Evolution: the Facts.

[refamat]

The one that can hide most successfully from the lion in the environment it inhabits, so it can make more copies of itself.



Actually, coloration and such are the easiest, most obvious cases which evolution can explain. Camouflage and the needs of sexual selection make it easy.

so, since you are better than many scientists, go ahead and explain the differences in the three species of "zebra" and why?

I really would like a clear understanding of color genetics since so far, a cladistics vs gene map for zebra stripes as well as cladistics vs gene map for equines in general is so far, very incomplete, according to the rags on nags I get. the fact that the hail from a common ancestor is shown, but the current genetics and branches is really fuzzy and stripes play a big part in that.

 

[refamat]

Beg to differ. Genomes exist only to replicate; survival, as a tool to further that replication, is desirable to that extent only, and no further. Competition does not imply any knowledge; it implies only faster, stronger, more flexible, whatever will allow one organism to get the food/water/oxygen/sulfides and leave another without, so that the first can replicate. Knowledge may be part of that; smarter is a good strategy in many cases, but in others it may be worthless. A virus has no "desire" to link into a genome; it does what its chemistry demands. A virus inside a cell is not competing because it has won the current round, it is in survival mode; outside the cell, the quality of its protein coat is a competition with other viruses and with the host.

how do you equate all that into competition? competition is the race to be the first and only, survival implies successful implantation of genetic material.
inside or outside the cell, it is the same, it's either defense and or survival.
there is no competition..the sperm swim toward chemical signals, no competition, just attraction, the sperm engages the egg..the egg causes the sperm to loose it's "tail" (defense mechanism), egg sets up exclusion barrier to thwart other sperm from entering (defense mechanism)....virus enters cell, implants dna string into gene(s)..survival, virus leaves cell after gaining fuel to continue, survival, not competition.

misuse in the classroom of words can lead to misconceptions in the outside world.

 

[shadron]

so, since you are better than many scientists, go ahead and explain the differences in the three species of "zebra" and why?

I really would like a clear understanding of color genetics since so far, a cladistics vs gene map for zebra stripes as well as cladistics vs gene map for equines in general is so far, very incomplete, according to the rags on nags I get. the fact that the hail from a common ancestor is shown, but the current genetics and branches is really fuzzy and stripes play a big part in that.

Oh, and what did I say, exactly, that you deem to proclaim me "better than many scientists"? Was it my engineering background? Many of us seem to think so.

If you are expecting a clearer understanding of zebras from me than you get from real zoologists, you're barking up the wrong tree. I was pointing out that animal markings are usually explained by two simple needs: camouflage and sexual selection. Though there are exceptions (our own species, for example) those are the usual ones.

Why are there three species now? They was once one, I would hypothesize. They ranged over quite a wide area of the African plains. The plains aren't uniform; those in the north end live in a more arid habitat than the rest, and adapted somewhat to it, no longer intermingling with their less arid cousins. That left them open to evolving in a different direction from the rest. The larger heads may have been a cause or a result of the separation. Similarly, the mountain zebra adapted to the higher altitude mountainous areas near the plains.

The size of the stripes may be affected by the sorts of grass they live surrounded in, which will obviously change with the amount of water and the altitude of their environmants; I would assume that a drier vegetation would select for thinner stripes, but I'm not a zoologist and have not studied their habitats, as perhaps you have.

Speciation occurs when a subgroup discontinues breeding with the main group for any reason. At that point the two groups begin to drift their separate ways, perhaps eventually changing so much that they cannot interbreed, but perhaps not, as well.

 

[shadron]

how do you equate all that into competition? competition is the race to be the first and only, survival implies successful implantation of genetic material.
inside or outside the cell, it is the same, it's either defense and or survival.
there is no competition..the sperm swim toward chemical signals, no competition, just attraction, the sperm engages the egg..the egg causes the sperm to loose it's "tail" (defense mechanism), egg sets up exclusion barrier to thwart other sperm from entering (defense mechanism)....virus enters cell, implants dna string into gene(s)..survival, virus leaves cell after gaining fuel to continue, survival, not competition.

misuse in the classroom of words can lead to misconceptions in the outside world.

