| From: Kent | 21/10/99
13:10:56 |
| Subject: entropy and evolution | post id:
1473 |
| Hi Karl (et al), Are entropy and evolution compatible; the first tending to break down, the second tending to the more complex? | |
| From: Kothos | 21/10/99
13:13:51 |
| Subject: re: entropy and evolution | post id:
1475 |
Well they are compatible, because they affect different systems... You have to realise that the concept of evolution affects a life system, and entropy affects the whole universe. Life on Earth is a system contained entirely within the Universe. It will evolve as long as energy is input into it, and this energy comes from the entropic nature of the Universe. I don't know if I've phrased that at all well. I've probably just added to the confusion now... | |
| From: renee | 21/10/99
13:51:54 |
| Subject: re: entropy and evolution | post id:
1497 |
| To expand on Kothos's
explanation, you must understand that entropy operates on a universe-wide
scale. The energy input, to planet Earth is either INCREASING, or
remaining static. When the Sun ceases to shine and/or the planet's
radioactive materials have ceased decaying, then the energy input will
decrease. There is no reason to suspect that evolution automatically leads to more complexity over time. The Theory of Natural Selection suggests that the most efficient/fastest/smartest/toughest critter will survive, over it's competitors. There is no suggestion that more complexity is necessarily better. Conside the cockroach. Clearly a critter of ancient origins, yet one whose resistance to nuclear radiation is dramatically superior to that of humans. It is the very simplicity of the critter, which gives it the edge. A nuclear conflict may wipe out human beings, yet allow cockroaches to survive. This entropy argument is a hackneyed old one from those who are not critical thinkers. It is best to learn some science, so that you may argue coherently with them. People like that are pushing back the education systems all over the world. They are dangerous and unbalanced people. Trevor | |
| From: renee | 21/10/99
15:00:51 |
| Subject: re: entropy and evolution | post id:
1517 |
| Hi Kent, I guess you can assume both entropy and evolution have a relationship, because both are a result of randomness and disorder. ie; entropy is a measure of the chaos of systems and you could say that evolution is not leading in any particular direction, therefor in disorder. Renee<><><> | |
| From: Cam | 21/10/99
21:03:09 |
| Subject: re: entropy and evolution | post id:
1644 |
| This entropy argument is a
hackneyed old one from those who are not critical thinkers. It is best to
learn some science, so that you may argue coherently with them. People
like that are pushing back the education systems all over the world. They
are dangerous and unbalanced people. Reply: What do you mean? Which part of the argument is hackneyed? This is the 2nd law of thermodynamics here....how is that pushing back the education systems all over the world? "The increase of entropy in every natural, irreversible process measures the increase of disorder or randomness in the universe associated with that process." "Entropy provides a quantative measure of disorder." Chapter 18 The Second Law of Thermodynamics -from University Physics (extended version with modern physics) 9th Edition by Young & Freedman Addison Wesley 1996 i don't understand your tone of response. I am trying to learn some science, this attitude is really disconcerting. Would you class me as dangerous and unbalanced? | |
| From: Dr. Ed G (Avatar) | 21/10/99
22:47:50 |
| Subject: re: entropy and evolution | post id:
1665 |
| It's just that it's a standard
argument put forward by Creationist propagandists, and is the sort of
question that unfortunately sets alarm bells ringing in the minds of
people who've had to argue the point time and time and time
again. However, it is a valid misunderstanding and deserves to be explained in good faith each time it comes up. The thing is that entropy and indeed thermodynamics, relates to the thermodynamic evolution of isolated systems. As such the entropy, or disorder, in any isolated system will unequivocally increase steadily as a function of time. However, the Earth is not an isolated system. It is sitting right next to a huge thermonuclear energy source, the Sun. It is the input of energy of the sun that allows the entropy in biological systems to decrease. However, this doesn't run counter to thermodynamics because the total entropy of the Sun + Earth system still increases much more than enough to offset the decrease due to evolution (or indeed, the simple act of reproduction). It is important to note that this is not a post-hoc fudge to the laws of physics to disprove the creationists. This is all in the fundamental framework of thermodynamics that was nutted out well before Darwin's theory of evolution, or anyone's objection to it. The danger as I think Trevor sees it, is not in the question or its answer, but in the forces of Creationist ignorance that are not interested in hearing the answer. It is perhaps unfortunate and unfair, however, to jump to the conclusion that anyone who asks such a question is of this ilk. It's a valid question, and the answer is simply, "No, there is no conflict between evolution and entropy, so long as the Sun continues to provide us with enough energy to decrease entropy on a local scale." Soupie twist, Ed G.  | |
| From: Cam | 21/10/99
23:44:33 |
| Subject: re: entropy and evolution | post id:
1678 |
| Bear in mind also the fact that
the laws of thermodynamics are statistical laws. They are only valid if
you are dealing with a large enough group pf partiles. The laws of
thermodynamics tell you absolutely nothing about individual molecules
undergoing reaction (for example), but are bloody good at telling you what
will happen when you get 1023 of said
molecules. | |
| From: Kent | 26/10/99
14:53:52 |
| Subject: re: entropy and evolution | post id:
2526 |
| Well, I have provoked quite a
storm haven't I? I still think some questions remain unanswered however.
