Evolution Definition and 706 Threads

Hi, I am using a model that estimates pressure (P) in an intake manifold. I think there is a mistake in its equations but I cannot find it. To simplify the problem we can make the following assumptions: - Only air fills the manifold: air comes into the manifold through the throttle (mass...

Hey i was wondering how to express the time evolution operator U(t,to) to a momentum eigen state |p> for a particle moving in the xdirection under a zero potential, V= 0. The reason i need this is that iam told the only way to get the matrix element of the time evolution operator using position...

I've been trying to solve some questions using dirac notation, and most seem to be pretty straight forward (once you set everything up) but i always seem to get stuck when i try to find the matrix element and i can't seem to find the proper way to express the eigenstates given... so for example...

The ETS released exams date back to 86. Have the exams changed much in style or content throughout the years? Surely, the older exams are worth working through, but are the "newer'' exams like 96 or 01 more like the exams administered in the past few years?

does evolution violate the second law. from my understanding the second law only applies in a closed system and the Earth is an open system with an energy output. (the sun) so therefore entropy is increasing and it doesn't violate the law correct or incorrect?

So I've just read through http://blogs.discovermagazine.com/gnxp/2010/08/science-with-soul-sells/ and I found it *extremely* inspiring. Namely, this quote in particular: And so, I've thought - is there a significant number of people who are interested in these three subjects in particular...

My friend who thinks we were "created" keeps telling me that there's no link of a human evolving from a previous species.. Now I keep telling that there's tons of evidence in museums & whatnot, but is there any good links online that can clearly show him?

So I just watched a Nova documentary on epigenetics called "Ghost in your Genes"... I had never heard of epigenetics. Apparently its things being passed down amongst people by means other than our GENES and DNA. Things like smoking being passed down from grandparents to grandchildren and...

I can probably argue against evolution without biblical references? Anyone wish to hear my argument?

I'm currently reading a book that presents the different kinds of evidence for evolution. Throughout the book, the author claims that evolution can make certain testable predictions. For example, he writes about biologists who examined birds and reptiles and predicted that they'd find a common...

Is having a genetic advantage enough for evolution to occur? Doesnt a organism require some sort of knowledge (or instinct) in order to use such an advantage in order for it to be any sort of advantage? Example: we say the first step in the formation of a eye is a cell that is sensitive to...

I do not study biology, i enjoy physics a lot more, but recently while i was thinking about our origins a question aroused my interest. As i said i do not study biology, and i do not doubt evolution(this is asked out of honest curiosity). From my understanding all life started as a form of...

Evolution of Carbon dioxide from Sodium bicarbonate and potassium hydroxide??! Hi!:smile: Here’s a question my teacher asked me to solve about evolution of carbon dioxide, We know that carbon dioxide is obtained by the action pf dilute acids on any metallic carbonate or bicarbonate e.g...

I have been reading Charles Darwins Book "The Beginning Of Species" and it has got me thinking. Would it be possible to breed a NEW species of Mammal within a life time? i was thinking about using mice because their breeding cycle is quite short. Does anyone have any knowledge of anyone...

Second thread on the evolution of like, in the Archaen and Proterozoic eons. There are many kinds of eyes, and many have arisen quite independently; the classic example of convergent evolution. Did sexual reproduction arise more than once, independently? Is it too an example of convergent...

Do you guys think we reached the peak of our evolution? Is there any higher advanced form we can evolve into as time passes, or are we really at our peak? Natural selection doesn't appear to take place for humans anymore, since the average human isn't being weeded out by some physical defect.

I'm trying to get some real numbers for the probability of evolution occurring by random mutations, but cannot find anything helpful in the literature--- except that a single base-pair genome mutation occurs once in every 10exp-6 DNA replications. So I'm trying to use this meager...

DELETED because of immature thinking :(

I'm finding it hard to describe what I mean, but here it goes. According to the evolution theory monkeys, apes among others, and humans have a common ancestor - their hereditary line of ascent leads to a common forefather(s). As evolution predicts, let's say, male nipples is a proof that human...

I hope someone can help me out here, I am confused with a line of text I read - it is an example of a 2D Hilbert space with orthonormal basis e1, e2. The Hamiltonian of the system is the Pauli matrix in the y-direction. Given by the matrix: \sigma_{y} = (\frac{0, -i}{i, 0}) The eigenvectors...

i was wondering if anybody had any thoughts about the symbiotic relationship between us and viruses, and whether the fact that we are vehicles for them motivate them to to change us and modify our evolution.

Evolution is the greatest nano-engineer that ever existed. I always assumed that if anything was physically possible at everyday Earth temperatures, forces and velocities then it would have emerged naturally from evolution, since the evolutionary benefits are clearly enormous. eg that's why...

Hi, I stumbled on your website when looking for a good place to ask educated professionals. I'm 16, I have a question on evolution. Ok so let's say there are these birds on an island with a food source that require long pecks, but these birds have smaller pecks than needed. So after a...

Newbie...first post...apologies in advance. How soon after the big bang could intelligent, technological life evolve?