OK, I can see we are getting into a pissing match over a definition. There being no biologically specific definition for competition, I'll have to quote the Funk and Wagnalls:

com·pe·ti·tion –noun


1. the act of competing; rivalry for supremacy, a prize, etc.: The competition between the two teams was bitter.

2. a contest for some prize, honor, or advantage: Both girls entered the competition.

3. the rivalry offered by a competitor: The small merchant gets powerful competition from the chain stores.

4. a competitor or competitors: What is your competition offering?

5. Sociology . rivalry between two or more persons or groups for an object desired in common, usually resulting in a victor and a loser but not necessarily involving the destruction of the latter.

6. Ecology . the struggle among organisms, both of the same and of different species, for food, space, and other vital requirements.

I would prefer those definitions #6, 5 and 2, while I think you are referring to 4 and 3. Multiple sperm, approaching an egg, are in competition, for only one can implant; the rest are losers. A better energy source, a more efficient flagellum, resistance to the mother's defenses are all factors in his winning, though luck is always a factor as well, and a major component of genetic drift. The mere fact of survival, to the rest of the sperm, is a moot point. But the competition is real, willy-nilly.

But, if you continue to require your definition, then be pleased to do so.

 

[refamat]

Oh, and what did I say, exactly, that you deem to proclaim me "better than many scientists"? Was it my engineering background? Many of us seem to think so.

If you are expecting a clearer understanding of zebras from me than you get from real zoologists, you're barking up the wrong tree. I was pointing out that animal markings are usually explained by two simple needs: camouflage and sexual selection. Though there are exceptions (our own species, for example) those are the usual ones.

Why are there three species now? They was once one, I would hypothesize. They ranged over quite a wide area of the African plains. The plains aren't uniform; those in the north end live in a more arid habitat than the rest, and adapted somewhat to it, no longer intermingling with their less arid cousins. That left them open to evolving in a different direction from the rest. The larger heads may have been a cause or a result of the separation. Similarly, the mountain zebra adapted to the higher altitude mountainous areas near the plains.

The size of the stripes may be affected by the sorts of grass they live surrounded in, which will obviously change with the amount of water and the altitude of their environmants; I would assume that a drier vegetation would select for thinner stripes, but I'm not a zoologist and have not studied their habitats, as perhaps you have.

Speciation occurs when a subgroup discontinues breeding with the main group for any reason. At that point the two groups begin to drift their separate ways, perhaps eventually changing so much that they cannot interbreed, but perhaps not, as well.

There are three species because of stripe arrangement and gene count, it's always been that way. native peoples knew they were different a long time ago. how do you know speciation happens that way? is it a law of evolution? or are there other ways for a species to appear?
actually, if a zoologist knew about evolution really, he'd be a paleontologist instead of a specialized biologist-vet.

actually, if you were surprised by the 3 species of zebra, there were 4 species of striped equine, one is now extinct, totally viable with domestic horses and asses too!. last one died in the late 19th century I believe. and the experts have little clue if they are from separate lines or from one common ancestor with stripes. just educated guesses, and until the complete genomes are completed they won't know anything for sure.

but what do I know, I only have a geology degree and everyone knows geologists don't know squat about anything but dumb ol rocks.

 

[Dinwar]

but what do I know, I only have a geology degree

I suggest you start using your training, then. The issues you're raising are some that any geologist should be familiar with, at least to the point of being able to discuss intelligently. I mean, most of this (as well as most errors people make in terms of evolution) are discussed in introductory biology classes, the Gen Ed courses. If your paleo professors were worth anything, you've discussed these in far greater depth than your comments indicate.

how do you know speciation happens that way? is it a law of evolution?

It's a law of evolution when it comes to animals (plants, bacteria, and other organisms behave differently). Speciation in animals, using the biological species concept, occurs when reproductive isolation produces populations that will not interbreed, even when they are given the opportunity. There may be nothing physically preventing them (I'm thinking of fruit flies that lay eggs in pears and apples, and which have different mating seasons, but which are physiologically nearly identical), but if they will not interbreed they are different species.

(Well, in truth, as usual with biology, it's messier than that--different species have interbred and yielded viable offspring. Mules, for example, aren't always sterile. But that's another topic enitrely.)

or are there other ways for a species to appear?

