Tree of Life: What Creature Was at the Fork?

[Subduction Zone]

The first human had to arrive via a zygote created by two living entities. Humans would not exist today unless a pair of non-humans birthed a human. I already know your response. . .


For brevity, I'd like to restate in fewer words:

There was a period of time when non-humans gradually became more human-like.

Now, I'd like to complete the thought:

There was a period of time when non-humans gradually became more human-like until they became human.

If they become human, the becoming of human had to occur with a birth or it had to occur after birth. Which is it?

There is no one point when you can point to our evolution and say this generation is human, the previous generation was not.

Here is an apt analogy. Let's say you had a complete video record of your life. At exactly what second did you stop being a baby and become a child?

 

[Loudmouth]

If they become human, the becoming of human had to occur with a birth or it had to occur after birth. Which is it?

Neither. There was no single birth where the child was a human and the parents were a non-human.

 

[Kylie]

The first human had to arrive via a zygote created by two living entities. Humans would not exist today unless a pair of non-humans birthed a human. I already know your response. . .

Yes, that is my response. Any individual is the same species as its parents. The changes between parent and child is never going to be enough to call them different species. For such a change, you have to look at the differenceds that accumulate little by little over many generations.

What you are saying is no different to saying, "Squash nosed pugs would not exist today unless a pair of long nosed pugs birthed a squashed nose pug." We know this did not happen. The long nosed pugs gradually got squashier noses over many generations. You're still thinking in terms of Human or not-human. Stop doing that.

For brevity, I'd like to restate in fewer words:

There was a period of time when non-humans gradually became more human-like.

Now, I'd like to complete the thought:

There was a period of time when non-humans gradually became more human-like until they became human.

Almost right, but you've still got the "human" vs "not-human" thing going on.

If they became human, the becoming of human had to occur with a birth or it had to occur after birth. Which is it?

The becoming of human happened slowly over many generations. It did not happen in one generation.

But really, I'm way ahead of you in the conversation which may be the source of our circular discussion. Please see post #100 and let's talk specifically about that post and it's incorrect assumptions.

Okay. I'll quote that post again and reply to it...

I think we agree that humans once did not exist, now they do, they birth one at a time as did the ancestor immediately prior to human.

Yes, it all happened generation by generation.

There are many parameters that define human. One most important parameter is the ability for a human to procreate. It's important because without that ability, humans could not exist. It's also important for coherency for our topic.

This is right, but I suspect that you are thinking of these parameters as being either present or absent. This is not the way to think about it. It's like the difference between hot and cold. Can you say, "At temperature X degrees it is cold, but at temperature X+1 degrees it is hot." Of course you can't. Hotness is a property, but it has various degrees. As the temperature rises, it becomes less and less cold and more and more hot. The same thing happens with the features that make humans Human.

All humans of opposite sex can procreate. Conversely, if a human cannot procreate with another living entity, that other entity is not human.

By and large.

Referring to the purple-to-green illustration, different degrees of human-like is depicted in the area where the initial purple began to change to final green. So, the initial purple and final green is excluded as the initial purple is non-human while the final green is completely human. The very first pixel that wasn't initial purple had some change. That first changed pixel may ultimately represent multiple generations, but the first change must have initiated with an individual. Every adjacent pixel, moving from initial purple to final green, that is not the same color as its prior neighbor, represents another change towards human initiated by an individual. Again, that new color may represent multiple generations, but the actual color change must be attributed to a single birth. This paragraph now generally describes every change in color between initial purple and final green.

It didn't need to start with an individual. Many individuals in the population might have had the particular variation that developed into what humans have today. You seem to be fixated on the idea of it all starting with one individual.

Let's focus on the color change events. The color change represents only the change towards human and it must be the result of a birth. The color may not change again for a long time and there may be numerous individuals of the same color, but the only concern is the individual born of the new color as all others of the same color are offspring of the one born of the new color.

Again, mostly right, but stop thinking in terms of individuals. Start thinking in terms of populations, of groups. It is populations that evolve, not individuals.

Let's start at the first color change from initial purple or said another way, let's start at the first individual born with that first human element and ask a question. Can this first non-initial purple reproduce with a final green?

No, the difference between them is too great.

Or asked another way, can this first individual born with the first human element reproduce with a human? The answer must be either yes or no. If the answer is no, then we can advance to the next color change represented by a single birth and repeat the question. There will be a new color when the answer must be yes. The precise color is not relevant.

We have identified the first color that can reproduce with green. Said another way, we have identified the first living entity that can reproduce with human. Because this first living entity can reproduce with humans, we can call it human, or more specifically we can call it the first human.

It doesn't quite work this way.

Let's use letters for the moment instead of colours. We can go from A (the non human ancestor) to Z (modern Humans). A cannot breed with Z. In all likelihood, neither could B. What you seem to be asking is something like, "Will we ever get to a point where Q cannot breed with Z, but R can breed with Z?"

The answer to that is, once again, you are thinking in terms of absolutes. Either they can breed or they can't.

It would be better to say that Q has a small chance of getting Z pregnant, and R has a slightly better chance. S has an even better chance, and T has an even better chance again.

So it's not a situation of they either can or can't. It's more a situation of how LIKELY it is that sex between them could result in a pregnancy. As the generations passed, it became more and more likely that they would be able to successfully reproduce with modern humans.

 

[mzungu]

The first human had to arrive via a zygote created by two living entities. Humans would not exist today unless a pair of non-humans birthed a human. I already know your response. . .


