no specific natural (or unnatural) selection there is no evolution. Please Register or Log in to view the hidden image!
what are you talking about? are you saying there's no evidence of speciation? ---------------------- If you feel qualified to speak on this matter from an evolutionary platform, I would like to hear your (or anyone else who wishes to participate) professional commentary on Haldane's Dilemma please.
reply to spuriousmonkey You said, "mutations happen all the time in the genomes of humans, but inspector rightly points out that this doesn't mean automatically that the human species is evolving at the moment." That is EXACTLY what it means. Evolution is quite simply the change in gene frequencies over time. Then you said, "Mutation is just the basis for selection. If there is no specific natural (or unnatural) selection there is no evolution." Mutation is not the basis for selection, it provides ONE source of variation upon which selection can act.
"Evolution is quite simply the change in gene frequencies over time." ------------------------ You have just described micro-evolution. Also, let us not confuse evolution with adaptation. "Evolution" is such a broad term, simply meaning "change," that it can be stated quite honestly that adaptation qualifies as a type of evolution. However, when "evolution" is stated to the layperson, the concept is of one sort of organism, like a bacteria, through time, chance, mutations, and natural selection, becoming another sort of organism, like an elephant. If this is the sort of evolution being referred to, then adaptation is in a different category altogether. Adaptation is the process whereby a series of variations already within a population gets winnowed down to the few that are best suited to any particular environment. This is not a matter of adding anything new to the genetic material of the population, but simply weeding out what is not working as well as some other variations. For instance, a population of bears which wandered north at some point, gradually lost members with less fat, less aggressiveness, and darker fur, eventually leaving us with the white, aggressive, and fat-layered polar bear. There may have been some mutations or combinations which increased the fat or the aggressiveness or the lightness of color, but nothing which changed the essential "bear-ness" of the beast. This is radically different from the type of evolution which posits that some kind of unicellular organism through millions of mutations became that bear in the first place.
That is EXACTLY what it means. Evolution is quite simply the change in gene frequencies over time. gene frequencies will not change (efficiently) if there is no selective drive. The whole theory of evolution is based upon natural selection. I didn't quite realize you were a big fan of population genetics, but there are more ways to approach evolution in biological sciences. The new buzz words are for instance evo-devo (evolutionary research based upon developmental biology) and eco-devo (based upon ecology) i might have written a bad english sentence with 'Mutation is just the basis for selection', but i just meant to say that evolution is not just mutation. The mutation creates variation (as you said it so nicely) and natural selection can work with this variation. But if there is no consistent selection you can have all the mutation you want, but it won't get you anywhere constructive in a reasonable amount of time. Hence your statement 'That is EXACTLY what it means. Evolution is quite simply the change in gene frequencies over time.' is not correct in the sense that random mutation does not automatically cause change in gene frequency. Read On the origin of species...and count how much time Darwin spends on explaining selection. Selection is the KEYWORD in the evolutionary theory I am afraid and not merely change. Please Register or Log in to view the hidden image!
reply to inspector you speak very vaguely and one can only guess what you're talking about. you never answered my first question about speciation, after a blatantly wrong and misleading statement by you, i.e. "Macro-evolution does not occur." in regards to Haldane's dilemma, i presume you are talking about gradual accumulation of the fixation of genes in populations. If you are, please state explicitly what your questions are and I will try to answer them. Remember that trait fixation in a population does not occur at a steady state, mutations are only one of many sources of variation upon which selection can act, and gradual genomic changes is not the only way in which speciation can occur, (see Mayr 1982 The Growth of Biological Thought, Mayr 1982 Processes of speciation in animals, and Gould's theory of punctuated equilibrium). P.S. If you are a christian trying to promote creationism, don't hide it. let us know so we can ignore you and the moderator can put you back in the religion section of sciforums where you belong.
"P.S. If you are a christian trying to promote creationism, don't hide it. let us know so we can ignore you and the moderator can put you back in the religion section of sciforums where you belong." ------------------------ My religous beliefs are not the issue here and are, likewise, none of your business. Rather, the fallacy of evolution is the issue. You brought up Creationism, not me. Do not be afraid simply because someone is challenging your presuppositions. Having said that, what would you like to discuss?
why not quote some Darwin for a change...the theists love to quote their bible after all...why aren't we allowed to have this simple pleasure: from chapter IV 'Natural Selection '....On the other hand, we may feel sure that nay variation in the least degree injurious would be rigidly destroyed. This preservation of favourable variations and the rejection of injurious variations, I call Natural Selection.' If you follow this statement true, we would then have to say that any mutations that are harmful will not persist in a population. They will therefore not increase in your precious gene frequency. Then there are the mutations that don't do anyting (the neutral ones). You might see some slight changes in the gene frequency (if some mutations would happen more than others), but since they do not do anythiing (like changing one basepairof DNA, but still encoding the same Aminoacid) it would be basically unsensible to think in terms of gene frequency, since these differences are not functional. You then might to adopt this therory to think in terms of functional protein sequence frequencies. And then there are the beneficial mutations. The problem is of course you can only apply the term beneficial if you have some kind of selection in mind. For instance, a particular mutations gives the organism a higher capability to retain oxygen in its blood. This might be beneficial for a aquatic animal. But with the term beneficial you immediately picture a certain setting. This particular animal will have an advantage in a certain environment. But not every thinkable environment. There must be some cost-benefit analysis and this is were selection comes into play. If this functional genetic unit is deemed to be favortabe there will be a positive selection for it, and hence the frequency might increase over time in a population. Please Register or Log in to view the hidden image!
+++mutations are only one of many sources of variation upon which selection can act, and gradual genomic changes is not the only way in which speciation can occur,+++ i can't actually think of that many other important mechanisms that provide for genetic variation other than mutations, be it point mutations, deletions, duplications etc. so i was wondering what you were talking about. Please Register or Log in to view the hidden image!
"are you saying there's no evidence of speciation?" ------------------------- I have already addressed this. Micro-evolution occurs within a specific species via changes in allele frequencies. However, it has been proven scientifically that macro-evolution does not occur, i.e. from one species to another via radical DNA restructuring. Macro-evolution is based on circular reasoning and is, therefore, illogical.
