Evolution Definition and 735 Threads

I was studying evolution and speciation and an example was given in my textbook. It said that there is a species of red beetles and through variation a green beetle is formed and then is naturally selected as red beetles are easily seen by crows and green are not. My question is where does the...

Hi all, I have a spatial probability density function that is dependent on ##x##, space and ##t##, time. I am able to make a plot for spatial probability density for each point in time by specifying ##t## values by using the fplot function. However, I want an animation that allows me to see...

Homework Statement Variation during reproduction is beneficial to the species but not necessarily for the individual? Homework Equations Not any The Attempt at a Solution I only know about variation during reproduction is beneficial to the species but I don't know anything about how it is not...

I was pondering human evolution on different continents recently and some thoughts occurred to me: 1# the distance a region is from the equator determines the temperature of a climate all over the Earth 2# humans have probably been in regions of varying distances from the Equator long enough for...

What do we mean when we say that a system can't change (in time) because its evolution is unitary?

https://www.newscientist.com/article/mg23631500-500-the-very-first-living-thing-is-still-alive-inside-each-one-of-us/ "We can stop <<profanity deleted>> about the origin of life," says Loren Williams, a biochemist at the Georgia Institute of Technology in Atlanta. "We can see it."

I came to know that time evolution in classical mechanics is highly non linear. Is there any case that it become linear?

Homework Statement Part e) Homework Equations I know that the time evolution of a system is governed by a complex exponential of the hamiltonian: |psi(t)> = Exp(-iHt) |psi(0)> I know that |psi(0)> = (0, -2/Δ) The Attempt at a Solution I'm stuck on part e. I was told by my professor...

Consider the leading-order (LO) DGLAP ((Dokshitzer–Gribov–Lipatov–Altarelli–Parisi) equation $$x \mu^2 \frac{d xg(x,\mu^2)}{d\mu^2}= \alpha_s \int_x^1 dz P_{gg}(z) \frac{x}{z} g(\frac{x}{z}, \mu^2) + \dots\,\,\,\,\,\,\,\,\,\,\,\,\,(1) $$ Define an unintegrated parton density function (PDF) by...

Did the evolution of the eye include interaction/reaction with a specific frequency of light? Did the evolution of the lung include interaction/reaction with the air density, humidity, and temperature of its environment?

Scientists are looking for Earth like planets/bodies to find life on other planets/bodies, somewhere that is warm enough that liquid water can exist, and somewhere with basic organic molecules. Here's where I have a concern, in the 4 billion years of Earth's life, to our knowledge life had only...

In quantum mechanics time evolution is defined via a unitary operator $$U(t^\prime,t) = e^{-iH(t^\prime-t)}$$ Now let's forget about the fact that we know this exponential representation and that we know that the U's fulfill the group axioms, i.e. that we can multiply any two U's, regardless...

Homework Statement [/B] I'm trying to solve the following problem. (a) was easy but I am stuck at (b). Homework Equations [/B] Since we are told that the Hamiltonian is conserved, and the answer is in terms of the uncertainty of H, I assume I have to use the conservation of uncertainty...

At the time my story takes place, humans are in an evolutionary transition period. They have been able to modify DNA/genes so that people can have accessories, so to speak (communicator built into your arm, infrared sight, joints that can sustain falls from great heights, etc.), but very few...

Hello In evolution, the archetype rule is the "natural selection" rule. Are the other selection rules? (technological selection rules, cultural rules, etc) Thank you for your time. Regards, ORF

As a kind of off-thread elaboration on a thread on protein evolution, here is a Science news article on the evolution of mammalian chromosomes. By using full genome sequences, they are trying to trace back the evolution of mammalian genomes to their ancestral set of chromosomes. They only...

The Green's function is defined as follows, where ##\hat{L}_{\textbf{r}}## is a differential operator: \begin{equation} \begin{split} \hat{L}_{\textbf{r}} \hat{G}(\textbf{r},\textbf{r}_0)&=\delta(\textbf{r}-\textbf{r}_0) \end{split} \end{equation}However, I have seen the following...