For brevity, I'd like to restate in fewer words:

There was a period of time when non-humans gradually became more human-like.

Now, I'd like to complete the thought:

There was a period of time when non-humans gradually became more human-like until they became human.

If they became human, the becoming of human had to occur with a birth or it had to occur after birth. Which is it?

But really, I'm way ahead of you in the conversation which may be the source of our circular discussion. Please see post #100 and let's talk specifically about that post and it's incorrect assumptions.

I understand your frustration and understand your argument, but you need to think outside the box. If you are asking; at which point in time could modern humans be able to produce a 100% fertile offspring if they could mate with distant ancestors then the answer would be lets say 6. But keep in mind that even today we have children born which are not fertile or are not 100% fertile albeit at very low incidences.

Now also don't forget that 6 could produce 100% fertile offspring with 5 and 7 but not with 8 and 4.

Also the increments are almost infinite when it comes to % of fertility of the offspring.

 

[rush1169]

I think we agree that humans once did not exist, now they do, they birth one at a time as did the ancestor immediately prior to human.

There are many parameters that define human. One most important parameter is the ability for a human to procreate. It's important because without that ability, humans could not exist. It's also important for coherency for our topic.

All humans of opposite sex can procreate. Conversely, if a human cannot procreate with another living entity, that other entity is not human.

Referring to the purple-to-green illustration, different degrees of human-like is depicted in the area where the initial purple began to change to final green. So, the initial purple and final green is excluded as the initial purple is non-human while the final green is completely human. The very first pixel that wasn't initial purple had some change. That first changed pixel may ultimately represent multiple generations, but the first change must have initiated with an individual. Every adjacent pixel, moving from initial purple to final green, that is not the same color as its prior neighbor, represents another change towards human initiated by an individual. Again, that new color may represent multiple generations, but the actual color change must be attributed to a single birth. This paragraph now generally describes every change in color between initial purple and final green.

Let's focus on the color change events. The color change represents only the change towards human and it must be the result of a birth. The color may not change again for a long time and there may be numerous individuals of the same color, but the only concern is the individual born of the new color as all others of the same color are offspring of the one born of the new color.

Let's start at the first color change from initial purple or said another way, let's start at the first individual born with that first human element and ask a question. Can this first non-initial purple reproduce with a final green? Or asked another way, can this first individual born with the first human element reproduce with a human? The answer must be either yes or no. If the answer is no, then we can advance to the next color change represented by a single birth and repeat the question. There will be a new color when the answer must be yes. The precise color is not relevant.

We have identified the first color that can reproduce with green. Said another way, we have identified the first living entity that can reproduce with human. Because this first living entity can reproduce with humans, we can call it human, or more specifically we can call it the first human.

Green text indicates that you agree.
Blue text indicates that you agree with a qualification.
Red text indicates that you do not agree.

Starting with the blue text:
There are many parameters that define human. One most important parameter is the ability for a human to procreate. It's important because without that ability, humans could not exist. It's also important for coherency for our topic.
You agree with qualification:

This is right, but I suspect that you are thinking of these parameters as being either present or absent. This is not the way to think about it. It's like the difference between hot and cold. Can you say, "At temperature X degrees it is cold, but at temperature X+1 degrees it is hot." Of course you can't. Hotness is a property, but it has various degrees. As the temperature rises, it becomes less and less cold and more and more hot. The same thing happens with the features that make humans Human.

There are two points included in your response that render your qualification not applicable to what I've stated. The first point you made that causes a problem is that I'm talking about a specific human parameter of a human gamete while you are talking about all the parameters of being human as indicated by bold. Although my first sentence mentioned all parameters, the focus is on the human gamete.

The second point you made is a problem because you didn't realize that I was talking about a specific human feature rather than the set of all human features. That is, you include all features that changed during the non-human to human transition when making the cold to hot analogy. If you had realized that I'm talking about human zygote production, it would be clear that pregnant or not pregnant is not a matter of degrees (no pun intended).

I hope you can re-address my statement more directly. If you still disagree, please narrow your focus in your response.

The first red section:
While this section is lengthy, I can restate it as:
". . . the first [ color] change must have initiated with an individual [birth]."
You address this statement as:

It didn't need to start with an individual. Many individuals in the population might have had the particular variation that developed into what humans have today. You seem to be fixated on the idea of it all starting with one individual.

If many individuals in the population had a variation that developed into humans, where did that variation come from if it didn't start with one individual? I think it's impossible that a variation could exist in a population without having started with one individual, please help me understand how that works.

To the second blue section:
I can restate the point of that section as:
"The color change represents only the change towards human and it must be the result of a birth."
You address this statement as:

Again, mostly right, but stop thinking in terms of individuals. Start thinking in terms of populations, of groups. It is populations that evolve, not individuals.

In other words, you agree with the statement only if we stop talking about gamete compatibility and start talking about general features. However, we are talking about gamete compatibility, or at least that's what I'm trying to communicate to you. The topic is not about all the parameters that describe human. The topic is about the specific parameter of gamete compatibility. Do you agree with the statement when limited to the topic intended?

In the final red section I created a mental exercise of testing compatibility with a typical human gamete of today against every birthed creature starting at a point where compatibility is non-existent and continuing forward until compatibility is present. When compatibility is present, the first human has become.

You responded with a switch from colors to letters:

We can go from A (the non human ancestor) to Z (modern Humans). . . .What you seem to be asking is something like, "Will we ever get to a point where Q cannot breed with Z, but R can breed with Z?"

