Evolution My ToE

[YoursTrue]

This is an extremely simplified diagram that doesn't accurately depict the processes involved. I'm not even sure it's used anymore.

You're better off sticking with the detailed explanations that scientific-minded posters have provided for you instead. Or try Googling some academic sites on the subject.

That is only one of many diagrams showing how man evolved from chimpanzees.

 

[YoursTrue]

Well, the simple answer is that they *are* evolving. If you go back 1,000,000 years, the lions we see today didn't exist. Some other large cat existed instead. The same is true for chimps: the modern chimp didn't exist 1,000,000 years ago. But some other ape did that eventually evolved into chimps.

Your assumption that species are immutable is wrong. It's just that they change so slowly (usually), that there is very little change in the 5000 years of human writing. Remember that a mere 1 million years is 200 times as long as humans have had writing. And 1 million years is (usually) considered a *short* time period for evolution.

But we can use the fossil record and the genetics of species *today* and, to a limited extent, DNA acquired from fossils (if it isn't too degraded) to tell the genetic changes in species over time. And that *is* evolution.



Precisely. We also haven't had the time to see changes in the sun. Those tend to happen over the course of hundreds of millions of years.

I obviously can't speak for everything that is promoted by scientists re evolution. Especially because I don't understand the terms. But after I looked at the drawings in the charts used to show the evolution of chimpanzees or whatever to humans, evidently used to show the physical similarities, I wondered just how many couples it took to produce homo sapiens. It's hard to express. There are definite boundaries with chimpanizees, bonobos, lions, domestic cats, etc. Until this observable day. And yes, the idea that writing was accomplished only several thousand years ago, nothing in the written world that I know about shows that lions and giraffes (I use these distinct forms) were evolving. So I wonder if it took more than two couples to produce more of the same types. I hesitate to use the word kind, since there is confusion regarding that, I think. So for humans let's say, was it gradual transmission from whatever they came from distinctly? I mean, saying the "missing link" is not a scientific term. If I recall correctly, the LCA is the better term. So again -- assuming the better term is "LCA," if I remember correctly, would it be a male and female (whatever in the line of apes) in that LCA unknown so far, that started the humans, or would it be more than one couple? What do you and scientists in the mainstream believe about this? Somehow I find it hard to imagine that from chimpanzees somehow evolved one or more than one human male and female producing humans. But that's me. And again, I thank you for the conversation.
P.S. When I say 'immutable,' I mean that forms such as giraffes and lions are not seen to change to another type of form. I agree that dogs that are interbred can lose characteristics they initially had. This is not, however, like elephants evolving into whatever they may have been said to evolve into. Or from.

 

[YoursTrue]

Well, the simple answer is that they *are* evolving. If you go back 1,000,000 years, the lions we see today didn't exist. Some other large cat existed instead. The same is true for chimps: the modern chimp didn't exist 1,000,000 years ago. But some other ape did that eventually evolved into chimps.

Your assumption that species are immutable is wrong. It's just that they change so slowly (usually), that there is very little change in the 5000 years of human writing. Remember that a mere 1 million years is 200 times as long as humans have had writing. And 1 million years is (usually) considered a *short* time period for evolution.

But we can use the fossil record and the genetics of species *today* and, to a limited extent, DNA acquired from fossils (if it isn't too degraded) to tell the genetic changes in species over time. And that *is* evolution.



Precisely. We also haven't had the time to see changes in the sun. Those tend to happen over the course of hundreds of millions of years.

As far as I know, there are sunflares affecting the earth's atmosphere. I don't think it takes that long for observers or knowledgeable ones to see them or feel their effect.

 

[YoursTrue]

Remember that genes are stretches of DNA that encode for proteins. The genes are in the chromosomes.

So, for example, hemoglobin is a protein that carries oxygen in the blood. Both cats and humans have hemoglobin, but there are slight differences in the sequence of amino acids in the protein (and hence differences in the DNA--slightly different genes). The gene for hemoglobin is on chromosome 11 in humans. I wasn't able to find out which chromosome it is on in cats.

