My husband was asking me tonight about why things have stopped evolving.
If humans evolved from a single celled organism out of the ocean, why haven’t we found anything else in different phases of evolution?
Or, if we came from apes, why haven’t we seen once of them evolve?
What set the standards for this to just stop?
I mean they show us charts on how humans looked thousands of years ago,and how things progress but you don’t see people going through those changes now.
Now, I am not trying to start a debate with this, I just want some thoughts and I know how easy this can turn ugly. I am not a debater, and I normally stay out of the pit, and would love to hear what you have to say.
Every living species is evolving. Stick around for another 100,000 years (for large animals) and you’ll see it in action. If you’re in a hurry, you can see bacteria evolve in a much shorter timespan (years, if not months).
Arjuna34
If you watch somebody roll dice for half a second and don’t see them roll a 6, do you assume that it’s impossible for a 6 to be rolled? Evolution happens very slowly, and yet we have seen examples of it during our short time of paying attention. Given more time, we will see more.
Ok, this is my first post, so I figured I’d start with an easy one. You said that you have seen pictures of how people looked thousands of years ago; try millions. On an outwardly visible level, mankind has progressed very very little in the past few thousand years. Evolution is a very slow process when compared to human life span, or even the span of civilizations in general. Asking why we havn’t seen any changes is like asking why you haven’t noticed the continents moving in the past few years.
There is an article somewhere in the archives that deals with evolution, and I beleive it states that there is evidence of micro-evolution today. Search through there, maybe Cecil has already tackled this question for you. I belveive the article had something to do with creationism.
Again, if I’m in error on any of my facts here, feel free to correct me. (Like I needed to give anyone permission…)
Okay, I understand that it would take a looooong time, but shouldn’t there be humans still comming out of the ocean and in different forms?
It can’t be like “well, we have human A and human B over here, so nobody else can come out and they are the one to reproduce and eventually evolve.”
By using the ocean I am not saying that I believe that is where life started, I am just using for simplicity on my part. Sticking with one mode of thought so to speak.
There are some folks on the board who work in genetics and will probably be able to provide a muhc better answer but then they might not spot this or whatever:
Anyhow that being said, I read some time back that there is a long term project going on (it has to be long term) which is basically a group of geneticists who are tracking DNA drift in order to mark the rate of evolution. Of course you can only get a sample every generation so it will be decades and maybe centuries before they see anything inarguably conclusive but the crux of it is that we are constantly (constant as in with each generation not each person undergoing changes in his/her lifetime) mutating and finding new ways to be alive and thus evolving. The purpose of this data collection is a bit vague to me as it seems a collecting of information for the sake of collecting information but there has been some speculation as to what could be done with such data.
You could determine which traits are becoming predominant in the specis. You could track potential developments. Because you are collecting DNA samples methodically and from specific people and descendants of those people you can more accurately map the DNA and learn or hope to learn what does what. Tons od stuff more that is way over my head (actually all of it is but I still think it’s neat).
Meanwhile they are doing much the same thing with various animals and insects to see much the same thing as well as to determine what can be done to stimulate evolution (if it can be stimulated). Sinch you can get away with doing a lot of shit to a carp that you can’t do to a people. This bit of reasearch kinda creeps me out because it seems like they are learning how to manipulate as well as track evolution but then, like I said, it’s over my head.
not really, evolution happens on a species wide basis. essentially you have species A which then mutates into species B. If species B is better suited to survive than species A, it eventually takes over, thus eliminating species A. Now its a LOT more complicated than that. I’m sure there are factors such as crossbreading that would spread the genes throughout the species.
Since mankind has evolved so much that we can now adapt technologies to make us better suited to survive, we may have hit something of a stopping point in our evolutionary process. Since we no longer need to develop natural ways to overcome nature and survive, there would be nothing to insure that these mutations are spread throughout our species. I’ve not heard any scientific data to support this, but it does seem to have a certain logic to it.
If you want to see THAT dramatic an evolution (from ocean-based life to humanoid) you’ll have to wait much longer than 100,000 years - try 50 to 100 million years at least. For all we know a new species of dolphin is about to branch out and become a land animal … but it would take tens of millions of years, so we’re not going to see much evidence of it.
Remember that evolutionary changes are the result of many, many tiny changes that gradually occur over huge periods of time. The best way to see evolution in action is to watch bacteria evolve. Since they reproduce so much quicker than humans, they evolve much faster also.
Arjuna34
Don’t geneticists use fruit flies in experiments because they can watch how they evolve? IIRC, fruit flies reproduce so quickly that a genetic mutation can easily be traced through sucessive generations within a short period of time. That is: you can blast a population of fruit flies with a billion rems, go away, come back in a couple of weeks and see if the grandchildren or great grandchildren of the original population have 2 heads, or 13 wings, or have all their legs on backwards…
Is that correct, or am I mis-remembering? If I’m correct in thinking this, that would be an example of being able to see evolution in action…
As for why we’re not seeing humans evolving (aside from the time factor), it’s entirely possible that human evolution has slowed WAAAAAAAYY down due to the fact that we now force the world to fit our convenience, rather than the other way around…
I wouldn’t count blasting fruit flies with radiation as evolution, since we’re forcing it to happen 
BTW, as Cecil discussed, humans are still evolving.
