"Best" evidence for evolution.

Faith writes: I'm very aware of the principle of falsifiability, and very aware that you are wrong about the falsifiability of dinosaurs to birds etc. Although it's probably not completely impossible, science about the distant past is just not falsifiable.

Oh come on Faith how many times over the 18 years you've been posting here have you been told that finding a rabbit fossil in the Cambrian would falsify the ToE? Several thousand I'd say.

It's not just a catch phrase, it means that the fossil record is organised by time and finding organisms out of place in time would totally destroy the theory.

For example, if your flood had actually happened fossils would be scattered through the geological record randomly with respect to their age but non-randomly with respect to their size and density. That would falsify the ToE and would have been immediately obvious to the creationist geologists 200 years ago.

Faith writes: Yes that's right but overall it's too easy to rationalize away anything that doesn't fit when it's in the past where it can be reinterpreted instead of definitively identified as false.

Nonsense, the simple fact is that you can't find the evidence to falsify it, and if you could, science would already have done it.

Faith writes: Give us a sequence of mutations and selections that could get us from a reptile to a mammal, or just a reptilian organ to a mammalian organ. The generalities are just a way to hide the fact that it's impossible.

Right, you want us to genetically sequence all the intermediaries from animals millions of years extinct in order to satisfy your incredulity? (But of course even if that was possible, you wouldn't accept it anyway.)

This is what we have

Evolution of the mammalian middle ear and jaw: adaptations and novel structures

Faith writes: Give us a sequence of mutations and selections that could get us from a reptile to a mammal, or just a reptilian organ to a mammalian organ. The generalities are just a way to hide the fact that it's impossible.

Right, you want us to genetically sequence all the intermediaries from animals millions of years extinct in order to satisfy your incredulity? (But of course even if that was possible, you wouldn't accept it anyway.)

This is what we have

Evolution of the mammalian middle ear and jaw: adaptations and novel structures

Faith writes: OK, to you it's all about microevolution and I can't get across what I'm talking about.

There's no such process as macroevolution, that's just a term used to describe the point (which in reality doesn't exist, or at least can't be found in real life) where the evolution of a population of organisms can no longer interbreed with its parent population.

The two terms micro and macroevelotion didn't exist when I studied the subject - there was and is just evolution. The process of evolution. It never stops and it never changes one species into another in a single leap. It adds variation, it doesn't reduce it. You're just factually, proveably wrong about these things.

Faith writes: I think I'd include all reptiles in one species

You reckon a sparrow is the same species as a crocodile, snake and tortoise?

but I'm not committed to sorting all this out.

Luckily we don't need to rely on you to 'sort it out'. There's been a couple of centuries worth of global scientific effort put into it. Starting with creationists themselves.

Faith writes: How very strange. I'm talking about classifying all reptiles together as a species and you throw in a sparrow, a bird, as if I'd included it which of course I had not. This discussion is for the sake of trying to improve communication so don't throw birds into the reptile species please.

Birds are reptiles:

quote:

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Archosauriformes (Greek for 'ruling lizards', and Latin for 'form') is a clade of diapsid reptiles that developed from archosauromorph ancestors some time in the Late Permian (roughly 250 million years ago). It was defined by Jacques Gauthier (1994) as the clade stemming from the last common ancestor of Proterosuchidae and Archosauria (the group that contains crocodiles, pterosaurs, dinosaurs, and birds);[4]

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Archosauriformes - Wikipedia

Faith writes: We're talking about what *I* said or so I thought. The establishment opinion is not relevant to what *I* said.

If you're using words like 'species' and 'reptile' you are using 'establishment' terms. If you wish to say something else you're going to have to define your terms.

And besides that's a big fat disingenuous deceit anyay: You don't call birds reptiles and neither do I and neither does anyone else.

Uh? I don't call snakes or tortoises or crocodiles reptiles either - I call them what they are. But if you ask me for examples of reptiles I'll say tortoise, snakes crocodiles and birds because that's what they are.

Your personal taxonomy is relevant only to you, but you've told that all reptiles are the same species - even without including birds, that's plain dumb. You reckon a snake a crocodile and a tortoise are the same species?

Faith writes: To me there's nothing arbitrary about it, it's determined by the particular characteristics of the creatures. I think those characteristics are very specific and easily recognized myself

So are crocodiles, snakes and turtles the same species?

but I guess if one is steeped in the evolutionist way of looking at it all they seem arbitrary.

They seem arbitrary because they are. The taxonomic system was based on the 'particular characteristics' of organisms. That's exactly how taxonomy works. It's a staggering painstaking analysis of the anatomy and features organisms.

It started in the early 1700s and has been developed - mostly by creationists - ever since. The are based simply on what things look like - just like say you want to do, but have no idea what's involved - and got very highly detailed very quickly.

What's really interesting about it is that when DNA came along it confirmed almost all of it. It didn't have to, but it did.

I know you won't but it would do you good to read about Linnean taxonomy

Linnaean taxonomy - Wikipedia

Faith writes: I don't know if turtles belong to the reptile Kind or not.

And yet you claimed that all reptiles *are* the same species. Changed your mind?

I said I'm aiming for a general concept, the specifics would take working out.

There already is a general concept (plus specific and detailed mapping of all known organisms on earth). It was developed by creationists and if it had been developed by little green aliens - or even yourself - it would look the same. That's because features are features - objective facts that can be observed and categorised by anyone.

Yes apparently some species can be distinguished from others by their DNA.

All of them can.

Even some subspecies or breeds can be identified. So what?

Think Faith, think.

The taxonomic map of all known species was built solely on what organisms looked like - two legs, 4 wings, 23 segments, evergreen leaves, head/thorax/abdomen, thorns cloven hoof, 8 petals, tuberous roots, yellow sepals etc etc etc.

