Is evolution as simple as we think?
November 27, 2012 at 12:02 am #17088
Evolution is generally seen as a response system to the environment. For example, it gets cold so an species is selected for a thicker coat. The genes needed for this would be created by random mutations.
My question is why, if mutations are what cause these changes, there was no evolution of lifeforms for 2 billion years after blue-green algae appeared 2.6 billion years ago. Even if the physical environment was stable, would there not have been other factors such as competition that, coupled with mutation, would have formed a new kind of life form. Considering the relatively short/recent diversification of life, it seems unlikely that, following the current interpretation of evolutionary processes, that no new life forms would have formed in such a long period of time.
Sorry for the vagueness of the question, any thoughts or links to relevant papers would be appreciated.
November 27, 2012 at 12:47 am #113087jinx25Participant
‘Evolution’ never happened. Its is the greatest myth i am aware of EVER. It is utter fraud science and exists only in textbooks. We have 6,000 years of eye witness testimony
of which no one has ever observed a fish bring forth anything other than a fish. If someone wants to believe by faith that contrary to every observed law of nature in written history a fish can bring forth something other than a fish that is their own personal religion and has NO basis in science. For people at uni ask your professors for LITERATURE of a mutation adding NEW genetic information (NEW nucleotides for NEW protein), neofunctionlization is a myth for the most part but see if he gets angry or if he actually can cite something (100% can NOT).
November 27, 2012 at 1:28 am #113089
Well recorded history only reaches back as far as 4th millennium BC. Evolution requires a much longer time period. Besides even in recorded history there is evidence for evolution such as the domestication of animals. They are still the same organism, but have changed even in the this small time period.
You are welcome to your view but i didn’t create this thread to argue whether or nor evolution exists.
November 27, 2012 at 7:32 am #113091
Dayren, what do you mean by there was no evolution of organisms during that time?
As far as I understand, there has been evolution of organisms basically whenever there first was competition for resources or space to live, which would be pretty soon after life emerged (local competition would happen almost instantly on the evolutionary time scale).
However, most of the "tools of the trade" of more complex organisms were yet to evolve (such as enzymes for oxidative energy metabolism and many others), so there could not be advanced organisms for this long time. The atmosphere of that time could not support very complex life forms and it did not drive the evolution towards oxygen-based life, unlike the oxygen-rich atmosphere created by the blue-green algae did later. That is why most of the early eukaryotes appeared only after the oxygenation of the atmosphere around 2 billion years ago and this finally sped up the rate of speciation to a completely new level.
November 27, 2012 at 2:29 pm #113097
I mean that, like you said, complex organisms didn’t evolve for a long time. If there was a sudden evolution into complex life, why did it happen in the first place? Surely the simple life forms that evolved into the more complex life forms would have benefited more in terms of survival by remaining as simple organisms. And why weren’t the conditions previously suitable for complex life? Yes, today’s complex organisms could not survive in such conditions, but if evolution sees complex life as an advantage surely it would have found a way to form complex organisms suited to the harsh conditions.
November 27, 2012 at 3:23 pm #113098JackBeanParticipant
because it simply didn’t have the way to evolve into complex organism. Something had to happen.
November 27, 2012 at 4:41 pm #113101RapParticipantquote dayren:
Its a slow process – evolution HAS found a way to form complex organisms suited to harsh conditions, like Earth’s moon for example. Humans. But it takes time. Another aspect of the evolution of complex organisms is the development of sexual reproduction, which allows the existence of large long-lived complex organisms by speeding up the production of diverse genetic material beyond that provided by mutation. All of this takes time, and it took less time for oxygen-emitting organisms to terra-form the Earth and to develop sexual reproduction to evolve than it would have taken for complex mutation-dependent organisms to evolve in the harsh conditions, which might not even be possible.
