Mokele

Because of stable environments. If the environment remains stable, then organisms will tend to arrive at a local optimum, a peak in the fitness landscape. It may not be the *true* optimum (and I'd argue never is), but organism evolution is constrained by numerous factors, and once at a peak, an organism will remain in "stasis" until either a) a mutation occurs that allows the organism to reach a different, higher peak in one big jump (very rare to nigh impossible) or b) the fitness landscape changes due to alterations in the environment (either biotic or abiotic). Take crocodilians. For the most part, they've been very evolutionarily stable over time, and have retained the same basic form. However, when environmental change altered the fitness landscape, they've evolved into unusual forms quite rapidly (including splay-toothed vegetarians and what can only be described as like the bastard child of a croc and a pelican). So long as their environment remains more or less the same, they'll retian their overall form. Actually, the appearance of the major phyla in the Burgess Shale has been linked to the one or possibly several gene-duplication events of developmental genes. As usual, duplicated genes can evolve to suit new purposes, and in this case, those new purposes were often developmental, leading to an increase in the possible complexity of body plans. As organism body plans diverged, we saw the origins of modern phyla. Mokele

IMHO, it's highly unlikely that life originated more than once on Earth, regardless of whether it formed on Earth or came here, mostly because of the codon sequence. Your genes are translated into protiens 3 bases at a time, and each combo of 3 bases (called a codon) gives a specific amino acid, and these amino acids are linked up in the sequence of the codons indicating them, forming a protien. The codons are very specific about which amino acid they code for, but, so far as we know, there is no actual *reason* why GCC codes for alanine rather than leucine. The most likely explanation is that, when protien synthesis was just appearing, this code just happened to be the one that was arrived at. However, all life on earth uses the same code. Given that there's no *reason* for this code, and that instances where they no longer have to make their own protiens (such as mitochondria) lead to diversions from it, it's very, very likely that all life on Earth arose from a single common ancestor (regardless of how that ancestor showed up on Earth) Mokele

Then show us a single, peer-reviewed source for this. And no theory, either; empirical evidence or nothing. Mokele

There's also a good bit of Nitrogen (protiens, mostly) and phosphorous (DNA and other things like ATP and phospholipids). Plus there's a fair bit of Sodium, Chlorine and Potassium in solution in our body's water (one way of looking at it is that we never left the ocean, we just took it with us internally, since our body fluids are of very similar concentration to sea water). Oh, and some iron in the red blood cells and muscles. Mokele

The sad thing is I don't know if you're joking because I've done the same thing (roughly, I've never played halo 2 myself).

Actually, unless we're just covering humans, most behaviors are pure instinct. Even in humans, we have more instinct that most people realize. I never said they weren't. I merely said that there is an interaction between the traits and the environment that can alter the expresion of those traits. This does *not* mean that the traits are not produced inherent in the person, only that they are malleable. This is supported by the fact that heritability studies have shown that many personality traits are *highly* heritable between parents and offspring, even when adopted kids are used as the sample. Mokele

Yes, but apes are a clade within monkeys, so monkeys on their own would be a paraphyletic grouping. Ergo apes are a type of monkey, if you want to be strictly monophyletic about things. Mokele

Why would the soul connect to the body at a blood pump? That makes about as much sense as claiming the soul connects to the body at the kidneys. After all, they're pretty vital too. Or why not the reproductive organs? Their activity certainly seems to be more tightly correlated to the presence of my love than heart activity changes. If you're going to post this stuff, keep it in Psuedoscience, where it belongs. Mokele

Yes, they are. I have a lot of lesbian friends (in fact, more than all other sex/orientation combos combined), and all display the same reaction to breasts as males. Mokele

D&D doesn't produce homicidal feelings? You must've had better DMs and other players than me... Mokele

Seldom used? Um, I pulled that definition from my first-year psychology textbook as the definition of personality. My body is also influenced by the environment, does that make it not mine? Or not the product of genes? The fact of the matter is that genes and environment interact to produce our bodies and brains. Because there is some environmental input, or some learning, does not mean that the modified aspect does not exist, only that it is mutable. Mokele

Yes, especially in terms of my favorite pet, my Tegu. Since lizards are predominantly instinctual, and he's been with me his whole life, I feel it's a fairly good bet that "Darwin 2" would be very similar to the current lizard. Mokele

Well, you kind of can, via fMRIs, PET scans and the like. With those you can measure what parts of the brain are activated by particular stimuli and problems. It's not *quite* measuring thoughts directly, but it can measure mental phenomena in a way. Of course, it'll be much more useful once these machines a) have sharper resolution and b) are smaller than a volkswagon. Research subjects typically have difficulty engaging in daily life activities with a magnet the weight of a Buick on their head. ;-) Mokele

Pot, this is the Kettle calling with information about your external hue.

