Evolution Definition and 735 Threads

I am no biologist, but I have read a few laymen books on evolution and I have a bit difficulty accepting one part of evolutionary theory, The notion that genetic mutations and genetic variances occur solely by chance. It would seem to me, that the evolutionary process would favor organisms...

Earth first formed about 4.6 billion years ago, condensing out of the gases & dust in the proto-Sun's Planetary Disk. But, for about the 1st billion years, the proto-planet was repeatedly pummeled by swarms of Impactors. They deposited gargantuan quantities of energy onto the Earth's surface...

It seems likely to me since the first tools we used as primates-early man. Think about it, those early, pre-homosapien primates who have mutated an inheritable trait which makes them smart enough to discover the benefits of rocks, sticks etc. to enhance their ability to gather food will...

Would highly recommend the book reviewed here - shows how evolutionary models are supplanting the simple physics-based models of neoclassical economics http://www.sciam.com/arti...mics-skeptic-january-2008 Evonomics Evolution and economics are both examples of a larger mysterious...

That is, if these cells even had anything to do with it. We're only going by the endosymbiotic theory.

Evolution mutations not completely random according to an experiment I wondered for a while where to post this link, but since it will probably provoke questions on the origins of this new guiding mechanism of evolution, i decided it had to land here(it will be a matter of time till someone...

Homework Statement Suppose the state of a single-mode cavity field is given at time t=0 by |\Psi(0) \rangle = \frac{1}{\sqrt{2}}(|n \rangle + e^{i\phi}|n+1 \rangle) where phi is some phase. Find the state |\psi(t)\rangle at times t > 0. Homework Equations I'm a little...

Hi, I'm trying to derive a wave equation for a gaussian wavepacket for both the position (x) and the momentum (k), for a wave packet of width sigma, at some initial position x0 and with an initial momentum k0. Now I have worked out the initial wavepacket equation to be: psi(x) =...

Hi There, A square pulse of light has the form f(x) = A exp(ik0x) for |x| < L/2 and f(x) = 0 everywhere else. I want to know how that pulse evolves overtime. I want to graph it in Mathematica. I did a Fourier transform to find the wave number spectrum, with the general form: F(k) =...

What role do you think variations play in the process of evolution?

I'm not quite sure where to put this, in Physics or Biology. Mentors, please move this to the most appropriate location. A common argument put forth by creationists/intelligent design proponents is that evolution/abiogenesis violates the second law of thermodynamics, by causing a decrease in...

The general consensus I think is that evolution is still occurring in modern times but just being driven by different factors than geography, climate, predation, etc. But doesn't the process require time as well? Flora and fauna (including humans) evolve characteristics because of...

could we do QM without time evolution ?? that is the idea, could we perform QM without referring to any coordinate called 'time' in the sense that the Hamiltonian and Schroedinguer equation would be H \Psi (x) =0 and time and energy only appear as the pair (p_0 , t) the idea is ...

A frequently seen opinion, for example expressed by Popper in reflecting over what he calls the "the fundamental problem of chance in his classic "The logic of scientific discovery", is to reject the subjective interpretation of probability because he thinks it is not falsifiable. This really...

hey folks, i'm just curious. are there any biologists who don't accept the theory of evolution? if yes, how do they scientifically explain the diversity of species (other than believing in Intelligent Designing stuff)? cheers

Evolution bibliography [Urgent] Hi, I'm writing an article for my college magazine. As always, I'm already behind the deadline. I need to include a very basic bibliography on evolutionary theory. I've included Richard Dawkins's The Selfish Gene and The Extended Phenotype as introductory...

My knowledge of biology is very limited and I know just the basics, so please enlighten me. This evolution phenomenon has started way way back in the past and as a result, today we see varieties of species including humans. My question is: are WE (present species) still being evolved and...