This is a silly question. It depends on your definition of "species" (not all of us agree on one common definition, or even if the term is valid/useful), and the taxa in question. As I said, for animals, yes, this is it. For plants, hybredization can cause speciation. Bacteria are just weird, and I don't pretend to understand them.

actually, if a zoologist knew about evolution really, he'd be a paleontologist instead of a specialized biologist-vet.

I'm a paleontologist, and I thought *I* was fairly hard-core about how my science provides the best explination of evolution. You leave me in the dust. I mean, even I'll admit that the squishy biologists (a term I use to annoy my sister, who's studying to be a nurse) have valid evidence for evolution! I mean, the whole concept of using DNA to study evolutionary relationships is pretty much exclusively a squishy biology thing, as is ontology, behavioral studies, the entirety of The Origin of the Species, all fruit fly studies, the whole "Let's see if we can build a dinosaur from a bird" thing, animal husbandry, genetic engineering....

Paleontologists study how evolution happened to occur in the Earth's past. We do not presume to have a monopoly on the topic of evolution. We cannot look forward very well (no rocks from the future), and we are limited to morphology (more or less). In short, paleontologists study how evolution DID happen. Everyone else can freely discuss how evolution COULD, CAN, and MUST NECESSARILY happen (in other words, the theoretical framework).

 

[jimbob]

Shadron, of course by "camouflage" you should also include the use of "warning" colours that are easy to see as well, both for real threats, and for mimicry of another "dangerous" organism.


If a trait is selectively neutral, genetic drift can also account for it. But other than that, I'd think that you have covered all the bases.

Refamat, Your style seems pretty aggressive; I don't really see why it is warranted in this case.

What is wrong with the statement that animal markings evolve due to conferring a selective advantage via protective colouration or sexual selection (or genetic drift if selectively neutral)?

 

[refamat]

Oh, and what did I say, exactly, that you deem to proclaim me "better than many scientists"? Was it my engineering background? Many of us seem to think so.

If you are expecting a clearer understanding of zebras from me than you get from real zoologists, you're barking up the wrong tree. I was pointing out that animal markings are usually explained by two simple needs: camouflage and sexual selection. Though there are exceptions (our own species, for example) those are the usual ones.

Why are there three species now? They was once one, I would hypothesize. They ranged over quite a wide area of the African plains. The plains aren't uniform; those in the north end live in a more arid habitat than the rest, and adapted somewhat to it, no longer intermingling with their less arid cousins. That left them open to evolving in a different direction from the rest. The larger heads may have been a cause or a result of the separation. Similarly, the mountain zebra adapted to the higher altitude mountainous areas near the plains.

The size of the stripes may be affected by the sorts of grass they live surrounded in, which will obviously change with the amount of water and the altitude of their environmants; I would assume that a drier vegetation would select for thinner stripes, but I'm not a zoologist and have not studied their habitats, as perhaps you have.

Speciation occurs when a subgroup discontinues breeding with the main group for any reason. At that point the two groups begin to drift their separate ways, perhaps eventually changing so much that they cannot interbreed, but perhaps not, as well.

your answers are based on observations you've made only and not of what research experiences. Why do I say you "seem" to think you know more is because your engineering would most likely be faulty too. Since I have been a technician for 30 years before becoming a geology type with a minor in anthro, I have replaced many engineers because the thought processes engineers have are often faulty and do not cut to the quick like they should.
Grass sizes would not explain why a horse in the 19th centenary had stripes on its legs when it was a "purebred" animal.
Your thinking does not account for ancestral horse species which all may have been striped and that the three distinct species are not related any closer than a quarter horse would be to any single one zebra species.

 

[refamat]

I suggest you start using your training, then. The issues you're raising are some that any geologist should be familiar with, at least to the point of being able to discuss intelligently. I mean, most of this (as well as most errors people make in terms of evolution) are discussed in introductory biology classes, the Gen Ed courses. If your paleo professors were worth anything, you've discussed these in far greater depth than your comments indicate.

