Why do fossil records only show one-directional evolution when the earth returns to more primitive s

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posted on Jul, 30 2012 @ 05:40 AM
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I initially asked this question concerning information presented in this posting. This tread discusses the fact that grizzly bears split from polar bears four to five million years ago; but, polar bears are now cross-breeding with grizzlies, as they are pushed further south due to loss of habitat.

Considering the fact that it appears that these two species are evolving to a more primitive state, or devolving, my question is simple: If the earth has been in and out of ice ages and warming periods for millions of years, why is this trend not evident in the fossil records of millions of other species? I have no agenda (religious or otherwise). I just find it odd that organisms do not return to a former form as the earth reverts to a more primitive state. It appears to make too much sense that this should happen, for it not to have occurred over and over again in history.

There have been a few other threads started that are relative to this topic, but have had little response. The concept of backwards evolution, or devolution, seems to be a rather taboo subject in the biological world. This Wikipedia (I know...Wikipedia) discusses it some, but with no real answers. A very few species are cited that possibly did return to a less complex state, but nothing near as complex as a mammal. The article also mentions


Dollo's law, which states that evolution is not reversible.


The climate change that we are currently facing does not sound nearly as devastating as some of the impact, eruption, and ice age events that earth has experienced in the past. If these bears are reverting to a former state, what is so different this time, that we have not seen this before?




posted on Jul, 30 2012 @ 05:55 AM
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I think of evolution as a sort of boiling pot.

The hottest parts are representative of areas where evolution progresses. Either due to intelligence, culture or even simple adaptation to it's current environment.

The coldest parts would be where evolution is slower. Less danger, less requirement to adapt. Less environmental change. etc.

We see many different examples of fossils from all periods of life as far as we can extract and examine. It's not all one-direction.

Whales are examples of aquatic life entering the domain of land, and then going back to water. For all intent and purpose, a whale or a dolphin, are structurally similar to mammals like us. Yet they're swimmin with teh fishes!!

If you have the chance to add onto every century of your own civilisation, it would be a veritable tower.

Same with organic life.. if it's given free range to evolve unhindered, you get more complex life.

If you're SOOL then you stay micro, or simple.. no eyes, and huge nose hairs for example !

*Waves at uncle Geoffrey.. ''Hi!!'' *
edit on 30-7-2012 by mainidh because: (no reason given)



posted on Jul, 30 2012 @ 05:59 AM
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I am no expert on evolusion, or its reversal, but I shall throw in my pennies worth.
From my understanding, evolusion occurs for different reasons.
1) the environment that an animal lives in changes, and the ways an animal adapts to its new environment causes an evolusionary change.
2) a minor change genetically may give an animal a strength above others around it, which makes it a stronger choice when it comes to choosing a mating partner, meaning the change in the animal is spread to more offspring.

I dont think the mating between the 2 breedsof bear can be classed as backwards evolving. It is purely a change to the polar bears environment, causing it to act differently, causing different mating habits.

I once pondered over human evolution, with the following question...
Autism is becoming more widespread, so could this be the next step in the human evolution process?
My conclusion was that autism has always been around, but labelled differently, and more specialists are placinf more people into the autistic spectrum for a bigger varietu of reasons, and in the past, has been mis-diagnosed.
If autusm was a step in evolution, you could class that as a backward step, but on deeper thought, is it?
Some with autusm have a greater use of their brain than most people, and this could be a way of nature stopping us from further harming the planet. I choose to go with mis-diagnosis, and that its not evolution.



posted on Jul, 30 2012 @ 07:20 AM
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Originally posted by supertrot
I initially asked this question concerning information presented in this posting. This tread discusses the fact that grizzly bears split from polar bears four to five million years ago; but, polar bears are now cross-breeding with grizzlies, as they are pushed further south due to loss of habitat.

Not quite. They are different colours of basically the same species. A bit like White European and Black African humans.