Homework Statement http://img379.imageshack.us/img379/1864/screenshothw4pdfapplicamd7.png Homework Equations H|\psi > = E_n |\psi > The Attempt at a Solution About part 1 of the question: I can find the eigenfunctions of psi_1 by comparing coefficients with the well known...

Problem Describe the evolution in time of \phi_1 = A \sin \omega t \cos k(x+ct). Attempt at Solution We have that \partial^2 \phi_1 / \partial x^2 = -Ak^2 \sin \omega t \cos k(x+ct) \partial \phi_1 / \partial t = A \sin \omega t (-kc \cdot \sin k(x+ct)) + A \omega \cos \omega t \cos...

Hi, I am trying to calculate the time evolution of a density matrix. Like if there is a mixed state with 50% of |x, 0> and 50% of |y, 0>. After time t due to time evolution, the kets become: |x,t>= e^(-i/h Ht) |x,0> and so on. Is it ok to use these kets instead of the original ket to...

First, sorry for any grammar errors because English is my second language. This thread got me thinking about atheism and evolution: http[:]//www[.]physicsforums.com/showthread[.]php?t=124428 From the most of replies in that thread I came to conclusion that people who don't believe in GOD...

I heard a long time ago (im 18, so perhaps "a long time ago" lacks perspective, I guess I was 12 or something at the time) about an experiment that would have a colony of common fruit flies or mayflies onboard the space station to see how they evolved in a (as good as) zero gravity environment...

There have been countless discussions about the thought experiment about Schrodinger's cat in a box, and how to describe the state of the cat before and after the box is opened, leading to all sorts of bizarre notions like a half dead/half alive cat inside the box, and I certainly don't fully...

why is there very rapid mass loss in the superwind phase. my notes simply say "because the envelope attains positive binding energy". Firstly, how can binding energy be positive by definition?! Secondly, I am not entirely sure what the lecturer is talking about? what makes the envelope...

why after hydrogen exhaustion (of low mass stars) does the the core become isothermal. (according to my notes) I mean, after exhaustion, its all helium, and it keeps on contracting right? So by the virial therem it must heat up (so by definition, it is NOT isothermal)! Indeed it must do so...

we well know that, a coherent state keeps to be a coherent state in its evolution does similar conclusion hold for a squeezed state?

I read in my textbook that the wavefunction of a particle evolves causally when unobserved. but isn't it constantly being observed or detected in some sense by its gravitational effects?

Evolution: 24 myths and misconceptions The following myths are debunked: - Everything is an adaptation produced by natural selection - Natural selection is the only means of evolution - Natural selection leads to ever-greater complexity - Evolution produces creatures perfectly...

http://www.sciencedaily.com/releases/2008/04/080417112433.htm In 1971, biologists moved five adult pairs of Italian wall lizards from their home island of Pod Kopiste, in the South Adriatic Sea, to the neighboring island of Pod Mrcaru. “Striking differences in head size and shape...

[SOLVED] Evolution Operator If U=Exp[-iHt/h] is the evolution operator, and H the hamiltonian one, i can't figure out how to derive the following equation. Let`s call |E> an eigenstate of H, E it`s eigenvalue and |J> a random basis. Then: <J|U|E>=Exp[-iEt/h]*<J|E>. ??

I have a question about the Dirac Equation. I know that if I have a given initial state in non-relativistic quantum mechanics, I can find the Fourier coefficients using that state, and then write down the wavefunction for any time. But if I have an initial state wavefunction (that is, the...

Homework Statement An +x-polarized electron beam is subjected to magnetic field in the y-direction. What is the probablity of measuring spin +x after a period of time t. Homework Equations Time evolution operator U = e^{-i/\hbar \hat{H} t} The Attempt at a Solution Since the...

stellar evolution pathways...? I find this especially interesting since the trajectories of stars on the HR diagram are more or less based on this assumption. But obviously, small perturbations can lead to major changes in the long-run. But it seems that most of those changes involve only...

