Saturday, July 14, 2012
Friday, April 20, 2012
Okay, this should be fun. I do have quite a bit that I’d like to say about various topics that have been brought up on both sides. Some of these have already been addressed, but I may have an additional perspective to offer. Others have been addressed sufficiently that I’ll just let them go. As Diana did, I intend to go more or less chronologically through the arguments that have been made so far. I will attempt to maintain as much order in my thoughts as possible, but please be forgiving if this is a little disjointed. I’m writing it on the fly, and would rather spend time double-checking a few facts than trying to organize this into a proper paper. That said, let’s get right to it. We’ll start by going back to nearer the beginning of this discussion, and work our way through to the end (or at least the end as of when I started writing this, so here’s hoping further posts can wait until I’ve finished).
To begin with, in reference to the cause (for want of a better word and with the understanding that “cause” is inaccurate) of the Big Bang, Jim argued thusly: “Either it [the matter] formed from something else--in which case there WAS time--or it just exited in a timeless limbo until it suddenly went bang…which implies some change in state, which implies time. What triggered the transition?”
Diana’s response of “don’t know,” is accurate on a personal and societal level. To the best of my knowledge, physics has not yet answered that question. But there are some ideas about it. Superstring theory has some things to offer, as do a number of other hypotheses. What we do understand is that the universe, at the moment of the Big Bang, existed as a quantum state, which brings certain “weirdnesses” to the table, such as the particles that pop in and out of existence which Diana mentioned later. Further, as far as we can tell, not only spacetime, but also the very laws of physics were born in the Big Bang. It is indeed conceivable that whatever existed “before” the Big Bang--whatever that means--needn’t obey the laws of physics we observe today. Certainly, we need not worry about causality absent time.
Chains of causality tend to end up in an infinite regress. Whenever one posits some cause for another event, one immediately raises the question of what caused that cause. Christians and other theists like to posit an “unmoved mover” which they call their God as the prime cause, itself uncaused. Well, I’m sorry, our scientific understanding of the moment of the Big Bang may not (yet) be complete, but if they get to assume their god is uncaused, then why can’t we say the same thing about the Big Bang? There’s no reason to assume that one is any different from the other in this regard, so wouldn’t it make more sense to stop our infinite regress with the known rather than add another step into something for which we’ve no evidence, when we’re still left with exactly the same conundrum at the end?
Jim then turns to another topic and offers “I don’t swallow whole the ‘billions and billions of years’ explanation that Evolutionists use. In both cases, I still want the details.”
Diana took issue with the use of the word “evolutionists,” a thought which I share. But I think I may be able to offer a little more clarity on the billions of years matter. Since Jim mentioned evolution specifically, I assume we’re talking here about biological origins. Cosmic origins requires billions of years, too, in a different way. But when it comes to biological evolution, time really is the answer. I’ll discuss the process of natural selection a bit later, but for now, let’s just consider the time-scales we’re talking about here.
We now know the age of the Earth within a certain reasonable margin of error to be about 4.55 billion years old, and that it took about a billion years for the first life to form. So we have about 3.5 billion years to get from the origin of life (a topic I leave off for another time) to where we are today, with brains capable of bothering to ask such questions. The question, of course, is whether or not this is long enough for such incredible complexity to evolve by purely natural means. The answer? A resounding “yes.” Let us take just one example--the eye. I choose this because it is a classic favorite of creationists, who like to assume that we simply don’t have enough time for the trial & error methods of evolution to have produced something so intricate. In fact, image-forming eyes have evolved independently numerous times, operating on various principles. Calculations have been done to make extremely conservative estimates of how long this process of evolution through gradual steps would take to produce an eye--these conservative estimates are on the order of hundreds of thousands of years--orders of magnitude removed from the time available. So yes, there is plenty of time for evolution to have worked. The other part of that equation (natural selection, namely) will have to wait for a moment, but I shall return to it soon.
David then objects to evolution as an explanation for biodiversity because the second law of thermodynamics would prevent a climb “upward” on the hierarchy of complexity. Jim counters by briefly explaining speciation, which I’ll come back to for a bit more detailed an explanation later, and Diana links to a source on the second law of thermodynamics (which I admittedly have not yet read) and adds that the second law of thermodynamics only applies to closed systems, which life is not. For the moment, I’ll simply state that this is a true description of thermodynamics’ second law, and promise to return to this thought in a moment. Again, I’m moving chronologically, and it seems that the real “meat” of this topic shows up in later paragraphs.
David’s argument regarding causality seems to be missing some steps between “causality” and “god.” As I mentioned above, the god hypothesis really cannot help us to escape from an infinite regress, and I think the best place to stop any infinite regress is with the known. Sure, we can keep probing the limits of our knowledge, and we should, but unless we can come up with some sort of terminal limit, we can always ask what caused the cause. Until we can know the ultimate answer to that question--and I personally feel our physics is getting damned close to that--we stop with what we know, rather than postulating an unknown agency with unknown characteristics who surely must also be subject to the same laws of causality (after all, allowing any breach of causality negates the necessity of putting forth an additional hypothesis in the first place).
