What forces cause evolution? Are humans still evolving?
Topic: What forces cause evolution? Are humans still evolving?
June 20, 2019 / By Deziree Question:
I watch the animal planet a lot and I realized that animals have extremely specified skills designed specificly for their environment and scientist blame evolution, a "random" change in dna sequence that if provides an advantage thrives. But I don't understand if the dna change is random how is it always perfect for the environment does our dna somehow know what environment we live in? I know some mutations aren't good but some are wierdly accurate as to solving environmental problems.
Are humans still evolving? I think so I personally think people today are better looking but idk if that counts as evolving I also think girls seem to "mature" at an earlier age maybe social pressures to look good are enough to cause evolution?
Best Answers: What forces cause evolution? Are humans still evolving?
Candy | 10 days ago
Random mutation drives evolution, but it's only half of the equation. To get evolution, you also need natural selection (which is not random). With mutations, you get a bunch of tiny changes, but those changes aren't always perfect. They're usually neutral, and they're sometimes detrimental. That's where natural selection comes in. The individuals that have a beneficial mutation have a higher chance of surviving - which translates into a higher chance of living long enough to reproduce (and have offspring that inherit that beneficial mutation). The individuals with detrimental mutations have a lower chance of surviving, so they're less likely to pass that mutation on.
So, yes, it does look pretty amazing when nature comes up with a solution to a problem - but the process is a trial-and-error one, and you don't see the countless victims of a detrimental mutation that died off along the way.
As for human evolution, we *are* still evolving, but it's a very slow process. Mutations don't show up in the person that acquires them - they only show up in the offspring. That means that evolutionary steps occur each generation. Humans have a generation time of around 25 years, and since significant changes take hundreds of generations to show up, we can't expect to see it happen. I think what you're describing is more of a combination of modern medical technology, cosmetics, fashion, and diet. It's remarkable how much of one's appearance is based on non-genetic factors.
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Originally Answered: Im curious as to how scientists come up with theories such as humans evolving from apes when they werent there?
Well, I'm going to assume for your sake you actually want to know the answers and are not just trying to disprove the theory, although I may be wrong.
We have no reason to believe those things have changed any. Sure, it's possible, but it is also possible you don't exist. You have to start from somewhere, and I would say that believing the laws we see now have always been the same when we have no reason to believe they have changed is a good place to start.
As for how the theory of evolution arose (which, by the way, does not describe how life originated as much as it deals with how it has changed since then), start by reading the books "Darwin and it's Discontents" (Michael Ruse), "The Origin of Species" (to get an idea of how Darwin formulated his theory, but realize the theory has changed a good deal since then), and if you are religious, "Creation or Evolution" (Denis Alexander).
I won't go into more details here because if you don't really care and just want to argue, I have better things to do. If you really do want to know, the resources to answer your questions are out there and you should go read them.
What do you mean by this: "I on the other hand know that isn't true, it had to be variable." If you know it was variable, how to you come to that conclusion?
Good luck answering your questions.
Got it. I would say though that there are many observations in nature that all can only be explained if those laws have not changed. For a biology example, organisms are adapted to the current laws. It would have been quite difficult for all life to evolve using one set of laws and then adapt to a new set, or even a single new one. I mean, can you imagine what would happen if gravity changed!? Or if all of a sudden oxygen and hydrogen started or stopped reacting to form water!? There are other examples from different fields, but I am only knowledgeable of them to the point of understanding them, and could not explain them to others.
The answer you're looking for is natural selection. There are other forms of selection, but natural selection is the place to start when understanding evolution, and the central insight of Darwin's work.
Mutations occur all the time at the genetic level. Lots and lots of them. Most do nothing. Many are harmful. Ones that give an advantage, however, will cause the organism to have an advantage. When a mutation occurs that gives an organism an advantage in an environment, that organism will persist and *** its genetic code to its offspring. Over time, that advantage will become a dominant trait.
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It is not that the changes are "perfect". All they have to do is create a advantage. An advantage that means more food, for example, means more to share with offspring, some of which will inherit the gene. Now there are more with the gene, and when one of them gains an advantage that can be passed on, there will be a population with two advantages. Interbreeding with an individual with neither of those advantages, but possessing a third advantage, will produce a generation with three advantages, and so on. Sometimes the change may not produce an immediate benefit, but will be an advantage in a new environment, whether due to change or migration.
Humans are evolving, but we are changing our environment, so the major trends are difficult to assess. Culture is learned, not inherited.
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Humans are still evolving but it isn't quite the same as thousands of years ago. There were four dominant factors: Mutation, Survival of the Fittest, Weather and Wars. Mutation still occurs. Survival of the fittest is less of a factor as we counteract the genetic deficiencies and sicknesses that would kill prematurely or inhibit procreation. Weather is largely eliminated. Wars are not as prevalent but often involve genocide and rape. The whole issue comes down to the gene pool and procreation. The more that society supports the weak or defective, the more that degrades the gene pool. But this probably doesn't matter much in the short term.
