Let's start at the beginning? maybe?

[YoursTrue]

Let's try. So I'm looking at an introduction to evolution. (Evolution 101) And little by little I'd like to discuss it without rancor, if possible. This is from berkeley edu. It starts by giving a definition of evolution, saying, "Biological evolution, simply put, is descent with inherited modification. This definition encompasses everything from small-scale evolution (for example, changes in the frequency of different gene versions in a population from one generation to the next) to large-scale evolution (for example, the descent of different species from a shared ancestor over many generations). Evolution helps us to understand the living world around us, as well as its history." An introduction to evolution - Understanding Evolution

 

[Pogo]

An excellent place to start, I haven't looked at the site in a while but I will refresh my memory.
First thing you should notice is that the definition does not include abiogenesis, evolution starts with a replicating entity and whether god did it in a warm pond as Darwin said or something else, evolution is what happens next to that entity.
read the first couple of pages and then come back with questions.

 

[YoursTrue]

Let's try. So I'm looking at an introduction to evolution. (Evolution 101) And little by little I'd like to discuss it without rancor, if possible. This is from berkeley edu. It starts by giving a definition of evolution, saying, "Biological evolution, simply put, is descent with inherited modification. This definition encompasses everything from small-scale evolution (for example, changes in the frequency of different gene versions in a population from one generation to the next) to large-scale evolution (for example, the descent of different species from a shared ancestor over many generations). Evolution helps us to understand the living world around us, as well as its history." An introduction to evolution - Understanding Evolution

@Pogo et al, hopefully respectfully.
So getting back to the information, it brings out that biological evolution is that of descent with inherited modification. (OK, that's what it is said to be, and understood because we have examples around us that demonstrate this and can be observed--a very important point as far as I am concerned, such as those of inherited characteristics such as long or short legs, shapes of eyes, color of skin, etc.) Now the "descent of different species from a shared ancestor over many generations" is something to be explored as far as I am concerned. The website explains species as: "A group of individuals that actually or potentially interbreed in nature." For me, this requires further explanation. And it goes on to say, "In this sense, a species is the largest gene pool possible under natural conditions. For a more detailed explanation, see our resource on species in Evolution 101." So, accordingly, a "species is the largest gene pool possible under natural conditions." I would have to have clarification on that as to what it means and ostensibly that is offered in the link.

 

[TagliatelliMonster]

Now the "descent of different species from a shared ancestor over many generations" is something to be explored as far as I am concerned.

What do you mean precisely when you say it is something "to be explored"?

Also, I'ld add that if you would stick to the thread title of "start at the beginning", this would already be getting ahead of yourself.

Let's first stick to the short term evolutionary change of "reproduction with inherited modification".
Let's first explore that one and really understand it, before getting ahead of ourselves of what that does over longer periods of time.

I assure you that once the concept of "reproduction with inherited modification" really sinks in, specifically the accumulation part of such "modification", the rest will follow logically as the inevitable consequence of what that means over longer periods. And by "longer" periods, I'm talking 10 of thousands / 100s of thousands of generations / millions and millions of years.

Really understanding the consequences and implications of "reproduction with inherited modification" will also inform you how that will shape evidence that we would expect to find in terms of comparative anatomy, structure of DNA, etc.

All these are crucial concepts to understand before trying to move on to "macro evolution".


Ask whatever question you wish on this subject.
I'ld also like to say that I applaud this thread and hope it is a genuine attempt at approaching the subject step by step in an honest and genuine manner.

 

[exchemist]

@Pogo et al, hopefully respectfully.
So getting back to the information, it brings out that biological evolution is that of descent with inherited modification. (OK, that's what it is said to be, and understood because we have examples around us that demonstrate this and can be observed--a very important point as far as I am concerned, such as those of inherited characteristics such as long or short legs, shapes of eyes, color of skin, etc.) Now the "descent of different species from a shared ancestor over many generations" is something to be explored as far as I am concerned. The website explains species as: "A group of individuals that actually or potentially interbreed in nature." For me, this requires further explanation. And it goes on to say, "In this sense, a species is the largest gene pool possible under natural conditions. For a more detailed explanation, see our resource on species in Evolution 101." So, accordingly, a "species is the largest gene pool possible under natural conditions." I would have to have clarification on that as to what it means and ostensibly that is offered in the link.

It is populations of organisms that evolve. The reference to the size of the gene pool that can interbreed is a way of defining the relevant population. The relevant definition has to be the population that can interbreed, since it is by interbreeding within a population that traits are passed on between generations.