As for the dependence between mass and time, special relativity, and such things indicating omnipresence, I’m afraid we’re approaching the limits of my knowledge of physics. To the extent of my knowledge, I don’t think the conclusion follows from these premises--which is to say, I don’t see lightspeed travel as indicating anything resembling actual omnipresence but only an existence outside of the confines of time (whatever that is). I further don’t think that David’s understanding of special relativity is correct, but I shall defer to someone with greater physics than I to address this point.
This would also raise some other theological questions. If we grant David’s assertions (which I don’t, but will do for the purposes of argument), then what do we make of the warping of spacetime that occurs at high mass and high speed (perhaps even faster than light, though I won’t even begin to speculate whether there’s actually any real possibility of that)? Say we somehow manage to put a man--alive--into a black hole. Considering the sort of warping of time that occurs under such conditions, would we consider him a god? I think not, but if existence outside of the normal confines of time is our definition of a god, then I’m not sure what choice we would actually have.
We then move on to whether or not random processes can lead to random results. I would say no--at least not unless there is a non-random element to the equation. If we’re talking about order in the universe, the argument holds no water at all. The universe, obeying natural law, is precisely as ordered as it is, no more, no less. It’s the product of very nonrandom interactions based upon physics. Biology is a bit trickier, and yes, natural selection is the answer. Technically speaking, as Diana pointed out, we’re not talking about actual randomness, but we are talking about events that, for all intents and purposes, we might consider random. We can talk about the genetic mutation, which is a more or less random event, or we can talk about the shuffling of chromosomes during sexual reproduction, which produce gametes with a “random” orientation of one of about 8,380,000 possible combinations (in the case of humans--some have more, some have fewer). In any case, though these slight changes may be random, they are then subject to natural selection. In a generation, one doesn’t do much better than blind chance, but over the course of thousands or hundreds of thousands of generations, these changes accumulate. With large sample size, random anomalies go out the window, so we can see this gradual accumulation of beneficial changes and weeding out of less desirable changes. That’s the basic mechanism of evolution. David’s assertion that it is not verified in modern science is just wrong. My library is full of books that contain very detailed accounts of experiments that have done just that, as well as accounts applying that principle to observations in nature and making testable--and successfully tested--predictions regarding biological populations.
If you want to see how this works, do a bit of web searching a find a good “Biomorphs” application. Biomorphs are the brain-child of Richard Dawkins, who used them to illustrate how natural selection can work. Essentially they are computerized “organisms” with several “genes” controlling certain aspects of their appearance. They then “reproduce” with heredity. So you take your first population, select which one survives and then the computer breeds from that one, generating random mutations on the genes in its offspring--each mutation not accounting for more than, say, a 5% change on that gene. You then select another survivor and breed from that one. You can breed for whatever characteristics you want. Long legs, short legs, lots of squiggly lines, whatever. And though we’re employing artificial selection rather than natural selection, the proof of concept stands. From random mutations in various individuals within a population, it is possible, with selective pressure, to achieve a sort of ordered complexity.
We can also look to selective breeding for an example. Take the humble banana. It is possible that you’ve eaten one today, but I’ll be willing to bet that if you did, it was not a wild banana (http://atheonomy.files.wordpress.com/2011/11/wild_banana.jpg). Wild bananas are actually fairly disgusting. Their color is not as appealing as we’d like to think, their shape is not as nice as we’re used to, and they’re full of seeds. No, what we eat are dessert bananas. These have been selectively bred--evolved--to match the characteristics we want to find in a delicious snack. We’ve done the same thing with virtually every food crop and domestic or farm animal we use. Yapping little Chihuahuas and giant Great Danes can both trace their ancestry to wolves. Cows are virtually useless animals in the wild, have been modified by selective breeding to the point that I don’t believe they’d actually survive outside of captivity. These are all examples of evolution in action. They’re illustrations of the process of selection, or accumulation of small changes over time.
As for the modern day requirements that the strong should protect the weak contradicting natural selection, not at all. There are two ways to approach this problem, both equally valid. The first is to question whether or not there actually is a contradiction there. The second is to explain how an apparently contradictory behavior might have evolved by natural means. Diana already made some good points, and I already mentioned The Selfish Gene, but I’ll elaborate on these points.
First and foremost, evolution is a descriptive science. It is not normative. We can understand the mechanisms behind evolutionary change without espousing their moral proclamations. For instance, there are indeed times when ruggedly individualistic and ruthlessly competitive “warfare” might be selected for. In such circumstances, the “fittest” organism is the one that murders its companions in their sleep to avoid having to share resources, say. It is possible that this may be naturally selected for (it’s actually much more subtle than that as I’ll explain in a moment, but run with me for a minute). It’s also possible that humans, with our brains, can choose not to obey our genetic drives. Our genes “want” us to have sex. Our sex drives evolve because its in the genes’ interest to have us doing the dirty a lot for the purpose of replication. The more we replicate the better a gene’s chance of survival. But now, though we still have a sex drive, we can disconnect it from reproduction. We can use condoms, the pill, abortion, or any number of methods to prevent unwanted offspring from springing off, in direct conflict with the genetic drive. The same CAN be true with morality.
