16 Feb 19
According to Wikipedia:
Speciation is the evolutionary process by which populations evolve to become distinct species. The biologist Orator F. Cook coined the term in 1906 for cladogenesis, the splitting of lineages, as opposed to anagenesis, phyletic evolution within lineages. Charles Darwin was the first to describe the role of natural selection in speciation in his 1859 book The Origin of Species. He also identified sexual selection as a likely mechanism, but found it problematic.
There are four geographic modes of speciation in nature, based on the extent to which speciating populations are isolated from one another: allopatric, peripatric, parapatric, and sympatric. Speciation may also be induced artificially, through animal husbandry, agriculture, or laboratory experiments. Whether genetic drift is a minor or major contributor to speciation is the subject matter of much ongoing discussion.
Rapid sympatric speciation can take place through polyploidy, such as by doubling of chromosome number; the result is progeny which are immediately reproductively isolated from the parent population. New species can also be created through hybridisation followed, if the hybrid is favoured by natural selection, by reproductive isolation.
Creation of new genetic information via (randomly occurring) beneficial mutations is not a factor, so a relatively short timeline is needed for this form of evolutionary change to occur.
18 Feb 19
@lemon-lime saidI'm not following your logic. Why can't speciation happen slowly?
According to Wikipedia:
[quote]Speciation is the evolutionary process by which populations evolve to become distinct species. The biologist Orator F. Cook coined the term in 1906 for cladogenesis, the splitting of lineages, as opposed to anagenesis, phyletic evolution within lineages. Charles Darwin was the first to describe the role of natural selection in speciation i ...[text shortened]... ot a factor, so a relatively short timeline is needed for this form of evolutionary change to occur.
18 Feb 19
@wildgrass saidIt's no wonder you're not following my logic, because I'm not claiming it can't happen slowly. I'm claiming it can happen rapidly.
I'm not following your logic. Why can't speciation happen slowly?
Slow or fast is not mutually exclusive.
I'm comparing punctuated equilibrium to the process of speciation among a small select group of animals. PE tells us the Emperor is not naked, he IS wearing clothes. Those clothes are there (or at least were there) and he's wearing them as we speak. We can't see them but trust me, those clothes are as real as you or me or reality TV.
PE tells us there weren't enough samples of intermediary species to insure them showing up in the fossil record, so I'm supposed to believe a lack of physical evidence serves as proof of rapid transition which in turn validates the premise behind punctuated equilibrium... really?
If this sort of speculative reasoning can pass as hard science, then I certainly have no reason to dismiss the possibility of diverse life forms all emanating from small packages (animals) of information rich DNA.
18 Feb 19
2 edits
@wildgrass saidWhat I said earlier about rapid speciation being unacceptable has more to do with who is asking the questions and making statements.
I'm not following your logic. Why can't speciation happen slowly?
Questions and statements will be perceived differently depending on whether they are posed by a creationist or an evolutionist. It's just a fact of life, so don't get hung up by what you think I meant. My point here is that it shouldn't matter who is making the statements or asking the questions.
For example, on the previous page I asked "... who doesn't think speciation could account for a relatively small number of life forms reacting to intense and variable (post flood) environmental pressures, thereby rapidly filling the earth with a diversity of living things?"
I hope this clears up any confusion over what I meant by "unacceptable".
18 Feb 19
@lemon-lime saidYou hope in vain.
I hope this clears up any confusion over what I meant by "unacceptable".
18 Feb 19
1 edit
@humy saidOkay, I'll make this simpler to understand.
You hope in vain.
If an evolutionist and a creationist make the same exact claim, using the same exact words, which of those statements will carry more weight?
In other words, who will you most likely believe?
19 Feb 19
@lemon-lime saidYou said "a relatively short timeline" is needed in order for speciation to occur. I assume this is because intermediates are not seen in the fossil record?
It's no wonder you're not following my logic, because I'm not claiming it can't happen slowly. I'm claiming it can happen rapidly.
Slow or fast is not mutually exclusive.
I'm comparing punctuated equilibrium to the process of speciation among a small select group of animals. PE tells us the Emperor is not naked, he IS wearing clothes. Those clothes are there (or at lea ...[text shortened]... ssibility of diverse life forms all emanating from small packages (animals) of information rich DNA.
If you run across a tree which is down and spongy and mossified in the forest, would you demand data showing it at various stages of decay before you conclude it had fallen and decayed?
Or could you infer, based on existing information, that the tree was once standing? Would you need to see the tree in (brief) flight to infer causality?
19 Feb 19
1 edit
@wildgrass said
You said "a relatively short timeline" is needed in order for speciation to occur. I assume this is because intermediates are not seen in the fossil record?
If you run across a tree which is down and spongy and mossified in the forest, would you demand data showing it at various stages of decay before you conclude it had fallen and decayed?
Or could you infer, based o ...[text shortened]... hat the tree was once standing? Would you need to see the tree in (brief) flight to infer causality?
You said "a relatively short timeline" is needed in order for speciation to occur. I assume this is because intermediates are not seen in the fossil record?
Relatively short timeline simply means much less time than it would take to create new information via chance beneficial mutations. Speciation doesn't require the formation of new genes, so the only comparison I'm making here is between macro-e and speciation. My comparison of speciation with PE has to do with what can be proven and what can't.