There are also genes for proteins that help digest food. Again, those are very similar in both cats and humans.

And, in fact, the vast majority of genes will be the same for both cats and humans: they code for proteins that do the same thing in humans and in cats--structural proteins, like collagen, digestive proteins, like the serine proteases, etc.

The other aspect of this is that chromosomes tend to have a LOT of non-coding pieces: stretches of DNA that don't code for any proteins, or, for that matter, not for anything at all. Sometimes, these are genes for proteins that have been permanently 'turned off' and have afterwards mutated to the point of uselessness. Other places are long stretches of repeating cododn that seem to be more structural.

It is actually these non-coding regions that are the biggest differences between the chromosomes of cats and humans. Again, the chromosomes are how the genes are stored. There are NOT 38 'cat chromosomes' in humans, even though the genes they store are often similar. They are arranged differently and genes that are on the same chromosome for cats may well be on different ones in humans (and vice versa).

OK, so human genes are not built on genes from other animals, or am I wrong about this?
So I'm assuming that because the genes for hemoglobin are different from cats to humans, that is why humans cannot take feline blood in their bodies for medical purposes and expect to live?
OK, I've been doing a little research on this, and see that there are explanations saying that like humans, cats and dogs have differing blood types or something like that. But that is not really my question. Would cat's hemoglobin, or blood, be able to be successfully transfused into a human, would they have the same "type"? Or would it kill the person in any case?

 

[Polymath257]

I obviously can't speak for everything that is promoted by scientists re evolution. Especially because I don't understand the terms. But after I looked at the drawings in the charts used to show the evolution of chimpanzees or whatever to humans, evidently used to show the physical similarities, I wondered just how many couples it took to produce homo sapiens. It's hard to express. There are definite boundaries with chimpanizees, bonobos, lions, domestic cats, etc. Until this observable day. And yes, the idea that writing was accomplished only several thousand years ago, nothing in the written world that I know about shows that lions and giraffes (I use these distinct forms) were evolving. So I wonder if it took more than two couples to produce more of the same types. I hesitate to use the word kind, since there is confusion regarding that, I think. So for humans let's say, was it gradual transmission from whatever they came from distinctly? I mean, saying the "missing link" is not a scientific term. If I recall correctly, the LCA is the better term. So again -- assuming the better term is "LCA," if I remember correctly, would it be a male and female (whatever in the line of apes) in that LCA unknown so far, that started the humans, or would it be more than one couple? What do you and scientists in the mainstream believe about this? Somehow I find it hard to imagine that from chimpanzees somehow evolved one or more than one human male and female producing humans. But that's me. And again, I thank you for the conversation.
P.S. When I say 'immutable,' I mean that forms such as giraffes and lions are not seen to change to another type of form. I agree that dogs that are interbred can lose characteristics they initially had. This is not, however, like elephants evolving into whatever they may have been said to evolve into. Or from.

Well, once again, we can look at fossils from 1 million years, or 10 million years ago and compare them to the animals we see now. And, if we plot what the animals alive at each point in time look like, we find that similar animals tend to live both close together geographically, but also close together in time.

But, for example, there were no modern giraffes 10 million years ago. They simply did not yet exist. Instead, there were animals related to the giraffe (which we can tell by bone structures, teeth, etc) with shorter necks, etc.

And you are correct, to be down to only two individuals would be incredibly detrimental to a species. But it is populations that evolve, not individuals. Genes are mutated and passed along to children, and those changes spread through the population, changing its characteristics over many generations. And that is evolution: changes in species over geological time.

Remember that the LCA of any two species was a population of animals (or plants, if you want to study them--same principles apply). So, there was a common ancestor of dogs and cats. There was a common ancestor before that for dogs, cats, bears, and other carnivores. We have the fossils of those ancestors. Even if you don't like to think of them evolving into the species we have today, those animals did exist in the past, they were different than any alive today, and they had anatomies that had characteristics common to the mammalian carnivores *and to no other species*.