Actually I am, it depends on what camp you are in I guess as to how things happen. I believe in punctuated evolution, I also believe that dna can only point to relationships, the regression software used is totally out of line and faulty. I also believe that an impactor did not kill off the dinosaurs (show me the bones, and I already know about those that were relocated by natural processes)

It's a law of evolution when it comes to animals (plants, bacteria, and other organisms behave differently). Speciation in animals, using the biological species concept, occurs when reproductive isolation produces populations that will not interbreed, even when they are given the opportunity. There may be nothing physically preventing them (I'm thinking of fruit flies that lay eggs in pears and apples, and which have different mating seasons, but which are physiologically nearly identical), but if they will not interbreed they are different species.

(Well, in truth, as usual with biology, it's messier than that--different species have interbred and yielded viable offspring. Mules, for example, aren't always sterile. But that's another topic enitrely.)

So, you do not accept the studies of lizards in the last 40 years as much more than words on paper for someone to get a degree and mean little in the real world of evolution and only theoretical?

This is a silly question. It depends on your definition of "species" (not all of us agree on one common definition, or even if the term is valid/useful), and the taxa in question. As I said, for animals, yes, this is it. For plants, hybredization can cause speciation. Bacteria are just weird, and I don't pretend to understand them.

Ok, your talking interbreeding being a key term. Are you just basing your answers on what you have read and been told and not reading up on something before you dive in? you comment about me, but frankly, you are extremely biased on what is and isn't evolution it would appear.
In equines, you have 32, 44, 46, 62, and 64 chromosomes, all can interbreed, and some of the offspring can be fertile. there is a law there that describes which ways will produce fertility.

I'm a paleontologist, and I thought *I* was fairly hard-core about how my science provides the best explination of evolution. You leave me in the dust. I mean, even I'll admit that the squishy biologists (a term I use to annoy my sister, who's studying to be a nurse) have valid evidence for evolution! I mean, the whole concept of using DNA to study evolutionary relationships is pretty much exclusively a squishy biology thing, as is ontology, behavioral studies, the entirety of The Origin of the Species, all fruit fly studies, the whole "Let's see if we can build a dinosaur from a bird" thing, animal husbandry, genetic engineering....

So, explain how building a dinosaur from a bird is squishy. seems pretty sound and based in fact at this point (species of chicken with teeth, getting tail vertebrae to grow, it's only about switching on and off genes, and then the soft tissue issue, which won't provide dna, but does provide more proof that birds are dinosaurs and not a distinct branch of archosauria.

Paleontologists study how evolution happened to occur in the Earth's past. We do not presume to have a monopoly on the topic of evolution. We cannot look forward very well (no rocks from the future), and we are limited to morphology (more or less). In short, paleontologists study how evolution DID happen. Everyone else can freely discuss how evolution COULD, CAN, and MUST NECESSARILY happen (in other words, the theoretical framework).

This is not the present view of paleontology it seems, there are now those who do go into what you call squishy biology stuff and how it pertains to the rock record and how it proves evolution works, and where to look today.

Frankly, your kinda closed minded and thats ok, takes all kinds, but camping is a tricky position, especially if all your doing it for is to defend your thesis or the thesis you based your work on.

 

[Dinwar]

I'm not sure how your response is a response to what I said. You said:

actually, if a zoologist knew about evolution really, he'd be a paleontologist instead of a specialized biologist-vet.

Which is completely wrong. Many aspects of biology deal with evolution, in great detail. A knowledge of evolution in no way directs one towards paleontology. Oh, I get that the lines are blurry--anyone who's ever looked up the definition of "fossil" can see that--but paleontology isn't the only way to learn about evolution. In my mind it's the BEST way, but obviously others disagree.

I also believe that an impactor did not kill off the dinosaurs (show me the bones, and I already know about those that were relocated by natural processes)

Never mind. You obviously don't know nearly as much as you think you do. Let's start with the fact that NO ONE said that the impact killed the dinosaurs. They said that the dust generated by the impact reduced the amount of solar radiation coming to the planet for roughly 1000 years, which in turn killed the dinosaurs. You're confusing proximal and ultimate causation and demanding evidence to support a straw-man theory no one's proposed, while saying (in essence) "If you can't prove my straw-man theory you have to accept mine". Oh, and there's the little fact that the dinosaurs aren't extinct. (For reference, look at the work of Gerta Keller and Alvarez.)