Considering the fact that it appears that these two species are evolving to a more primitive state, or devolving, my question is simple: If the earth has been in and out of ice ages and warming periods for millions of years, why is this trend not evident in the fossil records of millions of other species? I have no agenda (religious or otherwise). I just find it odd that organisms do not return to a former form as the earth reverts to a more primitive state. It appears to make too much sense that this should happen, for it not to have occurred over and over again in history.

A completely wrong conjecture base on a completely wrong analysis of the bears.


There have been a few other threads started that are relative to this topic, but have had little response. The concept of backwards evolution, or devolution, seems to be a rather taboo subject in the biological world. This Wikipedia (I know...Wikipedia) discusses it some, but with no real answers. A very few species are cited that possibly did return to a less complex state, but nothing near as complex as a mammal. The article also mentions

Ok so where are you going with this.......Is this another anti evolution thread in disguise?



posted on Jul, 30 2012 @ 07:54 AM
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The animal or human is a constantly changing lifeform whether we feel it happening or not. The cells of every organism is going to alter its make up to coincide with the enviroment that it resides in. if that enviroment changes, so will the organism.

Do not think of it as de-evolution, think of it as one orgnaism changing to better survive the enviroment it is forced to live in.

Example: You live in Florida all of your life so you are used to that enviroment and climate. As a result your hair is thinner and likely takes a while to grow in a full beard on average.

Then you move to Canada or Alaska where its colder...as a result your body will grow thicker hair faster than before so that the body can stay warmer and retain more heat.

The end result? You now have hairy arms, back, legs, and face with hair that grows faster because you changed the enviroment in which you live. A subtle change but one you can notice if paying attention.



posted on Jul, 30 2012 @ 07:59 AM
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Could we please refrain from using the term "de-evolution"? It is a term that doesn't make sense, unless you don't get evolution.
edit on 30/7/12 by Thain Esh Kelch because: (no reason given)



posted on Jul, 30 2012 @ 08:13 AM
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Originally posted by supertrot
I initially asked this question concerning information presented in this posting. This tread discusses the fact that grizzly bears split from polar bears four to five million years ago; but, polar bears are now cross-breeding with grizzlies, as they are pushed further south due to loss of habitat.

Considering the fact that it appears that these two species are evolving to a more primitive state, or devolving, my question is simple:


Your premise for your question is incorrect. Polar bears are not "de-evolving", they are adapting to the new circumstance and have found a way to pass on their genetics. Those hybrid genetics will be different, but more capable of survival in the altered environment than the sea ice dependent pure polar bears. They are not de-evolving, they are adapting, and in fact, in circumstances like this: where one branch in a species interbreeds with another because of complex environmental pressures to produce hybrids, is an avenue FOR further evolution. Evolution is not a linear line, it is a series of multiple movements down infinite paths of least resistance; these paths often circle on themselves as the environment changes.


Originally posted by supertrot
If the earth has been in and out of ice ages and warming periods for millions of years, why is this trend not evident in the fossil records of millions of other species?


First of all the entire fossil record in its entirety cannot give us a definitive picture of the evolution of any species. We have more information on some than others, but we are guessing on ancestry based on finite aspects of morphology that seem to carry through, like teeth for example; but it is still a guess. The fossil record, in terms of evolution, is like looking at one square inch of a 100,000 square inch picture. You don't even know really what the picture is, or where your little square is.


Originally posted by supertrot
The concept of backwards evolution, or devolution, seems to be a rather taboo subject in the biological world.


Well yes, I suppose, because by and large it doesn't exist. Evolution is a series of genetic accidents responding to environmental pressures, this includes the process of hybridization. Any animal that can cross breed shares a common ancestor, but they have evolved since leaving this common ancestor, and so when/if they come together again, the offspring present something different yet again from that shared ancestor, and environmental pressures will continue to act upon the descendants of those hybridized offspring to produce something even more different.


Originally posted by supertrot
A very few species are cited that possibly did return to a less complex state, but nothing near as complex as a mammal.


Dinosaurs were pretty complex, many just as complex as any mammal; some more so. There are alot of factors that influence complexity, and we are finding that many of the species that came before us were far more complex than we had originally given them credit for.