The answer to that is, once again, you are thinking in terms of absolutes. Either they can breed or they can't.

It would be better to say that Q has a small chance of getting Z pregnant, and R has a slightly better chance. S has an even better chance, and T has an even better chance again.

So it's not a situation of they either can or can't. It's more a situation of how LIKELY it is that sex between them could result in a pregnancy. As the generations passed, it became more and more likely that they would be able to successfully reproduce with modern humans.

Pregnancy is absolute. If "Q has a small chance of getting Z pregnant" then there is absolute sexual compatibility between Q and Z. Either the two gametes can create a zygote that produces a fertile, viable offspring or they cannot. It's not a matter of degrees. If Q and Z can produce a zygote, then R is no longer on topic. However, P would necessarily enter the topic, but since you indicated that Q was the first letter that exhibited sexual compatibility with Z, you've illustrated the first human (in my mind).

If you would, please compose a new iteration addressing the reds and blues and my corresponding comments against our disagreements.

 

[rush1169]

I understand your frustration and understand your argument,

but you need to think outside the box.

:o

If you are asking; at which point in time could modern humans be able to produce a 100% fertile offspring if they could mate with distant ancestors then the answer would be lets say 6. But keep in mind that even today we have children born which are not fertile or are not 100% fertile albeit at very low incidences.

Now also don't forget that 6 could produce 100% fertile offspring with 5 and 7 but not with 8 and 4.

Your presentation is concise and easy to follow and I'd like to explore your post. However, it has an element of ambiguity that I have to address.

If a 6 is fertile with a modern human gamete, what number are we assigning to modern human?

A modern human gamete is 100% fertile with a 6.
A 6 is 100% fertile with a 5 and 7.
A 6 is not 100% fertile with 4 and 8.

So, a modern human gamete must be represented by either a 5 or 7. To maintain a 'going forward' position, I'll assign the modern human gamete to a 7. With that assignment, 8 must refer to a future gamete of a entity that doesn't exist today and 4 must refer to an earlier gamete produced by an entity that didn't live when 6 was alive. The topic I've presented is not concerned with 4 (purple) or 8 (whatever color establishes after green).

So 7 is logically established as a modern human gamete. I'd like to remove the '100%' term because fertility is a 0% or 100% proposition when considering the production of a fertile, viable offspring. The word fertile necessarily implies 100% and 'not fertile' necessarily implies 0%. Therefore, we can rewrite the construct as:

A 7 is fertile with a 6.
A 6 is fertile with a 5 and 7.
A 7 is not fertile with a 5 (a given in your scenario and logically so, see above)

The 6 could mate with either a human (7) or a life-form (5). What 'name' we give to 5 is arbitrary, but we know it is not fertile with 7 which indicates calling it human would be the least logical name to assign it since we're focused on fertility as being a requirement of same-named creatures. Let's just stick with 5 so that I can complete my thought. Six needs a name, but it exhibits fertility with human (7) and 5. On one hand, it's fine to call it human because of it's fertility with human. On the other hand, it's fine to call it 5 (or any other name besides human). Since it's fine to call 6 human, we have arrived at the first human.

Footnote: (A 6 is not fertile with 4 and 8) is eliminated as being off topic.

Also the increments are almost infinite when it comes to % of fertility of the offspring.

I didn't include this last sentence in the body of my response, because this statement is true when thinking about chances of a pregnancy occurring between two gametes that begin with any percentage greater than a 0% chance of zygote production. However, the discussion is about two gametes that begin with the potential (ie >0%) of producing a viable, fertile offspring. While it may be multiple attempts are required to fulfill whatever % is assigned to the probability of the conception, once the conception is established the probability is moot.

 

[mzungu]

Your presentation is concise and easy to follow and I'd like to explore your post. However, it has an element of ambiguity that I have to address.

No ambiguity but a simple mistake. Sorry. The correct answer would be 7. But we are talking about at least some possibility of a fertile offspring even if it is less than 1%.

The time scales between 8 and 7 etc. should be considered as many generations. In fact I should not be using whole numbers but something like 8.000000000 - 7.999999999 - 7.999999998 - etc. The actual values are not important as what I am trying to put across is that each generation is different to the previous albeit at very minute levels. Over time these differences grow and the % of fertile offspring drops as we go back.

Sorry but English is not my mother tongue and thank you for pointing out my mistake.

 

[Loudmouth]

The 6 could mate with either a human (7) or a life-form (5). What 'name' we give to 5 is arbitrary, but we know it is not fertile with 7 which indicates calling it human would be the least logical name to assign it since we're focused on fertility as being a requirement of same-named creatures.

There are modern humans alive today who can not conceive a child together because they are genetically incompatible. Are they not human?

Also, what is and isn't human is a completely arbitrary decision that is retroactively assigned by us. There was never a moment where non-human parents gave birth to a human child. It doesn't work that way. This is why we keep giving you analogies to help drive this point home. There was no point where a Middle English speaker had a child who spoke perfect modern English.

Also, the gradients of colors in those diagrams represents an entire population, not a single individual. The color at any one spot is the average of that entire population. In each generation there will be new alleles that increase in number, and alleles that dwindle in number. This can only happen with a population view, not an individualistic view.

 

[rush1169]

No ambiguity but a simple mistake. Sorry. The correct answer would be 7. But we are talking about at least some possibility of a fertile offspring even if it is less than 1%.

The time scales between 8 and 7 etc. should be considered as many generations. In fact I should not be using whole numbers but something like 8.000000000 - 7.999999999 - 7.999999998 - etc. The actual values are not important as what I am trying to put across is that each generation is different to the previous albeit at very minute levels. Over time these differences grow and the % of fertile offspring drops as we go back.

