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Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: |
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Author | Topic: MACROevolution vs MICROevolution - what is it? | |||||||||||||||||||||||||||||||||
RAZD Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: |
Please remember that this is the genetic determinist, i.e., darwinian, explanation for 'how the giraffe got its long neck'. So of course there is no 'conflict' between the example and genetic determinism. And nothing in your post has anything to do with what macroevolution is or what is different from microevolution. The topic is MACROevolution vs MICROevolution - what is it?, so please see if you can focus on that issue. I look forward to your posting on this issue.
I look forward to it. Good. That thread is now open and you have replied, therefore you do not need to keep making off-topic posts here. Everyone else please stop responding to off-topic posts, and stick to the issue here: what is MACROevolution and how does it differ from MICROevolution? Enjoy. Edited by RAZD, : linked, clarified
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RAZD Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: |
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RAZD Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: |
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RAZD Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: |
Thanks tesla,
it would appear that "macro evolution" has been understood as a complete species change from one species to another, and not cross breed-able. micro evolution seems to be defined as evolutionary adaptions by a species to adjust to environments. i believe its possible for one species to be born of another and not crossbreed-able with the original species, for the simple reason of the "apparent" evolution of the dog. That works for me.
my thoughts (since you want a creationist opinion: either stage either is a stage of evolution , or is not. Question: why would creationist definition\usage differ from what scientists\science use? Does that accomplish anything but confusion?
who coined the term macro evolution? I don't know. Enjoy. by our ability to understand RebelAAmericanOZen[Deist ... to learn ... to think ... to live ... to laugh ... to share. • • • Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click) • • •
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RAZD Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: |
Let's look at what university biology websites have to say about microevolution and macroevolution:
quote: Microevolution - small scale evolution - is the changes in gene frequency in a population from one generation to the next. Macroevolution - large scale evolution - is the descent of different species from a common ancestor over many generations.
quote: So again: Microevolution - Changes in the genetic composition of a population with the passage of each generation. Macroevolution - The gradual change of living things from one form into another over the course of time, the origin of species and lineages by descent of living forms from ancestral forms, and the generation of diversity. So what is the difference? What happens to cause macroevolution that does not occur by microevolution? Enjoyby our ability to understand Rebel American Zen Deist ... to learn ... to think ... to live ... to laugh ... to share. Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)
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RAZD Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: |
So what is the difference? What happens to cause macroevolution that does not occur by microevolution? My take on it:
(1) The process of Microevolution involves the change in the frequency distribution and composition of hereditary traits within breeding populations from generation to generation, in response to ecological challenges and opportunities. Mutation can cause change in the composition of hereditary traits carried by individuals of a breeding population, but not all mutations do so. In addition there are many different kinds of mutations and they have different effects (from small to large). Natural Selection and Neutral Drift can cause change in the distribution of hereditary traits within the breeding population, but they are not the only mechanism that does so. The ecological challenges and opportunities change when the environment changes, the breeding population evolves, other organisms within the ecology evolve, migrations change the mixture of organisms within the ecology, or a breeding population migrates into a new ecology. These changes can result in different survival and reproductive challenges and opportunities, affecting selection pressure, perhaps causing speciation, perhaps causing extinction. Mutations of hereditary traits have been observed to occur, and thus this aspect of microevolution is an observed, known objective fact, rather than an untested hypothesis. Natural selection and neutral drift have been observed to occur, along with the observed alteration in the distribution of hereditary traits within breeding populations, and thus this aspect of microevolution is an observed, known objective fact, and not an untested hypothesis.
(2) The process of Macroevolution involves the development of new species, the formation of nested hierarchies of descent of new species from common ancestor populations, and an increase in the diversity of life. This looks at the continued effects of microevolution over many generations, where the accumulation of changes from generation to generation become sufficient for new species to develop that are different from the ancestral parent populations. This lineal change in species is sometimes called phyletic or arbitrary speciation.
(a) The process of Phyletic Speciation involves a lineage of descent from an ancestor population accumulating sufficient differences through microevolution that, when compared to the ancestor population, it would appear to be a different species. This is sometimes called arbitrary speciation because it is difficult to agree on where the line of division from one species to the next occurs, how many times this occurs in a given lineage, and because the definition of species itself is fairly arbitrary. The amount of change in phyletic speciation can be compared to the changes seen in divergent speciation between parent (ancestral) populations and the daughter (descendant) populations as a check on the amount of change to be considered.