Then DNA analysis comes along and shows that in almost all cases the map developed entirely on what organisms look like matches their DNA patterns too. Two different methods producing more or less the same map. So the map is correct.

If you had the training, patience and time to do it, you would produce the same map.

If you are claiming otherwise, you need to explain exactly why.

Faith writes: I wasn't talking about a bottleneck, I was talking about the emigration of a smallish number of individuals from a parent population to form a new daughter population in reproductive isolation.

That's a bottleneck.

Just this smaller number of individuals will produce a new set of traits for a new composite phenotype over a few generations of breeding in isolation, and depending on the number of individuals this will involve some level of reduced genetic diversity.

Yes, that's what bottlenecks do.

If two bison separate from a herd of 100,000, the two have less genetic diversity than the 99,998. (But overall there is no reduction in diversity.)

If 50,000 separate there is probably no loss of genetic diversity. But so long as they never meet again the two populations will diverge.

Mutations don't enter into it. They may contribute a change from time to time but there's no reason to think they contribute more than that.

And that exactly what they do do - introduce a change from time to time. That all evolution is.

Faith writes: Make it a hundred that separate from a population of a thousand. I'm not talkinjg about a bottleneck

That would be a bottleneck.

I'm talking about some normal number that would emigrate,

There is no such thing as a 'normal number'. There is a minimum number though, that's the number at which the likelihood of survival is higher than the likelihood of extinction. That's actually quite a high number.

If half the population emigrates then there will probably not be a lot of change but there will probably be some, and in this case in both populations.

The two populations will stay the same for as long as there's no environmental pressure for them to change. If the environments are the same, there will be little change. If they are different there will be greater change. (See Darwin's finches) If they are very different it's probable that one or both populations will go extinct.

You may be interested in this

quote:

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Following a population bottleneck, the remaining population faces a higher level of genetic drift, which describes random fluctuations in the presence of alleles in a population. In small populations, infrequently occurring alleles face a greater chance of being lost, which can further decrease the gene pool. Due to the loss of genetic variation, the new population can become genetically distinct from the original population, which has led to the hypothesis that population bottlenecks can lead to the evolution of new species.

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Faith writes: Absolutely, juist what I'm talking about although I haven't regarded such a large portion of a population to be a bottleneck. But as usual that's just a semantic glitch people like to throw ibnto the discussion from time to time.

Facts aren't glitches.

No problem, the wpoint is that the smaller population WILL lose the infrequently occurring alleles and under those circumstance some dramatically new traits can develop and create a new composite phenotype quite different from the parent population and all the others in the ring species. This is due to the loss of genetic diversity, in this case the loss of the low frequency alleles. Just what I've been saying has to happen.

Nobody disagrees with you. It's a statement of the bleeding obvious.

And they call the resulting new population with its own new traits a "species."

No they don't. They're still the same species.

I'd call it a "subspecies" or variation myself,

Then you'd be wrong, it's the same species.

another population will develop out of this one two by the emigtation of some number to a new location where it will also develop its own peculiar composite phenotype due to reduced genetic diversity.

It's what happens after separation that matters. Separation itself doesn't change anything. After a small population separates and survives it is more susceptible to genetic drift. Genetic drift is an evolutionary event where genes are shuffled over time causing a diversion from the main group. Over time mutations start to increase genetic diversity in the isolated population and it eventually recovers but may be sufficiently different from the original group to not be able to mate with it. Then we have a new species. But the animals would still be very similar - they'd still be the same genus.

Evolution above genus takes a very long time and will be made up of many different evolutionary events.

Bottlenecks probably mostly kill species because of the reduction on genetic diversity causing a genetic 'meltdown' or the population being too small to physically survive. But if they do survive gene diversity can and does recover.

Faith writes: In "ring species," yes they do call each subsequent population a "species."

No they don't. It's separation plus time that creates a new species.

Ring species are spread out in a chain where the very long chain creates the separation A B C D E F G etc. eg B never meets G so even though there are links to G the two populations can differ over time. But these forms are relatively rare, you're better sticking to physical separation to understand it better.

Separation brings about the isolation of a new set of gene frequencies. If this new population persists in reproductive isolation those new gene frequencies will eventually produce a new composite phenotype, or new "species" or "subspecies." There may also be genetic drift but it's the blending of the set of gene frequencies that is the main thing that brings about the new composite phenotype.

I doubt anyone would disagree with you, this is all standard stuff.

Of course I'm disagreeing with mainstream evolutionist theory

Not so far you're not.

I argue that genetic drift is not the main influence and neither are mutations,

You don't argue that, you just assert it.

it's the mixing of the new set of gene frequencies created by the population split that is the cause of the new "species" or "subspecies" or "variation" etc.

So now you go wrong. Population isolation is only one of the drivers of evolution, it often starts the process but simply shuffling existing genes is not enough to create the diversity of life that we see.

Reduced genetic diversity is always part of this picture as you can't get new phenotypes unless you lose the old ones.

Reduced genetic diversity is only part of the picture when population isolation occurs. Not all evolution starts with a bottleneck and other genetic and environmental changes are necessary to make radical changes over time. These require mutations. Mutations allow ape ancestors to become modern apes and humans. Their genomes show those mutations. Modern apes and humans have the same genomes but with a number of changes. We share the same phenotype but with a number changes. The changes are mutations.

Faith writes: it's how you get a new populaton of a different color of bear from the parent population's color, a new type of wildebeest from ththat of the main population, new raccoom markings from those of the parent population, new markings on the salamanders of each new subpopu;aton in a ring species.

Nope, for example in the case of the peppered moth we KNOW that it changed it's colour because of a gene mutation and the change fixed into the population by natural selection. No isolation of a sub-population involved, just mutation followed by selection. Classic evolutionary theory.