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Evolution is heritable change. That means only those changes that are encoded in the DNA will be passed along to future generations. A classic example is piano playing. No matter how skilled a person has become in playing the piano, his/her children cannot inherit this ability and they must learn to play and practice if they want to be any good. Now, imagine, if the ability to play the piano is no longer a luxury, but a necessity for life, then only the best piano players are likely to survive. In that case, all children would learn to play the piano as soon as they are capable of learning. Since piano playing is now essential for survival, any genetic change that may arise at random but that helps them play the piano better (e.g. a brain that can process musical information better or hands that are very agile, or a brain that is adapted for learning and remembering) would be favored, since they will help a person survive. What if someone were to have mutations that make them worse piano players? It is as likely to arise through mutations as the good genes, but the bad genes are disadvantaged, and they will be eliminated because survival is at stake. Over many generations of such harsh selection, we end up with a population that plays the piano much better than other populations of humans in which piano playing is not essential for survival. That is what is called natural selection, and it is what causes positive changes in the genome.
Since a person is more than just a piano player, he/she has other traits, such as hair color, eye color, nose shape, etc. In a population in which only piano playing ability is key to survival, these other traits are called selectively neutral. That means they have no bearing on whether a person survives or not. These selectively neutral traits also evolve, but they evolve by a different mechanism than natural selection. Instead of being favored one way or another, these neutral traits may become established through chance. If, by chance, the best piano players have red hair, then red hair will become more common, not because red hair is advantageous, but because they are linked to good piano players by pure chance.
Therefore there are two mechanisms that can cause evolutionary change: natural selection and random genetic drift. Natural selection will always result in changes that are adaptive to the environment. Therefore it is no accident that people who live in the tropics, with lots of sunshine, will have dark skin, since dark skin blocks harmful UV rays and is therefore adaptive. Random genetic drift, however, operate differently, since the traits involved are selectivey neutral. Going back to the piano playing population. Since piano playing is a survival skill, other attributes becomes less important. For example, if a fat and ugly piano player is going to live, whereas a slim and handsome person who cannot play a single tune is going to bite the dust, then looks will become a selectively neutral trait. As such, the piano playing population is going to be more highly variable in terms of personal appearances than another population in which beauty is more highly valued. Over the course of many generations, the piano playing population may look more ugly on average than other cultures due to pure chance, or they may look better on average due to pure chance. Random genetic drift therefore is less predictable, and it does not always result in directional changes, unlike natural selection.
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Originally Answered: Atheist don't believe in GOD, so did evolution cause these problems in Humans ?
In a way, yes.
Our brain has two hemispheres, and each hemisphere operates differently.
The left side of our brain is the intellectual side.
It is the source of all language, all thoughts, all sense of separateness, all problem-solving, our ability to see patterns, our sense of time, our worry, etc.
It is the problem solver, and it is what makes us able to manipulate our environment (tools, technology, medicine/dentistry, etc).
It operates like a serial processor. It processes things one after another, in an orderly manner (which is where our sense of time comes from).
The right side of our brain is the experiential side.
It is the source of awareness of the moment, of a sense of joy and awe, a feeling of being connected to all, and a sense of universal love.
Researchers dealing with brain hemispheres have dubbed our right hemisphere the "God brain" because of the feelings that predominate and the way we experience being, when the right hemisphere is more active than the left hemisphere.
It operate like a parallel processor .. it processes everything all at once. Everything.
Yes, the higher evolutionary function of our brain has increased the functioning of both hemispheres.
And the increased left-brain function has made us more-than-animal.
Unfortunately, the better man becomes at manipulating and controlling life, the more we worship our intellectual functioning.
And the busier our life gets, and the louder our environment gets (city noise, constantly playing our music) .. the LESS we connect with our "God brain". The less we feel the joy, awe, love and unity of life.
This is what meditation/centering prayer/contemplative prayer is about .. reconnecting with right-brain.
Yes, as our intelligence as a species increased, so too does our sense of being separate from others (left brain) and that is the source of all selfish behavior. So too does our lack of faith, of resting in the moment, of being like the lilies of the field.
It doesn't HAVE to be that way.
We CAN retrain our brains so that there is a higher degree of right-brain functioning, even as we go about our life (our jobs, our communication .. all of these require left-brain functioning).
It's not evolution that has caused the problem .. it;s our choices on how we use our mind and where we put our attention.
Certainly, in a more-rural quieter landscape, there is a higher demand for overall awareness of what's going on around us. In our urban, hectic enviornments, we tend to block out everything that is distracting and focus on our task .. this increases left-brain function and shuts down right-brain function.
But our lifestyle is our choice. And with training, we CAN go about our urban hectic lifestyle while yet retaining some of the experiential quality of right-brain functioning.
Without the evolution of intelligence, we would be like the bird in the bush outside our window. We would lack the ability to control and manipulate our environment, to communicate with each other .. but we would not have the ability to connect with the sense of infinite love either (that the right-hemisphere brings us).
Both our strength and our weakness result from the evolution of the human brain.
WHAT we DO with it .. is our choice.