Evolution?

[Tomk80]

This is exactly another head of the monster I am waiting for, the dynamics.

According to what you said, then there should be no extinction in between the few big events of mass extinction.

Why not? Even if there is no mass extinction, the environment is rarely stable. There are too many forces working at the same time to ever make it completely stable. Even if the environment changes slowly, adaptation is not a guarantee. Chance, you know.

Every species would have enough time to adapt minor changes. Also, there should be no speciation when the environment was stable for a couple tens of millions of years, because there would be no reason to change anything. Did the fossil record says against either of these assumptions/consequences?

That slow changes happen just as well. Change happens, can be slow or fast. Courses of rivers change over longer periods of change, mountains arise slowly, continents split apart or are pushed together. All gradual environmental changes. The Ice age didn't set in within a minute, it was a gradual process and we can see the adaptations to that arising gradually in the fossil record (in the last years excavations in the Netherlands have shed light on this regarding different human species). We see the start of grasses in the fossil records, where they have slowly taken over plains and where horses (and possibly humans) evolved to benefit from this gradual transition. Cichlid fish in Lake Victoria show an incredible amount of variability originating in just the last 14000 years. We see the arms races that are run between different species and the results of those arms races.

Again, the environment is not a stable system. Even if the changes happen slowly, they do happen continuously in various time frames all over the earth. This is not rocket science, watch a nature program!

So, what would be the next head? How about this one:

Why would any bacteria change (naturally) in the past, say, 30 years? Every type of bacterium has its niche. Have those niches changed in the past three decades? If some did, then could we correlate the changes among the bacteria and their niches? I bet we knows very little about it. We simply deal with the consequence when whatever type bacterium appeared mysteriously.

Yes, niches change. For example, we see the evolution of hemoglobin S and A in humans in reaction to malaria. Because malaria does not eradicate the whole population in one go, humans have time to slowly evolve resistance. If enough people adapt and gain some kind of resistance, the bacteria will need to adapt subsequently. We have seen the evolution of highly deadly ebola and neurenberg viruses to a less deadly variant, which enhances there capability to spread (a sick but living person can serve as a source of infection more easily than a dead person).

How would bacteria change when the earth is warming up? What kind of mutation is beneficial to lives in this type of environmental change?

We don't know how global warming will effect evolution. Probably global warming will slowly increase the habitats of tropical species. With this, animals will move quicker than plants, since they can just move to another location, while plants are dependent on the next generation. What effects this will have we cannot predict, there are too many variables in play. To what area will they move, will they fit into the habitat there, will diseases move with these organisms or stay behind, will the organisms now living in that new habitat be able to adapt quickly enough to compete with them?

How many heads I have chopped off? What's to come?

You have yet to present a cogent argument that actually shows you have ever even watched a simple nature program on television.

 

[Naraoia]

This is exactly another head of the monster I am waiting for, the dynamics.

According to what you said, then there should be no extinction in between the few big events of mass extinction. Every species would have enough time to adapt minor changes.

That's most certainly not true. Even if you disregard all environmental variables (which, as Wiccan said, never stay quite constant), you still have the organisms themselves. Mutations don't cease to happen when the crisis is gone. Creatures will still evolve, and in doing so they affect others sharing their habitat.

Who's to say you can't lose out in an evolutionary arms race? Who's to say a disease can't wipe out a rare animal? Or just weaken a population enough that it can no longer resist other pressures like predators or bad seasons? (IIRC canine distemper virus almost did wipe out black-footed ferrets, although the ferrets are a rather extreme case of "rare")

Ecological communities are complex, dynamic systems in their own right, and they won't just stay the same when you leave them alone.

Also, there should be no speciation when the environment was stable for a couple tens of millions of years, because there would be no reason to change anything.

Maybe it would be like that if there existed such a thing as an unchanging environment.

Did the fossil record says against either of these assumptions/consequences?

The fossil record, IIRC, shows a lowish background rate of extinction (which happens not to be in my ecology notes , but there is a line that says mass extinctions account for only an estimated 4% of all extinctions in earth history). I don't know how constant fossil ecosystems are, how long your average fossil fauna lasts or how much communities regarded as one fauna change from first appearance to disappearance. I do know that the geological record doesn't show much stability on a 10 Ma scale.

In the town where I study you can go down to the sea and look at some interesting cliffs at low tide (well, you can look at them any time you like, only you can't actually go near when the tide is in). At the foot of the cliff there is marine limestone with myriads of crinoid fragments (someone in a field practical even found a whole crinoid). On top of that there are flat layers of sandstone, riverbeds, traces of plant roots, worm burrows, even two thin Carboniferous coal beds (plus other stuff I don't remember from said practical). All layered neatly on top of each other. All coming from very different environments, as far as I can tell with my one-semester knowledge of geology. And I don't think it even spans the whole Carboniferous.