In several threads where I've seen the redshift issue discussed there's been some confusion about this point, Must we treat cosmological redshift as a purely kinematic (relativistic)doppler effect or as the time dymamics of the metric space? Or both views can be made to converge?

Has social complexity increased with evolutionary changes? Put another way, is complex social behavior a strong survival trait in general?

Is the evolution of our technology and medicine leading to "de-evolution"? First off, I have a very limited biology background, so I apologize now. Secondly, it's hard to show emotion through typing; what I'm saying in not meant to be derogatory or offensive to anyone. Survival of the...

Do you think that the human species will survive long enough to produce a new subspecies or a separate species? Personally, I think we are doomed to kill ourselves off prior to an new development. However, our species comes from a long line of individuals that have adapted and survived many...

Is evolution (Darwinian) considered part of the science of cosmology? or would that be another subject entirely?

I was just wondering where we agree that evolution began. I heard it was from the firtst single cell organism but that does not make sense as the organism must have already been evloving with it nucleus and DNA. Do we consider the formation of DNA evolution? Do we consider molecules to...

I am trying to write a differential evolution in FORTRAN, but I am a bit confused by the concept. I've read through Storn and Price's explanation of the concept, but I'm still not getting it. Can anyone offer a dumb-ed down version of what exactly a differential evolution is?

This has been giving me head aches for the past so many days and it reflected in the "Random Evolution" thread too. But i think it deserves a new thread as googling for "evolution free will site:physicsforums.com" doesn't give satisfactory results. So here is the question. Does the theory of...

Hello is is a continuation of a discussion that got started in the special relativity section but is a split-off and more appropriate here. The question is does evolution add information to the genome?

For the sake of simplicity, I'm dropping unnecessary constants like \hbar . I'm working on a problem in quantum control theory, and trying to find a test case to synthesize the ternary Toffoli gate. Unfortunately, I cannot seem to find a basis that admits a possible solution. In order to...

How can we say that evolution is random when it is based on choice aswell? For example the first creatures that came onto land made a choice to do so. Sure they were probably pushed there to survive but they still made the choice. Throught out evolution these decisions were made and evolution...

Consider system with Hamiltonian H. If this system is attached to inertial observer its evolution is described by unitary operator: U_t = \exp(t H) where t is time measured by inertial observer. What if the observer accelerates (with constant acceleration in its comoving frame). Is it stil...

dear readers, i have a friend of mine who just doesn't believe in evolution!. i just find that very hard to believe as i thought the theory of evolution was one of mankinds strongest to date!. the thing is that he is an intelligent man!(he is a chemist for goodness sake!). every time i try...

Hi there, I'm new to the forums and I came here for a specific purpose. I am not in school at the moment, but rather I am writing a science fiction novel and want to make sure that my science is as close to accurate as possible (though I understand that this may be impossible in some respects)...

When you hear those crazies talking about a 6000 year old universe, they show little belief in God narrowing a concept of a supreme all poewerful force to something trivial so they can unserstand it. The way I get simpletons to understand it is that if you burn oxygen and graphite O2 and C...

I don't know much about biology, my background is in maths and physics. Hopefully someone else here knows it better than me. Anyway, I was wondering if evolution would go the same way if it were repeated again with the same (or very nearly the same) initial conditions. I'm not sure how much...

I am planning to make an evolution simulator fairly soon, and am wondering just what as been done like this before. My plan is to make a simulator in that I can create a "world" with many environments, release some type of primitive "organism" and than have random mutations occur when they...

I know that it has been 'proven', but my question is, has it actually been observed by somebody? Yes, we can see the similarities between different subspecies and species but that alone is not proof that they evolved from each other. Has anyone actually seen it happen?

Do similarities between plantae protist and diatoms arise from convergent or divergent evolution? The Attempt at a Solution I think they are from convergent evolution however I can't think of a reason why, I know they are paraphyltic on the evolution tree of life. It could be that...

With advances in medicinesin 1800s and now the avg life expectancy being higher than reproductive age what could be driving human evolution? something like : Hundreds of Human Genes Still Evolving http://www.livescience.com/health/060308_human_evolve.html I understand genes could change...

Recently several papers have been published related to entropy and evolution. According to Daniel F. Styer ("Entropy and evolution", Am. J. Phys 76, Nov 2008) and Emory F. Bunn ("Evolution and the second law of thermodynamics" Am. J. Phys 77, Oct 2009) entropy is decreasing due to evolution...

I realize this might not be likely, but I'm sure it could happen. I'm just trying to figure out how improbable this scenario may be: How likely is it that two different species could undergo convergent evolution to such an extent that members of the different species could interbreed? In...

Is it culture or genes or both that drive some groups to have high completed family sizes?

what new on evolution

I know there have been debates on the roles of punctuated equilibrium, phyletic gradualism, and punctuated gradualism. It would seem to me intuitively that evolution would be a dynamic process combining mechanisms, but of course intuition can be misleading. Is there a mainstream...