Sorry but English is not my mother tongue and thank you for pointing out my mistake.

No problem and it wasn't truly ambiguous as human=7 was easily deduced, but I did point it out to help others. I don't think the exact numbers you use matter in your post nor my reply. Expanses of time have been established. Oh, I see you pointed out that the actual values are unimportant. That each generation is different is established in this thread, as is each birth. That fewer individuals would have gametes fertile with human gametes as we go back in time is also established in this thread. Your reply to my post didn't contribute additional information nor disagree with what I said. I think we have a meeting of the minds!?

 

[rush1169]

There are modern humans alive today who can not conceive a child together because they are genetically incompatible. Are they not human?

I don't understand your statement. Yes, they are human. Are you saying that an individual is born with a genetic defect that renders it sterile? Are you saying that there are two individuals that are incompatible with each other, but compatible with most anyone else? Are you saying they are both sterile? Those are rhetorical questions because your statement is outside the scope of the discussion.

Also, what is and isn't human is a completely arbitrary decision that is retroactively assigned by us. There was never a moment where non-human parents gave birth to a human child. It doesn't work that way. This is why we keep giving you analogies to help drive this point home. There was no point where a Middle English speaker had a child who spoke perfect modern English.

We are trying very hard to stay on topic. The topic consists a logical 'following' back in time of a human gamete and it's eventual incompatibility with the gamete of it's ancestor - see post #100 for the full run-down.

Also, the gradients of colors in those diagrams represents an entire population, not a single individual. The color at any one spot is the average of that entire population. In each generation there will be new alleles that increase in number, and alleles that dwindle in number. This can only happen with a population view, not an individualistic view.

The 'gradients of colors diagram' originally included chimps, bonobos, humans, LCAs of chimp/bonobos, and LCAs of humans/chimp/bonobos. I agree, at that time the color gradients represented populations of changed creatures. However, future posts by me described a finer resolution to the picture such that focus should be on the initial-purple to final-green area and, since a color change must be initiated by an individual birth, we've further zoomed to a closer examination and discarded the resultant same color creatures that followed that first individual. It seems you've not followed this thread closely and as a result your commentary lacks coherency with what we are currently discussing and creates an appearance of going in circles.

 

[Kylie]

There are two points included in your response that render your qualification not applicable to what I've stated. The first point you made that causes a problem is that I'm talking about a specific human parameter of a human gamete while you are talking about all the parameters of being human as indicated by bold. Although my first sentence mentioned all parameters, the focus is on the human gamete.

This is lightswitch thinking. Either it is or it isn't. Either it is Human or it is not human. This is not they way to think about evolution. Remember, evolution is a gradual change, not an instant one. How far do you have to go in order to go a long way? 1000 miles? Maybe. But does that mean that 999 miles is not a long way? There is no point where a distance is "not a long way" and yet an extra mile is "a long way."

The same thing goes for the parameters of being human. As the human ancestors evolved, their traits gradually became more an more human. You've gotta start thinking in terms of a continuous spectrum, not absolute yes/no ideas.

The second point you made is a problem because you didn't realize that I was talking about a specific human feature rather than the set of all human features. That is, you include all features that changed during the non-human to human transition when making the cold to hot analogy. If you had realized that I'm talking about human zygote production, it would be clear that pregnant or not pregnant is not a matter of degrees (no pun intended).

Let's take a human trait and call it A. Let's define A as something that all humans have, and any life form that does not have A is not a human. As the human ancestors evolved, they had a trait that was Not-A. As the generations continued, the trait gradually drifted away from being Not-A and became more and more A-like. There would have been a point where it was halfway a long, halfway between Not-A and A. There was never a point where it was 100% Not-A in one generation and 100% A in the next.

If many individuals in the population had a variation that developed into humans, where did that variation come from if it didn't start with one individual? I think it's impossible that a variation could exist in a population without having started with one individual, please help me understand how that works.

Think of hairiness in Humans. There are some people who are just naturally hairier than other people. No, at the moment, the level of hairiness is not under a selective pressure, so evolution doesn't act on it. But, a similar thing happened in a species of elephant. As the weather became cooler (over a long time), the hairier individuals survived better because they were better able to cope with the cold. Over many generations, this hairiness became more widespread, leading to wooly mammoths.

In other words, you agree with the statement only if we stop talking about gamete compatibility and start talking about general features. However, we are talking about gamete compatibility, or at least that's what I'm trying to communicate to you. The topic is not about all the parameters that describe human. The topic is about the specific parameter of gamete compatibility. Do you agree with the statement when limited to the topic intended?

I still thinking you are looking at this with a yes/no attitude.

Pregnancy is absolute. If "Q has a small chance of getting Z pregnant" then there is absolute sexual compatibility between Q and Z. Either the two gametes can create a zygote that produces a fertile, viable offspring or they cannot. It's not a matter of degrees. If Q and Z can produce a zygote, then R is no longer on topic. However, P would necessarily enter the topic, but since you indicated that Q was the first letter that exhibited sexual compatibility with Z, you've illustrated the first human (in my mind).

No, pregnancy is not absolute. People can have conditions that make it very hard for them to conceive. I had trouble getting pregnant, for example. It is certainly not a case of "Male and female have sex, female gets pregnant." There are any number of reasons why that might not be the case, and any number of reasons why pregnancy might be easier or harder to acheive than on average.