(b) The process of Divergent Speciation involves the division of a parent population into two or more reproductively isolated daughter populations, which then are free to (micro) evolve independently of each other. The reduction or loss of interbreeding (gene flow, sharing of mutations) between the daughter populations results in different, independent, evolutionary responses in the daughter populations to their respective and different ecological challenges and opportunities (including the existence and impact of the other daughter population/s on survival). Independent evolution within each subpopulation results in divergence of the subpopulations from each other. Divergent speciation forms a branching pattern of descent from a common ancestor pool, and results in added diversity of species. Further instances of divergent speciation adds further to the branching pattern and results in a nested hierarchy pattern.
| ^ a / \ / \ / \ / ^ b / / \ / / \ e d c Phyletic speciation with the development of new species by extended microevolution in a lineage of descent has been observed to occur, and thus this aspect of macroevolution is an observed, known objective fact, and not an untested hypothesis. Divergent speciation with the development of new species by the reproductive isolation of daughter populations has been observed to occur, and thus this aspect of macroevolution is an observed, known objective fact, and not an untested hypothesis. The formation of nested hierarchies of descent from common ancestor populations has been observed to occur, and thus this aspect of macroevolution is an observed, known objective fact, and not an untested hypothesis. The addition to diversity by increasing the number of species and higher groupings has been observed to occur, and thus this aspect of macroevolution is an observed, known objective fact, and not an untested hypothesis. One single example that shows all of these processes in the fossil record is:
Thus the essential difference between microevolution and macroevolution is divergent speciation and the resulting formation of nested hierarchies. Enjoy Edited by RAZD, : minor revs/addsby our ability to understand Rebel American Zen Deist ... to learn ... to think ... to live ... to laugh ... to share. Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)
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RAZD Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: |
in Peppered Moths and Natural Selection Message 327 Big_Al35 says
You and some others here have introduced mutation into the equation. This may account for genuine micro-evolution but has nothing to do with the example I was discussing. Can you define micro-evolution? Can you define macro-evolution? Enjoy.by our ability to understand Rebel American Zen Deist ... to learn ... to think ... to live ... to laugh ... to share. Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)
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RAZD Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: |
Hi Big_Al35
RAZD writes: Can you define micro-evolution? Can you define macro-evolution? Can you? Yes. Do you want to discuss those definitions* and see where you agree\disagree and why? Do you want to do it here (with comments made by other people as well), or would another format (say a "Great Debate" as a one-to-one discussion) be more acceptable? Enjoy. * Note that I can also back up my definitions with common use in the field of biology and references to actual course material used in university courses.by our ability to understand Rebel American Zen Deist ... to learn ... to think ... to live ... to laugh ... to share. Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)
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RAZD Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: |
Hi Big_Al35
RAZD writes: Do you want to discuss those definitions* and see where you agree\disagree and why? Please define macro-evolution for me and maybe we can take it from there? That's starting from the top down rather than the bottom up, so we will then need to fill in the definitions that go into it, but here goes:
(A) The process of macroevolution involves forming a nested hierarchy by descent of new species from common ancestor populations, via the combination of divergent speciation and phyletic speciation, and thus resulting in an increase in the diversity of life. Simply put, the species that exist at a point in time are different from their ancestors, and there are new species compared to the ancestral populations. Note that a process is something that is ongoing, something that can be observed in some way, and not a theory. Note further that both these types of speciation have been observed in the natural world as well as in the fossil record. Enjoy. Edited by RAZD, : subtitleby our ability to understand Rebel American Zen Deist ... to learn ... to think ... to live ... to laugh ... to share. Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)
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RAZD Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined:
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Hi Big_Al35
Which one is it? ... They mean the same thing, but we can use the one I just gave you in message 108: what is macroevolution? for this discussion.
... And why would you need a definition from me when you have so many available to yourself? To make sure we are using the same meaning, and not just the same sounds. It is important in science to be specific about meanings of words used in order to communicate ideas clearly, and this is why it is important to use the scientific usages when discussing science. Enjoy. Edited by RAZD, : link changeby our ability to understand Rebel American Zen Deist ... to learn ... to think ... to live ... to laugh ... to share. Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)
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RAZD Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: |
Hi Big_Al35,
Sorry for the delay, but I've been recovering from chemo and it isn't pretty.
