Is there evidence for macroevolution?

Oh, really? What differences are those? Where does "too many" start and not too many end?Could you post your answer in the appropriate thread since this is off topic here. Bible and "kind"

Holy crap! I just started this post yesterday Anyways, I like what Flies Only said, but Flies I don't understand why it's a bad arguement to say, "but...it's still a fish". Because, it is.I just want to know how macroevolution works and what is the evidence for it. You had said the fossil record, I'm assuming you mean the human fossil record going all the way back to australopithicus afarensis? ie: there was first A, then B, then C, D, E, F, then us (theoretically speaking). So by that model we can say that each "link in the chain" (sorry I don't know the scientific term) had it's own population and...then what? How does A get to B again?-Sean

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Anyways, I like what Flies Only said, but Flies I don't understand why it's a bad arguement to say, "but...it's still a fish". Because, it is.

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If a fish evolved into an amphibian (moved onto dry land) could I argue it is microevolution since it is still a vertebrate? The micro vs macroevolution is a "name game", by including two organisms into the same name you can deny macroevolution. Evolution isn't evidenced by what we choose to call organisms, or what groups we choose to put them in. Evolution is evidenced by speciation and change.

Just as we've seen new species arise today. When we look back 2,3 or 6 million years we only get 'snapshots' of the process. For this reason we see somewhat bigger jumps than the appearance of an isolated non-interbreeding population that might "look" a lot like the others it rose from.We see the results of that breeding isolation after, maybe, 10,000 generations.Remember that what we see in not the steps in a simple linear progression either. There was probably a bush of different species, some close to our ancestral line and some less so. Our family tree must have been pretty liteally a tree, just like your personal one is. With the few hundred snap shots we have to date it is tricky to suggest which ones are for sure on our direct linage and which aren't. We may,in fact, have no samples of our absolutely direct ancestors in the more distanct past but only their close cousins. For more recent cases (H. erectus) I think we can be pretty sure we are looking at our ancestors.

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Macroevolution is a scientific term and is commonly found in textbooks on general biology and on evolution. I think a relevant definition would be that used by Francis Futuyma in the Third edition of his classic 'Evolutionary Biology'.

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Futuyama writes:

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Macroevolution: A vague term for the evolution of great phenotypic changes, usually great enough to allocate the changed lineage and its decendants to a distinct genus or higher taxon.

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Scientific terms are not vague. If the term is "vague", then it is not a scientific term. By using the word "vague", Futuyama seems to be indicating that it does not have a precise meaning.

Scientific terms can be pretty vague. "Species", for example, has many definitions, and individual definitions often produce vague boundaries.

I agree with this...to a point: However, when this is put forward as an argument saying that we have never seen an example of "macroevolution", then all it really does is show that you don't understand evolutionary theory. You see, Mission for Truth, it will always (or at least in our lifetime and for many, many, many future generations yet to come) be a fish.You also say: Not necessarily. Look at the Therapsids and look at us (humans). Boy, talk about macroevolution!You continue with: This is another typical mistake made by many people. Evolution doesn't say it's a straight line from A-->B-->C-->D-->E-->F. Some died out while others adapted and survived. Like NosyNed said...it's more of a bush (I think he used tree...but big deal), with a common ancestor branching out to many other related (but not often directly) species.I guess my question to you would be: "where do you draw the line between micro and macroevolution?" If you understand anything at all about the ToE then you know that in all likely-hood we will never witness first hand, any radical morphological changes during speciation. It is simply too short a time period for us to observe major changes.Having said that, I guess I would add that IMHO, people that continuing to argue in favor of microevolution while at the same time argue against macroevolution may fall into into a category NosyNed opened up a few days back about examples of dishonesty (No, Mission for Truth, I am not calling you dishonest because I do not really know your level of understanding of the ToE. Please, do continue to ask questions, and with hope we can help you gain a better understanding about what the ToE really says).

