by cofty 266 Replies latest watchtower beliefs
DJS... just finished a revision session and like to come here to switch off a little. I have my last exam on Wednesday, a nice feeling :D
It helps that I don't need to pass it as I am already done, so coming here is no biggie right now.It helps me wind down and stops my brain firing at 100 mph, so I can nod off.....
Snare,
Excellent! I'm proud of you. I'm a couple of years behind and it will be a PhD rather than an MD, but you are an inspiration. Now go to sleep!
snare&racket I agree that we don't have a golden standard and that we might never do. If you take my filter I don't see why it wouldn't work. You add enough rules and exceptions and you will cover everything specially since is a finite example. The only thing I have seen that you cannot count is some types of infinity but we are talking of a discrete sets here.
Will it be practical probably not. Theory is not always possible (timespace, physical limitations etc.) for example I see problems at work that if we try to do them a certain way it will take us 100 years of computational power to do. So obivously I am not going to suggest to my boss that we should give it a try because it can be done but we'll gave it done after we die.
For example taking your blood red example. Since you know humans of different eras or enviroments have different shapes you could do it 2 ways I can think of.
Brute force: You look for every single variation and train every image. So if the blood cell is part of that set it passes the test.
Some other way: Since the shapes are irregular why not use volume or weight. You say if the bood cells are x +/- e cm^3 then it passes the test.
Sure this test alone would include blood cells of many other type of species but keep adding rules to the filter. You can OR and AND, and XOR the rules I don't see why it wouldn't work.
If you had access to the data of all species I don't see why it wouldn't work.
Is it practical: NO, probably to complex that is close to impossible.
Is it possible: Only in theory.
I think atrapado hit the nail on the head when he wrote:
From this quote what I gather was that Dawkins is saying you cannot define the essence of rabbit based on this. I see no proof that you cannot define a rabbit just that his method didn't work. All I was trying to say was "sure we don't have a definition or a definition that we agree" but that doesn't proove that a definition doesn't exits or that someday we'll find or agree on one.
The issue here is one of nomenclature -- "what is a species?" I brought up a related problem, which is "when does a species stop being one species?" If, for instance, sickle-celled humans could not reproduce with round-celled humans. This is easy to imagine, even though it is not true. Imagine that the developing embryo of a hybrid human always died early in development, as it was developing its circulatory system, because it was receiving conflicting instructions to create red blood cells with mutually incompatible traits, or because its mother's circulatory system was not compatible with it and thus the womb was inhospitable.
This would mean that we had two distinct groups of humans in the world. We would have to create a new species name, like H. secula (Latin for "sickle"), for the sickle-celled humans. According to this scenario, the first person who was born with sickle cells was the first member of that species, even if it was not recognized at the time they were born. Where this gets confusing is that, if a person is born who cannot reproduce with any other kin of his family, no matter how closely or distantly related, then his line would immediately die out.
Therefore, there must be a gradually declining reproductive compatibility in nature between diverging groups. We could measure this as a percentage of fetus viability. The first generation that evolves in some way may have 99.5% viability with his ancestors, and establishes offspring of his own which evolve a tiny bit more. They have 99% viability with the first generation's parent generation. The third generation has 98.5% viability, and so on.
According to this reasoning, one could at least define a genetic point where offspring were statistically less likely to be possible between two groups (<= 50%). If we defined that line as the demarcation between species, then absolutely there was a first human, who could not reproduce with contemporaries from related families who were slightly more simian than he was. Fortunately he had enough relatives who were closer genetically, but not too close, that his line was viable.
Now, this is all following the notion that species are defined by their ability to reproduce with each other, and looking at Wikipedia, I see this is only one way to define a species. But according to this long-accepted definition, I fail to see why there cannot be a first member of any given species. This is not questioning evolution, this is questioning the system of nomenclature's limits and definitions.
If you take my filter I don't see why it wouldn't work. You add enough rules and exceptions and you will cover everything specially since is a finite example.
That's been explained at least five times to you. Unknown unknowns, arbitrary definitions, lack of prediction, not knowing what to do when your tests produce inconsistent results, etc.
The only thing I have seen that you cannot count is some types of infinity but we are talking of a discrete sets here.
Infinite set work just fine in math.
Now, this is all following the notion that species are defined by their ability to reproduce with each other, and looking at Wikipedia, I see this is only one way to define a species. But according to this long-accepted definition, I fail to see why there cannot be a first member of any given species.
Because it would have no partner to reproduce with (in sexual reproductive scenarios) and would die off. This is why populations evolve into new species, not individuals.
I did address that, Viviane, see my 2nd and 3rd to last paragraphs. The suggestion that there can be no first human because everything evolved from something else seems to me to suggest that there are no humans at all. You cannot eat your cake and have it too. Either there are species which can be defined, and one of those species, H. sapiens, has a nickname, "human", or there are no clear species distinctions and therefore no such things as humans. In this way of looking at things, there is only life, and some life can interbreed, and some cannot. Wikipedia says:
Jody Hey described the species problem as a result of two conflicting motivations by biologists:
1. to categorize and identify organisms;
2. to understand the evolutionary processes that give rise to species.
I did address that, Viviane, see my 2nd and 3rd to last paragraphs.
I read those. You are trying to make the case for a first of a species and then prop it up by describing a population evolving. As you said, you can't have your cake and eat it too.
The suggestion that there can be no first human because everything evolved from something else seems to me to suggest that there are no humans at all.
That's not the suggestion. It's that speciation occurs is a population, not an indivual. Why is that so hard to grasp?
Either there are species which can be defined, and one of those species, H. sapiens, has a nickname, "human", or there are no clear species distinctions and therefore no such things as humans. In this way of looking at things, there is only life, and some life can interbreed, and some cannot. Wikipedia says:
That's been brought up several time, mainly bu Cofty and myself to point out some of the errors in the suggested tests and the arbitrary nature of terms.
Apog, with respect, you are using wikipedia to look up the definition of species, yet you want to present a mechanism for defining all species.. may I humbly suggest a little humility. Is there not a teeny weeny bit of your mind saying maybe you are not fully aware of all the facts and variables?
This is how the experts do it... what exactly is at fault here?
Hey this thread has come a long way while I was sleeping.
Very interesting arguments. I have to say that it makes sense to me there is not one single first human. A generation of a certain species would all be mating at the same time and probably have multiple numbers of offspring all around the same time, the evolutionary changes would have been so small and unnoticiable at the time but I would agree that a particular generation would all have similar evolutionary changes, that eventually led to humans.
Kate - Dawkins never called all church-goers ignorant. Stop trying to derail the thread.- cofty
I agree, Dawkins catagorised individuals as uneducated church goers. However I am sorry the thread nearly got derailed, I was trying to get posters to post on a more appropriate thread, but hey I am not that influential it didn't work. But the thread is going good and staying on topic. Good thread Cofty.
Kate xx
