Mr. Mushrooms said:

zouden said:

Yes but evolution has been observed countless times, in the fossil record, in the field, and in the lab. There is no better theory to explain the diversity of life. If you think you have a better theory, I'd like to hear it. Otherwise I'm sticking with evolution.

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Actually, macroevolution is only an interpretation of the fossil evidence.  That's akin to saying alien spacecraft have been observed.  It's a weak argument.  The same for in the field.  We cannot observe speciation and we haven't.  We can look at two different yet very similar organisms and hypothesize they will break into different species.  As you know, speciation is supposed to take a long, long time. 

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zouden said:

Yes but evolution has been observed countless times, in the fossil record, in the field, and in the lab. There is no better theory to explain the diversity of life. If you think you have a better theory, I'd like to hear it. Otherwise I'm sticking with evolution.

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zouden said:

I'm just waiting to learn why evolution isn't a scientific theory.

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zouden said:

Mr. Mushrooms said:

zouden said:

Yes but evolution has been observed countless times, in the fossil record, in the field, and in the lab. There is no better theory to explain the diversity of life. If you think you have a better theory, I'd like to hear it. Otherwise I'm sticking with evolution.

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Actually, macroevolution is only an interpretation of the fossil evidence.  That's akin to saying alien spacecraft have been observed.  It's a weak argument.  The same for in the field.  We cannot observe speciation and we haven't.  We can look at two different yet very similar organisms and hypothesize they will break into different species.  As you know, speciation is supposed to take a long, long time. 

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As I said earlier, I don't see any better theories explaining the diversity of life on earth.

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Quote:

Let us turn to the prevailing view of the ontological status of species. Ghiselin (1974) and Hull (1978) suggest that instead of viewing species as natural kinds we should think of them as individuals. Hull draws the ontological distinction this way. (Instead of the phrase ‘natural kind,’ Hull uses the term ‘class.’) Classes are groups of entities that can function in scientific laws. One requirement of such laws is that they are true at any time and at any place in the universe. If ‘All copper conducts electricity’ is a law, then that law is true here and now, as well as 100,000 years ago on some distant planet. Copper is a class because samples of copper are spatiotemporally unrestricted —copper can occur anywhere in the universe. Individuals, unlike classes, consist of parts that are spatiotemporally restricted. Think of a paradigmatic individual, a single mammalian organism. The parts of that organism cannot be scattered around the universe at different times if they are parts of a living, functioning organism. Various biological processes, such as digestion and respiration, require that those parts be causally and spatiotemporally connected. The parts of such an organism can only exist in a particular space-time region. In brief, individuals consist of parts that are spatiotemporally restricted. Classes consist of members that are spatiotemporally unrestricted.

Given the class/individual distinction, Ghiselin and Hull argue that species are individuals, not classes. Their argument assumes that the term ‘species’ is a theoretical term in evolutionary theory. So their argument concerning the ontological status of species focuses on the role of ‘species’ in evolutionary biology. Here is Hull's version of the argument, which can be dubbed the ‘evolutionary unit argument.’

The Evolutionary Unit Argument: Since Darwin, species have been considered units of evolution. When Hull and others assert that species are units of evolution, they do not simply mean that the gene frequencies of a species change from one generation to the next. They have a more significant form of evolution in mind, namely a trait going from being rare to being prominent in a species. A classic example of such evolution is the change in frequencies of different colored peppered moths in Nineteenth Century England. Prior to the industrial revolution, most peppered moths were light gray and few were coal black. During the industrial revolution, selection caused the frequency of coal black peppered moths to dramatically increase.

A number of processes can cause a trait to become prominent in a species. Hull highlights selection. Selection causes a trait to become prominent in a species only if that trait is passed down from one generation to the next. If a trait is not heritable, the frequency of that trait will not increase cumulatively. Hereditary relations, genetic or otherwise, require the generations of a species to be causally connected. Reproduction requires the generations of a species to be causally and hence spatiotemporally connected. So, if species are to evolve in non trivial ways by natural selection, they must be spatiotemporally continuous entities. Given that species are units of evolution, species are individuals and not classes. (For recent responses to the Evolutionary Unit Argument see Dupré 2001, Reydon 2003, and Crane 2004.)