If I've understood correct, every particle in the universe exists in a waveform, which I've understood to mean propability where the particle does exist? Then which I've understood is, that the wave transforms into a particle only when observed, is this correct? Then if it is correct, how...

Hi, my Name is Markus and I'm from Germany, I have more a lingustic & IT background with basics in physics from school times (some years ago, I have to say). I have a couple of more holistic questions, hope that is ok, please let me know, Have a great day!

Hello. I am trying to prove that the uncertainty in energy for a normalized state limits the speed at which the state can become orthogonal to itself. The problem is number 2 on https://ocw.mit.edu/courses/physics/8-05-quantum-physics-ii-fall-2013/assignments/MIT8_05F13_ps6.pdf Having issues...

Origins of various modern human populations has been the subject of a few posts recently. Below is a link to a Science mag news article on this subject. Modern Archeology has been using new tools, such as DNA analysis (of modern populations and ancient dead people) and isotope analysis (on dead...

Q: Why arthropods have not evolved to be huge? 1. Homework Statement Arthropods have not been able to achieve great size because (1) the type of organ systems they possesses could not support·such a development (2) they would be unable to successfully reproduce (3) chitin is brittle and must be...

Homework Statement I am not sure about (c) and (d). Firstly, I calculated the eigenvector of A : |v_1> = ( |2 > - |1> )/ √(2) ,eigenvalue -2 |v_2> = ( |2> + |1>) / √(2) , eigenvalue 2 For (c), basically it follows from part (b) where the probability of a_1 is given by the formula | <v_1 | ψ...

This paper offers a "first link of a chain", bridging physical and, psychological or linguistically, mental notions of meaningful information. https://arxiv.org/pdf/1611.02420.pdf Meaning = Information + Evolution Carlo Rovelli CPT, Aix-Marseille Universit ́e, Universit ́e de Toulon, CNRS...

Hello guys, I have a question that came up to my mind while thinking about the evolution of our universe and quantum mechanics. It involves cosmology so maybe that was the right spot to post it, and of course the moderators can do it if they feel it's more adequate for the thread, but my...

Heads up, I only recently got into quantum mechanics and don't feel like I got a solid grasp on the material yet. 1. Homework Statement Given is the wave function of a free particle in one dimension: \begin{equation} \psi(x,0) = \left( \frac{2}{\pi a^2} \right)^{1/4} e^{i k_0 x} e^{-x^2/a^2}...

Will it be possible for an organism to evolve in order to adapt to conditions at space?

Please someone help me understand the concept of the actual occurrence of speciation. Cataclysmic Evolution may account for some species but not many, it could only practically apply to asexual species and would undermine genetic diversity. Actually I can save a lot of explanation by clarifying...

Homework Statement A particle in an infinite potential well ##V(x) = 0, -\frac{a}{2} \leq x \leq \frac{a}{2}##, and infinite elsewhere is in it's ground state. Subsequently, the potential is removed and the particle is free to move. How does the probability distribution in x and p change...

The path on an HR diagram after a star leaves the main sequence stage is known as post-main sequence evolution. In the graph, it consists of 2 parts: sub-giant branch and red giant branch. The near-horizontal is the former one, and the near-vertical is the latter one. Subgiants are...

I am busy with an effort to show how the energy density parameters evolve over time in an update of the LightCone7 calculator. See the posts on the thread Steps on the way to Lightcone cosmological calculator. As part of this effort, I ran into some difficulties with deciding how to find and...

i have found one article state something like this:"""Any real evolution (macroevolution) requires an expansion of the gene pool, the addition of new genes (genons) with new information for new traits as life is supposed to move from simple beginnings to ever more varied and complex forms...

Hi forum, I followed through Feynamn's derivation to show the different times taken for light by the parallel and perpendicular paths of the Michelson Morley apparatus. He showed that it took longer for light to go to the far mirror and back if it were parallel to the direction the whole...