November 29, 2012 at 7:39 pm #113129
dayren, you have some misconceptions about evolution. To answer your overall question, yes evolution is an incredibly simple concept. However, the details are more complex but that’s what makes it fascinating! Below, I’ve quoted a few things from your last post and responded to them.
"Surely the simple life forms that evolved into the more complex life forms would have benefited more in terms of survival by remaining as simple organisms."
Why would you think that? Anything that allows an individual to reproduce more than its competition will benefit it and lead to its evolution. In general, that means increased complexity but that is not always the case, as shown by cave-dwelling organisms that lost their eyes – they were benefited by saving the energy that went into producing and maintaining eyes that were unneeded. Hence, they had a survival advantage by losing a trait that had once been beneficial
"And why weren’t the conditions previously suitable for complex life?"
The conditions may have been suitable (I’m not a geologist or paleobiologist) but if there was no complex life with the necessary traits to take advantage of it, it doesn’t matter.
"Yes, today’s complex organisms could not survive in such conditions"
We don’t know that for sure and can never know it, since we can’t go back in time.
"but if evolution sees complex life as an advantage surely it would have found a way to form complex organisms suited to the harsh conditions."
Evolution is directionless in the present. We can look backwards in time and see a direction – e.g., from small dinosaurs without feathers to those with feathers to birds that can fly and back to lack of flight in aquatic penguins. However, we cannot predict (and neither can evolution) what traits will be beneficial in the future. If the traits weren’t available, then no organism could take advantage of the conditions.
November 30, 2012 at 8:21 am #113137quote dayren:
In many cases that is true. The most numerous organisms on the Earth are still the prokaryotes, which in many ways can be said to be "simple" organisms. So one could argue that it is the most effective form of life even in today’s world. This is especially true in harsh environments that are short of nutrients or are otherwise inhospitable. In most places, however, it was beneficial to evolve into something more complex just to gain that edge in competition. If you were a bit bigger, faster and meaner than the others, you could, for example, eat the others for lunch. Of course, not everyone can afford to be big and mean, since it requires more energy and nutrients, so there has always been room for tiny, energy-efficient and simple forms of life. The food chain looks like a pyramid largely because of the same reasons (the few apex predators forming the top).quote dayren:
Perhaps. Or perhaps not: it is also possible that with the building blocks available on the Earth, the only way to "power up" large and complex organic life forms is to use oxidative metabolism. It is possible that other methods of energy production are simply too ineffective, or if they are effective (like nuclear fission!), they cannot be utilized by cellular metabolism. So it is possible that complex life forms could only emerge after the atmosphere contained enough oxygen. Being able to utilize oxygen gave also an enormous competitive edge because oxygen was most likely toxic to early organisms relying on anaerobic metabolism, but that alone would not drive evolution towards more complex life forms – just towards a switch from anaerobic metabolism to aerobic one. But after this, the new and highly effective means of energy metabolism was available, supporting the growth of new, multicellular life forms.quote thoffnagle:
I have been under the impression that it is commonly accepted view among scientists that the Earth’s early atmosphere was a reducing one with no oxygen and thus unable to support multicellular life as we know it. That does not necessarily mean it could not have been able to support any complex life forms, but based on our current knowledge of life the only organisms that could have survived on young Earth were similar to Archaea – prokaryote life forms capable of tolerating extreme conditions and utilizing anaerobic metabolism and uncommon energy resources (that would be too ineffective for any larger organism).
Of course in science you cannot say that you "know" anything with 100% certainty, but as far as I am aware the scientist have a pretty good idea of what the conditions on the young Erath must have been (based on, for example, geological data and our knowledge of other rocky planets in our solar system etc.) and that there are no ongoing major scientific arguments concerning the key topics of our planet’s development.
