Luminal

Just wondering... I don't understand why a true 'seed' AI program has never been developed after numerous decades of this concept existing in some form or another. In it's most simple form, seed AI does this: 1) A program with preexisting functionality performs some change upon itself; any part of the program can be. The change can be entirely random or partially guided by the programmer. 2) If the program crashes or cannot compile, return to step 1. Otherwise, run the program again and test its performance against its original performance. 3) If new performance is superior in its functionality, then the new version is used and returned to step 1. If inferior, return to step 1 with original version. Eventually, tests for different functionality can be implemented, whether that be pattern recognition, language, or other intelligent behavior. The concept being, if implemented correctly, that there will be an exponential feedback of positive changes after enough time. Thus my question: why hasn't something like this ever moved past the initial stages and entered an exponential feedback cycle? In essence, this is similar to natural evolution, except that it has several significant advantages, namely: the ability to store previous versions and step back to them when insurmountable obstacles are encountered; the synergistic relationship of existing intelligent organisms (humans) helping to guide their evolution; generations being as fast as the execution of the program (often measured in seconds), whereas in nature the shortest generations are ~20 minutes and the longest generations are decades or even centuries.

Well, this question could refer to any cell type in the body, but blood provides the easiest example. In red blood cell production, erythropoiesis, if the source of this production (certain bone marrow from what I gather) was replaced with a cell with a different genes (either genetically modified cells or cells from a different organism), would the new blood cells' DNA eventually come to be the most common in the body? If so, what long-term effects would this have on the organism?

I was curious if there was any condition or side-effect of medical treatment that caused one to have a smaller body (not thinner necessarily... body fat ratio not affected or affected minimally) in general, particularly the skeletal frame and possibly the organs. I know there are plenty of things that cause an increase in body size, naturally or unnaturally, just wondering if the opposite existed. This question isn't completely limited to humans; other examples in nature would be appreciated as well. Or is growth basically a permanent effect on organisms? Obviously, I'm speaking of changes that don't end in the death or severe harm. Thank you.

Well, there are several ways I that I'm aware of, including neural networks. For example, a feedforward NN has 10 possible outputs (4 operators and 6 variables), and is looped as many times as the value of the left-most variable (recursion). So, if u is the left-most variable and equals 4, the NN's looped 4 times, with the first output going to the left of the =, and the next 3 going to the right. Next time the NN is run, it will loop a # of times equal to the new left-most variable's value. By the way, when an operator is the output, it must be between two variables otherwise the NN is repeated until a variable is the output. Note: In C++, this would be accomplished through template functions. I'm not too sure about other languages, though.

Here's an example I found from a quick Google search, involving a cellular automaton: http://forum.wolframscience.com/archive/topic/788-1.html My own example: in a program the variables u, v, and w are given a value by the user each loop, while x, y, and z are determined within the program (initialized randomly the first loop). There are many higher-order functions in the program dependent upon the interaction of these variables. - The first loop: y = ux + wy. In another part of the program, the variable on the left (y in this case) is the number of times a function is called. One of these functions determines the order of variables and the operations used in the previous step. - The second loop: x = vyu * uw - y. Now with the fundamental rules changed, including the variable chosen in upcoming functions, the emergent properties change as well, possibly even creating new ones or eliminating old ones. It may be possible that this system would eventually converge upon some repeating pattern, except that there is input from the user (analogous to sensory input in the brain). The rules are forever changing in an unpredictable way and nonlocal information is preventing convergence. I think understanding, classifying, and reproducing emergence is one of the greatest frontiers left in science.

He wouldn't be the only one. I just read this entire thread, sighing inwardly at the OP. Then I noticed the date. Let's think... January of 2004... I was a senior at a fundy Christian High School in the deep South, and a creationist. It's hard to believe sometimes how much can change in four and a half years.

Interesting. What would be your take on the distinction between 'weak' and 'strong' emergence given a mathematical approach? Depending on how you define these terms, there could be upwards of 3-4 different types of systems (if you have a sturdier definition, disregard these): 1 - Uniform: The system has the same properties as its parts. For example, the properties of elements stay generally the same throughout changes in quantity. 2 - Weak Emergence: The system's parts interact in such a way that the system has properties that a single part cannot have, due to nonlocality or chaos. For example, weather systems or feedforward neural networks. 3 - Strong Emergence: The system's parts interact in such a way that it cannot be predicted by either viewing a single part or all the parts individually. The emergent properties are creating feedback to the components. For example, recurrent neural networks. 4 - 'Very Strong' Emergence - Same as above, except the feedback from the higher-order system is additionally changing the basic rules of its components. For example, the left and right hemispheres are communicating (with their individual neurons producing strong emergence), and one of the regions stimulates the release of a certain neurochemical in the other, which alters the underlying conditions for its neurons to fire temporarily. Little, if anything, can be predicted seeing as the rules are updating constantly. A different mathematical model would be needed each time the rules renewed. Sorry if that meandered a bit.

Would you consider it even possible to explain holistic or emergent systems through mathematical language? Emergent systems supervene on their components, potentially changing the lower-order rules at each juncture, and in turn the altered rules affect how the system behaves at the emergent level. There's no point one can "step in" and measure any quantity meaningfully. And without meaningful quantification, how can math describe these systems? To understand some of it, you must understand (nearly) all of it. I know that it seems unscientific, but there may be certain phenomena that to understand we must use means that are minimally mathematical. Another way of putting that is: it may take holistic intelligence to understand holistic systems, including intelligence itself.