But let’s look a little more closely at how morality may have evolved. In my earlier post, I mentioned The Selfish Gene, a book which I still heartily recommend. It’s a terrific read, and you’ll find yourself with a wonderful new perspective on the process of how evolution occurs by the time you’re done. I intend now to elaborate on these thoughts.
As I indicated, we can view genes as “selfish” in the sense that, though they have no conscious feeling, they “want” to reproduce themselves. In reality this is just the manifestation of natural processes, but we can anthropomorphize them here to help us to understand what we’re talking about. So the genes want to reproduce. How do they do that? They can’t just copy themselves directly and spread these copies far and wide. No, instead they must code for building bodies. These individuals they construct will either be able to survive and reproduce or not. The way natural selection works, basically, is that genes that code for better individuals reproduce more than genes that code for lesser individuals. So on the topic of morality, the question we need to ask is whether or not coding for moral behavior or moral tendencies is an evolutionarily advantageous strategy.
In order to gain a proper understanding of the intricacies of this line of thought, you’ll have to break into the fields not only of biology and, later, psychology, but also games theory. We’re not going to go into great detail here. If you want the detail, again, turn to Dawkins for the answers, as I’m not about to copy down all the information contained in his 350-some-page book. But basically, the conclusion is that selfish genes, in many cases, code for decidedly NON-selfish behaviors. Various environments require various strategies, but one of the most common ones is reciprocal altruism, or behaving altruistically at the start, and then simply mirroring the behaviors of those with whom one interacts. If they behave altruistically, too, then everyone’s getting along. If they betray, then so do you.
These behaviors can evolve because sometimes it is advantageous to behave cooperatively, particularly to those with whom one is genetically related. Trying to understand all the factors rapidly becomes extremely complex, and I don’t have the time to explain it here, but I think I’ve at least sufficiently made the case that natural selection doesn’t require amoral acts, but could require precisely the opposite.
In the middle of this, Jim makes an interesting statement that I think warrants some attention. He first concedes accumulated change over time until a population becomes classified as a new species, but then says, “As far as I know…evolution has yet to observe directly the change of one species into an entirely different one--say from a flowering plant into a cow, or even a spore-bearing plant into a gendered flowering plant. My complaint with Evolution is it uses the ‘billions and billions of years’ argument to get from single-celled organisms that reproduce asexually, to gendered multi-cellular organisms.”
Well, this is an interesting can of worms we’ve opened here, and I don’t have the time to explain all of the work that’s been done on the evolution of specific traits such as sexual reproduction. But let’s briefly take this statement one point at a time, and see what we can do with it.
First, it’s impossible for evolution to directly observe most speciation events. They simply take too long. We may be talking about thousands of generations. Even in organisms that reproduce fairly rapidly, this is a very long time. On the other hand, we have actually be able to do so, in some limited cases. While speciation means something somewhat different in asexually reproducing organisms, we have witnessed its equivalent in bacterial species, simply because they are among the few who can reproduce rapidly enough for us to have done so. I wouldn’t be surprised if similar work has been done with certain insects as well, but I’m unaware of it. When you get to other things, you simply don’t have the time to reproduce that many generations before the observers--and their children and their grand children--are all long dead and the experiment is forgotten.
We also don’t get from flowering plants to cows. I assume that was offered sarcastically, because it’s completely opposite of how evolution actually works. We don’t just have a species that turns into something else. Any individual gives birth only to individuals of its own species--always. There is never a moment when a mother gives birth to a daughter of a different species. If this were to happen, I think we’d all be on the phone with the people at the Institute for Creation Research asking for their opinions about this strange new phenomenon. No, what we must understand is that “species” is just a human-applied shorthand for classifying things. We like to put organisms into neat little boxes. Most of the time, they fit. There are some exceptions. But when we talk about evolution, we have to start tracing ancestral lineages, and what we find is that the further back we go, the more similar things become. First we blur the lines between species A and species B. Then, moving further back, we blur the lines between species AB and species C. Further back, we blur the lines between ABC and D. And so on. It really is just as simple as accumulated change over time. If the word “species” is the hang-up, then just drop it, because it doesn’t really matter. That’s just a descriptive word. What’s really happening is that daughters are slightly different from mothers, are slightly different from grandmothers. Parents with multiple offspring find variation between their children. We’re all intimately familiar with this principle on a local scale on the order of about 100 years or less (the human lifetime). Well, we just need to multiply EXACTLY the same process by a couple billion years, and evolution is the product.