If you're going to attack me and insult me, at least get your own facts straight while doing so. I'm not perfect, and I'll take any insult I've earned, but come on, at least understand the science you're arguing.

Ok, your talking interbreeding being a key term.

What I was specifically referring to here is the biological species concept. If you're using a different one (and if you're talking paleontology, you should), please define it.

So, explain how building a dinosaur from a bird is squishy.

Simple--you shut off/turn on various genes. They've done some of it with emu embrios (I remember because my uncle had emus at that point, and I was specifically not allowed to come into possession of ANY emu eggs that weren't fully cooked. Not that I had access to a genetics lab, but my family thought it best to not take chances). The whole point of those experiments is to demonstrate the pathway between non-avian dinosaur and birds.

it depends on what camp you are in I guess as to how things happen.

No. Things happened in the past how they happened. The only thing the various "camps" in science do is debate various explinations. I'm 90% sure this is just a poorly-worded sentence on your part, but I want to be absolutely clear on that.

I believe in punctuated evolution, I also believe that dna can only point to relationships, the regression software used is totally out of line and faulty. I

This is simply silly. Particularly the first part. Punctuated equilibrium is ONE tempo (it's actually an end member of a continuous series of evolutionary tempos). Whether an organism fits that tempo or not depends on the taxa. Gastropods most certainly do. Formas tend not to.

especially if all your doing it for is to defend your thesis or the thesis you based your work on.

I'm curious, what is it you think my work is?

 

[Marduk]

There are three species because of stripe arrangement and gene count, it's always been that way. native peoples knew they were different a long time ago. .

Not unless they were well travelled they didn't

the Grévy's zebra is not present in the same locations as the mountain and plains Zebra, and the mountains and plains Zebra are only present together in a handful of countries

so perhaps you can link to something that supports your unfounded and illogical assertion, because I gotta tell you, so far you are not a very credible source, you said it best yourself

but what do I know, I only have a geology degree and everyone knows geologists don't know squat about anything but dumb ol rocks.

 

[jimbob]

Bump from post#687

Refamat, Your style seems pretty aggressive; I don't really see why it is warranted in this case.

What is wrong with the statement that animal markings evolve due to conferring a selective advantage via protective colouration or sexual selection (or genetic drift if selectively neutral)?

This was all that Shadron was saying.

 

[refamat]

Bump from post#687

Refamat, Your style seems pretty aggressive; I don't really see why it is warranted in this case.

What is wrong with the statement that animal markings evolve due to conferring a selective advantage via protective colouration or sexual selection (or genetic drift if selectively neutral)?

This was all that Shadron was saying.

if, the geneticists have not completed a gnome mapping yet on equines, to allude that something such as striping is due to current locations is premature. Horses evolved in the area now known as North America and as ture horses can show stripes, there must be an ancestral gene for this which was common to the breed early on. that it re-expresses itself in three distinct species, as shown by chromosome counts, on a regular basis and other species infrequently would only be a re-expression for some purpose, but does not answer why there are three species of zebra.

 

[refamat]

I suggest you start using your training, then. The issues you're raising are some that any geologist should be familiar with, at least to the point of being able to discuss intelligently. I mean, most of this (as well as most errors people make in terms of evolution) are discussed in introductory biology classes, the Gen Ed courses. If your paleo professors were worth anything, you've discussed these in far greater depth than your comments indicate.

It's a law of evolution when it comes to animals (plants, bacteria, and other organisms behave differently). Speciation in animals, using the biological species concept, occurs when reproductive isolation produces populations that will not interbreed, even when they are given the opportunity. There may be nothing physically preventing them (I'm thinking of fruit flies that lay eggs in pears and apples, and which have different mating seasons, but which are physiologically nearly identical), but if they will not interbreed they are different species.

(Well, in truth, as usual with biology, it's messier than that--different species have interbred and yielded viable offspring. Mules, for example, aren't always sterile. But that's another topic enitrely.)

This is a silly question. It depends on your definition of "species" (not all of us agree on one common definition, or even if the term is valid/useful), and the taxa in question. As I said, for animals, yes, this is it. For plants, hybredization can cause speciation. Bacteria are just weird, and I don't pretend to understand them.