December 1, 2012 at 1:14 am #113145quote dayren:
I see this again and again. Evolution is NOT a RESPONSE system. Evolution is OUTCOME or END RESULT of genetic mutation/drift + selective pressure or absence of it (diversification process). If you put a live chicken in the fridge for a long time, it will die. There is no "response to environment", mutations at will, etc. However, if you put a million (billion?) chickens in the fridge – one or two might survive (those that happened to have random required mutations that allow then to withstand the cold). Keep them and their progeny in the fridge for a long time and you get new pure breed variety.
December 1, 2012 at 1:43 am #113147RapParticipantquote Cat:
This answer makes me uncomfortable, but before I disagree, how do you distinguish a response system from an outcome system? Is there a test I can apply that will decide this question?
December 1, 2012 at 7:37 am #113151
Evolution does not respond to situations, it (through mutations) simply provides possibilities. For example, it the climate gets colder, evolution does not respond by providing fur, feathers, blubber, etc. to insulate against the cold. If there are individuals that are able to withstand the colder temperatures, they will survive better than those that can’t. If no individuals of that species can tolerate the cold,the species goes extinct.
April 28, 2013 at 3:35 pm #113747quote thoffnagle:
Exactly. Genes/alleles were always there in the gene pool. If the rest of the population would not have been eliminated by adverse conditions, the particular combination would have been rare…
May 2, 2013 at 4:02 pm #113768quote Cat:
No, they got into the gene pool via mutation. They were retained in the gene pool because they were either beneficial or neutral.
May 4, 2013 at 8:07 pm #113777quote thoffnagle:
Thanks. I will retract word "always". I meant to say "Genes/alleles were already there in the gene pool."
May 10, 2013 at 12:45 am #113797yourmotherParticipant
no, it’s not
May 20, 2013 at 2:01 pm #113833
If they are not, organism would not be able to adapt and will become extinct.
June 3, 2013 at 3:24 pm #113899animartcoParticipantquote dayren:
I think the reason that it took so long for rapid evolution to get under way was because it took ages for the simple life forms to create enough free oxygen to allow more complex forms to develop. Once they had developed they largely displaced the simple life forms, although most of them do still exist in smaller numbers.
June 6, 2013 at 3:53 pm #113913quote animartco:
I seem to have read somewhere that the simpler life forms still far outnumber and outweigh the more complex life forms. E.g., there are ten times(?) as many bacterial cells in/on your body as there are human cells that make up your body. Without all of those bacteria, we’d be screwed!
June 15, 2013 at 8:02 am #113954LuxorienParticipant
I just find the title of this thread hilarious. It would be like asking, "Is rocket science as simple as we think?!"
Admittedly, evolution is, at its heart, a deceptively simple idea, but the implications are endlessly complex and fascinating.
June 27, 2013 at 6:22 pm #114022quote Cat:
That does not mean that new genes aren’t/can’t be created through mutations and mistakes during mitosis/meiosis. A classic example is that DNA strands can break and be reattached in the wrong place causing duplication of genes or the entire genome can be duplicated erroneously. This extraneous DNA, if further modified can become an entirely new gene that provides the organism with a new trait. So, you are still not entirely correct that the "genes/alleles were already there in the gene pool." They may not have been.
June 27, 2013 at 6:28 pm #114023quote Luxorien:
You’re right about evolution being a simple concept but far more complex in practice. The simplicity of the concept and its everyday use in agriculture and animal husbandry is why it boggles my mind that people don’t believe that it happened and continues to happen.
At a scientific meeting that I attended, a speaker pointed out that the commonly used phrase, "It ain’t rocket science" really should be "it ain’t ecology." Ok, it was a more ecologically-minded conference but he made a good point. Rocket science is based on Newtonian physics that is well understood. Ecology, on the other hand, is FAR more complex and not understood anywhere nearly as well.
June 30, 2013 at 3:42 pm #114033quote thoffnagle:
You are right and wrong at the same time. Translocation and duplication take place – fact. This can result in a new trait – fact. However, we talking about the SAME (already present in the gene pool) DNA material.