Evolution was first suspected by looking at fossils. People studying them noticed that the species alive at any time were different than at other times in ways that suggest that species change their characteristics over the course of millions of years. It was only later that we learned enough about DNA and genetics to understand the mechanisms of those changes.

 

[Polymath257]

OK, so human genes are not built on genes from other animals, or am I wrong about this?
So I'm assuming that because the genes for hemoglobin are different from cats to humans, that is why humans cannot take feline blood in their bodies for medical purposes and expect to live?

Actually, no. The reason is that our immune systems (another group of proteins) react to each other. So, you would get an immune response. And that response would be rather similar to what would happen if you were given the wrong blood type (which is also an immune trigger) from another human.

OK, I've been doing a little research on this, and see that there are explanations saying that like humans, cats and dogs have differing blood types or something like that. But that is not really my question. Would cat's hemoglobin, or blood, be able to be successfully transfused into a human, would they have the same "type"? Or would it kill the person in any case?

If you could transfuse *just* the hemoglobin and get it into the red blood cells, a human would be perfectly fine with a cat's hemoglobin and vice versa. The cat hemoglobin would be able to carry oxygen in human bodies in the same way that human hemoglobin does. At that level, there isn't a significant difference.

The blood types are a very different thing, related to the immune system, not the genetics of the hemoglobin.

Even more, we know that chimps and humans share some blood types. So, if you matched the blood types, a chimp's blood would work in a human and vice versa. With no ill effects at all. Just like a regular transfusion between people of the same blood type.

Humans and cats are unrelated enough to not have overlapping blood types.

 

[Polymath257]

As far as I know, there are sunflares affecting the earth's atmosphere. I don't think it takes that long for observers or knowledgeable ones to see them or feel their effect.

Correct, but not what I am talking about. Stars change over very long periods of time.

 

[YoursTrue]

Correct, but not what I am talking about. Stars change over very long periods of time.

I'll accept that because I believe that stars have characteristics that can cause them to change, and because I believe they have observably been changing. Stars are not said to be alive, though, are they?

 

[YoursTrue]

Actually, no. The reason is that our immune systems (another group of proteins) react to each other. So, you would get an immune response. And that response would be rather similar to what would happen if you were given the wrong blood type (which is also an immune trigger) from another human.



If you could transfuse *just* the hemoglobin and get it into the red blood cells, a human would be perfectly fine with a cat's hemoglobin and vice versa. The cat hemoglobin would be able to carry oxygen in human bodies in the same way that human hemoglobin does. At that level, there isn't a significant difference.

The blood types are a very different thing, related to the immune system, not the genetics of the hemoglobin.

Even more, we know that chimps and humans share some blood types. So, if you matched the blood types, a chimp's blood would work in a human and vice versa. With no ill effects at all. Just like a regular transfusion between people of the same blood type.

Humans and cats are unrelated enough to not have overlapping blood types.

Well then, there shouldn't be a problem in blood drives or when hospitals go short on blood if chimps and humans share some blood types, should there? Except that animal activists may get riled up at the thought of taking blood from chimpanzees.

 

[YoursTrue]

My biggest problem is that my keyboard driver is a bit wonky on my laptop. Evidently, the computer gets busy and either misses a few characters or repeats a character several times. I end up having to go back and look for red underlines, which means I often miss words that are 'correct' but not the one intended.

I also tend to write while looking at the keyboard and only looking at the screen every line or so. That also tends to multiply errors.

Plus, I am not as good of a proofreader as I should be. I often hit 'Post Reply' and then realize how poorly the text reads.

That happens to everyone, I think. I notice pieces written in news articles on the web, including google reports, which have misspelled words or letters left out. Not often, but it happens.

 

[YoursTrue]

Well, once again, we can look at fossils from 1 million years, or 10 million years ago and compare them to the animals we see now. And, if we plot what the animals alive at each point in time look like, we find that similar animals tend to live both close together geographically, but also close together in time.