I want to clairfy something: Is it true that without DNA mutations it would be impossible to start with a population of x wild wolfs and breed a chihuahua, or poodle? Lets say your only goal is to start with a very large population of wolfs who on average weigh 100 lbs, your goal is to create a...

In case you haven't already heard, when the Republican Candidates were asked, "Who doesn't believe in evolution?" 3 of them raised their hand. If you didn't see it, I attached the clip below...

How does evolution work? It seems that evolution has determined many of the circumstances of the world we find ourselves in. Here are a few examples: (1) Cosmologists tell us that our present astronomical universe --- a conglomeration of planets, stars and clustered galaxies, together with...

Is there any reason that evolution can't take place in an artificial environment? I contend that, just as hybrid swarms of plants in Nature can stabilize into new species, the process of prolonged hybridization can artificially create new species. I have been told that these hothouse plants...

[SOLVED] Calculate time evolution of Schrodinger wave equation Homework Statement At time t=0 particle is in state: \psi\left(x\right)=\sqrt{2}A\phi_{1}(x)+\frac{A}{\sqrt{2}}\phi_{2}(x)+A\phi_{3}(x) where \phi_{n}(x) are eigenfunctions of 1-D infinite potential well. a) Normalize...

I'm currently reading this article by Ken Miller on a plausible account of how the blood clotting mechanism in vertebrates might have evolved. There's some things I don't understand but which I hope someone here will explain to me: Here's the article...

Let me preface this by saying that economist Gregory Clark argues in "A Farewell To Alms" that one of the factors for the success of the industrial revolution was evolutionary in nature: disease killed off poorer members of the society and their position was taken over by sons of the wealthy who...

Might galaxies in filaments http://pil.phys.uniroma1.it/twiki/bin/view/Pil/GalaxyStructures" for spirals? An extented flattened curve means more DM further out; the original discovery route of DM.

Homework Statement At t=0, a given wavefunction is: \left\langle\theta,\phi|\psi(0)\right\rangle = \frac{\imath}{\sqrt{2}}(Y_{1,1}+Y_{1,-1}) Find \left\langle\theta,\phi|\psi(t)\right\rangle. Homework Equations \hat{U}(t)\left|\psi(0)\right\rangle =...

http://blog.wired.com/wiredscience/2007/12/evolution-battl.html Why? :confused: They had their butts kicked in Dover, PA. And have been proven wrong, that ID is not a science. So why do they persist?

I am reading a paper about self-similar.but this concept,evolution function,really troubled me.and i have seached wiki,but it didn't work.can anyone explain it wisely or provide a clue about it.

I got this link from someone: http://www.buzzle.com/editorials/10-27-2004-60892.asp I'm suspicious as no other science website has this as a main story, and it's strangely under the "editorial" directory. Give me your thoughts. Fact or fiction?

Homework Statement At t=0, the particle is in the eigenstate S_x , which corresponds to the eigenvalues -\hbar \over 2 The particle is in a magnetic field and its Hamiltonian is H=\frac{eB}{mc}S_z . Find the state at t>0. Homework Equations Eigenstate of the Sx is...

I believe I read the Black Death or Black Plague that effected Europe created a noticeable genetic bottlenecking in Europeans. HIV is still relatively new, but has anyone heard or have any ideas how HIV may effect human genetics and culture?

Okay I have a question. In micro-evolution, traits change among the same species, enough of these changes leads to macro-evolution. What is macro-evolution other than a different name and a series of small changes? A change big enough so that the new organism is no longer of the same species...

I've just finished reading Darwin's Origin of Species - A Biography and I realize I'm not much closer to understanding the subtleties of evolutionary theory. At least, I think I'm not. What Darwin brought to the world, while it rocked the foundations of biology, was not his alone. The concept of...

I was wondering if anyone knew anything about epidemic models which take into account the ability of a disease to mutate. Basically I’m curious if there are any existing models which could predict how a rapidly changing disease might affect the progression of an epidemic, or how slower...