So, what would be the next head? How about this one:

Why would any bacteria change (naturally) in the past, say, 30 years?

Some possible reasons: viruses, big evil bacterium-eating eukaryotic predators, resistance in a yummy host organism... well, anything that just randomly happens to creatures that interact with them. Plus all the non-living things from black smokers to ponds that still keep changing even on such short time scales.

Every type of bacterium has its niche. Have those niches changed in the past three decades? If some did, then could we correlate the changes among the bacteria and their niches? I bet we knows very little about it. We simply deal with the consequence when whatever type bacterium appeared mysteriously.

Do you understand your own question? Because I don't.

How would bacteria change when the earth is warming up? What kind of mutation is beneficial to lives in this type of environmental change?

Depends. Does the warming come with less rain? Then maybe something that increases drought resistance is helpful. Does it come with more rain? Then stop wasting your resources on drought resistance and allocate more to growing. Does the warmth bring new viruses from the tropics? Find a way to avoid, or to recognise and destroy them. New competitors? Outpace them. New predators? Avoid or deter them.

You see, it's always more than one factor at work. You have to take as many as possible into account to place a bet on the success of whichever kind of mutation.

How many heads I have chopped off?

None I can see...

What's to come?

Who's to say?

 

[Nathan Poe]

This is exactly another head of the monster I am waiting for, the dynamics.

According to what you said, then there should be no extinction in between the few big events of mass extinction. Every species would have enough time to adapt minor changes. Also, there should be no speciation when the environment was stable for a couple tens of millions of years, because there would be no reason to change anything.

Nope, your forgetting there's more going on than "big events of mass extinction." What about predators? changes in climate? diminished food supply?

What about all of the above at once?

How many heads I have chopped off? What's to come?

Don't flatter yourself.

 

[juvenissun]

Bacteria are not a species; they are a domain, which contains kingdoms, which contain phyla, which contain classes, which contain orders which contain families which contain genera, which contain species, which contain strains which contain individuals. There are lots and lots of different species of bacteria.

Very good. So, could you tell me one or two "families" of bacteria?

 

[juvenissun]

Why not? Even if there is no mass extinction, the environment is rarely stable. There are too many forces working at the same time to ever make it completely stable. Even if the environment changes slowly, adaptation is not a guarantee. Chance, you know.


That slow changes happen just as well. Change happens, can be slow or fast. Courses of rivers change over longer periods of change, mountains arise slowly, continents split apart or are pushed together. All gradual environmental changes. The Ice age didn't set in within a minute, it was a gradual process and we can see the adaptations to that arising gradually in the fossil record (in the last years excavations in the Netherlands have shed light on this regarding different human species). We see the start of grasses in the fossil records, where they have slowly taken over plains and where horses (and possibly humans) evolved to benefit from this gradual transition. Cichlid fish in Lake Victoria show an incredible amount of variability originating in just the last 14000 years. We see the arms races that are run between different species and the results of those arms races.

Again, the environment is not a stable system. Even if the changes happen slowly, they do happen continuously in various time frames all over the earth. This is not rocket science, watch a nature program!


Yes, niches change. For example, we see the evolution of hemoglobin S and A in humans in reaction to malaria. Because malaria does not eradicate the whole population in one go, humans have time to slowly evolve resistance. If enough people adapt and gain some kind of resistance, the bacteria will need to adapt subsequently. We have seen the evolution of highly deadly ebola and neurenberg viruses to a less deadly variant, which enhances there capability to spread (a sick but living person can serve as a source of infection more easily than a dead person).


We don't know how global warming will effect evolution. Probably global warming will slowly increase the habitats of tropical species. With this, animals will move quicker than plants, since they can just move to another location, while plants are dependent on the next generation. What effects this will have we cannot predict, there are too many variables in play. To what area will they move, will they fit into the habitat there, will diseases move with these organisms or stay behind, will the organisms now living in that new habitat be able to adapt quickly enough to compete with them?


You have yet to present a cogent argument that actually shows you have ever even watched a simple nature program on television.

Yes, another head of evolution monster emerged: The variation of environment.

If something seemingly evolved, it was caused by the changing of environment. If something did not evolve, it was caused by the stability of environment. If something evolved fast, the environment must have changed fast. And there are A LOT, A LOT different environments, in conditions, in size of area, in distribution/association, in duration, etc. So, either a life change, or not change, there is ALWAYS a good reason for it.

So, the environment is a convenient, and is usually a perfect shield/tool, which could be used to defend/interpret virtually ANY feature of evolution. It seems that the environmental factor is used in the argument as a consequence, rather than a cause of evolution: "if a life changed this way, then the environment must have been that way."