But, for example, there were no modern giraffes 10 million years ago. They simply did not yet exist. Instead, there were animals related to the giraffe (which we can tell by bone structures, teeth, etc) with shorter necks, etc.

And you are correct, to be down to only two individuals would be incredibly detrimental to a species. But it is populations that evolve, not individuals. Genes are mutated and passed along to children, and those changes spread through the population, changing its characteristics over many generations. And that is evolution: changes in species over geological time.

Remember that the LCA of any two species was a population of animals (or plants, if you want to study them--same principles apply). So, there was a common ancestor of dogs and cats. There was a common ancestor before that for dogs, cats, bears, and other carnivores. We have the fossils of those ancestors. Even if you don't like to think of them evolving into the species we have today, those animals did exist in the past, they were different than any alive today, and they had anatomies that had characteristics common to the mammalian carnivores *and to no other species*.

Evolution was first suspected by looking at fossils. People studying them noticed that the species alive at any time were different than at other times in ways that suggest that species change their characteristics over the course of millions of years. It was only later that we learned enough about DNA and genetics to understand the mechanisms of those changes.

I am not speaking of only two individuals of those which produced humans in the evolutionary process, but it takes a human couple or a gorilla couple insofar as we now know to produce a human baby or gorilla baby. So I can't figure how it happened. Since (not if) it takes a human to produce a human, and a gorilla to produce a gorilla. And especially can't figure if it takes more than one human couple evolving from whatever they are said to evolve from to start what is called the human race. I am not contesting, by the way, that brown-skinned people mating with brown-skinned people have a pretty good chance of producing brown-skinned people, similarly with lighter skinned couples. And so forth. That is genetic predisposition, I suppose. Not evolution making another form of being.

 

[YoursTrue]

Actually, no. The reason is that our immune systems (another group of proteins) react to each other. So, you would get an immune response. And that response would be rather similar to what would happen if you were given the wrong blood type (which is also an immune trigger) from another human.



If you could transfuse *just* the hemoglobin and get it into the red blood cells, a human would be perfectly fine with a cat's hemoglobin and vice versa. The cat hemoglobin would be able to carry oxygen in human bodies in the same way that human hemoglobin does. At that level, there isn't a significant difference.

The blood types are a very different thing, related to the immune system, not the genetics of the hemoglobin.

Even more, we know that chimps and humans share some blood types. So, if you matched the blood types, a chimp's blood would work in a human and vice versa. With no ill effects at all. Just like a regular transfusion between people of the same blood type.

Humans and cats are unrelated enough to not have overlapping blood types.

OK, I see that wikipedia talks about xenotransfusions, from animals to humans.

 

[YoursTrue]

@Polymath257: While wikipedia says one thing, PubMed at NCBI says something a bit different. NCBI says, "From 2000, because of progress in xenotransplantation and the need of blood supply, xenotransfusion is again being considered. Pigs are the best potential donors. The development of alpha-1,3-galactosyltransferase gene-knockout pigs has overcome the first hurdle to xenotransfusion. The main obstacle to porcine red blood cell transfusion is now the cellular response involving macrophages or natural killer cells."
Xenotransfusions, past and present. - PubMed - NCBI

 

[Dan From Smithville]

Sounds like fairy tales to me.

It seems like a fairy, but most of those are interesting.To be fair, it is not based on reality or Christian theology, so it was doomed before it was unveiled for us.

 

[TagliatelliMonster]

I obviously can't speak for everything that is promoted by scientists re evolution. Especially because I don't understand the terms. But after I looked at the drawings in the charts used to show the evolution of chimpanzees or whatever to humans, evidently used to show the physical similarities, I wondered just how many couples it took to produce homo sapiens. It's hard to express.

A lot. Millions of years worth of generations, each generation consisting of thousands to millions of couples.

There are definite boundaries with chimpanizees, bonobos, lions, domestic cats, etc.

Actually, that's not really true.
They look like definite boundaries, because each of these species has been on their own evolutionary path for a long time. So they had a lot of time to diverge.

