Just ONE question on evolution

I think the easiest way to grasp evolution is still Darwin's original theory. It's just two observations and a postulate.

Observation one; organisms produce more offspring than can be supported by the environment. That might not sound right to you, but if you look into it, you'll find it's accurate.

Observation two; all organisms exhibit variations from each other which can be passed to offspring. All right, some things clone themselves, but that's a refinement of the observation, it doesn't obviate it.

Postulate; over time, those variations which tend to increase survival and reproduction rates will come to dominate a given population.

That's it. Everything else stems from that.

Originally posted by Astyanax
I would not necessarily come to this conclusion. The incidence of carcinogens and other dangerous substances in urban environments has been high since Roman times at least, and almost certainly earlier. Indeed, some mediaeval and early modern environments were probably more toxic than their equivalents today. People cooked in lead pots, ate mercury to cure their diseases and did all kinds of crazy things.

The low incidence of cancer in former times is more likely to do with the fact that cancer is mainly a disease of late maturity and old age, and until fairly recently most people did not live long enough to experience it.

Or simply that people back in those days didn't know what cancer was and could only describe such diseases as witchcraft. Also, while we have the capabilities to detect cancer in the body, such as those that would develop in the intestines and kidney for eating and drinking lead, mercury, etc, while those that lived back then couldn't and thus didn't document it. Doing autopsies is a fairly new thing.

Originally posted by jiggerj
Evolution has yet to be describe to me in a way that sticks in my head. Can someone explain IN LAYMAN'S TERMS what I am about to ask.

In evolution I would expect to find many samples of a species with gradual changes that has taken place over millions of years. In the image below, there are three skulls of Australopithecus afarensis (that I manipulated). The first specimen lived 3 million years ago (I don't know the exact years, so I just wrote 3 million). This one has a very bony brow.

The second one lived 2 million years ago. Through the process of evolution, as this species moved closer and closer to becoming human, I would expect to find subtle differences, but this creature would still be called Australopithecus afarensis, only with a less severe bony brow.

Then the one that lived only a million years ago I would expect to find the bony brow gone, but still considered Australopithecus afarensis.

Is this, in fact, what science is finding? Because if we aren't finding subtle differences in any given species, how can it be considered evolution?

How can these identical (in every way) skulls be millions of years apart.
Look at the white bits connecting theactual remains - completely identical, the teeth are identical as well.
One skull photographed 3 times and labelled as coming from 3 different periods in time.
My opinion - epic fail.

Originally posted by rnaa
reply to post by jiggerj

 

Huh? You make it sound like each moth CHOSE the safest environment. Is that possible?

Did you miss the part where I explained that the magpie found the white and brown moths easier in the forest?
Did you miss the part where I explained that the magpie found the black and brown moths easier in the glacier?
Did you miss the part where I explained that the magpie found the white and black moths easier in the muddy pond?

This means that the magpie was able to eat the white and brown moths in the forest easily, but the black moths were left (mostly) alone, and thus able to reproduce consistently with other black moths. Likewise with the brown moths at the pond, and the white moths at the glacier.

The individuals didn't choose the 'safe' environment, they just wandered around and went where ever they went. When the magpie showed up the individuals that were in the 'safe' environment survived better than the individuals that were in the non-safe environment. No proactive choice is involved just chance.

Even after the magpie shows up, some 'wrong' colored moths will wander to the other micro environments, and they will be easily picked off by the magpie. Those that for some reason have a gene that keeps them on their 'home' turf will tend to survive and pass that gene on to their offspring. So over just a few generations, natural selection will weed out that part of each sub-population that wants to continue to wander around and reward those who stay put.

That is what is called 'natural selection'.

Ya know, it's really starting to P me off when people accuse others of missing something when in fact, it's YOU that missed a point. If the magpie DIDN'T eat the black and white moths it's because they were camouflaged against a white and/or black background. But in order for these moths to stay safe they have to REMAIN in their safe environments. How would moths KNOW to do this??? Do each and every one of them think: "I am a white moth, so I better not fly to an area that isn't white." "I am a black moth, so I better stay in a black environment so magpies can't see me and eat me."

Of course they can't think. So, how come they don't simply fly away and get eaten?

Originally posted by Sailor Sam

Originally posted by jiggerj
Evolution has yet to be describe to me in a way that sticks in my head. Can someone explain IN LAYMAN'S TERMS what I am about to ask.

In evolution I would expect to find many samples of a species with gradual changes that has taken place over millions of years. In the image below, there are three skulls of Australopithecus afarensis (that I manipulated). The first specimen lived 3 million years ago (I don't know the exact years, so I just wrote 3 million). This one has a very bony brow.

The second one lived 2 million years ago. Through the process of evolution, as this species moved closer and closer to becoming human, I would expect to find subtle differences, but this creature would still be called Australopithecus afarensis, only with a less severe bony brow.