Someone mentioned that entropy only affects large complex systems and not
individual particles (excuse my science-jargon illiteracy). But isn't DNA
a hugely complex system in itself. And surely a process such as evolution
which takes eons to develop is in itself large enough to qualify as
similarly complex. Also, biology isn't a separate system at all - it has to exist within the bounds of the laws of physics. Biology is intrinsically tied up, nay founded on physical laws (I remember a little of the jumble that was highschool biochemistry). So duel on, dear readers. I'm loving it! | |
| From: Adam Ashby | 26/10/99
15:16:01 |
| Subject: re: entropy and evolution | post id:
2540 |
| Kent, I think you should re-read
the above explanations again, particularly Dr Ed's. When we talk about
entropy, it is not the complexity of the system which matters, but whether
or not the system is isolated from its surroundings. Entropy always
stays the same or increases in an isolated system (one with no energy
input or output connection to the "outside world"). The Earth, and the life on it, is not an isolated system. It continually gets energy from the Sun. Therefore, the entropy of things on the Earth can decrease, though only at the expense of an increase in the entropy elsewhere (i.e. turning the "organised" energy from the sun into useless heat and releasing the heat back into space). There is no conflict between entropy and evolution, and no scientific disagreement on this topic (except for the non-debates stirred up by creationists who don't understand either entropy or evolution or both). You are correct that biological systems must adhere to physical laws. They do. One caveat, already mentioned by Terry, is that the entropy of a system is a statistical quantity. As such, it is subject to random fluctuations. However, the larger the system, the smaller the fluctuations become. So, when we talk about macroscopic quantities of atoms, for example, the fluctuations are almost always insignificant.. JR | |
| From: Adam Ashby | 27/10/99
10:27:00 |
| Subject: re: entropy and evolution | post id:
2778 |
Entropy and Evolution, the differences. According to a texbook called Boilogy, 'The Unity and Diversity of Life' Starr and Taggart (1998) States, Entrophy: 'A measure of the degree of disorder in a system(how much energy has become disorganized and dispersed, usually as heat, that it is no longer readily available to do work) Any organized system tends toward entropy without energy inputs to make up for the flow of energy out of it'. States Evolution One theory 'Genetic change in a line of decent over time; brought about by microevolutionary processes (gene mutation, natural selection, genetic drift, and gene flow." I hope these explations, help you Regards Adam | |
| From: Kent - yes, ignorant me again | 12/11/99
15:01:36 |
| Subject: re: entropy and evolution | post id:
6884 |
| I still don't quite get it (being
a layperson). Surely the affect of the introduction of an energy source
such as the sun would create a catalyst effect; thereby increasing the
likelihood of (bio)chemicals to break down to their simpler
components. The mutations that we see tend to back this up (so far as I know): mutations tend to be in the direction of less complexity (when DNA goes missing) or the same level of complexity (DNA swapping places). Even natural selection tends to select from the existing diversity of populations. Take a common genetic disorder - albinism (is this counted as a mutation?). It is relatively common for people to be born without the pigment-programming gene - they then have albinism. I don't think there is such a thing as very light-skinned people having dark-skinned children (unless there is a recessive "throwback" thing happening). This would require extra DNA to be created. To me it makes more sense to say that white people evolved from black people, as it is relatively easy to lose DNA and very hard (impossible?) to gain DNA, which is what would be required for black people to evolve from whites. Just a thought! | |
| From: Martin B | 12/11/99
15:27:21 |
| Subject: re: entropy and evolution | post id:
6889 |
| Hi Kent Sorry to hear about your inferiority complex. :-) (Some of the most intelligent questions and answers in here come from interested laypeople, so don't let that bother you.) As I have remarked, this is not really my field, but I think I can spot two things tath may be increasing confusion. First is the process of natural selection. Yes, the vast majority of mutations are harmful, or at best neutral to the individual - as we might expect from entropy considerations. However the process of natural selection means that the harmful mutations are quickly forgotten, while the successful mutations are remembered, perhaps for a long time. So when we look back along an evolutionary lineage, we see a long line of successful mutations. We don't see the vast majority of unsuccessful mutations. Second is the way DNA acts to shape organisms. DNA codes to produce proteins. The proteins then biochemically act in organisms to ... do all kinds of whacky things. Different genes will code for different proteins, which will do different things in different cells. YKWIM. A change of just a single base-pair in a single strand of DNA is just a tiny change in the structure of the DNA molecule. Yet this smalkl change may have a dramatic effect. DNA is not like a computer program, where an extra feature requires extra programming of new information. All humans share more or less the same amount of DNA and does not need to be created or destroyed to produce a mutation. The chemical DNA can undergo many other kinds of changes. Most of the genes in our DNA are redundant or 'useless' (So maybe DNA is like a Microsoft programme) so this provides plenty of 'spare parts' for an erroneous copying to select from. But the point I'm trying to make is that DNA is not a set of 'information' that needs to be explained. It is a chemical. Don't confuse the effects at an organism level with the requisite changes at a biochemical level. | |
| From: Kirsten | 12/11/99
16:08:24 |
| Subject: re: entropy and evolution | post id:
6898 |
| Point one - energy input into a
system is what allows it to 'overcome' entropy, the sun is providing
energy which would be a catalyst against entropy, if
anything. Point two - I agree with what Martin B was saying, just a further note that albinism and white (i.e. caucasian) have different genetics. An albino can have dark skinned children (if their partner isn't an albino too) as the condition is recessive. White and dark skin are the result (probably) of environmental pressures favouring one over the other in a particular region. (and point 3 re. Archaeopteryx (yes I know it was a different thread) read Richard Dawkins 'The Blind Watchmaker' for a briliant explanation of how 5% of something is useful and can evolve successfully - in short, if 5% of a feature means that you are slightly less likely to die than your neighbour, then it is worth it. In the case of wings Dawkins mentions the fact that if you can survive a fall (say by gliding) that someone else can't, you win (meaning survive pass on those genes for 5% wings...)). Kirsten. | |