In the line of human ancestors as they evolved into humans, you will never find that one generation had a 0% chance of getting a modern human female pregnant, while the generation after had a 100% chance.

 

[mzungu]

This is lightswitch thinking. Either it is or it isn't. Either it is Human or it is not human. This is not they way to think about evolution. Remember, evolution is a gradual change, not an instant one. How far do you have to go in order to go a long way? 1000 miles? Maybe. But does that mean that 999 miles is not a long way? There is no point where a distance is "not a long way" and yet an extra mile is "a long way."

The same thing goes for the parameters of being human. As the human ancestors evolved, their traits gradually became more an more human. You've gotta start thinking in terms of a continuous spectrum, not absolute yes/no ideas.



Let's take a human trait and call it A. Let's define A as something that all humans have, and any life form that does not have A is not a human. As the human ancestors evolved, they had a trait that was Not-A. As the generations continued, the trait gradually drifted away from being Not-A and became more and more A-like. There would have been a point where it was halfway a long, halfway between Not-A and A. There was never a point where it was 100% Not-A in one generation and 100% A in the next.



Think of hairiness in Humans. There are some people who are just naturally hairier than other people. No, at the moment, the level of hairiness is not under a selective pressure, so evolution doesn't act on it. But, a similar thing happened in a species of elephant. As the weather became cooler (over a long time), the hairier individuals survived better because they were better able to cope with the cold. Over many generations, this hairiness became more widespread, leading to wooly mammoths.



I still thinking you are looking at this with a yes/no attitude.



No, pregnancy is not absolute. People can have conditions that make it very hard for them to conceive. I had trouble getting pregnant, for example. It is certainly not a case of "Male and female have sex, female gets pregnant." There are any number of reasons why that might not be the case, and any number of reasons why pregnancy might be easier or harder to acheive than on average.

In the line of human ancestors as they evolved into humans, you will never find that one generation had a 0% chance of getting a modern human female pregnant, while the generation after had a 100% chance.

I think Rush is insisting for the sole purpose of finding a way to include the supernatural into ToE. There is no other explanation! Your examples can be understood very clearly by any layman.

 

[Kylie]

I think Rush is insisting for the sole purpose of finding a way to include the supernatural into ToE. There is no other explanation! Your examples can be understood very clearly by any layman.

I do hope not.

 

[rush1169]

I am trying to understand something and I'm trying to communicate to you what I don't understand with the hope that you understand it better than me and can communicate back the missing element(s) needed for me to gain understanding. Your responses have helped me focus my misunderstanding down to a pinpoint topic. This is what I've figured out:

If I take a human gamete of a person alive today and test it for sexual compatibility against every creature that has ever been born, there must be, for humans to exist today, a birthed creature that is compatible and it's parents are not. There had to be a first. The only two alternatives are: 1) That human gamete is never compatible or 2) that human gamete is compatible with every creature since life started. Neither alternative is tenable.

I realize some who have posted here and some who are just lurking this thread disagree and that's OK - I need only to gain understanding for myself. Thank you all for your help as I've reached clarity and coherency. My conclusion is there must have been a first human and that human must have been born of a pair of non-humans. You don't have to agree and, of course, you are welcome to continue posting why you don't agree, but of the explanations presented, none, in my mind, are logically coherent.

I've been taught by some that there was never a first human, I've been taught by some that a pair of non-humans cannot birth a human. Until now, I've never questioned either notion. In fact, as this thread started, I was really just wondering why in a 'tree of life' nobody could identify nodes and my thought process continued to ever finer levels of detail until it brought into question my unchallenged acceptance of both notions as they relate to the fact that humans exist.

If there were never a first human, then humans cannot exist. A first is required. Since there was a first human, it must have been birthed by a pair of non-humans and it required dual sexual-compatibility.

For me, it follows that this realization must extend to all creatures that graduated from non-existent to existent. Every creature that has existed started with a first individual that required dual sexual compatibility. This realization has kicked-off a whole new set of questions and inconsistencies of what I thought I knew - it's exciting to me as I continue my journey of continuing education.

Thank you to everyone who participated in this thread and I hope all of you realize that even though we may disagree your posts have greatly enhanced my understanding of life.

 

[Kylie]

If I take a human gamete of a person alive today and test it for sexual compatibility against every creature that has ever been born, there must be, for humans to exist today, a birthed creature that is compatible and it's parents are not. There had to be a first. The only two alternatives are: 1) That human gamete is never compatible or 2) that human gamete is compatible with every creature since life started. Neither alternative is tenable.

No. I've explained this many times.

Okay. I'm a woman. Any typical male today has a certain percentage of getting me pregnant. Let's call it 100% compatible (it's no, because there are some guys who are sterile, and there are other factors as well, but let's just use 100% for the sake of the example).

If I go back a single generation, any typical male will have a 99.999999999999999% chance of being compatible.

I go back another generation, and it's 99.999999999999998% chance. And the generation before that is 99.999999999999997%. Keep going back and you'll get to a point where a typical male has a 50% chance of being compatible. And keep going back further and you'll eventually get to a point where a typical male has a 0% chance of being compatible. But the generation after this 0% male will not have a 100% chance of being compatible, will he? He'll have a 0.0000000000001% chance of being compatible.

Now, I've explained to you many times that you need to stop thinking in terms of human and non human. This is a lesson you need to learn. There is no point of separation. There is a gradual change. You'll never get any further in your understanding until you learn this. You MUST learn this concept of gradual changes.