Arjuna34
You’re correct. Fruit flies and certain plants were used by one of the first geneticists, whose name escapes me at the moment. He discoverd that some traits are dominant and others recessive.
Bacteria are much more useful than fruitflies, because they go through dozens (if not hundreds or thousands) of generations per day.
True… but it’s essentially forced evolution, so I thought it an appropriate illustration.
Also true… but isn’t it possible that we have slowed it down? After all, hairy people don’t have an evolutionary advantage in a cold when the non-hairy people can simply beat something that is hairy over the head with a rock and steal its hair! Seems to me that if evolution is to take place at normal speed (whatever that speed is), then the good genetic mutations must have a clear advantage over the members of the population who do not have that mutation.
oops… that should have been “in a cold CLIMATE”
Damn!
There can’t be any “new” humans. Human beings all belong to the same species because we all share a human ancestor. Anything that will “come out of the ocean” cannot, by definition, be human.
Are you saying that new species just suddenly appear from the place where life started? This is not the case. New species come (in many cases) from separated populations of an existing species.
The answer to the OP is that, like others have said, things have not stopped evolving.
So, I work with fruit flies, and I am mutagenizing them tomorrow (with a chemical called ethyl methonyl sulfonate). Fruit fly generation time is 10 days (at least for D. melanogaster at 25 deg centigrade). We cannot regularly see evolution, because conditions in our lab do not change often enough. We also control to prevent genetic instability.
In the wild, however, and I will have to dig up the cites, certain Drosophila populations have been shown to have speciated over a decade or so. This happened when a population was split by a geographical boundary and each half inbred for a long time. After about a decade, IIRC, the populations did not maintain viable interbreeding capability. This is usually do to things like chromosomal rearrangement and transposon/retrotransposon insertions.
One good example for fruit flies is the Hawaiian kipukas (sp?). These are little canyons that have been divided by lava flows. Each one has its own little population that is slightly different from the one next to it. You can trace various characteristics through the different populations and see how they have evolved.
One other point regarding why we don’t see “new humans” evolving: our ancestors faced a very different environment than our current relatives do. In a nutshell, the human niche is already filled, and it would be very difficult for another species to outcompete us and take it over.
I think of flying squirrels as an example of a species that is still evolving. Okay, so all species are still evolving, but flying squirrels are an example with some overt indicators that I can use.
Lots of species today are capable of true flight. Flying squirrels are not one of them. They simply glide from tree to tree. Birds, bats, wasps, and the like are capable of true flight. Were there ancestors? I don’t know about the cases of bat and flying insect ancestors, but there is a lot of good evidence that birds have ancestors that could not - truly - fly. They probably began as a leaping species, and then some developed membranous attachments to their arms, which could extend leaps through gliding.
Sound familiar? Who is to say that a flying squirrel (or a flying falanger, or whatever) isn’t simply a step on the extremely long “evolutionary ladder” between a ground squirrel and the “true-flying squirrel” of the far future? I mean, no one knows where evolution is going, precisely because it takes so long to show any obvious changes. That’s why I like to pick “halfway creatures” - creatures which seem outwardly like a combination of two other - to show how it might be in effect.
The lungfish is another example. Are there no fish coming out of the water to settle on lend? Some do it every day. Their life-cycle doesn’t change, not in the amount of time that the science of biology has existed, anyway. But their adaptations are still absolutely fascinating.
If we hadn’t discovered the lungfish, and some kid made up the idea, people would say “Pish-posh! A fish that just “grew” lungs one day, and can sit on rocks for hours without its gills emersed in water? File that next to unicorns and dancing snowmen!” The point is, we accept the lungfish as a fact because we’ve seen it. Now we have to accept that there are other facts that we can’t see.
I have heard (though I do not recall the source), that human genes contain code that is no longer used (and most animal life forms do), like code for scales and gills.
What actually constitutes evolution? If the code is already there, tried and true, yet not normally used, when it is used, would that be considered evolution or is it just specialization (which occurs within generations and is obvious (example: hair color change after climate/habitat change) rather than millions of years and is inconsistent (example: cold blooded life form laying egg containing a warm blooded life form)).
I am still skeptical about evolution (even after college biology classes), since it appears to break a number of physical laws, which should apply to life forms as well since they are made of the same atoms…
Edge
(Please only responds constructively, beliefs do not prove anything, scientific facts do.)
Evolution can happen in a short period of time, but you need a small population and you have to be in right place to see it. The best recent example is Rockeye salmon in Lake Washington. In the 1930s, there was one distinct species, but now there are two. Evolution in 12 to 14 generations. Not bad.
http://www.futureframe.de/news/001023-2.htm
And don’t forget, current theory is that if you’re well suited to a stable environment, then there is no no real pressure to evolve. Some fossil species hung on for 10s of millions of years with virtually no change, so the relative stability of humans over the last couple of years is no big surprise.
This question is like asking “Why did my fingernails not grow today?”
[sub]Well, if your fingernails took a billion years to grow, it would[sub]