I'm critical of the reasoning behind punctuated equilibrium for the same reason I would question the veracity of a student who consistently shows up without his homework because "the dog ate it". If it happened once then it could be true. But if it happens at regular intervals then it's probably not true. The only evidence the completed homework exists (or existed) is the claim that it had existed... before the dog ate it.
If you run across a tree which is down and spongy and mossified in the forest, would you demand data showing it at various stages of decay before you conclude it had fallen and decayed?
No.
Or could you infer, based on existing information, that the tree was once standing?
Yes.
Would you need to see the tree in (brief) flight to infer causality?
No.
By the way, inference to the best explanation sounds a lot like one of the tenets of intelligent design.
19 Feb 19
2 edits
@lemon-lime saidWhat does this got to do with what you mean by "rapid speciation being unacceptable"? You have seemed to have changed to topic so not to make the statement "rapid speciation being unacceptable" "simpler to understand"
Okay, I'll make this simpler to understand.
If an evolutionist and a creationist make the same exact claim, using the same exact words, which of those statements will carry more weight?
In other words, who will you most likely believe?
19 Feb 19
@humy saidI've been trying to help you connect the dots. In a previous post I asked:
What does this got to do with what you mean by "rapid speciation being unacceptable"? You have seemed to have changed to topic so not to make the statement "rapid speciation being unacceptable" "simpler to understand"
...who doesn't think speciation could account for a relatively small number of life forms reacting to intense and variable (post flood) environmental pressures, thereby rapidly filling the earth with a diversity of living things?
So now I'll ask you directly, do you think speciation could account for a relatively small number of life forms reacting to intense and variable (post flood) environmental pressures, thereby rapidly filling the earth with a diversity of living things?
Bear in mind that if your answer is 'yes', you could be accused of tearing down one of the main objections to the Noah's ark story.
19 Feb 19
@lemon-lime saidIs the flood meant to be localized or global? For a global flood there's obvious questions regarding why there are any animals in the Americas and Oceania. If it's just Africa, Europe and Asia, then that is still an unimaginably large area to fill in less than one thousand years. Then there's the technical point that two members of a species does not make for a viable population. There is no evidence for a recent global flood. There isn't enough water. So no, I don't think that there is any scientific support for the Noah's ark story.
I've been trying to help you connect the dots. In a previous post I asked:...who doesn't think speciation could account for a relatively small number of life forms reacting to intense and variable (post flood) environmental pressures, thereby rapidly filling the earth with a diversity of living things?
So now I'll ask you directly, do you think speciation ...[text shortened]... r is 'yes', you could be accused of tearing down one of the main objections to the Noah's ark story.
19 Feb 19
1 edit
@lemon-lime saidIntelligent design is clearly not the best explanation in this case. It's not a real explanation of anything, simply a place holder for unknown information.You said "a relatively short timeline" is needed in order for speciation to occur. I assume this is because intermediates are not seen in the fossil record?
Relatively short timeline simply means much less time than it would take to create new information via chance beneficial mutations. Speciation doesn't require the formation of new genes, so the only com ...[text shortened]... he way, inference to the best explanation sounds a lot like one of the tenets of intelligent design.
19 Feb 19
@wildgrass
As a matter of fact, 'intelligent design' was a political ploy of the religious right in their continued work to force creationism to be taught along side evolution in a science class. That POV becomes less and less tenable as time goes on and more science is done to refute that stance. It is nothing more than a concerted anti-science POV and they would LOVE to kill evolution completely but that will never happen. What IS happening is their street cred goes down yearly. That is a good thing.
19 Feb 19
@wildgrass saidI didn't say intelligent design is the best explanation, I said 'inference to the best explanation' is one of the main tenets of intelligent design. You illustrated this idea and how it works with the example of a fallen tree in the forest.
Intelligent design is clearly not the best explanation in this . It's not a real explanation of anything, simply a place holder for unknown information.
19 Feb 19
Is the flood meant to be localized or global?
Global
For a global flood there's obvious questions regarding why there are any animals in the Americas and Oceania. If it's just Africa, Europe and Asia, then that is still an unimaginably large area to fill in less than one thousand years.
According to creationist literature the event coincided with the separation of land masses. Complete separation didn't happen overnight, so there was plenty of time for animal life to spread out and occupy those separate land masses. I don't know where you got the idea it must have happened in less than one thousand years, but I suppose I shouldn't be surprised that creationists are not all on the same page in regard to a timeline.
Then there's the technical point that two members of a species does not make for a viable population.
Species existing now, or species that may have existed then? It's likely animals on the ark didn't look anything like the animal life we see today.
There is no evidence for a recent global flood. There isn't enough water.
Why would a global flood need to be recent? There is evidence of an ancient global flood, and yes, there would have been enough water.
So no, I don't think that there is any scientific support for the Noah's ark story.
There's plenty of evidence, in fact more of it than I have time to go over with you here. I'm retired now, so I have more time to revisit what I've learned over the past 18 years. Even so, I don't want to spend every moment of my retirement years trying to encourage you to look into something you've already decided is not true and not based on science.