As for the origin of sexual reproduction, that is a legitimately difficult question, and it’s one I’m not going to answer for two reasons. One, I don’t know the answer off the top of my head, and two, it would likely be an extremely complex answer that requires significant background in cellular biology or genetics to understand. But here are a few things I will say about it. Mitosis, or cellular division, is at the root of asexual reproduction. Meiosis, or a reduction-division (which you can think of as the opposite of fertilization if you wish), is at the root of sexual reproduction. What we find is that meiosis would be selected for because it brings a lot of variation to the table. While mitosis must rely simply on the occasional mutation, or copying error of the genome, meiosis by its very nature shuffles chromosomes so that offspring have a different genetic composition than the parents. This can rapidly increase the rate of change and variation within a population, so its obvious why this would be selected for--populations capable of adapting more rapidly to changing environments are more likely to survive. So the real question is simply: what is the precise sequence of events that lead to the origin of meiosis? And that’s the answer I won’t be providing here. It would require more research than I have time to do at the moment. But I will say that it is meiosis that we must explain. All the other functions of sex and gender can easily follow as a result of natural selection once we have a method of sexual reproduction.
The evolutionary origin of meiosis is a legitimately interesting question, but there’s nothing about it that would suggest anything other than an evolutionary origin. The physical structures involved are even the same as those involved in mitosis, from which meiosis fairly obviously evolved. There are a few novel innovations in meiosis, sure, but they’re exactly the KIND of novel innovations one would expect in evolution. Especially true for these innovations because there’s such strong selective value in them.
David then states that, “it still seems though that natural selection is not observed.” I’m wondering what you mean by this, David. I’ve already mentioned above how we can use artificial selection to mirror the effects of natural selection. In addition, we can observe the direct effects of natural selection in nature, so either you mean something by “not observed” that I’m unfamiliar with, or you’ve just not done your homework, because there are plenty of examples. Even just spending an hour at a library or museum ought to provide a large number of them.
Regarding gradual change leaving species in vulnerable states, this is not really true. It is true that all species are in vulnerable states just in the sense that as environments change, there will always be winners and there will always be losers. That’s just the way the world works. An example that could drive this point home is climate change. The global warming we’re facing today if we don’t make some significant changes would not be good news for us--we would be the losers, likely unable to adapt to the changing environment fast enough. But some other critters would absolutely love it. There are some bacteria, for instance, for whom a hotter, drier climate would be a major boon. So in that sense, such vulnerable states do exist.
In fact, that’s why meiosis is so important, as I mentioned above. There are numerous organisms, mostly plants, that vary their reproductive patterns. In times of environmental stability, it makes sense to use mitosis to simply produce (mostly) identical copies of oneself. If one has a stable, working system adapted to the environment, rapid change is at best unnecessary. However, in times of environmental change--and believe you me, periods of relative global stability are rare--it makes more sense to have variation within the population so that the organism can adapt more rapidly, and in these times, these organisms do reproduce sexually.
But the crux of the issue, I think, is your claim that, “a fish with half a leg or even one leg is not going to be a good mutation, thus the idea of punctuated equilibrium (only breaking physics periodically rather than gradually in my mind).”
Let us first divorce the two components of this statement, and promise to return to punctuated equilibrium after I’ve handled the first part.
It’s a common creationist argument to muse “what good would half an eye be?” And the standard response to that has been “One percent better than 49% of an eye, and 2% better than 48% of an eye,” and so on. But we’re not talking here about just taking 50% of the cells that make up an eye and saying that this is better than 49% of them. No, we’re talking about functionality. And in this case, the evolution of the eye is very well understood, and I’ll outline it VERY briefly.
We begin with a creature that is completely blind. No eyes, nothing. Can’t see anything. But at some point in its evolution, a mutation occurs that produces a small patch of photosensitive pigments on its skin. This would be a most beneficial mutation indeed! It’s hardly an eye, but it allows the creature to distinguish light from dark. This would have benefits in predator avoidance, for instance. It would also allow the creature some rudimentary motion-detection ability, as shadows moving between the pigment and the light source would register as a change in luminosity.
Now we imagine another mutation. In this case, the photosensitive cells recess slightly into a small pit. This also is not a great change, but it also would have naturally selected benefits in that the creature would now be able to determine the direction from which the light is coming. Perhaps not with great resolution, but slightly. In a pit, a light source will illuminate one side more than the other. Now the animal has an even greater advantage. And this process will continue with the pit becoming more and more recessed, allowing greater and greater resolution of the direction of the light source.
Eventually, the pit becomes so recessed that it becomes more of a hole with a small opening at the surface. Well this is essentially a pinhole camera! Of course this is beneficial! Now the creature has the ability to discern actual IMAGES rather than just direction of light source. They won’t be of great resolution, but it doesn’t matter. Our animal can now see shapes, so perhaps it can distinguish predators from indifferent creatures in the environment.
And then some mucous covers this pinhole, forming a rudimentary lens. Again, a small change, producing enough of a benefit that natural selection can act upon it. And gradually, this lens will get better and better until we get the advanced lenses we see today.
Yes, this is a simplification. I don’t have the time or inclination to write a formal scientific paper on the evolution of the eye--it’s been done. This is meant simply to illustrate that gradualism actually can account for the things we see in biology today. And as I indicated above, this process can take place on the order of hundreds of thousands of years--a period of time so slight that it may not even be noticeable in the fossil record!
Granted, you didn’t actually ask about the eye. I simply chose it because it’s a relatively easy transition to visualize without a lot of training in biology. I’ll now turn to the point you actually did raise, which is a fish forming legs.