Individuals that are too different to interbreed with fertile offspring (e.g. a horse mating with a donkey) can't pass on their traits to successive generations and therefore do not contribute to "descent with inherited modification". So if one is considering the evolution of a species called "horse", one does not include "donkeys".

That is all it means.

 

[Heyo]

@Pogo et al, hopefully respectfully.
So getting back to the information, it brings out that biological evolution is that of descent with inherited modification. (OK, that's what it is said to be, and understood because we have examples around us that demonstrate this and can be observed--a very important point as far as I am concerned, such as those of inherited characteristics such as long or short legs, shapes of eyes, color of skin, etc.) Now the "descent of different species from a shared ancestor over many generations" is something to be explored as far as I am concerned. The website explains species as: "A group of individuals that actually or potentially interbreed in nature." For me, this requires further explanation. And it goes on to say, "In this sense, a species is the largest gene pool possible under natural conditions. For a more detailed explanation, see our resource on species in Evolution 101." So, accordingly, a "species is the largest gene pool possible under natural conditions." I would have to have clarification on that as to what it means and ostensibly that is offered in the link.

Critics of creationism often harp on how creationists can't define "kind". That's throwing stones in a glasshouse, as biologists have equal problems defining "species". You won't get more clarification, as that is inherently an ambiguous concept. Not only do different fields of biology use different definitions, but there simply is no clear edge. Breeding success is stochastic, not binary. E.g.: horses and donkeys are considered different species because they usually don't have fertile offspring. But one in 10,000 (iirc, don't quote me on that number) mules are fertile.
So when did speciation occur between horses and donkeys? When the success was less than 50%, 10%, 5%?
This also leads to a seeming paradox in ring species. When you have populations A, B, C, D, E of the same species where A and B can interbreed without problems, B and C can, C and D and D and E - but A and E can't.
And there is also a time problem that is theoretical, as we can't test for it. A stable population inhabits a region for a long time without splitting off in different species but, through genetic drift, changes in appearance. When do you call them a different species? They possibly wouldn't be able to interbreed with a member of the old population, but there is no way to test when that threshold had passed. And that threshold would be a moving target.

I hope I didn't confuse you, as our goal here is understanding. But it is important to know about the ambiguous nature of the species concept at its edges. It works fine as long as you don't look too closely.

 

[TagliatelliMonster]

Critics of creationism often harp on how creationists can't define "kind". That's throwing stones in a glasshouse, as biologists have equal problems defining "species". You won't get more clarification, as that is inherently an ambiguous concept. Not only do different fields of biology use different definitions, but there simply is no clear edge. Breeding success is stochastic, not binary. E.g.: horses and donkeys are considered different species because they usually don't have fertile offspring. But one in 10,000 (iirc, don't quote me on that number) mules are fertile.
So when did speciation occur between horses and donkeys? When the success was less than 50%, 10%, 5%?
This also leads to a seeming paradox in ring species. When you have populations A, B, C, D, E of the same species where A and B can interbreed without problems, B and C can, C and D and D and E - but A and E can't.
And there is also a time problem that is theoretical, as we can't test for it. A stable population inhabits a region for a long time without splitting off in different species but, through genetic drift, changes in appearance. When do you call them a different species? They possibly wouldn't be able to interbreed with a member of the old population, but there is no way to test when that threshold had passed. And that threshold would be a moving target.

I hope I didn't confuse you, as our goal here is understanding. But it is important to know about the ambiguous nature of the species concept at its edges. It works fine as long as you don't look too closely.

Exactly. Such is the nature of gradual change over time. There is no "first horse". There is no clear "line", or in the case of evolution, "generation" where you can say "NOW it's a horse!" while its parents are not horses.

That exact concept is beautifully illustrated in this famous analogy example:

As the question at the bottom asks: what is the "first" purple word? What is the "first" blue word? At which point "exactly" did red turn to blue?

Whatever you answer is going to be arbitrary. Any word you pick to say "now it's definitly blue!", the couple words preceeding and following it... they are going to be pretty much blue also. There is no "first" blue word. At best, there are shades of blue gradually becoming "really" blue from shades of purple, which in turn gradually became "really" purple from shades of red. No clear line at all.