Then the one that lived only a million years ago I would expect to find the bony brow gone, but still considered Australopithecus afarensis.

Is this, in fact, what science is finding? Because if we aren't finding subtle differences in any given species, how can it be considered evolution?

How can these identical (in every way) skulls be millions of years apart.
Look at the white bits connecting theactual remains - completely identical, the teeth are identical as well.
One skull photographed 3 times and labelled as coming from 3 different periods in time.
My opinion - epic fail.

Holy crap! That's good. Epic fail. No reason for you to return here. Wow!

Originally posted by Astyanax

Species don't turn into other species overnight.

That's exactly my point. But it seems that what we're seeing is how one species suddenly dies off and a new species suddenly appears around the same time. We're not seeing gradual changes within a specific species. And, that bothers me.

reply to post by jiggerj

That's exactly my point. But it seems that what we're seeing is how one species suddenly dies off and a new species suddenly appears around the same time.

Care to give me an example of this situation where one species suddenly dies off and another suddenly appears?

reply to post by jiggerj


But it is NOT sudden. IT is gradual. We do not have fossilized (or actual remains) for every generation of these creatures. We are bloody lucky that we have any remains to be fair, as having remains survive that long is good luck, rather than to be expected.

So I will ask again, are you even willing to be convinced about evolution? I know my mind is open to alternatives, if people are willing to be polite, and show evidence.

Originally posted by Noinden
reply to post by jiggerj

 

But it is NOT sudden. IT is gradual. We do not have fossilized (or actual remains) for every generation of these creatures. We are bloody lucky that we have any remains to be fair, as having remains survive that long is good luck, rather than to be expected.

So I will ask again, are you even willing to be convinced about evolution? I know my mind is open to alternatives, if people are willing to be polite, and show evidence.

Oh no, I do believe in some form of evolution. I'm just not informed enough to understand it all. Doubt I ever will be. But, that shouldn't stop people from asking questions.

reply to post by jiggerj

Ya know, it's really starting to P me off when people accuse others of missing something when in fact, it's YOU that missed a point.

I didn't mean to offend, I was just trying to draw attention to the part of my comment that answered your question.

If the magpie DIDN'T eat the black and white moths it's because they were camouflaged against a white and/or black background. But in order for these moths to stay safe they have to REMAIN in their safe environments. How would moths KNOW to do this??? Do each and every one of them think: "I am a white moth, so I better not fly to an area that isn't white." "I am a black moth, so I better stay in a black environment so magpies can't see me and eat me."

Of course they can't think. So, how come they don't simply fly away and get eaten?

So, did you read the last paragraph of my reply, or did you just get pissed off at my insensitive wording at the beginning and skip right to the keyboard?

Yes, some white moths would fly back to the pond or over to the forest and get eaten and therefore not breed. But some would stay put and live and breed. And, by the way, the magpie would occasionally find one of the white moths on the ice, and sometimes wouldn't catch a black one on the ice. But overall, the white ones have the advantage on the ice.

Only the moths that live to breed are able to pass their genes onto the next generation; those that can produce more offspring or offspring with a better chance to themselves breed win the race. Evolution is just exactly that simple.

Evolution is about populations over time; that means generations, not individuals. The white ones with the tendency to stay put on the ice are able to pass that tendency on to their descendants. Simple as that.

Another example of this is the introduction of peregrine falcons to places where the raptors were not previously found. Pigeons are cliff dwelling birds. They are prey for peregrines. Pretty soon the lighter colored pigeons at Devil's Tower in Wyoming were a thing of the past. They were just too easy to pick off it seems. The rock is dark and from above a white dot moving over dark rocks is pretty easy to track.

Light and dark pigeons are of course the same species, but the sudden introduction of a skilled predator has altered the gene pool of pigeons in at least one place on Earth.

Originally posted by jiggerj

Originally posted by Noinden
reply to post by jiggerj

 

But it is NOT sudden. IT is gradual. We do not have fossilized (or actual remains) for every generation of these creatures. We are bloody lucky that we have any remains to be fair, as having remains survive that long is good luck, rather than to be expected.

So I will ask again, are you even willing to be convinced about evolution? I know my mind is open to alternatives, if people are willing to be polite, and show evidence.

Oh no, I do believe in some form of evolution. I'm just not informed enough to understand it all. Doubt I ever will be. But, that shouldn't stop people from asking questions.

No worries, so has anything become easier to understand?

Originally posted by jiggerj

Originally posted by Astyanax

Species don't turn into other species overnight.

That's exactly my point. But it seems that what we're seeing is how one species suddenly dies off and a new species suddenly appears around the same time. We're not seeing gradual changes within a specific species. And, that bothers me.

Really? Do you look identical to every other person around you? And if you want to take it even further, compare an asian, an african, a european and an eskimo, and tell me they look identical?

