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Member (Idle past 1662 days) Posts: 20714 From: the other end of the sidewalk Joined: |
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Author | Topic: Two species of crow evolving ... | |||||||||||||||||||||||||||||||||||||||||||
RAZD Member (Idle past 1662 days) Posts: 20714 From: the other end of the sidewalk Joined: |
quote: Sexual selection. 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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Admin Director Posts: 13108 From: EvC Forum Joined:
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Thread copied here from the Two species of crow evolving ... thread in the Proposed New Topics forum.
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Tanypteryx Member Posts: 4597 From: Oregon, USA Joined: Member Rating: 9.2
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An interesting article RAZD.
I didn't come to appreciate sexual selection as a mechanism of evolution separate from natural selection until I read The Evolution of Beauty: How Darwin's Forgotten Theory of Mate Choice Shapes the Animal World”And Us by Richard O. Prum. From Goodreads:
quote: quote: What if Eleanor Roosevelt had wings? -- Monty Python One important characteristic of a theory is that is has survived repeated attempts to falsify it. Contrary to your understanding, all available evidence confirms it. --Subbie If evolution is shown to be false, it will be at the hands of things that are true, not made up. --percy The reason that we have the scientific method is because common sense isn't reliable. -- Taq
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Faith  Suspended Member (Idle past 1701 days) Posts: 35298 From: Nevada, USA Joined: |
The usual mountain out of a molehill or evolution out of mere variation. Yes sexual selection. Microevolution. Separate populations defined by feather color. Microevolution. To call it speciation is to indulge in the usual self deception that keeps the ToE fantasy alive.
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Percy Member Posts: 22953 From: New Hampshire Joined: Member Rating: 6.9 |
Sexual selection is completely natural, so couldn't it be just one type of natural selection? There could be natural selection by food source, by terrain, by weather variations, by sexual cues, etc.
--Percy
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Tanypteryx Member Posts: 4597 From: Oregon, USA Joined: Member Rating: 9.2
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Sexual selection is completely natural, so couldn't it be just one type of natural selection? That is what I thought also.
There could be natural selection by food source, by terrain, by weather variations, by sexual cues, etc. Natural selection has a positive feedback loop that means increased frequency of certain alleles in a population and there may be a negative feedback loop decreases the frequency of others. We think of this as fit and less fit, when considering competition within a species or population, but it also can impact competition between species and whether one thrives and another goes extinct. Prum lays out a really compelling argument with many, many examples where characters are selected, usually by females, that have no positive effect on fitness. These characters can be appearance, behaviors or calls and are often combinations of features. I was quite surprised to have to revise my view on this topic.What if Eleanor Roosevelt had wings? -- Monty Python One important characteristic of a theory is that is has survived repeated attempts to falsify it. Contrary to your understanding, all available evidence confirms it. --Subbie If evolution is shown to be false, it will be at the hands of things that are true, not made up. --percy The reason that we have the scientific method is because common sense isn't reliable. -- Taq
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Faith  Suspended Member (Idle past 1701 days) Posts: 35298 From: Nevada, USA Joined: |
Natural selection has a positive feedback loop that means increased frequency of certain alleles in a population and there may be a negative feedback loop decreases the frequency of others. Of course. The black feathered population has more alleles for black feathers, and probably lots of homozygosity for black feathers at the feather loci too, while the grey population has more alleles for grey feathers and the same genetic situation. The black feathered population has correspondingly fewer alleles for grey feathers, which will eventually decrease to zero as reproductive isolation continues, and the grey population for black feathers. This ought to be elementary my dear Watson, but evo theory manages to complicate the simplest things. And of course it makes sense to categorize sexual selection as a type of natural selection, just as I've argued that geographic isolation is a form of natural selection too, as it isolates some particular collection of alleles and breeds them together to produce a new phenotype, which is all any selective process does. And again, all this is within microevolution, it's ridiculous to make the arbitrary fact that the two populations don't interbreed into "speciation." It's nothing but two variations that happen to separate, and may possibly have a genetic barrier to interbreeding although that is not necessary. If it does it could be because of the greater homozygosity of the characteristic feather color in each population and the more fixed loci each has the less ability to combine the two. Edited by Faith, : No reason given.
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Tanypteryx Member Posts: 4597 From: Oregon, USA Joined: Member Rating: 9.2
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This ought to be elementary my dear Watson, but evo theory manages to complicate the simplest things. Yep, facts and evidence are just so complicated.
And of course it makes sense to categorize sexual selection as a type of natural selection And of course, you don't have a fucking clue what you are talking about.
And again, all this is within microevolution, it's ridiculous to make the arbitrary fact that the two populations don't interbreed into "speciation." Oh ok, I'll send out an alert right away that a YEC is making up a new rule. You should expect action soon.