Homo Sapients has not evolved for one million years. The environment in the past 1 Ma "must have been" very stable. Oh, yes, this species and that species evolved a lot in Miocene time. So the environment in Miocene must have been very unstable.

If you think this is what evolution relies on, you are no better than a creationist in science.

 

[juvenissun]

Who's to say you can't lose out in an evolutionary arms race? Who's to say a disease can't wipe out a rare animal? Or just weaken a population enough that it can no longer resist other pressures like predators or bad seasons? (IIRC canine distemper virus almost did wipe out black-footed ferrets, although the ferrets are a rather extreme case of "rare")

Ecological communities are complex, dynamic systems in their own right, and they won't just stay the same when you leave them alone.

Here is another monster head: Interactions among lives.

However, it seems to be a good one and I don't know how to fight it.

 

[LewisWildermuth]

Here is another monster head: Interactions among lives.

However, it seems to be a good one and I don't know how to fight it.

So your current argument against evolution is that it explains everything too well and makes too many good predictions, therefore it must be false?

Um... Okay...

Thanks, but I think I'll stick with the tree bearing good fruits, not the tree that has not born any good fruit for the last 100 years.

 

[Tomk80]

Yes, another head of evolution monster emerged: The variation of environment.

If something seemingly evolved, it was caused by the changing of environment. If something did not evolve, it was caused by the stability of environment.

Where have I ever stated that evolution ever stops?

If something evolved fast, the environment must have changed fast. And there are A LOT, A LOT different environments, in conditions, in size of area, in distribution/association, in duration, etc. So, either a life change, or not change, there is ALWAYS a good reason for it.

Life always changes, only the speed of change differs. And yes, there are good reasons for that, just as there are good reasons for my car not going 80 km/hour continuously, or there are good reasons for a fire not burning at the same intensity in all situations.

So, the environment is a convenient, and is usually a perfect shield/tool, which could be used to defend/interpret virtually ANY feature of evolution. It seems that the environmental factor is used in the argument as a consequence, rather than a cause of evolution: "if a life changed this way, then the environment must have been that way."

In that line of reasoning, still the environment is not used as a consequence. Rather, patterns are used to determine causes. Again, this is not limited to evolution, it's a line of reasoning used in any and all sciences, in all theories. Our observations show Y, which means that X has to have functioned in this and this way.

Homo Sapients has not evolved for one million years. The environment in the past 1 Ma "must have been" very stable.

Homo sapiens only arises 130.000 years ago. In the last million years we discern at least 4 morphologically distinct Homo species.

In the last 130.000 years, Homo sapiens shows morphological changes. Compared to skeletons of early modern humans, we have a more delicate skeleton. And even in the past decades we have seen new traits arising, such as resistence to different disease causing agents (HIV, malaria), smaller chances on cardiovascular diseases and the arisal of nearly unbreakable bones. The question is whether these adaptations will spread through the whole human population, which again depends on many factors. For example, the spread of HIV resistance will be dependent on our ability to fight the disease using other means.

Oh, yes, this species and that species evolved a lot in Miocene time. So the environment in Miocene must have been very unstable.

Unstable compared to what? The Miocene as a period spans around 18 million years. The evolution of homo sapiens from it's common ancestor with chimps happened in the approximately 5 million years following the miocene, during which we discern at least 15 different species, organized in at least 3 families. And that's only humans. What do you compare with what, making the statement you do above?

If you think this is what evolution relies on, you are no better than a creationist in science.

The natural world is a complex system with many factors. If you want to have a theory that explains this, you need to take that into account. This does not make a theory a multi-headed hydra, it just makes it conform to reality.

 

[Tomk80]

Here is another monster head: Interactions among lives.

However, it seems to be a good one and I don't know how to fight it.

What, you want to argue that interaction doesn't happen either, just as all other things you are wrong about?

Seriously for a minute now, do you actually think you have put forth an argument of worth during this whole thread? I'm really curious about that.

 

[Wiccan_Child]

Yes, another head of evolution monster emerged: The variation of environment.

If by 'head' you mean 'facet', sure. But these heads have always been there; you aren't chopping down a Medusa, any more than a fish floundering on the shore erodes the cliff face. Anyway, let's get busy.

If something seemingly evolved, it was caused by the changing of environment. If something did not evolve, it was caused by the stability of environment. If something evolved fast, the environment must have changed fast. And there are A LOT, A LOT different environments, in conditions, in size of area, in distribution/association, in duration, etc. So, either a life change, or not change, there is ALWAYS a good reason for it.

Life always changes (read: evolves).
The environment is never stable.
The local environment in which a proposed evolutionary path is thought to have occurred is not a wildcard: we can deduce quite reliably what the environment was, how it changed, etc.

We do not use proposed evolutionary paths to determine what the environment was: that is determined by other means. And guess what? The evidence supporting the evolutionary path and the evidence supporting the environmental change have never yielded contradictory results.

