Question:
Is evolution a continuous process?
chartreuse_sweet
2007-07-19 06:42:27 UTC
Is evolution, as Darwin describes it, a continuous process?
What are your evidences for your views on the topic? Can we expect a big turn in the characteristics of various species in the future? If yes, what could influence this change?

What elements in our modern world may affect the next generation of humans (or other species)? What can be the manifestations of evolution in our modern world?
21 answers:
Ishan26
2007-07-27 05:31:35 UTC
Evolution is a continuous process. The speed and direction of evolution in a particular form may be different from others.

Macroevolution and microevolution have different characteristics.The prime source of evolution is mutation. Natural selection provides the adaptive channel and imparts directionality.
the_way_of_the_turtle
2007-07-19 17:55:08 UTC
>>Is evolution, as Darwin describes it, a continuous process?



As Darwin described it...not quite. As we know evolution now...absolutely. Evolution entails a build up of mutations that occurs over long periods of time affected by the natural environment. If one of these processes isn't occurring, the other most assuredly is.



>>What are your evidences for your views on the topic?



There are numerous papers that show build up of mutations in different species, and quite a few that document speciation due to natural selection. If you want a few examples, email me.



>>Can we expect a big turn in the characteristics of various species in the future?



I'm not sure what you mean by "a big turn"...what constitutes a big turn? And which species? It's probably likely that at least one (if not a few, if not many) species will develop new characteristics, especially if the rate of environment change continues at the pace it is theorized now.



One of the problems with predictions is the number of factors that are involved in causing the prediction to come true. The more factors involved, the less likely someone is to be correct about the prediction. And evolution is an extremely complex process with numerous factors involed, both within and outside the organism/populaiton. Making predictions of the nature of when an organism will show significant changes or even become a new species is an extremely difficult proposition. I know this is something of a cop-out on the answer, but it's true.



>>If yes, what could influence this change? What elements in our modern world may affect the next generation of humans (or other species)?



Again, there could be numerous elements. The proliferation of human technology is the most likely candidate (in my mind). Not only is it causing dramatic environmental changes, but it also breaks up and disturbs the equilibrium of many ecosystems.



>>What can be the manifestations of evolution in our modern world?



In my mind, the most likely manifestation will be the loss of specialized species in favor of more generalists. It's an extension of the theory of evolution that a generalist species (a species that can utilize various parts of environment for food, water, living space, etc.) is more adaptable to environmental changes, and therefore more likely to survive than specialist species (those species that can utilize only one of very specific parts of the environment for food, space, water, etc.).
#girl
2007-07-19 18:04:16 UTC
Evolution is the term used to describe changes to a species over time. This definition presupposes that this is a continuing process.



Can we expect a big turn in the characteristics of various species in the future? That depends on a number of factors. What is your timeline? If it's only one generation, probably not. If your timeline involves thousands of generations, probably so.



What changes will occur in the environment? Will these changes be gradual ( such as a build up of pollutants in our atmosphere) or sudden (such as the Earth being struck by a large meteor, or some lunatic detonating a nuclear device)?



What elements in our modern world may affect the next generation of humans (or other species)? The previous paragraph suggests some of these elements.



One thing that has not been addressed by prior answerers --- survival of the fittest. The other answers are presented as if an environmental change occurs, so the species adapts. No, this is not the case. Yes, a change occurs --- a natural disaster, a disease, gradual build up of pollutants. Those who survive due to strength, disguise, natural immunity or mental acuity are able to reproduce (have children). The characteristics that enabled them to survive are passed to the progeny that also survive and reproduce.



What can be the manifestations of evolution in our modern world? Nearsightedness is an example. In the early days of humans, most people were farsighted. Farsighted people were able to prepare for a predator better than nearsighted people because they would see the predator sooner and have more time to prepare. Most people were farsighted because nearsighted people were killed by predators and unable to reproduce. In our modern world, variations in vision are corrected with glasses, contact lenses and surgery. Nearsightedness and farsightedness no longer determine survival and ability to reproduce. Therefore, in modern society, nearsightedness is much more common.
anonymous
2007-07-19 17:26:43 UTC
> Is evolution a continuous process?