Originally posted by Thain Esh Kelch

Originally posted by jiggerj

Originally posted by Astyanax

Species don't turn into other species overnight.

That's exactly my point. But it seems that what we're seeing is how one species suddenly dies off and a new species suddenly appears around the same time. We're not seeing gradual changes within a specific species. And, that bothers me.

Really? Do you look identical to every other person around you? And if you want to take it even further, compare an asian, an african, a european and an eskimo, and tell me they look identical?

That's a very good point. Problem is, we are all still categorized as Homo Sapiens. What I gather from the comments in this thread, whenever our primitive ancestors evolved even in the slightest, they were re-categorized and re-named.

reply to post by jiggerj


The whole thing about species boils down to a genetic pool. A species and even individual organisms is often hard to define. The reason for the classification into species based on the bones is the existence of physical traits thought to distinguish species. A skull recently dropped in our yard by a scavenging dog was identified as a raccoon by checking the numbers of different type of teeth.

In the case of extinct species, deciding a species may be difficult at times because the bones may show some, but not all characteristics of known species. That begs the question if this is a variant or a new species. If it is decided that this represents a new species the question is then how is it related to known species?

Originally posted by jiggerj
How do these sub-species come about? I imagine that a tribe of one species splits up. Half of them stay where they are and never change. The other half goes off to face adversities in a new environment which causes them to evolve in certain ways in order to survive. Then that tribe splits up, and so on and so on...creating thousands of branches and sub-species.

Under this premise how could EVERY SINGLE branch die out and leave only us here today? Doesn't that seem highly improbable? Not only improbable, but for evolution to have worked this way it would have taken (in my opinion) billions of years.

You are correct in the first paragraph, but also interbreeding takes place among many sub species, so the genes split up and change, but then come back together thousands to millions of years later increasing genetic diversity.

The extinction of other intelligent hominids on earth is a mystery right now. Homo sapiens being the only intelligent beings, is relatively new, however. Just 20,000 years ago we shared the planet with several different other hominids and subspecies. Perhaps a natural disaster wiped most of them out. It may have had to do with the end of the last ice age or an impact event. Maybe homo sapiens killed the others off. We know sapiens and neanderthalensis bred together, as well as Denisovans and another mystery species. If you look in nature, there are many more sub species, but a line dies out when a disaster happens and they cannot adapt. For whatever we, we did while the rest perished. It could have been our location or numerous other factors.

Evolution and the rate of change is dictated by the environment. If a creature is well adapted there is no need for change. Sharks are a great example. They predate dinosaurs by like 200 million years. Yet, white sharks are still here and almost exactly the same, just a bit smaller.

Also that skull picture is obviously photo shopped. I don't know if that was intentional to show what happened, or what, but it's obviously not 3 skull samples separated by millions of years. I didn't even think they had more than 1 skull sample of afarensis.

The three skulls in the OP I realized were all the same skull. They turn out ot be the skull of the individual named "Lucy". You can find the skull part way down the page and if you look at the link to the image you see it is named:
australopithecus / lucy recontructed skull.jpg
The skull is 3 images of the species Australopithecus afarensis.

www.columbia.edu...

Australopithecus afarensis lived from approximately 4.1 to 2.7 million years ago in northeastern Africa.

The image in the OP lists the times for A. afarensis from 1 to 3 million years ago, which is incorrect.

Since this is obviously a hoax image do you mind me asking where this came from? Did you make this image?

Originally posted by Barcs

Also that skull picture is obviously photo shopped. I don't know if that was intentional to show what happened, or what, but it's obviously not 3 skull samples separated by millions of years. I didn't even think they had more than 1 skull sample of afarensis.

edit on 31-8-2012 by Barcs because: (no reason given)

Hmmm, you're the second I know of to miss what I wrote in the OP. I wrote: In the image below, there are three skulls of Australopithecus afarensis ***(that I manipulated)***.

I did this to explain what I would have expected to see from evolution.

Originally posted by stereologist
The three skulls in the OP I realized were all the same skull. They turn out ot be the skull of the individual named "Lucy". You can find the skull part way down the page and if you look at the link to the image you see it is named:
australopithecus / lucy recontructed skull.jpg
The skull is 3 images of the species Australopithecus afarensis.

www.columbia.edu...

Australopithecus afarensis lived from approximately 4.1 to 2.7 million years ago in northeastern Africa.

The image in the OP lists the times for A. afarensis from 1 to 3 million years ago, which is incorrect.

Since this is obviously a hoax image do you mind me asking where this came from? Did you make this image?

LOL How come everyone is missing what I wrote in the three teeny-tiny paragraphs of the OP? I wrote: In the image below, there are three skulls of Australopithecus afarensis ***(that I manipulated)***. To explain what I expected to see in the process of evolution.

Your claim is not as clear to others as you seem to think it is.

So in this case you contrived a situation that you think would be important. Why not use 3 different real skulls and stick to the real world?