 

[YoursTrue]

Critics of creationism often harp on how creationists can't define "kind". That's throwing stones in a glasshouse, as biologists have equal problems defining "species". You won't get more clarification, as that is inherently an ambiguous concept. Not only do different fields of biology use different definitions, but there simply is no clear edge. Breeding success is stochastic, not binary. E.g.: horses and donkeys are considered different species because they usually don't have fertile offspring. But one in 10,000 (iirc, don't quote me on that number) mules are fertile.
So when did speciation occur between horses and donkeys? When the success was less than 50%, 10%, 5%?
This also leads to a seeming paradox in ring species. When you have populations A, B, C, D, E of the same species where A and B can interbreed without problems, B and C can, C and D and D and E - but A and E can't.
And there is also a time problem that is theoretical, as we can't test for it. A stable population inhabits a region for a long time without splitting off in different species but, through genetic drift, changes in appearance. When do you call them a different species? They possibly wouldn't be able to interbreed with a member of the old population, but there is no way to test when that threshold had passed. And that threshold would be a moving target.

I hope I didn't confuse you, as our goal here is understanding. But it is important to know about the ambiguous nature of the species concept at its edges. It works fine as long as you don't look too closely.

No, you didn't confuse me, but the idea that fish evolved (changed eventually) to become human has no backup except in the mental gymnastics or imaginations of some men using fossils as proof of the conjecture. No evidence really. Because there is none. Right now I don't have too much time but I will get back to the discussion asap. Thanks.

 

[Jayhawker Soule]

Critics of creationism often harp on how creationists can't define "kind".

Some do ... sometimes. At best, it's a side issue.

I hope I didn't confuse you, as our goal here is understanding. But it is important to know about the ambiguous nature of the species concept at its edges. It works fine as long as you don't look too closely.

"The map is not the territory." -- Alfred Korzybski

Let's first stick to the short term evolutionary change of "reproduction with inherited modification".

^ This.

First and foremost, evolution deals with descent with modification simply because, if nothing changes, nothing changes.

 

[Jayhawker Soule]

No, you didn't confuse me, but the idea that fish evolved (changed eventually) to become human has no backup except in the mental gymnastics or imaginations of some men using fossils as proof of the conjecture. No evidence really. Because there is none. Right now I don't have too much time but I will get back to the discussion asap. Thanks.

... and the rabbit hole draws near.

 

[Evangelicalhumanist]

No, you didn't confuse me, but the idea that fish evolved (changed eventually) to become human has no backup except in the mental gymnastics or imaginations of some men using fossils as proof of the conjecture. No evidence really. Because there is none. Right now I don't have too much time but I will get back to the discussion asap. Thanks.

Your phrasing of the above tells me that you are not absorbing what you say you are reading. No "fish evolved (changed eventually) to become human." None, ever. A fish from 300 million years ago bred, had offspring and died a fish. It's offspring were all fish, some with very tiny genetic variations that may have made them more or less successful at producing more offspring than others. The more successful produced more offspring with that genetic variation, and perhaps another tiny variation in some of its offspring -- and then it died, still a fish, too.

But, 300 million years later, that is today, all humans have an ancestor in their lineage that was a fish -- and so do all of today's fish! That makes you and the salmon you ate very, very, very distant cousins, millions of times removed.

 

[sun rise]

but the idea that fish evolved (changed eventually) to become human has no backup except in the mental gymnastics or imaginations of some men using fossils as proof of the conjecture. No evidence really. Because there is none. Right now I don't have too much time but I will get back to the discussion asap. Thanks.

You ignore science with that statement and substitute fantasy for fact. It is the equivalent of going to the Himalayas and saying there are no mountains here.

 

[Heyo]

No, you didn't confuse me, but the idea that fish evolved (changed eventually) to become human has no backup

It has, plenty of it. And I thought it was the goal of this thread to understand how scientists found that out and what the facts and theories behind it are. We are willing to help you through evolution 101 - but if you are starting to dismiss evolution before you have understood the basics, I'm out. I thought you were finally interested in understanding evolution, based on how you started this OP.

 

[We Never Know]

No, you didn't confuse me, but the idea that fish evolved (changed eventually) to become human has no backup except in the mental gymnastics or imaginations of some men using fossils as proof of the conjecture. No evidence really. Because there is none. Right now I don't have too much time but I will get back to the discussion asap. Thanks.

Why stop at fish? Go back farther and we evolved from bacteria.