Not per se. In organisms which are well adapted to their environments, and with the environments not changing, the organism may not have a change in phenotype for very long periods of time. The classic example of this is Triops cancriformis, the modern version of which appears to be identical to a species extant in the Mesozoic era.



You should google around for "punctuated equilibrium" to get a better description -- if there aren't external selection pressures, then populations may not change over long periods.



> Can we expect a big turn in the characteristics of various species in the future? If yes, what could influence this change?

The populations which are best able to co-exist with mankind will be the ones that flourish.



> What elements in our modern world may affect the next generation of humans (or other species)?

In humans, it's the choice to have children. Women with educations and careers have fewer children than those who don't. You can speculate that in the future, girls will be less interested in having educations and careers. This might be a decrease in the average intelligence of the human species.
OPM
2007-07-19 22:07:15 UTC
It is important to understand what the word "continuous," implies. It has, in fact, a very defined mathematical meaning. In differential topology, you can create a continuous surface that appears to be a jump in lower dimensions. The jump occurs outside our view.



The popular culture example is a "tipping point," or the "straw that broke the camels back," but what it says is that you can have a continuous process that you cannot observe and so will appear as jumps.



To apply this to evolution consider the simple case of a mutation. Imagine humans have a specific set of codons that are always the same. If one child has a variation, that variation may pass through to their children. This transmission of course is unseen. It may be irrelevant, however when combined with a specific set of other genes in subsequent generations or when other mutations occur, a large outward physical manifestation may appear to have occurred, when in fact, it was not large, but many small but unobserved changes.



Now, because this is a "discrete" and not a "continuous" process, jumps are more likely. It is rather like not being able to purchase something for 1/7th of a dollar. You have to round and rounding introduces error into the system permanently and those errors may be impossible to remove from the system.



We cannot predict the future. Yellowstone's Caldera could erupt killing almost all human life. People who lived in particular niches or who were somewhat immune from the cold would bear particular advantages. Who they are and what that means is something we cannot know now. Likewise the ozone layer may collapse and who knows what may happen, or how global warming will impact survival.



Scientists are in fact tracking gene changes as they occur now by sampling global populations and watching differences propogate through the species.
Davis Wylde
2007-07-27 08:11:35 UTC
Yes, it is a continuous process. While Darwin was off on somethings he was spot on in the most significant areas.

I try to point to the human body though most think I take this too far.

I point to things like Wisdom teeth- people are being born without them at a graduating rate (we've no need for them.)

Appendix's - same scenario, they're disappearing.

I think in the next two hunred years or so human beings will no longer have hair on their bodies.

The truth is that we have started to evolve sociologically which includes adapting in that way, not by physical changed. So, instead of growing more hair beacuse we're cold, we build jackets and such- after hundreds of years I believe hair will no longer be a part of our physical make up.

Most people say that we won't be sexy and such and who would be attractive? The truth in the answer to that question also lies within history- sexual visions change, as they always have and they always will to continue the propagation of the species...

You do realize at some point in the 60-70's human beings had to think hairy smelly greasy horribly unhygienic hippies were sexy!
anonymous
2007-07-19 15:08:34 UTC
If you are sitting there waiting for one of the higher animals to suddenly disappear and reappear as a new species, you are wasting a lot of time. Same goes for a change is characteristic.



Obviously evolution is continuous. Fossil evidence shows that. But, there have been major shifts, brought on by major changes, like asteroid inpacts.



What has influences changes in the past? Dinosaurs die off due to a cataclysmic event that racked the whole of Earth. Millions of years later, mammals being to appear. So, out of the muck and rubble news species evolve.



You will never witness evolution. The next asteroid that slams in to Earth will more than likely kill a significant number of humans. Perhaps events post will see the eradication of Homo spp. Perhaps a different hominid will arise from the ashes. But it wont be in 70 years, nor 1000, maybe a million.