As you wind back two distinct populations of two distinct species with "definite boundaries", those "definite boundares" are going to get blurred more and more as you approach the common ancestral population.

This is the nature of gradualism.

Until this observable day

Rather: "ON this observable day". Not "until". Because as you approach the ancestral population, those boundaries get blurred more and more and gradually evaporate.

And yes, the idea that writing was accomplished only several thousand years ago, nothing in the written world that I know about shows that lions and giraffes (I use these distinct forms) were evolving.

Why would you expect that?
Such visible change would take a lot more time then a couple of millenia.
On the scale of a human lifetime and certainly without modern technology, it takes quite rigourous and discplined observation, data collecting and data analysis, to detect and work out biological evolution.

So I wonder if it took more than two couples to produce more of the same types.

Populations evolve, individuals don't.
It's through individuals that variation is introduced, but for that variation to become part of the common genepool, it needs to spread throughout the population, which takes quite a few generations, obviously. And that's what evolution is: the cross generation spread of variations through inheritance with reproduction.

So for humans let's say, was it gradual transmission from whatever they came from distinctly?

All of evolution is gradual.
Every individual ever born, was of the same species as its parents.

I mean, saying the "missing link" is not a scientific term. If I recall correctly, the LCA is the better term. So again -- assuming the better term is "LCA," if I remember correctly, would it be a male and female (whatever in the line of apes) in that LCA unknown so far, that started the humans, or would it be more than one couple?

In terms of how speciation happens, it's an entire population.

Somehow I find it hard to imagine that from chimpanzees somehow evolved one or more than one human male and female producing humans

That's indeed not how it happens.
Instead, the entire population gradually changes through the accumulation of variation / change in the common genepool.

No non-human ever gave birth to a human.
Just like no latin speaking mother has ever raised a spanish speaking child.
Instead, the latin spoken by an entire population gradually morphed into spanish spoken by an entire population.

Spanish isn't the product of a single individual or a single lineage within the latin speaking population. It's rather the result of accumulation of small changes over generations in commonly spoken language by the entire population.

Biological evolution is the same in that regard.

Ow and also: chimps and humans are cousins on the species level. We share ancestors. Humans didn't evolve from chimps. Rather both humans and chimps evolved from a common ancestral species.

At some point in the past, an estimated 8 million years ago if memory serves me right, this ancestral population split into two distinct populations. This can have lots of causes. Migration of a group to other regions is one. Geographic changes can be an another (like the formation of a river, through a population, "trapping" both groups on either side).

There no longer was interbreeding going on between both groups. So any genetic change in one never made it to the other. This puts them on their own evolutionary paths. One group went on to evolve into chimps and bonobo's. The other group went on to evolve into homo sapiens.

P.S. When I say 'immutable,' I mean that forms such as giraffes and lions are not seen to change to another type of form

First, the evolutionary timescales such happens on, wouldn't be observable as it takes many many human lifetimes.

Second, evolution doesn't work that way though... "forms" don't evolve into "other types of forms". They rather evolve into "subforms".

Human is a "subform" of primate.
Primate is a "subform" of mammal.
Mammas is a "subform" of tretrapod.
Tetrapod is a "subform" of vertebrate.
Vertebrate is a "subform" of eukaryote.

I agree that dogs that are interbred can lose characteristics they initially had. This is not, however, like elephants evolving into whatever they may have been said to evolve into. Or from.

Again, timescales are different. Also note that the breeding of dogs is largely a human undertaking. The evolution we see there, isn't something that would occur naturally.

In fact, many of the dog breeds we created this way, couldn't even survive in nature without human care.
Some of them are anatomically so skewed that they aren't even capable of natural reproduction anymore.

What dog breeds prove though, is that evolution happens.
If it wasn't for the processes of evolution, we wouldn't be able to create all these various dog breeds (and vegetables, and fruits and whatnot) that naturally do not occur, simply by artificially selecting breeding pairs, to breed for certain traits.