"This extraneous DNA, if further modified can become an entirely new gene that provides the organism with a new trait. " – Now this part is deduced and while it makes a lot of sense, it is only theoretical. There is no direct (experimental) proof of it.
July 1, 2013 at 6:46 am #114035quote Cat:
What you say above does not make any sense. It is irrelevant whether the nucleotides were already in the gene pool – what matters is their sequence. If the sequence changes it is always new genetic material when compared to the previous "version" of the genome. Most of the time it does not cause new traits to be expressed or if it does, the change is harmful. But occasionally it can produce something that is beneficial for the organism in its current environment – which might be different from the environment for which the previous genotype was "optimized".
Furthermore, new genetic material can be (and is) introduced to the genomes constantly. Nucleotides can be deleted, added or replaced during DNA replication and if an extra nucleotide is added to the gene’s sequence it is new DNA material in all senses of the word "new", including the fact that it was never in the gene pool before. This is an observed fact and happens in all known organisms from viruses to humans.
July 1, 2013 at 4:37 pm #114036quote Cat:
Your are just wrong. There is tons of evidence. See Taylor, J.S. and J. Raes. 2004. Duplication and divergence: the evolution of new genes and old ideas. Ann. Rev. Genet. 38:615-643. This paper is nearly ten years old and only took me a minute to find! Just because you don’t want it to be true, doesn’t mean that it isn’t….
July 4, 2013 at 4:48 pm #114045quote thoffnagle:
Your quote of this paper is precisely what is wrong with science today. It has not a shred of PROFF of anything. It is simply a summary of other people CONCLUSIONS. You need to provide FACTS of direct evidence and, as far as I know, they do not exist…
July 4, 2013 at 7:10 pm #114048
I’m going to jump in here to get something clear. Cat, are you claiming that there is absolutely NO evidence for the spontaneous appearance of ANY new gene with a NOVEL function in ANY genome?
July 7, 2013 at 1:42 pm #114050quote wbla3335:
Not exactly. I am saying that there is no DIRECT, reproducible evidence of it. You can deduce "new gene" events based on archeological data. However, such conclusions are based on quite a few assumptions which are not based on any facts whatsoever…
July 7, 2013 at 5:25 pm #114052quote Cat:
Thank you for your reply, but my question required a yes or no answer. By replying with "not exactly", I still do not know what your point is. What would be direct, reproducible evidence for the spontaneous appearance of a new gene with a novel function in a genome? And how can archaeology deduce "new gene events"?
July 7, 2013 at 9:34 pm #114053quote wbla3335:
My point is that something inferred from archeological data is given same weight as direct experimental evidence and then misrepresented as fact.
To give you an example:
You are presented with a black box. You cannot see what is inside that box. Than you hear "meow, meow" coming from it… You DEDUCE that you have a cat in the box. Than you open the box and find an iPod playing "meow, meow"…
So, as you can see in this example sound reasoning does not always lead to the right conclusion.
July 8, 2013 at 2:20 am #114055
I know what deduction is. I was hoping to get an example of archaeological evidence you claim deduces "new gene events".
July 8, 2013 at 8:46 pm #114060
July 8, 2013 at 9:34 pm #114062quote Cat:
I quickly scanned through the article (having read it before) and found no reference to what you are claiming. The closest thing that could have led to your misunderstanding was the bit about lactase persistence. If this is what you think refers to the appearance of a new gene, look up definitions of "allele" and "gene", then read up on allele frequencies within populations. If there’s something else I missed, please point me to it (page, paragraph).
July 13, 2013 at 12:57 am #114082quote wbla3335:
Please, read my post carefully. I gave this reference as an example of archeological evidence in general. I did not give it as an example of new gene discovery. This article gives you good details about DNA isolation and sequencing problems that arise with old samples…
July 13, 2013 at 4:04 pm #114087quote Cat:
Nice try, Cat. I had asked for an example of archaeological evidence of "new gene events". You provided a link to an article that you claimed provided evidence of "a "new gene" gained". Please read your own posts more carefully. I hope you at least now know the difference between genes and alleles.