The simple fact of the matter is, we don’t see a fish form half a leg, nor do we see one form one leg. We do know that amphibians evolved from fish--all life comes from the sea, ultimately--so we know that they got legs at some point, but again, by a much more gradual process, with each step more beneficial than the last.
It begins with the so-called lobe finned fish and ray finned fish. These are fish, similar to the mudskippers we see alive today, who can, for want of a better word, “walk” a short distance out of water, generally across a muddy surface. This is beneficial because it allows a fish to leave one body of water and get to a different nearby body of water. This helps it to escape from predators who may not have the same mutations, as well as to hunt for a new food source in the other body of water.
It is easy to imagine how progressive gradual reshaping of fins can eventually develop into legs, but what of the fossil evidence in favor of this claim? In fact, there’s actually quite a lot of it. If you go to your local science museum, you can probably find several examples of the intermediates, but I’ll tell you about my favorite: Tiktaalik. Tiktaalik is an extinct genus of lobe-finned fish from the late Devonain period. I won’t bother you with all of the details, but suffice it to say that it’s become a famous “fishibian” or “fishapod” (combination of the word fish with amphibian and tetrapod (four-limbed animal), respectively). Evolutionary theory made a prediction that we should find a fossil in this time period that had certain characteristics of both fish and tetrapods. Tiktaalik was discovered a few years ago and it fulfils this prediction brilliantly. Like fish, tiktaalik has gills, scales, and fins. Like amphibians, it has tetrapod rib bones, tetrapod mobile neck, and tetrapod lungs. Its limb joints and bones look exactly like an intermediate between fish and tetrapods, with tetrapod wrist structure and radiating fishlike fins instead of toes. Furthermore, we find that it fits precisely in a sort of “gradient” of fossils that we’ve discovered so far. Of course, tiktaalik itself may or may not actually be the ancestor that we’re looking for. Evolutionary science does not work that way--the transitional fossils we discover simply demonstrate the evolution of traits, not necessarily individual species or lineages.
I hope that’s enough to get your curiosity going, because there’s a lot of really great work that’s been done on this stuff, and it’s worth reading. I think, aside from going to museums to see for yourself, a good place to start would be reading Evolution: What the Fossils Say and Why It Matters by Dr. Donald Prothero. He’ll walk you right through many of these discoveries in much greater detail than I am doing.
The point here is, there are gradual changes that can accumulate to produce, over the course of many generations, quite different species. Sometimes we encounter difficult problems, but that’s not reason to suspect evolutionary theory is wrong--not after we’ve gathered so much evidence in favor of it--no, all the difficult problems are is an excuse to do more research. We should strive to solve them, not just assume that a deity did it, or that it’s impossible for evolution to have done so.
As for punctuated equilibrium, I think you’re misunderstanding what this actually means. When biologists talk about punctuated equilibrium, we’re not suggesting that gradualism goes on its merry way and then a deity steps in and breaks physics to get us past the difficult bits. Not even close. Punctuated equilibrium is still a completely natural process, and still an evolutionary process. It’s simply a departure from purely relying on neo-Darwinian gradualism. There are some noteworthy scientists who think it’s an accurate representation, some who do not. No one ever said there were no controversies left within evolutionary theory--only that evolution as a whole is no longer up for serious scientific debate, barring some new discovery that completely turns all of biology on its head.
Personally, I still hold more to gradualism than punctuated equilibrium, which I think has largely been oversold in pop science magazines. Of course punctuated equilibria are an important piece of our understanding, but I think it’s the icing in the gradualist cake rather than the other way around. I have reasons for thinking this that I won’t go into, but the overall point here is that punctuated equilibrium is not by any means a disproof of evolution. It is simply another hypothetical course evolution may have taken.
You also mention that “simultaneous spontaneous evolution of both sexes is then improbable.” But I don’t think that’s the question we should be asking. I think we should be asking “where did meiosis come from?” because once we answer that, I suspect we’ll have a very good model for the rest. Regardless, I see no reason to consider it particularly improbable, regardless of how complete or incomplete our understanding is. Since the physical structures in meiosis so closely resemble those involved in mitosis, it actually seems like quite a likely development.
As for your statement that “we cannot be simultaneously self-centered and species centered, yet in the evolutionary picture of time it seems both are needed,” this is partially true and partially wrong. We can look again at the gene-centered view of evolution. Of course we must be self-centered in that we’re wired in such a way that preservation of our genes is of highest priority. But this is not the same thing, necessarily, as behaving selfishly, as I’ve described above. I believe that every one of us is, at least unconsciously, self-centered, but that very unselfish behaviors emerge as a result of this. The millionaire who gives anonymously to charity, for instance. A very unselfish behavior, so how is there any self-centered motivation? Simple--he does it because it makes him feel good to do so. It’s as easy as that.
We then return to thermodynamics, a topic Diana already addressed, but I want to restate her commentary in my own words because it is important and bears repeating. Thermodynamics is the study of transformations of energy. Since heat is a convenient way of measuring this, thermodynamics has a lot to say about heat. The Second Law of Thermodynamics states, quite simply, that entropy, which David is defining as “disorder” but which is more accurately described as energy which is not available to do work, continually increases.