We humans have the ability now to shape our own genetic future. Therefore human evolution is now in the hands of humans. I don't think it is gonna be pretty.



I think the greatest hindurances to people trying to understand evolution is the time scale. We humans are generational animals. We know our parents and grand parents, children and grand children. Therefore humans are lock in to a very narrow time span. We live 70 years, we see people older and younger, by about that same number of years. So it is difficult to get a handel on events beyond that span. Most people cant get a grasp on 1000 years. That's 15 human generations. How could they possibly comprehen 1000000 years.



There was an excellent paper written by N. J. Matzke, Evolution in (Brownian) space: a model for the origin of the bacterial flagellum. http://www.talkdesign.org/faqs/flagellum.html. Try to read it. It is complicated, something I am sure the Creationist will not tolerate. If it aint simple it aint worth the time. Yes, from simple minds come simple answers.



Ther has been completed excellent work on how bacteria evolve.

Bacterial Evolution/Adaptation and Antibiotic Resistance

http://www.lsic.ucla.edu/classes/mimg/robinson/micro12/m12webnotes/Emerginginfections/m12bacterialevolution.htm



If you wanna understand evolution on a more user friendly time scale, try reading the following.

Origin and Evolution of Influenza Virus Hemagglutinin Genes

http://mbe.oxfordjournals.org/cgi/content/full/19/4/501



Indeed there are reams and volumes and tons of data, records, cold hard facts, bones, fossils, skeletons, amber blocks, ice cores, etc etc etc. That fully support the changes over time we refer to as evolution. Perhaps it is just too much for some people to comprehen.
William T
2007-07-19 13:58:44 UTC
There are so many variables in the time-line of any species that this question becomes almost impossible to answer. Evolution is a continuous process but the environment can suddenly change and precipitate a sudden jump in evolution. To say that evolution is only a slow process or only comprised of occasional jumps is a narrow view. Evolution is the result of natural selection and so if you recognize natural selection and understand it then you understand the essence of evolution and believe in it.
billgoats79
2007-07-19 13:54:26 UTC
Yes its continuous. Every reproduction is a small change in the genetic information of the species, over long periods of time, with environmetal factors selecting which is more likely to reproduce, you get evolution.

I do expect a lot of changes with most of the species on earth. Humans have had a large affect on the planet in the past several hundred years; other organisms are going to need to adapt.

It seems that in todays society, intelligent people end up spending more time at college and more time being involved with work and have less time for children. Therefore there are less genes for intelligence being passed on over all. After a few more generations of this, I'm a bit worried of the outcome. Smart people need to start breeding!
deleteme
2007-07-25 05:01:16 UTC
Evolution is all about self-maintenance program for the survival of a species. It's slow because it depends on transitions in DNA between generations. One is good DNA preserved because it had a chance to get with it, the other is random mutations in DNA. Sometimes no changes can happen because the evolution process encounters a minimum or local minimum. (A ball getting stuck in crater midway downhill)



I think we will see healthcare costs continue to grow as a consequence of our technology reprieving evolutionary mechanisms. AIDS is a good example. (Not saying either is right or wrong) You can either spend a bunch of money to cure and prevent a disease or you can let everyone with AIDS die hoping that spreading rate is less than death rate. But apply to any other potentially genetic or culturally hereditary disease.
anonymous
2007-07-19 14:07:49 UTC
I assumed it could take leaps when necessary - like the moth that was found on birch bark in UK, but the industry around some birch trees turned dark, so the moths did too.



It isn't always clear why changes happen or what they are for - to my untrained eye that is. In the generation known as The Baby Boomers, several physical changes have occurred that are different from their parents. Almost all hold a pen in an awkard fashion - either squeezing it, or strangling it, and their fingers are flexible and often damp. (The flexible thumb is brilliant for texting.) Many of them have had their wisdom teeth removed because there wasn't room for them.