Besides, a less complex state is not de-evolution. It is simply a more survivable series of traits for the species, at that moment. Also, polar bears and grizzlies interbreeding is not a less complex state, it arguably a more complex one. Polar bears are highly specialized, and grizzlies are wide ranging opportunistic omnivores that can survive in a greater range of environments, you bring that together, and you may get something very complex indeed.


Originally posted by supertrot
Dollo's law, which states that evolution is not reversible.

It is not.


Originally posted by supertrot
The climate change that we are currently facing does not sound nearly as devastating as some of the impact, eruption, and ice age events that earth has experienced in the past. If these bears are reverting to a former state, what is so different this time, that we have not seen this before?


As far as ELE impact events (like the one that brought about the end of the dinosaurs)... These events create a clean slate. They wipe out most of the flora and fauna, and things can basically evolve will nilly as most of the niches are wide open, which is a large part of why mammals are so complex. The things you mentioned may or may not comparable to our current climate change event. At this point, we really don't know.

I think you are stuck on the word de-evolve. In an evolutionary setting de-evolving would mean losing traits that help a species with survival, complexity isn't really the issue.
edit on 30-7-2012 by redhorse because: (no reason given)
edit on 30-7-2012 by redhorse because: (no reason given)
edit on 30-7-2012 by redhorse because: (no reason given)



posted on Jul, 30 2012 @ 09:09 AM
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reply to post by yorkshirelad
 





Ok so where are you going with this.......Is this another anti evolution thread in disguise?


I already said that I did not have a hidden agenda. I have no desire to play those kind of games. I am simply seeking answers to a question. I accept evolution as fact, as the evidence is everywhere. And no, I am not trying to push any type of religion.

The more I read about the bears, the more that example is falling apart. Some information says that grizzlies split from polar bears 4-5 million years ago; Other sources claim that polar bears split from brown bears a couple hundred thousand years ago. Climate change is still pushing them back together, possibly to an environment and diet similar to their ancestors.

Though the bear example is losing momentum, my initial curiosity still remains. It would seem that with multiple global upheavals that it would be advantageous for a species to revert to an earlier form--a form similar to that they took in the similar environment before.



posted on Jul, 30 2012 @ 09:15 AM
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reply to post by Thain Esh Kelch
 


The more I read the more realize that that devolution is a bad choice of terminology. I did not realize that that word is widely used by nut-bag fanatics. A better phrase would be "decreasing complexity by losing previously gained traits."
edit on 30-7-2012 by supertrot because: (no reason given)



posted on Jul, 30 2012 @ 10:38 AM
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reply to post by supertrot
 


The earth been in an ice age for the past 2.5 million years, in which the temperature has gone up and down globally. This is after the bears split into 2 separate groups. Evolution does not have to increase complexity. All it does is move toward the direction of the environment. There have been many extinctions as a result of the glacial periods during the ice age, the most notable ones were human ancestors like Neanderthal. At one point there were several species of hominid that lived together on the earth and interbred. The only thing is, interbreeding increases genetic diversity, it doesn't reduce it or somehow go back to the way it use to be. Neanderthals are a good example. They left Africa around 300-400 thousand years ago and adapted to the cooler environment. When Neanderthals and humans met back up around 80,000 years ago they bred and shared genes and is part of the reason the human race is so genetically diverse. Maybe in a million years or so polar bears and grizzlies won't exist. There will only be Pizzly bears, which are the left overs from polars breeding with grizzlies. I think this happens much more than we realize and is a bigger factor in evolution than we once thought.
edit on 30-7-2012 by Barcs because: (no reason given)



posted on Jul, 30 2012 @ 12:43 PM
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If evolution is true, then why would we still have the need for monkies or apes? Haven't we evolved past their requirement?



posted on Jul, 30 2012 @ 12:49 PM
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reply to post by DOLCOTT
 


1) That's like asking "Why are there still Africans if we came from Africa?"
2) Evolution doesn't have an end goal for all lifeforms to aim for, evolution ensures that lifeforms are fit for their environment. Apes were doing just fine until the last 100 years or so when we started scorching the earth.



posted on Jul, 30 2012 @ 12:59 PM
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reply to post by supertrot
 


The difference is that the climate changes that normally take thousands of years now happened over the course of less than 30 years.



posted on Aug, 2 2012 @ 07:59 AM
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reply to post by supertrot
 




The concept of backwards evolution, or devolution, seems to be a rather taboo subject in the biological world.