 

[Polymath257]

Well then, there shouldn't be a problem in blood drives or when hospitals go short on blood if chimps and humans share some blood types, should there? Except that animal activists may get riled up at the thought of taking blood from chimpanzees.

1. Chimps and tigers are pretty rare. It would be better to give them human blood for that reason.

2. Like I said, if you could get the hemoglobin into the red blood cells, there would be no problem. But that is a HUGE technical problem. It isn't so easy to get human DNA into a tiger's red blood cells.

3. Just like with transfusions between humans, we cannot ignore the blood types: that immune response can kill.

 

[Polymath257]

I am not speaking of only two individuals of those which produced humans in the evolutionary process, but it takes a human couple or a gorilla couple insofar as we now know to produce a human baby or gorilla baby. So I can't figure how it happened. Since (not if) it takes a human to produce a human, and a gorilla to produce a gorilla. And especially can't figure if it takes more than one human couple evolving from whatever they are said to evolve from to start what is called the human race. I am not contesting, by the way, that brown-skinned people mating with brown-skinned people have a pretty good chance of producing brown-skinned people, similarly with lighter skinned couples. And so forth. That is genetic predisposition, I suppose. Not evolution making another form of being.

Once again, it is not individuals that are changing. It is a population. You seem to be imagining a chimp giving birth to a human and that human having nobody to mate with. That isn't how it happens.

Instead, a whole population gradually changes from an ancestral form to the modern form. At one point in the past you have something like Homo habilus, which was a human ancestor that was remarkably ape-like. A big piece of the population changed to give the next stage: Homo erectus. And, again, a big part of the population shifted again. Each stage was more 'human' than the last.

A nice analogy is languages. Languages also change over time (like populations) and they need more than just two people to be speaking the language. But, if you go back 2000 years, there was no English language. If you go back 1000 years, what existed was a language that very few English speakers today could understand. Go back 400 years and people today could understand it, but it would sound strange.

At no point was there is a single (or even just a pair of) modern English speaker. The language shifted gradually and in a way that each generation understood both the generation before and the generation after. But over generations, the language changed a lot.

The same happens with populations and evolution. At no point are there just one or two of a drastically different species. Instead, the population changes slowly over the course of generations, getting new characteristics as it changes. But those small changes add up and the starting population and the final population can be quite different.

 

[Polymath257]

@Polymath257: While wikipedia says one thing, PubMed at NCBI says something a bit different. NCBI says, "From 2000, because of progress in xenotransplantation and the need of blood supply, xenotransfusion is again being considered. Pigs are the best potential donors. The development of alpha-1,3-galactosyltransferase gene-knockout pigs has overcome the first hurdle to xenotransfusion. The main obstacle to porcine red blood cell transfusion is now the cellular response involving macrophages or natural killer cells."
Xenotransfusions, past and present. - PubMed - NCBI

Yes, the immune response. I have pointed out that is an issue already. Cool article!

 

[SkepticThinker]

That is only one of many diagrams showing how man evolved from chimpanzees.

Humans didn't evolve from chimpanzees.

 

[Astrophile]

I'll accept that because I believe that stars have characteristics that can cause them to change, and because I believe they have observably been changing. Stars are not said to be alive, though, are they?

You are right; stars are not alive. Also, over millions or billions of years individual stars change, for example from main-sequence stars into red giant stars, or from asymptotic giant branch stars into planetary nebulae and white dwarfs, whereas biological evolution affects populations over many generations rather than individuals.

'Stellar evolution' is more like the life-cycle of an individual animal or plant than like biological evolution, and it is unfortunate that the same word has been applied to two such different processes. Adult stars do not give birth to baby stars that are slightly different from them, and there is nothing in the structure of a star that corresponds to the genome of a living thing. Also, the 'evolution' of a star, from a protostar to a compact remnant (e.g. white dwarf, neutron star or black hole) is deterministic and predictable, as is the life-cycle of an animal or plant, whereas the transformation of one biological species into another is neither deterministic nor predictable.