Whoop-de-freakin-do. And it doesn't occur to you that this could easily be environmental and cultural, rather than genetic? No, it does not explain the HIV rates in Africa, mostly because, while we do know that testosterone is an immunoinhibitor, I'm thinking that maybe, just *maybe* the African HIV rate has more to do with, oh, maybe the lack of condom use? Or the conditions of poverty that force women to work in the sex trade, therby becoming major vectors for the disease? Or maybe condoms? Or maybe that HIV originated in Africa and therefore has has more time to spread? Or maybe condoms? Are we seeing a pattern here? Correlation =/= causation. Here's a fact that'll cast that into the proper context: In America, Koreans score much higher than the average on all standardized tests, even when provided the same education. In Japan, where Koreans have long been an underclass, they score much more poorly, both in relative and absolute scales. How about another study: Black students and white students were <u>matched for SAT score</u> and given an SAT-like test. In one condition, they were told the test measured nothing, and, since they were matched for score to begin with, they scored equally well. But in the other condition, they were told the test measured innate academic capacity, and the black students scored lower *than the students with whom they were matched for SAT scores*. Clearly the social perception of black inferiority which you're peddling (all the while claiming not to be racist) actually affects performance of the race being subtly told that they're "less evolved" to use your own word. Nice backpeddaling there. It'd almost be believable if you didn't explictly call those of african descent "less evolved". ::shakes a metal-clad fist and fakes a deep raspy voice:: I'll get you next time, Gadget! Mokele

Well, crossing over mostly just shuffles genes around, without usually generating new alleles (though rarely it can), allowing genes that were previously inherited as a cluster to be acted upon separately by evolution. Also, mutation is more common than we think. A recent study in nature found that hominids have, on average, 4 mutations/individual/generation that affect the final structure of the protien, many more than previously suspected. However, the main problem is that it's a bit of a tautology. Mutation is defined as a process that alters the DNA sequence, especially that of genes, so whether the cause is replication errors, crossing over in the middle of a gene, chemical carcinogens/mutagens, or whatever, it's all technically mutation. So, by definition, any source of new alleles must be mutation, because changes in the genetic code are defined as 'mutation'. Mokele

So you're basically saying that humans will evolve into gods? If so, sorry, but several good sci-fi writers (and innumerable bad ones) have beaten you to that observation. Mokele

Of course not, and I'll thank you not to put words into my mouth. I said that appearance diverges, not that it was the only thing. Bullshit. Cite your source, and it'd better be a peer-reviewed scientific journal, or it's worthless tripe. First, we don't know that this is the product of genes rather than environment. Second, as I pointed out earlier, "blacks" is an invalid grouping for both phylogenetic and gene-flow reasons, ergo I am highly suspicious of such conclusions, as they run counter to evolutionary logic. Third, this does not in any way support that "blacks" are "less evolved". How about the fact that "blacks" (of some tribes) have a genetic resistance to malaria which "whites" lack? Given that malaria has caused more human deaths than wars, crime and murder combined, I guess that makes "blacks" superior, doesn't it? Mokele