I realize some who have posted here and some who are just lurking this thread disagree and that's OK - I need only to gain understanding for myself. Thank you all for your help as I've reached clarity and coherency. My conclusion is there must have been a first human and that human must have been born of a pair of non-humans. You don't have to agree and, of course, you are welcome to continue posting why you don't agree, but of the explanations presented, none, in my mind, are logically coherent.

No, you haven't been reading. I have said MANY times that there was never a point where non humans gave birth to a human.

If there were never a first human, then humans cannot exist. A first is required. Since there was a first human, it must have been birthed by a pair of non-humans and it required dual sexual-compatibility.

No, and I've already explained this. Was there a first green pixel in my diagram? Did it come from a non-green pixel?

 

[rush1169]

No. I've explained this many times.

Okay. I'm a woman. Any typical male today has a certain percentage of getting me pregnant. Let's call it 100% compatible (it's not, because there are some guys who are sterile, and there are other factors as well, but let's just use 100% for the sake of the example).

The above point I understand, but your use of 'compatibility' is not the same as my use. Two human gametes are compatible, it's proven by our existence and that is an example of my use of the word. Conversely, a human gamete and a dog gamete are not compatible. Your use of the word refers to the factors involved that can deter a conception. In my use of the word 'compatible', any talk of percentages are moot but if insisted then a pair of human gametes are 100% compatible and a human gamete and a dog gamete are 0% compatible. In other words, the potential exists between human and human and the potential does not exist between human and dog. The word 'potential' is used to describe the two gametes ability to produce a fertile, viable offspring.

I agree, once the potential is present then there exists a variable percent chance of production of a fertile, viable offspring. However, when talking about the potentiality of a pair a gametes, they either are compatible or they are not. There can be no degrees of potential. To further illustrate, you mentioned in another post that you and your husband had to make more than one try at pregnancy. You tried because the potential was there even though success was not 100%.

For the reasons I've mentioned, your following description of percentages carried out past a trillionth of a percent are not applicable to my conceptualization of the topic. Even so, I would like to add a comment or two.

If I go back a single generation, any typical male will have a 99.999999999999999% chance of being compatible.

I go back another generation, and it's 99.999999999999998% chance. And the generation before that is 99.999999999999997%. Keep going back and you'll get to a point where a typical male has a 50% chance of being compatible. And keep going back further and you'll eventually get to a point where a typical male has a 0% chance of being compatible. But the generation after this 0% male will not have a 100% chance of being compatible, will he? He'll have a 0.0000000000001% chance of being compatible.

When we arrive at a non-compatible (0%) entity (or generation), an individual from that generation birthed an individual that has a 0.0000000000001% chance of being compatible with today's human gamete. While I consider the fact that this individual has the potential to produce a fertile, viable offspring when mated with today's human as being compatible (100%), to maintain your percentages, we could say that if 10 trillion of today's human gametes were introduced to this individual's gamete we should expect a fertile, viable offspring to occur. The potential is there and it is the potential that is either 0% or 100%, or as I prefer to say, either not compatible or compatible.

It is that birth of that first individual that has within it the potential to reproduce with human that should be considered the first human. It can reproduce with humans. It is a human. It is the first human. Of course, we also have to deal with the fact that this individual must also retain potential to reproduce with others in the population that do not have human gamete compatibility, but that realization should be reserved for another time.

Now, I've explained to you many times that you need to stop thinking in terms of human and non human. This is a lesson you need to learn. There is no point of separation. There is a gradual change. You'll never get any further in your understanding until you learn this. You MUST learn this concept of gradual changes.

I promise I understand the concept of gradual change.

No, you haven't been reading. I have said MANY times that there was never a point where non humans gave birth to a human.

I promise I have been reading very closely. Repetition does not increase coherency in what is being repeated, but can increase coherency elsewhere.

No, and I've already explained this. Was there a first green pixel in my diagram? Did it come from a non-green pixel?

Regardless of the color and even as you described above, there was a first individual born with dual sexual compatibility. It could successfully mate with it's contemporaries who couldn't mate with modern human and it could successfully mate with modern human. There is no other way for humans to exist.

 

[mzungu]

The above point I understand, but your use of 'compatibility' is not the same as my use. Two human gametes are compatible, it's proven by our existence and that is an example of my use of the word. Conversely, a human gamete and a dog gamete are not compatible. Your use of the word refers to the factors involved that can deter a conception. In my use of the word 'compatible', any talk of percentages are moot but if insisted then a pair of human gametes are 100% compatible and a human gamete and a dog gamete are 0% compatible. In other words, the potential exists between human and human and the potential does not exist between human and dog. The word 'potential' is used to describe the two gametes ability to produce a fertile, viable offspring.

I agree, once the potential is present then there exists a variable percent chance of production of a fertile, viable offspring. However, when talking about the potentiality of a pair a gametes, they either are compatible or they are not. There can be no degrees of potential. To further illustrate, you mentioned in another post that you and your husband had to make more than one try at pregnancy. You tried because the potential was there even though success was not 100%.

For the reasons I've mentioned, your following description of percentages carried out past a trillionth of a percent are not applicable to my conceptualization of the topic. Even so, I would like to add a comment or two.



When we arrive at a non-compatible (0%) entity (or generation), an individual from that generation birthed an individual that has a 0.0000000000001% chance of being compatible with today's human gamete. While I consider the fact that this individual has the potential to produce a fertile, viable offspring when mated with today's human as being compatible (100%), to maintain your percentages, we could say that if 10 trillion of today's human gametes were introduced to this individual's gamete we should expect a fertile, viable offspring to occur. The potential is there and it is the potential that is either 0% or 100%, or as I prefer to say, either not compatible or compatible.