Essentially, heat is the most useless form of energy. Heat describes the random motion of particles, so this energy is unavailable to do work. In any reaction (a physicist will tell me if this is true, theoretically, of absolutely all reactions or if it is only true practically of any reaction worth considering), some of the energy will be lost as heat. This is the increase in entropy to which the 2nd Law refers.
Now, this is very important, because this understanding of what entropy actually is makes it very clear, as is expressed in our understanding of the 2nd Law, where it applies. In a closed system, which is defined as a system in which no energy is gained or lost, entropy always increases. There is also the possibility of an open system. This is a system in which entropy needn’t increase, because NEW ENERGY can be supplied into the system, and all that useless heat can escape the system and go somewhere else. The Earth is such an open system because it’s powered by the Sun. The Sun is a giant fusion reactor that, if you step outside at noon on a summer day, you’ll realize is constantly blasting us with new energy. The Sun is a giant entropy machine. Yes, biochemical reactions responsible for the complexity of life do come at a cost of entropy, but that price is not paid here on Earth. The entropy cost of these reactions is being paid by the Sun which constantly supplies new energy to the Earth. Yes, the Sun is generating lots of entropy which is part of the reason why it will one day “die,” several billion years in the future.
So, because we’re constantly being bombarded by photons from the Sun, we needn’t worry about the 2nd Law of Thermodynamics applying to biological systems. The more interesting question to ask is, how does that energy get harvested? And I won’t give the full answer, but the short answer is: photosynthesis. Photosynthetic bacteria and, later, plants, evolved a mechanism of using an enzyme to harvest an electron from water, use photons from sunlight to energize that electron, and, through a process far more complex than I have time to explain, use that energy to build organic molecules such as sugars which they can use as the energy storage for the organism. Other organisms incapable of photosynthesis are still dependent upon the process because we eat photosynthetic organisms, looking primarily for the glucose they used photosynthesis to produce. Our cells then break glucose down into its components, harvesting energy at every step. With this constant flow of energy from the Sun, whether an organism harvests it directly or indirectly, there’s no reason to suspect that there’s not enough energy to achieve biological complexity.
There’s also a misunderstanding about evolution being fully random, which Diana also addressed, and I think I may have covered earlier as well, but I want to hit it again, very briefly, because it’s simply wrong. Evolution is not random.
Let me go on a slight digression about randomness first, because though biology is my field of study, I also have a physics nerd somewhere inside my mind, and this can become a bit of a sticky point. If we put aside for a moment the uncertainties inherent to quantum mechanics, then it rapidly becomes clear that the universe, in accordance with physical law, must be fundamentally deterministic. Some people take issue when I say things like that, but there’s really no other way it could be. Now, quantum uncertainty injects some doubt into that. Do quantum mechanical phenomena achieve actual randomness, or do we simply lack the mathematics to explain their behavior at the present time? I don’t even begin to know enough physics to speculate, but my own suspicion is the latter. I doubt if anything is truly random, but it remains possible that there could actually be random events. For biological purposes, however, there are events that we don’t mind calling “random chance.” Sure, physical law ultimately determines where Particle X lands, causing Mutation Y in Organism Z, but since there’s no way of actually predicting these interactions, we can call them random.
Now, in that sense of the word, chance does enter into evolution, but it is by far the less important piece of that puzzle. To begin with, while random mutation does occur and is fundamentally important to the biological diversity we witness every day, the most rapid developments in evolution these days are simply the result of shuffling the genetic deck during sexual reproduction (though indeed, there’s a “random” element to that as well). So we take chance events, whether they’re mutations or shuffling of genetic information, to form a new organism. It won’t be very different from the parent(s), but there will be slight variation. It is the process of natural selection (along with sexual selection, and artificial selection and a few other things, but natural selection is the big important one) acting upon these mutations over the course of thousands, millions, billions of years that produces complexity. Natural selection is by no means a random process. Nor is it guided by an intelligence. It is, to paraphrase Richard Dawkins, nothing more than the nonrandom survival of randomly varying replicators.
So not only does the 2nd Law of Thermodynamics not have anything to say about evolution, but the most important part of the process is not even random to begin with!
Diana also already answered your question regarding who wrote the laws of physics, and I don’t have much to add to her answer, except to offer one additional thought. The laws of physics are not like municipal laws written by some legislature which can be violated and enforced. They are simply statements of things that always occur (they’re also not written in stone, as we could tomorrow make an observation counter to physical law, but for intents and purposes, they’re well-established enough that I don’t think we need to worry about it). We can write a law of gravity describing the mutual attraction between two objects and quantify that. There’s the law of gravity. But it says nothing about why. That’s where we need theory. Theories are the explanatory frameworks or narratives that explain all of our myriad facts and laws. Laws give us a mathematical framework based on observation on which to work. Facts are everywhere--they’re a dime a dozen. It is theory that is the real meat of science. It’s a national shame that our education does not address this (at least not until you get to university and perhaps sometimes not even then). Someone recently said in response to another debate I’d been having that 5th Grade science books regularly make the erroneous statement that laws are facts that have been proved. I was aghast at this (if not particularly surprised, as I’ve read Feynman’s stories about the time when he reviewed public school textbooks)!