Because "fish" isn't the name of a species. "Fish" is just a popular term used to describe certain animals that look a certain way. In other words it's what they call a "folk term.""Folk terms" aren't revelant to science because they're not a precise enough classification, and moreover, they're not hierarcheal. That's important. That's why you're able to be a human, a hominid, a mammal, an animal, and an organism, all at the same time.Evolution doesn't predict that new terms will spring up. It predicts that each of our classification terms will describe more and more species - i.e. that "human", instead of describing one species, will come to describe several. That's because evolution is a bush, not a ladder. It doesn't go up, it goes out. Asked and answered.You need to separate the concepts of species change and species separation. They're not the same thing. Populations can change over time without becoming a new species - even drastic change. New species only arise when a population splits into subpopulations that stop breeding with each other. That is, gene flow between those populations comes to a stop. Clear, yet?

Im pretty sure that this hasnt been said yet.The species definition that i have been taught to go by (doing a biology degree atm, so im hoping its upto date) is that it is a seperate species if they cannot breed and produce viable offspring (fertile offspring). The classic case that comes to mind are horses and donkey producing mules, mules are 99% of the time sterile. I think this is caused the majority of times due to varying chromosome numbers.Incidently going by this there are recorded instances this occuring with drosophilia in labs (and naturally), and mosquitoes living underground in tube stations.Unseul

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Give a man a fire and he's warm for a day. Set a man on fire and he's warm for the rest of his life....

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The species definition that i have been taught to go by (doing a biology degree atm, so im hoping its upto date) is that it is a seperate species if they cannot breed and produce viable offspring (fertile offspring).

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That is considered the "classical" definition of species. However, as a working definition in biology separate species are considered to be separate gene pools, or populations that don't interbreed. However, this doesn't discount the possibility of fertile offspring between the two species. A good example that has been mentioned is the apple maggot, which has split into two species that breed during different times of year. For all intents and purposes, these two gene pools are separate but this doesn't rule out fertile offspring if forced breeding (eg in vitro fertilization) were used.[This message has been edited Loudmouth, 05-04-2004]

Yeah..... for example, sharks are likely no more closely related to tuna than they are to humans. The first teleost fish (like tuna), IIRC, date from after the first tetrapods like us.

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Scientific terms can be pretty vague. "Species", for example, has many definitions, and individual definitions often produce vague boundaries.

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I would argue that it is not the definition themselves that are vague, but that in the application to the real world there are examples that blurr the lines. As a mathematician (perhaps - we'll see if the dissertation actually gets done), my bias is that definitions must be precise while acknowledging that in real life there will be some examples for which the definition may not precisely apply. If the "definition" starts of vague, then it isn't a proper definition. But, I don't want to start an argument on semantics. And at any point, there is no harm is using vague terms, as long as everyone recognizes that they are vague, and why and where they are vague. Which is the problem with creationists use of "macroevolution".

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As a mathematician (perhaps - we'll see if the dissertation actually gets done), my bias is that definitions must be precise while acknowledging that in real life there will be some examples for which the definition may not precisely apply.

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As a mathematician, what is the definition for "large sum" and "small sum", or maybe "improbable" and "probable". These definitions, like micro and macroevolution, are meant to qualitatively compare two things, or give a general trend. It is often the context of the situation that proscribes the use of large sum vs small sum or microevolution vs macroevolution. It is not that there are exceptions to a certain concrete definition, but the definition itself is not concrete.

Hello, Loudmouth.The words you use as examples don't have mathematical definitions. When teaching, I often use phrases like "big number" and "small number" to give the students an intuitive idea of what is going on in the particular problem, to help them understand, intuitively, the essential ideas of the concepts. But when I actually present the proof formally or work out the calculation, the words "big" or "small" do not appear.Of course, comparatives do exist. We can talk about one entity being "greater than" or "less than" another. As far as I know, terms like "probable" or "improbable" don't have meanings in mathematics except as comparitives. Same with "big sum" or "small sum", although here I'm not sure what you mean by these terms.

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When teaching, I often use phrases like "big number" and "small number" to give the students an intuitive idea of what is going on in the particular problem, to help them understand, intuitively, the essential ideas of the concepts.

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EXACTLY!! This is the purpose of macro/microevolution. Biologists use the term in exactly the same way, to give a general idea of what is being described without the intention of giving a concrete value to something.