I'm a paleontologist, and I thought *I* was fairly hard-core about how my science provides the best explination of evolution. You leave me in the dust. I mean, even I'll admit that the squishy biologists (a term I use to annoy my sister, who's studying to be a nurse) have valid evidence for evolution! I mean, the whole concept of using DNA to study evolutionary relationships is pretty much exclusively a squishy biology thing, as is ontology, behavioral studies, the entirety of The Origin of the Species, all fruit fly studies, the whole "Let's see if we can build a dinosaur from a bird" thing, animal husbandry, genetic engineering....

Paleontologists study how evolution happened to occur in the Earth's past. We do not presume to have a monopoly on the topic of evolution. We cannot look forward very well (no rocks from the future), and we are limited to morphology (more or less). In short, paleontologists study how evolution DID happen. Everyone else can freely discuss how evolution COULD, CAN, and MUST NECESSARILY happen (in other words, the theoretical framework).

here's the deal with your thinking...donkeys have 62 chromosomes, miniature donkeys only found naturally on two islands in the Mediterranean also have 62 chromosomes..so, isolation does not cause a change in chromosomes (you'll find the same holds true with Timneh African Grey Parrots and the Congo African Greys. Zebras have three different chromosome counts, but it appears that isolation is all that's needed for an accounting of this according to the experts here.

bye yall, have fun with your enlightened discussions

 

[six7s]

Zebras have three different chromosome counts...

bye yall, have fun with your enlightened discussions

gOD HATES NAGS!!11!!

 

[jimbob]

here's the deal with your thinking...donkeys have 62 chromosomes, miniature donkeys only found naturally on two islands in the Mediterranean also have 62 chromosomes..so, isolation does not cause a change in chromosomes (you'll find the same holds true with Timneh African Grey Parrots and the Congo African Greys. Zebras have three different chromosome counts, but it appears that isolation is all that's needed for an accounting of this according to the experts here.

bye yall, have fun with your enlightened discussions

Well, small populations are more prone to genetic drift, and this would include changing numbers of chromosomes.

PZ Myers has done an interesting article about how Chromosome number can change


And in this article (about the dover trial) he mentions that about 1:900 people have a different number of chromosomes and that this is often not a problem and usually doesn't even cause of reduced fertility.

 

[Dinwar]

here's the deal with your thinking...donkeys have 62 chromosomes, miniature donkeys only found naturally on two islands in the Mediterranean also have 62 chromosomes..so, isolation does not cause a change in chromosomes

*facepalm*

What you've demonstrated is that isolation does not cause a change in chromosome COUNT. This is only partially related to changing chromosomes.

Think of it this way: I have five red marbles. You have five red marbles. We have the same marbles (in the same way that two clones have the same genes). Now let's say you paint two of your marbles green. Suddenly, you don't have the same marbles as me.

The equivalent to painting the marble in population genetics is a mutation.

This is basic stuff you're getting wrong. I mean PRELIMINARY genetics stuff. Mendel and allels and all that.

 

[noreligion]

Think of it this way: I have five red marbles. You have five red marbles. We have the same marbles.

That excludes the possibility of him losing his marbles.

 

[Dinwar]

That excludes the possibility of him losing his marbles.

I figured I wouldn't belabor the obvious.

 

[JonathanQuick]

It's been my experience that all evolution-deniers do not understand evolution.

And you do. After all, "evolution" is extremely complex:

1. Random mutation, followed by
2. Natural selection.

Wow.

How can you be angry at folks who cannot follow this profoundly complex, 150-year-old theory? After all, it is contemporaneous with the Caloric Theory of Heat, which was completely discredited.

In point of fact, Darwinism also marched side-by-side with the Steady State Universe, which was discarded by Albert Einstein himself only with the greatest reluctance in the twentieth century. Catholic Priest, George LeMaitre, tried to show Einstein that the Primordial Atom (the Big Bang) derived from his Theory of Relativity, but Einstein would have none of it.

How unscientific of Einstein. In the same fashion, any discussion of the myriad problems with macro-evolution is impossible. All we get in response is "You don't understand evolution."

Such responses are condescending. They are arrogant. They are anti-scientific. And they are anti-intellectual. But there is little chance that Darwinists will ever change their reprehensible tactics.