As a rule, I presume, the reason for a sudden change in anything would be obvious, but I can't think of a reason for bendy fingers or fewer teeth,
wigginsray
2007-07-19 13:53:04 UTC
My understanding of evolution is that is CAN be a continuous process, but is not guaranteed. It's really important to separate the ideas of natural selection and evolution. Natural selection is inevitable; evolution depends on near-random events to progress species development. That being said, it is possible that human activities - in particular ones that deal with radiological emission and cloning technologies - are the most likely candidates for species change.
Indiana Frenchman
2007-07-19 13:51:14 UTC
Darwin saw evolution as a slow, continuous process, without sudden jumps. However, if you study the fossils of organisms found in subsequent geological layers, you will see long intervals in which nothing changed ("equilibrium"), "punctuated" by short, revolutionary transitions, in which species became extinct and replaced by wholly new forms. Instead of a slow, continous progression, the evolution of life on Earth seems more like the life of a soldier: long periods of boredom interrupted by rare moments of terror.
Ninja Showdown
2007-07-21 13:17:32 UTC
Why did all the humans evolve the EXACT same if evolution is determined by survival of the fittest? Kind of funny how all human have all the same body parts after millions of years yet every OTHER animal evolved different from their cousin....



HMMM



Read about the founder of evolution and how he was a racist



http://www.evolutiondeceit.com/chapter3.php



Is this what we want our kids believing?
ritukiran16
2007-07-19 14:17:53 UTC
I think you should study the following site: they have answered the first 2 questions here.

http://www.geocities.com/prasarns/phylogeny.html



for the 3rd, 4th, 5th and 6th Q you should consider what is called 'Cultural Evolution' http://mitpress.mit.edu/catalog/item/default.asp?tid=9935&ttype=2



and



“What is the future of Human Evolution?”



In his gentle critique of my earlier post in this series, Larry Moran proposes one reason why people sometimes mistakingly think that “evolution has stopped for humans.” The argument goes like this. First, you believe that evolution is what we in the business call teleological. This means that evolution is going somewhere in particular, towards a logical goal or resting place, to a state of some sort of perfection or ideal. Then you find out that there is a lot of “relaxed selection” going on. Relaxed selection is when some selective force is either reduced or removed so the population previously constrained by selection is now changing only through “neutral” or “random” effects (genetic drift). So now you are thinking, “Hey, evolution was going along just fine, with Natural Selection moving our fine species along in the right direction, and now it has stopped … with that relaxed selection thing … so evolution has stopped.” If evolution is progress and the progress is stopped then evolution must have stopped. Like if you are on a train heading towards Toledo, and the train goes off the tracks, then you might say that you are no longer going to Toledo.



But evolution is not progress. Evolution is change in allele frequency over time. If anything you think about evolution does not jive with that definition than you are on thin ice.



Not only is teleology belied by this principle, but so is overall directionality. Consider the following. (Careful, this is leading to a Trick Question that your gonna love!).



The distant ancestors of humans, not long after the chimpanzee-human split, can be compared to humans in the following ways:



Ancestors had larger teeth, humans smaller teeth.

Ancestors were very small bodies, humans much larger bodied.

Ancestors had small (chimp size) brains, humans have whopping big brains.



Compared to the last common ancestor of living humans and our closest relative, the living chimps, humans have teeth that are similar in size or smaller, bodies that are larger, and brains that are larger. But among all of the post-last common ancestor fossils, we see mostly large teeth. So it is reasonable to characterize human evolution as consisting of three trends: Reduction in tooth size, increase in body size, and increase in brain size.



Now, I’m going to “show” you (with words) four Australopithecine species that stand out from the crowd of the many other Australopithecines each in it’s own way.



Species A: Small teeth, small body, small brain



Species B: Large teeth, large body, small brain,



Species C: Large teeth, small body, larger brain



Species D: Large teeth, small body, small brain



One of these four is most likely in the direct lineage (or very close to it) leading to humans. The other three are almost certainly not in the direct lineage leading towards humans. Which one is closest to our direct ancestor, and why?