It's nothing but two variations that happen to separate, and may possibly have a genetic barrier to interbreeding although that is not necessary. If it does it could be because of the greater homozygosity of the characteristic feather color in each population and the more fixed loci each has the less ability to combine the two. Right, so you're just winging it, so to speak?What if Eleanor Roosevelt had wings? -- Monty Python One important characteristic of a theory is that is has survived repeated attempts to falsify it. Contrary to your understanding, all available evidence confirms it. --Subbie If evolution is shown to be false, it will be at the hands of things that are true, not made up. --percy The reason that we have the scientific method is because common sense isn't reliable. -- Taq
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PaulK Member Posts: 17919 Joined: Member Rating: 6.7
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quote: There is a lot of arrogant bluster there but no reason why this should not be considered an example of speciation in progress. In fact the reality of two closely related - but easily distinguished - populations occupying different geographical regions - despite the lack of geographical barriers is reason enough to suspect that something of the sort is happening. That has been known for some time (it is also true in Britain). Steve Jones discusses it in Almost Like a Whale (aka Darwin’s Ghost) I suppose that I should add the point that these crows have been considered separate species for a long time. The only new stuff is the genetic analysis - which includes evidence of selection. Edited by PaulK, : No reason given.
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RAZD Member (Idle past 1662 days) Posts: 20714 From: the other end of the sidewalk Joined:
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I didn't come to appreciate sexual selection as a mechanism of evolution separate from natural selection until I read The Evolution of Beauty: How Darwin's Forgotten Theory of Mate Choice Shapes the Animal World”And Us by Richard O. Prum. My pet theory is that sex is what has lead to increased intelligence in humans via more and more complex mating displays/rituals/song and dance. I also see sexual selection as a mechanism for creating stasis in a breeding population in a stable ecology. Mate selection operates at every mating opportunity, and thus can operate at a faster rate than other forms of natural selection in causing or suppressing changes to the breeding population. See Sexual Selection, Stasis, Runaway Selection, Dimorphism, & Human Evolution 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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Theodoric Member Posts: 9489 From: Northwest, WI, USA Joined: Member Rating: 6.1 |
I thought you ran away.
Facts don't lie or have an agenda. Facts are just facts "God did it" is not an argument. It is an excuse for intellectual laziness. If your viewpoint has merits and facts to back it up why would you have to lie?
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RAZD Member (Idle past 1662 days) Posts: 20714 From: the other end of the sidewalk Joined: |
From A test for claimed knowledge of how macroevolution occurs, Message 705:
quote: Classification is for our use in discussions, and they are subject to change when information provides new insights.
quote: Also see Two species of crow evolving ... on this possible crow speciation in process, apparently due to coloration:
quote: Breeding populations apparently separated by sexual/mate selection.
quote: This Koinophilia is similar to what I proposed for sexual selection in Sexual Selection, Stasis, Runaway Selection, Dimorphism, & Human Evolution and my discussion on the causes of stasis in breeding populations living in stable ecological habitats. This Crow mate selection is similar to the overlap of the end of ring species like the Greenish Warbler, another place where the definition of species is problematic.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 1662 days) Posts: 20714 From: the other end of the sidewalk Joined: |
Of course. The black feathered population has more alleles for black feathers, and probably lots of homozygosity for black feathers at the feather loci too, while the grey population has more alleles for grey feathers and the same genetic situation. The black feathered population has correspondingly fewer alleles for grey feathers, which will eventually decrease to zero as reproductive isolation continues, and the grey population for black feathers. This ought to be elementary my dear Watson, but evo theory manages to complicate the simplest things. What is complicated in this by "evo theory" when they are saying the same thing?
And of course it makes sense to categorize sexual selection as a type of natural selection, just as I've argued that geographic isolation is a form of natural selection too, as it isolates some particular collection of alleles and breeds them together to produce a new phenotype, which is all any selective process does. Indeed, but sexual/mate selection explains observations that seem to be at odds with survival (peacocks) and why populations tend towards stasis in stable ecological environments/habitats.
And again, all this is within microevolution, it's ridiculous to make the arbitrary fact that the two populations don't interbreed into "speciation." It's nothing but two variations that happen to separate, and may possibly have a genetic barrier to interbreeding although that is not necessary. ... Of course it is microevolution -- that's where all evolutionary change occurs, within the breeding population/s. Macroevolution is just microevolution over many generations with the accumulation of changes making descendant populations different from ancestral populations. Speciation is one of the observed elements of macroevolution when two daughter populations are isolated over generations, allowing different microevolutionary paths to be taken by the daughter populations until they differ from one another. The crows are evidence of this difference in results of microevolution over generations. Lack of interbreeding is the definition of species, so when this happens it is logical to call that a speciation event.
... If it does it could be because of the greater homozygosity of the characteristic feather color in each population and the more fixed loci each has the less ability to combine the two. Indeed, the two populations have diverged from one another genetically, and this has resulted in the apparent speciation event in progress. Whether you like it or not, this is how biology defines species and speciation events. 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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LamarkNewAge Member Posts: 2497 Joined: |
So this is "micro-evolution" stuff.
Back to macro-evolutionary stuff. Am I correct in my memory when I recall many creationists admitting that early birds have features common with reptiles? (usually saying God creates features that are "intermediate")
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