I am curious as to why modern science has become so heavily reliant upon a mathematical, reductionist approach in explaining observable/natural phenomena (there are exceptions, of course, including game theory, sociology, and macroeconomics). It seems that we have become addicted to explaining nature by disassembling it, rather than trying to understand how the parts influence each other in a higher-order, dynamic fashion. There is a place for reductionism in science, yet is there not also a place for emergence (in particular, strong emergence) and holism? There is a level of disdain for explanations that speak of strong emergence or holism that borders on viewing them as pseudoscience. A great deal of observable reality cannot be explained through a linear and/or reductionist approach, i.e. structures or properties that cannot be explained by their parts alone. This is because the products of the interacting parts "reach down" and affect the interaction of its own parts. Perhaps the answer is that math is very difficult to apply to such systems, thus attempts to explain these come off as unscientific. Take for example a cycle in which neurons in a subsystem of the human brain (say, the midbrain) interact for a few hundred milliseconds and then send a signal to another subsystem (say, the cortex), and the second subsystem's neurons interact for a period of time then send a signal back to the first subsystem affecting its future output... how can we explain such an interaction mathematically even knowing the details of every signal neuron during every millisecond? Each time the emergent signal is relayed in a full loop, not only do the rules of the system change, but the efficacy of individual synapses do as well. I don't have the answer, yet it doesn't mean we should abandon attempts to explain such structures in nature as these systems are as important, if not more so, than easily reduced systems.

Never mind.

You are primarily talking about the benefits of sexual dimorphism, not sexual selection. Yes, dimorphism is the result of sexual selection, but only one of many results. Sexual selection, in its broadest sense, is an accelerant to natural selection. While a potential mate may have survived long enough to mate, it may not mean it is the best choice out of all that are available. The female is usually the selector because she can only propagate her genes to offspring once every X number of weeks or months (years if you include time to raise young), while the male can do so several times a day. All of the advantages of sexual selection (with the sole exception of sexual dimorphism) would still exist in hermaphrodites. The hermaphrodite would take care in selecting who it allowed to impregnate "her" as the option only came around every so many weeks, months, or years (depending on species). Likewise, the same organism would have be strongly favored to go out and augment the perpetuation of its genes by impregnating someone else, in which case it's fitness would be judged by the potential mate. Regardless, the other advantages of being a hermaphroditic species still far outweigh something such as sexual selection. Simply the fact that they could bounce back from almost any near-extinction event with incredible speed would more than justify the existence of this system. I believe the true reason hermaphroditism does not exist in most animal species is a cache-22 of anatomy, intelligence, and lack of transitional stages. Since the two-sex system only requires an organism to execute only one role each, it was easier for primitive multicellular sexually-reproducing creatures to evolve this capacity. Once this system got a foothold in the earliest days of the animal kingdom, animal evolution greatly advanced and streamlined the two-sex system, namely highly specialized anatomical structures for both sexes. Tens of millions of years later, when animals possessed enough intelligence to switch between two distinct roles in sex, the current system was too specialized to suddenly make the switch to hermaphroditism. There are no transitional states from two-sex to hermaphroditism (no hill to climb). And with the extremely specific and complex sexual organs for both males and females in animals, it is difficult to see a mutation, or even several mutations, bridging that huge divide. One of the reasons it may have evolved in gastropods is that it occurred relatively early in their evolution when their sexual features were still primitive.

A hermaphrodite would have the same number of parents and grandparents as we do (except in rare cases of self-fertilization or incest). How are you arriving at the number of 2 grandparents?

Actually... since every hermaphroditic organism would be a potential mother, each would be able to sexually select who "she" allowed to mate with her, as do the females in many species currently. Then, when "she" decided to assume the role of a male and seek a mate, "he" would have to be fit in the eyes of a potential mother. The way I see it, sexual selection is still quite alive in hermaphrodites. However, it would require more intelligence to be able to switch between two roles, which may be the true reason it has not evolved. The simplest sexually reproducing multicellular species would have a M/F system by default because it only requires the ability to assume one role rather than two. And once you have large, complex multicellular organisms, evolving true hermaphroditism would quite a challenge, as the mature male and mature female anatomical features stem from the same embryonic source. What? 8 grandparents?

Yet I don't see how a two-sex system would produce more genetic diversity than hermaphroditism. Recombinations and mutations would occur no more or less often in either system. The only extra diversity in a two-sex system would come from a sex chromosome only one side possessed, such as the Y-chromosome in human males. Yet this seems to do more harm than it does good, as genetic diseases/conditions are more common without a second X-chromosome to step in. I know this well, considering I'm color blind.

How does it reduce genetic diversity? If anything, it would seem to increase it. If every organism is a potential mother and father, new mutations have multiple unique paths to take to enter the gene pool at large. I also thought of this, but did not mention it. Let's suppose that during the majority of such a hermaphrodite's life, it would pursue sexual partners as normal. However, if it could not find a mate, it would resort to self-fertilization. It's not an ideal choice, but far better than its genes dying off with it. Also, an important note: self-fertilization wouldn't produce a genetically identical offspring such as cloning would. The self-fertilized egg produced would have a different proportion of chromosomes than its parent. The original organism would have half its chromosomes from each parent, while the child could have possibly 3/4ths its chromosomes from its one of its grandparents (i.e. there would be several almost identical chromosomes that would pair up; I say almost because of possible mutations and recombinations). Not to mention, recombination would occur again. The end result would simply be an organism with less unique genetic information, thus having more genes in common with one of its two grandparents than its own parent. Still, greatly preferable to not passing on one's genes at all, and, if it happens to be the last remaining member of its species, greatly preferable to one's species going instinct. I was not aware of the article. I'd love to read it, though. Link? By "we" I meant all sexually reproducing species.