Well, since you know that this is a trick question, you know you must answer D, the one that has none of the traits that seem to be “leading towards” a human ancestor. And you would be right. The small teeth, large body, and large brain in each of the other three coincidentally seem to lead in the direction of modern humans. But do you know what? At the time that these species existed, there was not any such thing as a direction towards modern humans. Only in retrospect can we see a particular series of events or trend that led to something. And these particular traits, in these particular extinct hominids, just happen to appear to prenumberate modern humans. But they don’t. Coincidence? Well, yes.



This is not an unusual situation at all. For the most part, you cannot look at a given species or set of species and make predictions about what is going to happen in the future. If you see a trend going on, you might be able to use the trend to predict the short or medium term future of a particular feature. However, since you can only do that with features that happen to be changing with a certain trend, you may fail to recognize (because you can’t see into the future) some other major, and much more important change, that has not given any indication of happening yet.



So you are watching a species change it’s body size in a certain direction for a century or so, so you figure “In the future, the thing we’re going to notice about this species it that is will be bigger.” Then a while later the species also, and you did not predict or expect this, experiences a dramatic change in it’s diet which results in a change in social structure and thus mating system, and suddenly the big story with this lineage is all about it’s secondary sexual characteristics (like big antlers or something). Oh yea, and they’re a little bigger. But you missed your big chance to predict the future because, well, you can’t do that.



Frankly, you’ll do better with the stock market than you will predicting future evolutionary changes.



Here’s the thing. If we consider the question “What is the future of human evolution?” from an evolutionary perspective, the ONLY correct answer is this one: “We don’t know.” If someone shows up at your door (or in your favorite science magazine or newspaper) with such predictions, you know that they are not addressing this question from an evolutionary perspective. They are making it up, or they are misguided, or they are trying to sell you something.



If someone tells you they want to predict the future of human evolution, consider the words of the immortal Frank Zappa:



And I said look here brother-

who you Jiving with that cosmik debris? …

Don’t you know, you could make more money as a butcher?

So, don’t waste your time on me …



How these references were a help ... you have quite bit of research to do...

Look for a book on cultural evolution



all the best



ritu
temerson
2007-07-19 13:52:35 UTC
Future evolution takes time but the way the word looks today from a scientific point of view (not a doomsdayers) we might not have much left. Hope I didn't ruin your day
NADO
2007-07-24 03:01:25 UTC
Definitely, and the major influence in our life is the expansion and color-full foods and environments that are changing constantly, and there-as we are effected by it and changed"evolved" in order to adapt and survive in our new surroundings.
Ridhima
2007-07-27 13:24:53 UTC
evolution is a continuous process but it takes place slowly.

that is why the population is growing on and becoming more and more talented.
Kurtis G
2007-07-19 13:57:06 UTC
Evolution is a theory. A theory that is in large wrong.

How many times have you seen or heard of a genetic mutation that was an improvement from what the undamaged DNA of the species produce? NONE!

Species do get better at what they do, but they don't evolve into new species.

Many new species are introduce into the world every year, usually from crossbreeding. (Lots of new insects each year.)
richard d
2007-07-19 13:57:09 UTC
genesis 1-1 in the beginning GOD CREATED THE HEAVENS AND THE EARTH, AND THE EARTH WAS WITHOUT FORM AND VOID, AND DARKNESS WAS UPON THE FACE OF THE DEEP. AND GOD DIVIDED THE WATERS FROM THE WATERS AND HE CALLED IT EARTH. AND HE SAW THAT IT WAS GOOD.



GOD AND GOD ALONE CREATED ALL THINGS AND THERE IS NONE OTHER THAT HELPED HIM TO DO IT.



ANYONE THAT BELIEVE'S THE WORLD WAS JUST A GREAT EXPLOSION IS DECIEVED BY THE DEVIL WHO WAS THE ONE WHO TOLD DARWIN TO SPREAD THIS VICIOUS DOCTRINE TO CORRUPT AND DESTROY THE WORD OF GOD. IT WILL NOT WORK.



THIS IS NOT MY OPINION THIS IS TRUTH
Fresh
2007-07-19 13:55:50 UTC
Summer school, eh?


This content was originally posted on Y! Answers, a Q&A website that shut down in 2021.
Loading...