It isn't a taboo subject; its a nonsense subject. Evolution is about change over time, not about 'advancing to some ideal. There is no goal, there is only what works. If a change occurs that allows a creature to breed better than its fellows, then that change is perpetuated. If in the future, some environmental pressure causes that change to become a detriment instead of an advantage, it will disappear or at least go inactive in future generations. That is not 'devolution', it is continual change. The individuals that can produce the most successful offspring pass their genes on, the others don't. Simple as that.

If Grizzlies and Polar Bears are cross breeding, they weren't really two species in the first place (although definition doesn't really have any meaning to a biologist anymore either). If they were one population that split in two, and now they are coming together again, it isn't devolution either, it is just migration.



posted on Aug, 2 2012 @ 08:16 AM
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reply to post by DOLCOTT
 




If evolution is true, then why would we still have the need for monkies or apes? Haven't we evolved past their requirement?


What do 'our' evolutionary requirements have to do with 'their' existence?

Organisms change over time; Evolution is the study of that change. Evolution is true in the sense and to the extent that it meaningfully describes that change process.

Just because we evolved ways to deal with a wide range of habitat and are able to spread out across the planet doesn't mean that that is the only possible response to the problem of passing genes to future generations.

Humans evolved in parallel with Monkeys and Apes; we did not descend from them; we did not 'require' their existence for our emergence. Our evolutionary paths endowed us with different physical traits and different survival mechanisms, that's all.

We haven't evolved "past them"; we have evolved differently to them. We haven't reached a goal before them; there is no goal to reach other than passing genes on to future generations.
edit on 2/8/2012 by rnaa because: (no reason given)
edit on 2/8/2012 by rnaa because: (no reason given)



posted on Aug, 2 2012 @ 12:31 PM
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Originally posted by DOLCOTT
If evolution is true, then why would we still have the need for monkies or apes? Haven't we evolved past their requirement?

where did you get the idea that there is a "requirement" for anything? evolution is not a ladder.
also, we are apes.



posted on Aug, 2 2012 @ 12:57 PM
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Originally posted by Thain Esh Kelch
Could we please refrain from using the term "de-evolution"? It is a term that doesn't make sense, unless you don't get evolution.
edit on 30/7/12 by Thain Esh Kelch because: (no reason given)


Its just a play on evolution and devolving.. de-evolution. Its pretty easy to figure out what they are implying or speaking about.



posted on Aug, 2 2012 @ 01:21 PM
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reply to post by Advantage
 


"Devolving", if such a term was even applicable, would be when a mutation occurs in offspring that isn't favourable to survival and causes that particular line to terminate. Evolution isn't about "higher" and "lower" levels of adaptation, you either adapt to your environment or you do not. If it transpired many years from now that Man's exceptional cognitive capacities were in fact superfluous to requirements and a needless waste of energy, then evolving to lose that capacity and increase survival would not be "devolution", it would still be evolution.
edit on 2-8-2012 by john_bmth because: (no reason given)



posted on Aug, 2 2012 @ 01:23 PM
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If evolution is a species changing to keep up with the environment isnt it still evolution if a trait or feature is lost? Using the Alaska and Florida example, if you moved back to Florida and your hair thinned back to original thats evolution and adaptability at work. Even tho you are going back to the way something was in the past you are still evolving.


 
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posted on Aug, 2 2012 @ 01:28 PM
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reply to post by ElOsoDurmiendo
 


Correct. A lot of people get tripped up on this particular point: they think that evolution is about an upwards progression to some "end goal", i.e. given enough time, pigs will evolve to mankind's level of intellect and beyond because that's the "goal" of evolution, or that less intelligent and complex lifeforms are somehow "lower down" on the evolutionary scale. Of course, this is not the case at all.





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