So, the environment is a convenient, and is usually a perfect shield/tool, which could be used to defend/interpret virtually ANY feature of evolution. It seems that the environmental factor is used in the argument as a consequence, rather than a cause of evolution: "if a life changed this way, then the environment must have been that way."

Homo Sapients has not evolved for one million years. The environment in the past 1 Ma "must have been" very stable. Oh, yes, this species and that species evolved a lot in Miocene time. So the environment in Miocene must have been very unstable.

If you think this is what evolution relies on, you are no better than a creationist in science.

Fortunately, evolution is supported by every field of science, not just mere biology.

 

[ChordatesLegacy]

.

So, the environment is a convenient, and is usually a perfect shield/tool, which could be used to defend/interpret virtually ANY feature of evolution. It seems that the environmental factor is used in the argument as a consequence, rather than a cause of evolution: "if a life changed this way, then the environment must have been that way."

You are so off the mark again Juvy; take the fossil insects of the Carboniferous, within which there are many vary large species, now we know from modern biology that insect size is limited by the amount of oxygen in the atmosphere, so it would be fair to surmise that the oxygen levels in the Carboniferous were higher than present day levels. From this can we make a prediction about the Carboniferous that is testable, well yes, we could predict that to have higher oxygen level, primary production , i.e. plant life must have been far greater than at present and from the fossil record this is born out.

Put a little though into what you post.

 

[Radagast]

Very good. So, could you tell me one or two "families" of bacteria?

I hope the biologists here will correct me.

Bacteria -- Thermodesulfobacteria, Spirochaetes, and other phyla

Spirochaetes -- 3 families: Brachyspiraceae, Leptospiraceae, and Spirochaetaceae

Spirochaetaceae -- Treponema pertenue (causes yaws), Treponema pallidum (causes syphilis), and others.

 

[ChordatesLegacy]

Homo Sapients has not evolved for one million years. The environment in the past 1 Ma "must have been" very stable. Oh, yes, this species and that species evolved a lot in Miocene time. So the environment in Miocene must have been very unstable.

I do not know where to start, you are wrong on so many levels.

Human evolution last 1 million years. Please note that homo sapians have only been around for ~200000 years or so? but evolution has been occuring for ~3.8 billion years.

I would NOT call this stable, as you suggest

For once Juv'y do some homework before you post, perhaps then we will take what you say seriously.

 

[juvenissun]

I would NOT call this stable, as you suggest

For once Juv'y do some homework before you post, perhaps then we will take what you say seriously.

This chart is perfect to illustrate my point. You may say the environment in the past 20 Ma was not stable. I may say it was perfectly stable.

So, basically, the stability of environment (in short term or long term) is NOT QUALIFIED to be used as a factor in evolution.

 

[Wiccan_Child]

This chart is perfect to illustrate my point. You may say the environment in the past 20 Ma was not stable. I may say it was perfectly stable.

So, basically, the stability of environment (in short term or long term) is NOT QUALIFIED to be used as a factor in evolution.

Of course it is. The evidence is in: the environment does change, and it is never stable (relatively speaking), despite your protests to the contrary.

 

[Bombila]

This chart is perfect to illustrate my point. You may say the environment in the past 20 Ma was not stable. I may say it was perfectly stable.

So, basically, the stability of environment (in short term or long term) is NOT QUALIFIED to be used as a factor in evolution.

Good grief, do you think that chart represents summers and winters?

 

[Tomk80]

This chart is perfect to illustrate my point. You may say the environment in the past 20 Ma was not stable. I may say it was perfectly stable.

So, basically, the stability of environment (in short term or long term) is NOT QUALIFIED to be used as a factor in evolution.

Because changes in temperature never influence an ecosystem.

Juvenissun, can you actually try to make an argument that doesn't ignore data?

 

[juvenissun]

Because changes in temperature never influence an ecosystem.

Juvenissun, can you actually try to make an argument that doesn't ignore data?

How much data? May be you are looking at 100, and I am looking at 10,000. That would make big difference.

 

[juvenissun]

Of course it is. The evidence is in: the environment does change, and it is never stable (relatively speaking), despite your protests to the contrary.

Ha ha .. You hit yourself on the foot.

 

[juvenissun]

I hope the biologists here will correct me.

Bacteria -- Thermodesulfobacteria, Spirochaetes, and other phyla

Spirochaetes -- 3 families: Brachyspiraceae, Leptospiraceae, and Spirochaetaceae

Spirochaetaceae -- Treponema pertenue (causes yaws), Treponema pallidum (causes syphilis), and others.

Oh, that is what the class you are talking about. Yes, biologist will disagree with you.

Among 50+ chicken I raised in my yard, I can classify them in to "classes" too.