You make several huge errors here. 1) The assumtion that "black" is a valid race category. This is wrong. The difference between, various local tribes in africa would be much greater than the difference between the English and Australian Aborigines, on account of much earlier diversification. 2) Note that I said "would be". "Race" doesn't technically apply to humans; there are no populations of humans which have been geneticly isolated for sufficient time to accumulate sufficient distinctions. There's just plain too much gene flow in our species. There are local variations in all sorts of gene frequencies, such as skin color, blood type, etc, but rarely if ever in any consistent manner. Humans are one big race, with some environmental heterogeneity. 3) The mere idea of "less evolved" shows you lack of understanding of evolutionary biology. When a population splits into two species, *both* species continue to evolve. Similarly, if we ignore the massive gene flow and treat humans as "races" (factually inaccurate as that may be), when two "races" separate and go their separate ways, *both* will continue to evolve. If one remains in the ancestral region while the other migrates into new habitat, the accumulating genetic differences will cause them to diverge in appearance. However, to claim that any organism is "less evolved" than any other is simply wrong; they simply retain ancestral traits in some aspects, but evolve in others (such as parasite resistance or tumor supression, both of which have evolved very rapidly in humans, as a recent article in Nature, iirc, shows). Mokele

I disagree, mutation is the fuel of evolution, without which evolution grinds to a halt. Basically natural selection choses among variants, but in doing so it eliminates variation, preserving only the single best option. Once all variation has been eliminated, evolution stops, and can go no further. Mutation is required to add variation to the gene pool for evolution to work with. Technically, yes, if variation already exists, then evolution can happen without new mutation. But only in the short-term. Without mutation supplying heritable variation, evolution quickly runs out of "fuel", so to speak. To the best of my knowledge, it's just used to define what level people study, rather than correpsonding to any real dichotomy. I guess one could say there are differences, since in micro all the organisms involved can interbreed, but in macro they're doing the same but are in "teams". Still, for asexual species, that makes them the same since there's no exchange of genetic information anyway, and the mechanism is the same as well even in sexual species, it's just "scored" differently. But without mutation, where do the different alleles even come from in the first place? Genetic drift can act instead of natural selection, and it doesn't *require* mutation all the time, but, as I noted above, without constant mutation, any evolutionary process will eventually run out of fuel. After all, if you think of genetic drift like scooping a handful of multi-colored beads, and then basing the next generation on that, your diveristy will inevitably decline over time, and without mutation to introduce new diversity, one day you'll just have a pot full of beads that are all the same color. Mokele

To the best of my knowledge, however, thoughts and memories are *not* personality. From what I understand of it, "personality" refers to how individuals process informations (such as thoughts and memories), rather than the information they are processing. One individual might have a tendency to filter negative experiences through "rose colored glasses", while another might not. The actual experiences, thoughts and memories being filtered aren't the personality, but rather the personality is the presence or absence of the filter (for example). Individuals who have similar experiences will react to them differently and even think about things differently. We can quantify these persistent differences in information processing and test for them, and these *detectable* differences are called "personality". Mokele

"Big D", try actually reading the thread. You'll find that much of what you've stated has already been covered. If it hasn't been covered in this thread, do a search for posts by "Asian guy"; you'll find ample posts dealing with this in those threads. Mokele

My only problem with theories of the extra-terrestrial origin of life is that they don't really answer how life began, but rather they "pass the buck" to other locations which may have had more hospitable environments. Whether life arose on Earth, Mars or somewhere else, it still had to arise somehow, and from my POV that's much more pertinent to the topic that journeys life may have taken after originating. Plus, there's the issue of testability. We can amass evidence that shows extra-terrestrial origins of life to be possible, but, so far as I can think (which isn't that far on this subject since it's not my field) the only way to actually *test* the hypothesis would be to find life elsewhere and compare it with life on Earth for evidence of common origins (like if the codons translate the same way). Mokele

This thread makes me so very glad I started using my Ignore list. Mokele

Macroevolution simply refers to any evolution above the level of species, including speciation (in which a species diverges from another one). Since only a total moron would deny microevolution (since it's frequently and easily directly observed), they resort to denying macroevolution. But there are problems... 1) microevolution and macroevolution are only superficially distinct, and the factuality of one *proves* the factuality of the other by logical necessity 2) "Species" is a bit of a dodgy term anyway. We've got rough definitions, but none that *really* work for *everything*. This further highlights the artificiality of the distinction between "micro" and "macro". 3) Quibbles about definition aside, we have definitely observed speciation occuring. See here. 4) Since speciation has been observed, as well as microevolution, that effectively proves macroevolution, since microevolution results in the accumulation of differences between reproductively isolated populations. For more evidence, see here. Mokele