Humans, other animals, plants, fungi and almost all other forms of complex, multi-cellular life are known as eukaryotes. How eukaryotes evolved from simpler prokaryotic organisms is a major question in evolutionary biology. The current view is that eukaryotes evolved from the fusion between a...

I'm working on an experiment where I mimic biological evolution. I'm doing sexual reproduction to allow gene swapping because I see it as beneficial in terms of evolution. I got to wondering if I should include genders in my simulation. What is the evolutionary reason for only allowing half...

Dark Energy; origin and evolution I have read the threads but I still have some unanswered questions about the origin and evolution of dark energy. Has dark energy existed since the big bang? If so, why did it remain dormant for billions of years. Or did it spontaneously jump into existence...

hello PF, I want to know more about stellar evolution and about the end of the star's life. I want something that is not very superficial as i get bored when the content is not really deep. Thanks.

I'm wondering if the issue of bacteria and archaea having a single last universal common ancestor (LUCA) with eukarya diverging later, or all three having distinct common ancestors, has been clarified. I've seen a number of texts indicating the eukarya diverged much later, but also some...

Hi I am and athiest and I believe on evolution, but there is an aspect of it that I can't get to grips with. We know evolution doesn't have a conscious mind and that it is the natural blind process of survival of the fittest, based on mutations over generations that are useful to the species...

Hi everyone, In Carl Sagan's Cosmos there's a short animation video illustrating the shape of all human ancestors, starting from single cell organisms, morphing towards the modern humans. I've searched for a complete list of known human ancestors like that one, but I couldn't find anything like...

it is a common arrangement that say if evolution is true then why there is a monkey until this moment . I now that evolution is correct but who i can answer this question .

Homework Statement Hey guys, I have a question that asks; Assume an Electron Nuetrino (U1) is produced at t = 0. Find the state U(t) for later times t > 0. To give some context the question is based on a two state system where U1 = Collumn vector (sin(theta) cos(theta)) and U2...

Homework Statement The eigenstates of the momentum operator with eigenvalue k are denoted by |k>, and the state of the system at t = 0 is given by the vector |{ψ}>=\int \frac {dk}{2π} g(k)|{k}> Find the state of the system at t, |ψ(t)>. Compute the expectation value of \hat{P}. Homework...

Hi all, I have some troubles with some basics thermodynamic rules. I have a sealed tank filled with fuel at Patm and at a temperature T. In this tank after filling, is composed of 3/4 liquid and 1/4 gas. I was wondering how the pressure inside the tank will change if we change the boundaries...

Hello. First of all, I must say that I'm new to this forum, so I apologize if I'm posting in the wrong section. I'm a 17 year old with not that much knowledge about physics, so if what I'm talking about makes no sense or is completely stupid, just let me know. A couple of days ago I asked...

the second law of thermodynamic state that their will be more chaos, and natural selection in the opposite of that. maybe this is a stupid question but can somebody anser this

I refer to a Schwarzschild Black Hole as the simplest example, and a well defined time outside the hole, say the Schwarzschild time. The information paradox of BH deals with the question of what stuff has fallen into the hole, but I am not aware that it deals with the question when the...

In some texts of fundamental quantum mechanics, it introduces the wave packet by Fourier transformation of a momentum wave into a spatial version. This is easy to understand because, analogy to the optical wave, a typical beam could compose waves of more than one frequencies. The general form is...

Why do humans (and other mammals) get nauseated from dizziness or vertigo? I can see the evolutionary advantage of nausea from food poisoning, but I can't see the direct "link" between vertigo and vomit. I found something on verywell.com...

hey, this thread might be a bit longer, but I have already calculated everything and I am quiet sure that it is right :) Just need someone who confirms me or not :) 1. Homework Statement Time evolution of probabilities. An electron inside a quantum well of length L is at time t = 0 in the...