Just to clarify can you give me an example of this in the natural world? First we need to understand what "this" is -- in this case speciation. What do you think speciation is? This may seem round about as answers go, but we need to understand each other. Enjoyby our ability to understand Rebel American Zen Deist ... to learn ... to think ... to live ... to laugh ... to share. Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)
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RAZD Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: |
A lot of time has passed since I started this thread, and I've learned a lot in the process ... from Introduction to Evolution (work in progress)
quote: Edited by RAZD, : . Edited by RAZD, : .by our ability to understand Rebel☮American☆Zen☯Deist ... to learn ... to think ... to live ... to laugh ... to share. Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)
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RAZD Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: |
However as far as I can tell from the article the record starts with forams and ends with forams. Rather than seeing "hundreds of speciation events" they have documented the development of hundreds of varieties of the same species. Thus we have not observed "macro"evolution in this case. You do realize that foraminifera is a subphylum ... right? So this is like saying you started with placental mammals and you ended with placental mammals and all that is documented is varieties of placental mammals ...
quote: The Linnaean taxonomic system was developed ~200 years ago but the concept and definition of species has changed since. Since there are known hybrids between Linnaean species and genera it does not fit well the Biological Species concept based on the ability to produce viable offspring. Perhaps we should be using different words for Linnaean vs Biological species but for now the word "species" can have different meanings. For now at least the Linnaean taxonomic system provides a way for scientists to specify particular organisms.
Yep the Linnaean system is becoming more and more unworkable as we develop the cladistics further, see the "unranked" categories above, inserted because the Linnaean system wasn't adequate to explain the evidence. Isn't it great how science adapt to new information, rather than cling with dogmatic fervor to unreasonable views? With cladistics we don't need to worry about problems cause by an artificial classification system such as Linneaus developed: it has served it's purpose, but it is time to retire. Also with cladistics we see that the important element is genetic isolation -- the lack of breeding behavior is sufficient. There is also a braided pattern that occurs during the speciation process -- see Interweaving Evolution & Hybrid Vigor for more. Enjoyby our ability to understand Rebel☮American☆Zen☯Deist ... to learn ... to think ... to live ... to laugh ... to share. Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)
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RAZD Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: |
A "foram" is a single-celled ocean plankton, either free-floating or else bottom dwelling. The series starts with a single-celled ocean plankton, and ends with a single-celled ocean plankton. Or more specifically the fossil shells of a single-celled ocean plankton. Yes a rather generic description for the whole Subphylum. Just like a description of mammals as "... a clade of endothermic amniotes distinguished from reptiles (including birds) by the possession of a neocortex (a region of the brain), hair, three middle ear bones and mammary glands. Females of all mammal species nurse their young with milk, secreted from the mammary glands." ... and of course the descendants of mammals will always be mammals ... The summary article you linked to is based on the one I provided in Message 1 and it goes on to say
quote: Classify the genus and species of the forams in the study. When we go to the article in Message 1 that this data is taken from they say
quote: Many speciation events, hundreds of species lineages, a virtually complete fossil record with all the transitionals ...
The only evolution in evidence is the shape of the shells. Yep little critters, but we get the whole skeleton in these fossils. Is this a problem for you? As noted in Message 1: "This is the essence of the debate: when does change become sufficient to be "macro"evolution and how does it occur." For scientists using the technical definition for "macro"evolution this occurs when we have speciation and the formation of nested hierarchies of descent. This is seen in multitudes in this record of the Foraminifera subphylum. If you want to see more change than that, you are going to have to define when it will be enough to convince you. Like the people quoted in Message 1 that somehow never really got around to doing that. It seems a common creationist ploy -- as long as you never define something like this then you can argue it hasn't occurred ... all you need to do is move the goalposts every time evidence is presented. Enjoyby our ability to understand Rebel☮American☆Zen☯Deist ... to learn ... to think ... to live ... to laugh ... to share. Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)
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RAZD Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: |
Why?
You should ask the scientists, I only report what they said (and that others agreed with). Of course that would mean effort on your part, but it is not my job to do your homework. Enjoyby our ability to understand Rebel☮American☆Zen☯Deist ... to learn ... to think ... to live ... to laugh ... to share. Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)
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