It is that birth of that first individual that has within it the potential to reproduce with human that should be considered the first human. It can reproduce with humans. It is a human. It is the first human.

No it is not human! Having 0.0000000000001% chance of getting a fertile offspring from a modern human does not delegate it to the modern humans as this % cannot maintain a viable population.

I promise I understand the concept of gradual change.

No you don't.

I promise I have been reading very closely. Repetition does not increase coherency in what is being repeated, but can increase coherency elsewhere.

Regardless of the color and even as you described above, there was a first individual born with dual sexual compatibility. It could successfully mate with it's contemporaries who couldn't mate with modern human and it could successfully mate with modern human. There is no other way for humans to exist.

You still don't understand. The reason I suspect why is because you want to include the Adam and Eve concept into it all. That my good man will not work! If you are trying to reconcile genesis with ToE then I am afraid you are barking up the wrong tree. If on the other hand you paid more attention to the science you would not have the reservations you are having on the subject. You simply cannot have the "FIRST" human. It has been explained to you so many times that it is getting to be tedious.

 

[Kylie]

The above point I understand, but your use of 'compatibility' is not the same as my use. Two human gametes are compatible, it's proven by our existence and that is an example of my use of the word. Conversely, a human gamete and a dog gamete are not compatible. Your use of the word refers to the factors involved that can deter a conception. In my use of the word 'compatible', any talk of percentages are moot but if insisted then a pair of human gametes are 100% compatible and a human gamete and a dog gamete are 0% compatible. In other words, the potential exists between human and human and the potential does not exist between human and dog. The word 'potential' is used to describe the two gametes ability to produce a fertile, viable offspring.

I agree, once the potential is present then there exists a variable percent chance of production of a fertile, viable offspring. However, when talking about the potentiality of a pair a gametes, they either are compatible or they are not. There can be no degrees of potential. To further illustrate, you mentioned in another post that you and your husband had to make more than one try at pregnancy. You tried because the potential was there even though success was not 100%.

Yeah, so even between me and my husband there was not a 100% compatibility.

For the reasons I've mentioned, your following description of percentages carried out past a trillionth of a percent are not applicable to my conceptualization of the topic. Even so, I would like to add a comment or two.

Why are they not applicable? If it makes any difference to the reproductive potential then natural selection can act on it.

When we arrive at a non-compatible (0%) entity (or generation), an individual from that generation birthed an individual that has a 0.0000000000001% chance of being compatible with today's human gamete. While I consider the fact that this individual has the potential to produce a fertile, viable offspring when mated with today's human as being compatible (100%), to maintain your percentages, we could say that if 10 trillion of today's human gametes were introduced to this individual's gamete we should expect a fertile, viable offspring to occur. The potential is there and it is the potential that is either 0% or 100%, or as I prefer to say, either not compatible or compatible.

We had an individual that had a 0.0000000000% compatibility with a modern human. That individual produced an off spring that had a 0.0000000001% compatibility with a modern human. But you must also remember that the 0.0000000001% individual had a 99.9999999999% compatibility with any individual from the generation its parents came from.

And secondly, the potential is not 0 or 100. There are infinitely many stages in between. You;ve got to stop thinking in such black and white terms, as I;ve told you before.

It is that birth of that first individual that has within it the potential to reproduce with human that should be considered the first human. It can reproduce with humans. It is a human. It is the first human. Of course, we also have to deal with the fact that this individual must also retain potential to reproduce with others in the population that do not have human gamete compatibility, but that realization should be reserved for another time.

But it also had an equal compatibility of reproducing with individuals that lived as far before it's time as it was before our time.

Think of it this way. Let's say we have modern Humans today, and this individual lived 500,000 years ago (let's say it was Homo heidelbergensis, which lived about that time). Let's say it had a 0.0000000001% chance of getting a modern human pregnant (it probably didn't, but we're just using it as an example. So, with a gap of 500,000 years, there is a 0.0000000001% chance of pregnancy. But, it would also have a 0.0000000001% chance of getting pregnant an individual that lived 500,000 years BEFORE it - a creature that lived a million years ago, such as homo erectus. So, if we should call Homo Heidelbergensis a human because it had a chance of breeding with modern humans, shouldn't we also say homo erectus is also really just Homo Heidelbergensis because it had a chance of reproducing with them? And since we've already agreed that all Homo Heidelbergensis are really modern humans, doesn't that make Homo erectus modern humans are well? And the species that lived before them Modern Humans? Of course it doesn't, no more than it means that the purple in my diagram is really a shade of green.

I promise I understand the concept of gradual change.

Then you need to learn that there can be stages in a gradual change that are different, even though there is very little changes in consecutive generations.

I promise I have been reading very closely. Repetition does not increase coherency in what is being repeated, but can increase coherency elsewhere.

But you keep making the same flawed judgements.

Regardless of the color and even as you described above, there was a first individual born with dual sexual compatibility. It could successfully mate with it's contemporaries who couldn't mate with modern human and it could successfully mate with modern human. There is no other way for humans to exist.

*sigh*

EVERY individual has dual compatibility (if you want to phrase it like that). I am compatible with individuals in the past, but the further back you get them from, the less likely they will be compatible with me. And I will be compatible with individuals from the future, but the further into the future you get them from, the less likely I will be compatible with them.

The same argument applies to you, and the people who lived a hundred years ago, a thousand or a million years ago.