"The earliest fossil evidence for life on Earth is bacterial (Fig. 1). Layered macroscopic sedimentary structures known as “stromatolites” record the existence of bacteria (and possibly archaea) dating back 3.45 billion years"

Bacterial Influences on Animal Origins

Animals evolved in seas teeming with bacteria, yet the influences of bacteria on animal origins are poorly understood. Comparisons among modern animals and their closest living relatives, the choanoflagellates, suggest that the first animals used flagellated ...

www.ncbi.nlm.nih.gov

 

[YoursTrue]

Why stop at fish? Go back farther and we evolved from bacteria.

"The earliest fossil evidence for life on Earth is bacterial (Fig. 1). Layered macroscopic sedimentary structures known as “stromatolites” record the existence of bacteria (and possibly archaea) dating back 3.45 billion years"

Bacterial Influences on Animal Origins

Animals evolved in seas teeming with bacteria, yet the influences of bacteria on animal origins are poorly understood. Comparisons among modern animals and their closest living relatives, the choanoflagellates, suggest that the first animals used flagellated ...

www.ncbi.nlm.nih.gov

Someone here said we ARE fish because it is guaranteed by some scientists that is so. So ok, you think you're a fish and an ape, and you think possibly that I'm a fish and an ape. Have a good one. Oh, and also bacteria. (OK) (What about dust?)

 

[YoursTrue]

Why stop at fish? Go back farther and we evolved from bacteria.

"The earliest fossil evidence for life on Earth is bacterial (Fig. 1). Layered macroscopic sedimentary structures known as “stromatolites” record the existence of bacteria (and possibly archaea) dating back 3.45 billion years"

Bacterial Influences on Animal Origins

Animals evolved in seas teeming with bacteria, yet the influences of bacteria on animal origins are poorly understood. Comparisons among modern animals and their closest living relatives, the choanoflagellates, suggest that the first animals used flagellated ...

www.ncbi.nlm.nih.gov

I'm not stopping at fish, but it's a convenient thing to bring up. But of course maybe plants have a different "tree of life." Right?

 

[YoursTrue]

It has, plenty of it. And I thought it was the goal of this thread to understand how scientists found that out and what the facts and theories behind it are. We are willing to help you through evolution 101 - but if you are starting to dismiss evolution before you have understood the basics, I'm out. I thought you were finally interested in understanding evolution, based on how you started this OP.

Help me? Ok, so start at the beginning. And go no further for a while. I'm willing to listen to your postulates. Go ahead, please. So what's the first thing that science knows about or is SURE to have come up as living matter?

 

[YoursTrue]

Your phrasing of the above tells me that you are not absorbing what you say you are reading. No "fish evolved (changed eventually) to become human." None, ever. A fish from 300 million years ago bred, had offspring and died a fish. It's offspring were all fish, some with very tiny genetic variations that may have made them more or less successful at producing more offspring than others. The more successful produced more offspring with that genetic variation, and perhaps another tiny variation in some of its offspring -- and then it died, still a fish, too.

But, 300 million years later, that is today, all humans have an ancestor in their lineage that was a fish -- and so do all of today's fish! That makes you and the salmon you ate very, very, very distant cousins, millions of times removed.

So humans are? or are not? fish. That's one question.
But either way, are you saying that humans evolved FROM fish (in the long, long genetic run). Would you agree with that as an adequate explanation of what you believe?
Doing a bit of reading about this, "There is nothing new about humans and all other vertebrates having evolved from fish. The conventional understanding has been that certain fish shimmied landwards roughly 370 million years ago as primitive, lizard-like animals known as tetrapods."
Do you believe that?
"According to this understanding, our fish ancestors came out from water to land by converting their fins to limbs and breathing under water to air-breathing."
See, that's what it says. We're more like primitive fishes than once believed, new research shows
Lots of interesting changes in scientific thinking. Yup -- lungs just developed, somehow -- surviving mass extinctions and so forth. So have we or have we not, in your opinion based on science and nothing else, evolved genetically from -- fish? Really it's a yes or no answer. Somehow. Maybe...

 

[Evangelicalhumanist]

Doing a bit of reading about this, "There is nothing new about humans and all other vertebrates having evolved from fish. The conventional understanding has been that certain fish shimmied landwards roughly 370 million years ago as primitive, lizard-like animals known as tetrapods."
Do you believe that?

"According to this understanding, our fish ancestors came out from water to land by converting their fins to limbs and breathing under water to air-breathing."

Have a look at the mud skipper.

 

[John53]

Have a look at the mud skipper.

Been shown to her 4 times that I know of then brushed by her calling them fish that flop about in mud that don't prove anything.