As the great man himself said, the golden rule of science is, if it disagrees with experiment, it’s wrong. Sure, there’s guesswork involved at the hypothesis formation stage, but then we test those hypotheses. If they pass a lot of tests, they become theories and are accepted as tentatively right--at least until someone else disproves it. So what we should really be asking with regards to all of this stuff is: what agrees with the experiments? And the answer, after hundreds of years of some of the most rigorous work humanity has ever done, is that both Big Bang cosmology and the theory of evolution are in perfect agreement with experimentation.
Now let’s look at the age of the universe. Jim rightly corrected you that the Solar System is not necessarily as old as the entire universe (and in fact we know that it is much younger), but I think some of the most important stuff here is your assertion that “current metrics for the 13.5 billion years proposed are not verified.” Unless you’re trying to demand absolute proof before you consider something “verified,” which is something every scientist knows is impossible and so should not ever wedge its way into such a discussion, then this is flat wrong. We know the age of the universe is about 14 billion years (within reasonable error margins) because we can take its expansion pattern and work backward to the Big Bang and the number we come up with is about 14 billion years. How do we know its expansion pattern, you ask? Because we can power up some big telescopes and see it for ourselves! If you want the maths that actually confirm this, I shall have to leave that for an astrophysicist to answer.
Now, the formation of the Solar System is a more recent thing, and again, I will defer to an astrophysicist for the full explanation, but basically, the Solar System began as a cloud of particles and gas. As this solar nebula collapses in upon itself due to gravity, a few important things happen. Of course, a star forms at the center, but a spinning disc of matter is left over, and this disc eventually also collapses, forming the planets and moons and asteroids and what-have-you that make up the solar system. This occurred roughly 4.5 billion years ago. The solar nebula that started the whole thing off was likely the debris left after the death of another star. So no, the Earth isn’t as old as the Universe--not by a long shot.
The rest of your points along these lines depend upon things like a variable speed of light and the decay of the moon’s orbit. These are arguments I’ve heard before, and I think Diana handled them adequately, as I don’t actually know the physics well enough to make statements of my own.
One thing I do want to hit briefly is your claim that the Sun’s radius was once bigger, a conclusion you reached apparently because it’s burning up and so losing mass. If that is not the assumption you make, please elaborate further as I’m confused. What I can say is that the Sun’s radius was not larger once upon a time, and if I’m correct in my assumption of why you think that, then I believe it’s a misunderstanding of what gives the Sun its size and density. It’s only slightly related to its mass, actually. While it’s true that it is constantly losing mass (it is shooting particles out into space all the time, after all), it is not the Sun’s mass that determines its radius, nor is it in any danger of “burning up” or “burning out” anytime soon. The Sun’s radius is actually the product of an interesting thing called “gravitational equilibrium.” Essentially, because the Sun does have mass, and a lot of it, the desire is for it to collapse in on itself. But because fusion occurs at the Sun’s core, which heats up gas and causes an increase in gas pressure, this force of gravity is countered by the gas pressure, so the Sun remains mostly stable in size. It isn’t burning like a candle and losing mass…it’s fusing atomic nuclei, and those are two very different things. Of course, at the end of its life when it becomes a red giant, it will experience a rather extreme gain in radius, but that’s a question of the future, not of the past, and we don’t have to worry about it for billions of years.
We then go back to thermodynamics, and I have very little to add that I’ve not already said above, except a comment on one line. You said that you cite conservation of energy and claim the universe is a closed system, so that the 2nd Law should apply to everything in the universe. I think that’s where the fundamental mistake is. Sure, with every reaction within the closed system of the universe, entropy increases…but that entropy increases for the entire system. Because the Sun provides energy to Earth, all that entropy can be radiated into space as heat, and the Earth can actually decrease in entropy LOCALLY as long as the 2nd Law is satisfied that entropy increases in the Universe as a whole. Richard Dawkins describes it as “like a ram pump, which uses the energy of a flowing river to pump a small quantity of the water uphill.”
Diana explained correctly that micro- and macro-evolution are nonsense distinctions, but I’d like to elaborate a little further. If one wishes to make such a distinction, one would describe microevolution as the changes that occur within a handful of generations and macroevolution as the larger changes that occur at the lines where we would distinguish species. But as I’ve already said, species is just a man-made concept that we biologists use to make our lives easier. Nature doesn’t care where we draw these lines. And I think I can illustrate that point with some lovely little salamanders who live in California.