July 20, 2013 at 4:17 pm #114106quote wbla3335:
Saying this a few more times would not make it true. Your post only proves my point that people want to hear what they want to hear and not what is actually being said. See my original post below:quote Cat:
While you asked for archeological evidence of gene gain, I provided general reference. The gene gain would be ascertained by some other research group based on data from this research – it’s not like they are going to re-sequence it on their own. I think you are fully capable to google yourself to find what you are looking for.
P.S. I know difference between genes and alleles probably better than you do. I also know that it has nothing to do with this conversation.
July 20, 2013 at 10:29 pm #114109
That’s the best you can come up with after a week? I think I’ll let the readers of this thread judge for themselves our relative levels of denial and scientific expertise. I only jumped into this thread briefly to clarify your position for others, which I think I have accomplished. Best of luck in some day freeing yourself from those beliefs of yours.
August 12, 2013 at 11:32 am #114174animartcoParticipant
I think Biohazard has given the answer. Diversity had no need to start before the first life had spread right across the planet. Competition is the driving force of evolution, and before then there was none.
November 14, 2013 at 4:26 pm #114724bioduchampParticipantquote Cat:
i like this explanation!
June 6, 2017 at 12:33 pm #116226VladParticipant
Folks, let me to try and revive the thread. First, a question to dayren: what are the reasons to believe that “there was no evolution of lifeforms for 2 billion years after blue-green algae appeared 2.6 billion years ago”?
Second, are there reasons to believe that accidental (accidental!) mutations tend to happen in response to an environmental pressure? That is, does the probability of emergence of a chicken or two (out of million/billion of them), able to survive in the cold, depend on actual exposing a lot of chickens to low temperatures (fridge or no fridge)?
The very vision of biological evolution heavily depends on the answers to the above two questions.
July 10, 2017 at 7:51 pm #116235GeniusIsDisruptiveParticipantquote thoffnagle:
"If the traits weren’t available"?
What on EARTH is that supposed to mean?
In response to the opening post, evolution is not just AS simple as we think, it is much SIMPLER.
1. Random mutation, almost always worthless or harmful, followed by
2. *Selection*, on the rarest of occasions when the *selection* is conducive to survival and higher rates of reproduction.
Thus we see that the end result of humanity is Darwinian Islam. Muslims reproduce as if that function was their prime directive.
And then millions of them kill, or support the killing, of those not their kind. This will, they insist, take place until all humans on earth are like them.
At the other extreme, atheists have far fewer children, and when they do father them, only ~30% retain their atheist beliefs into adulthood. For a group so enamoured with their own *intellectualism* and *rationality*, atheists aren’t doing so well compared to those lovely Muslims.
Atheism – the ultimate Darwin Award Winner.
July 10, 2017 at 7:59 pm #116236GeniusIsDisruptiveParticipantquote animartco:
"No need to start." Oh please.
Semantics and wordplay are not science, not truth, not common sense.
Random mutation is THE driving force of evolution, in theory. Pray tell, what precludes random mutations in organisms?
Anyone? Anyone? Anyone?
Now as to what, precisely, blue-green algae evolved INTO, nobody has stated, but given that the new organism is supposed to be more fit, better able to survive, why then did the blue-green algae continue living to this very day? That competitive advantage obviously didn’t displace blue-green algae, or any other organism anybody can name.
Finally, a very interesting perspective on the "Tree of Life."
Darwin’s original book had only one diagram, viz., the Tree of Life.
It was unlabeled as to any names, genera, species, anything. A barren stick tree, signifying nothing.
Today, the stick tree is much bigger, more colorful. But you note that only the tips are labeled, no branches, no base.
With all the billions spent on research and after 150 years of concerted effort, is this the best biologists can do? A tree with only tips named?
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