The conclusion that species are individuals has a number of interesting implications. For one, the relationship between an organism and its species is not a member/class relation but a part/whole relation. An organism belongs to a particular species only if it is appropriately causally connected to the other organisms in that species. The organisms of a species must be parts of a single evolving lineage. If belonging to a species turns on an organism's insertion in a lineage, then qualitative similarity can be misleading. Two organisms may be very similar morphologically, genetically, and behaviorally, but unless they belong to the same spatiotemporally continuous lineage they cannot belong to the same species. Think of an analogy. Being part of my immediate family turns on my wife, my children and I having certain biological relations to one another, not our having similar features. It does not matter that my son's best friend looks just like him. That friend is not part of our family. Similarly, organisms belong to a particular species because they are appropriately causally connected, not because they look similar (if they indeed do).

Another implication of the species are individuals thesis concerns our conception of human nature (Hull 1978). As we have seen, species are first and foremost genealogical lineages. An organism belongs to a species because it is part of a lineage not because it has a particular qualitative feature. Humans may be a number of things. One of them is being the species Homo sapiens. From an evolutionary perspective, there is no biological essence to being a human. There is no essential feature that all and only humans must have to be part of Homo sapiens. Humans are not essentially rational beings or social animals or ethical agents. An organism can be born without any of these features and still be a human. From a biological perspective, being part of the lineage Homo sapiens is both necessary and sufficient for being a human. (For further implications of the individuality thesis, see Hull 1978 and Buller 2005.)

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Quote:

The idea of a value-free science presupposes that the object of inquiry is given in and by nature, whereas contextual analysis shows that such objects are constituted in part by social needs and interests that become encoded in the assumptions of research programs.  Instead of remaining passive with respect to the data and what the data suggests, we can, therefore, acknowledge our ability to affect the course of knowledge and fashion or favor research programs that are consistent with the values and commitments we express in the rest of our lives.  From this perspective the idea of a value-free science is not just empty but pernicious.

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zouden said:

I don't think it's true to say we can't observe speciation. We can observe it in the fossil record.

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Silversoul said:

We can observe one species following another in the fossil record.  We have not yet observed one species giving birth to another.

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Silversoul said:

zouden said:

I don't think it's true to say we can't observe speciation. We can observe it in the fossil record.

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We can observe one species following another in the fossil record.  We have not yet observed one species giving birth to another.

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Silversoul said:

zouden said:

I don't think it's true to say we can't observe speciation. We can observe it in the fossil record.

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We can observe one species following another in the fossil record.  We have not yet observed one species giving birth to another.

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zouden said:

Silversoul said:

zouden said:

I don't think it's true to say we can't observe speciation. We can observe it in the fossil record.

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We can observe one species following another in the fossil record.  We have not yet observed one species giving birth to another.

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Well that's because one species can't give birth to another. That's not how speciation works.

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OrgoneConclusion said:

Look Zu-zu, until I see a horse give birth to a zebra, I am not buying any of your sci-fi crap.

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OrgoneConclusion said:

Look Zu-zu, until I see a horse give birth to a zebra, I am not buying any of your sci-fi crap.

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http://www.lifeinthefastlane.ca/wp-content/uploads/2007/06/zorse_horse_zebra.jpg

Half way there.

OrgoneConclusion said:

Look Zu-zu, until I see a horse give birth to a zebra, I am not buying any of your sci-fi crap.

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Dear Sir, may I interest you in a Zorse?


Or perhaps a Zonkey would better suit Sir's taste?


And for the most discerning gentlemen, we have a very special Zorse, born of a horse with x-linked mosaicism in the fur genes. Truly a one-of-a-kind!