In the mountains surrounding California’s Central Valley there lives a genus of salamanders called Ensatina whose habitat forms a horseshoe shape in the mountains around the Valley. On the Western end of the horseshoe, we find Ensatina eschscholtzii, one species of these salamanders. We find another species, Ensatina klauberi on the Eastern end. Simple enough, but what complicates the issue is that if we start at the Western end and travel all the way around the horseshoe, we find no less than 19 Ensatina populations. Again, simple enough, but here’s where it gets interesting. The E. eschscholtzii and E. klauberi populations at the ends are geographically separated from one another and indeed, as scientists have found, are incapable of interbreeding. By most definitions, we’d call them different species. But each of the 19 populations around the horseshoe CAN interbreed with its immediate neighbors. This constitutes what we call a “ring species.” Essentially, the evolutionary intermediates in this case are not extinct but are alive and well in the California mountains! This raises interesting questions regarding what a species is--because if the various intermediates that link humans and chimps to our common ancestor were still alive, would we consider ourselves distinct species? Maybe, maybe not, and that’s the point--it’s a made-up word. It doesn’t really mean anything.
So micro- and macro-evolution actually describe the EXACT SAME process. It’s just a question of where one wants to draw the imaginary “species line,” and a question of the timescales involved. If you want, you can think of microevolution as occurring within a few generations and macroevolution occurring over the course of many thousands of generations. That’s why the terms don’t actually mean anything to biologists.
You ask for an explanation--presumably you mean an explanation for life, the universe, and everything--that does not require the laws of physics to be ignored. I put to you that both Diana and I have provided significant portions of that explanation (the whole thing, of course, involves millions of volumes of scientific knowledge that won’t fit into this discussion). I also put to you that postulating a deity who exists outside of the laws of physics is exactly the sort of argument you claim to be against! Or if, on the other hand, you claim that this deity exists WITHIN the laws of physics, then I believe science has already conclusively disproved your hypothesis.
In your final paragraph before Diana’s response, you say that “If evolution were true, we have already had at least half that many generations of bacteria in the lab and haven’t seen anything new evolve.” I take issue with this statement on two levels. First, you don’t define half of WHAT number of generations of bacteria. If you’re talking about half the total number of bacteria that have existed, I think you need to check your arithmetic as there have been about 3.5 billion years of the little guys, and we didn’t discover them until Antonie van Leeuwenhoek found them under his microscope in 1676. Half of 3.5 billion is 1.75 billion. Let’s go ahead and round up and say we’ve known about them for 400 years. Subtract 400 from 1.75 billion, and you’re off by a rather large factor, methinks.
You are also mistaken when you say that evolution hasn’t been observed in the laboratory. It has, both in formal laboratories and in the laboratory of nature. For just one example, consider antibiotics, that wonder of modern medicine. Well, bacteria have been evolving, you see. We now are faced with such a massive threat from antibiotic resistant bacteria that the FDA is moving to regulate use of antibiotics in livestock. Why? Because if bacteria become immune to antibiotics, as they’ve been doing, we face a public health nightmare even greater than the one caused by the recent anti-vaccination movement responsible for who-knows-how-many deaths. We could also look to HIV. The virus that causes AIDS is terrifying because it evolves faster than we can develop drugs to combat it. None of this would make any sense except in light of evolution. In fact, as the famous saying goes, nothing in biology makes sense except in light of evolution.
Finally, moving along to some things you said after Diana’s response.
“I know general theories of evolution started with extremely gradual mutations, yet the fossil record does not indicate this, and there isn’t time for those mutations to have developed the variety of life we currently see.”
I’ll start with the second point first, because it’s the easiest one to answer: We’ve got 3.5 BILLION years. Granted, it’s a difficult number to conceptualize, but give it a try. How much more time do you want? I’ve already shown the evolution of the eye, as just one example, can take place in a couple hundred thousand years as a CONSERVATIVE estimate. Plus, species didn’t wait for one another to evolve. A fair amount of the complexity we see is the result of coevolution, which you can think of as a sort of evolutionary arms race. A predator evolves some new trick, so its prey has to evolve some new defense, and so on and on. It really doesn’t take all that long, on the geological time scale.
Regarding the fossil record, I’ve mentioned one example, tiktaalik. I could list thousands more if you want, but that would be a pointless exercise, I think. What’s more important is that fossilization is a relatively rare process. It doesn’t show every species, not even close. It takes conditions to be just right to get a fossil, so all we have are snapshots of evolution. But those snapshots do fall into place. We can’t see every step, but we can see certain lineages and the evolution of certain traits. Again, I will recommend Dr. Prothero’s book, however. The second half of the book contains LOTS of examples of evolution in the fossil record. Plus, we also have other forms of evidence, from genetics, comparative anatomy, etc., in addition to fossils.
Finally, I had intended to put a couple arguments of my own, just to see where it would take this discussion, but I’ve decided that I’ve gone on quite long enough, considering that most people probably wouldn’t write out this long a reply to a Facebook thread, so I’m going to hold those back, at least for now. What I will close with is this. David, don’t take this as condescension as it is not intended that way--I’m simply curious-- but you keep alluding to the fact that your position as a physicist is a large part of why you hold the thoughts that you do. And yet, your opinions clash with much of what we understand to be true in physics. I’m wondering what your area of research in physics actually is, and if it does not bother you that most of your colleagues would find many of your claims to be false?
All the best,