 

[rush1169]

the potential is not 0 or 100. There are infinitely many stages in between.

I think we have identified a 'sticking point' between us that needs further fleshing out before we can continue. That sticking point concerns gamete compatibility. I explained my understanding of gamete compatibility and why it appears to be an all-or-nothing issue. You responded by saying that gamete compatibility is not yes/no but that gamete compatibility can be expressed as a percentage of compatibility.

I say you either get a fertile, viable offspring or you do not. You disagree, but don't explain why my assertion is wrong or the alternative scenario. We've reached agreement that there was a time when a human-compatible gamete began to exist. We agree, given sufficient attempts, that gamete could form a zygote with a human gamete. Now my question is, what 'degrees' exist between that zygote becoming a fertile, viable offspring and that zygote not becoming a fertile, viable offspring? It seems, without any way around, that a birth occurs, fully formed and reproductively functioning or not. On or off. 100% or 0%. True or false. Black or white. I cannot understand, based on what you've posted, how, if two gametes form a zygote that results in a fertile, viable birth that that birthed individual could be a certain percentage of fertile and viable.

I do understand using a percentage applicable to two humans having sex and that percentage being assigned to describe the chance of zygote formation and subsequent birth, but I am clueless as to how a percentage other than 0% or 100% could be attributed to a pair of gametes that both have the correct properties to join to form a zygote. In other words, we know a human gamete and a dog gamete do not have the correct properties to join and form a zygote (0%) and we know a pair of human gametes do have the correct properties to form a zygote (100%), but what is the nature of the product formed by a gamete that has a greater than 0% compatibility and less than 100% compatibility with a human gamete? It's seems nonsensical to contemplate the idea of, for example, 5% compatible gametes. Does that mean 5% of the time you'll get a birth of a fertile, viable offspring? That can't be the case, because the former 5% refers to compatibility of gametes to form a zygote where the latter 5% refers to all the other factors that come into play that result in a fertile, viable offspring. The former 5% is nonsensical because the pair of gametes either work when paired or they do not work when paired.

I hope I've explained what I don't understand clearly enough that you understand my lack of understanding sufficiently to explain the infinite degrees of compatibility between gametes.

 

[Kylie]

I think we have identified a 'sticking point' between us that needs further fleshing out before we can continue. That sticking point concerns gamete compatibility. I explained my understanding of gamete compatibility and why it appears to be an all-or-nothing issue. You responded by saying that gamete compatibility is not yes/no but that gamete compatibility can be expressed as a percentage of compatibility.

I say you either get a fertile, viable offspring or you do not. You disagree, but don't explain why my assertion is wrong or the alternative scenario. We've reached agreement that there was a time when a human-compatible gamete began to exist. We agree, given sufficient attempts, that gamete could form a zygote with a human gamete. Now my question is, what 'degrees' exist between that zygote becoming a fertile, viable offspring and that zygote not becoming a fertile, viable offspring? It seems, without any way around, that a birth occurs, fully formed and reproductively functioning or not. On or off. 100% or 0%. True or false. Black or white. I cannot understand, based on what you've posted, how, if two gametes form a zygote that results in a fertile, viable birth that that birthed individual could be a certain percentage of fertile and viable.

I do understand using a percentage applicable to two humans having sex and that percentage being assigned to describe the chance of zygote formation and subsequent birth, but I am clueless as to how a percentage other than 0% or 100% could be attributed to a pair of gametes that both have the correct properties to join to form a zygote. In other words, we know a human gamete and a dog gamete do not have the correct properties to join and form a zygote (0%) and we know a pair of human gametes do have the correct properties to form a zygote (100%), but what is the nature of the product formed by a gamete that has a greater than 0% compatibility and less than 100% compatibility with a human gamete? It's seems nonsensical to contemplate the idea of, for example, 5% compatible gametes. Does that mean 5% of the time you'll get a birth of a fertile, viable offspring? That can't be the case, because the former 5% refers to compatibility of gametes to form a zygote where the latter 5% refers to all the other factors that come into play that result in a fertile, viable offspring. The former 5% is nonsensical because the pair of gametes either work when paired or they do not work when paired.

I hope I've explained what I don't understand clearly enough that you understand my lack of understanding sufficiently to explain the infinite degrees of compatibility between gametes.

Think of it as a hole in one. If I hit the golf ball, what are the odds of it going straight into the cup? Probably pretty small. But that's starting from the tee (golf aficionados, please forgive my no doubt incorrect use of the terminology!).

But let's say I move closer to the hole. Now, I have an improved chance of getting a hole in one, don't I? It may still be a small chance, but it has nonetheless improved. Let's say I keep moving closer and closer to the hole. As I get closer, my chances of making a hole in one keep getting better. And when the ball is sitting on the edge of the hole, my chances of getting a hole in one are just about certain.

And yet, the hole in one is ALWAYS going to be a yes/no option. Either I get a hole in one or I don't. But the chances of getting it keep increasing. My potential for achieving the hole in one increases as I get closer. There's no magical distance where I have a 0% potential of a hole in one and then an extra step gives me a 100% potential for a hole in one.

If I am at a point where I have a 50% potential for a hole in one, I'll find that I generally get holes in one half the time, but the other half of the time I miss and the ball doesn't go in.

Likewise, the genetic compatibility is different over two individuals separated by many generations. The fewer generations between the two individuals, the greater the chance of genetic compatibility, even though the production of a fertile offspring is a yes or no thing.

Do you understand the golf analogy?