Question for Evolutionists

[Loudmouth]

I'm not so sure, and I'm speaking as a lifelong theistic evolutionist. Like I said, speciation occurs when two related populations become sexually incompatible (though that's only a rough definition). You can have related populations which have been separated for millions of years and share a smaller percetage of genes, yet can still successfully reproduce.

IOW, the line between microevolution and macroevolution is gene flow. When you have different microevoutionary events accumulating in two independent populations, then you have macroevolution. Microevolution is change from one generation to the next in a population with unrestricted gene flow. Macroevolution is divergence over time due to microevolution in each of the populations and restricted gene flow between the populuations.

To use an analogy, the evolution of french over time involved micro changes from one generation to the next. The same for spanish. However, each of those languages accumulated different changes. French speakers could still understand french speakers from one generation to the next, and the same for spanish speakers. However, due to the different changes in each language it caused them to diverge from their common ancestral tongue to the point that french and spanish speakers could no longer freely communicate.

 

[Dizredux]

Let's stay on topics guys.

Hmm... I'm not really sure whether this really is a "weakness" in evolutionary theory or just my own ignorance. Probably the latter.

I would say speciation. Even today people cannot agree on what actually makes a "species" - we cannot even agree on the definition. The idea is that it is the point where two separate but related populations become sexually incompatible; that is, when they cannot have offspring. Yet hybrids, even fertile ones, still occur quite often.

One of the problems is that nature does not operate in neat categories especially at the edges. I don't have time to do a lot of writing but you might look at the Wiki article on Species Species - Wikipedia, the free encyclopedia and the article on Species Problem Species problem - Wikipedia, the free encyclopedia

Most working biologists tend to use Mayr's Biological species concept which focuses on the idea of reproductively isolated populations. Here it is not can different populations reproduce is do they? If they don't they are reproductively isolated and can be considered as separate species.

Genetics has not helped solve the problem - if anything it's made in more complex. Two separate populations which diverged millions of years ago and share far fewer genes than we would expect can still produce fertile offspring.

Sounds interesting could you give some more information on this?.

Similarly, speciation seems to occur differently between different kingdoms: it's easier for two different species of plants to reproduce than it is for two different species of mammal, for example.

And speciation is easier in plants. As I understand it plants can spectate in one generation Look up Polyploidy.

I also suspect is why many creationists try to draw a line between micro- and macro-evolution.

Perhaps but many of them follow the idea that somehow, in someway, there has to be something wrong with evolution and they try to draw a line to find a way to deny evidence of evolution past speciation.

This is a rushed post but you bring up some interesting and well thought out questions and I wanted to respond.

Dizredux

 

[anyathesword]

The marsupial/placental convergences are a bit spooky. I will agree with you there. We can simply state that this might evidence tighter constraints on fitness peaks than we previously thought, but that is really starting with the conclusion.

However, genetics does offer us a way of testing convergence, and IMHO it offers one of the best sources of evidence for evolution and one of the best refutations of the "common designer" argument.

Creationists will argue that a designer would reuse the same design, and would reuse the same gene sequences to produce those designs. Convergent evolution completely puts the smack down on that argument. Take the convergent evolution of the vertebrate and cephalopod eye. According to creationists, they should have a similar design since they look the same and operate in the same environment. Is this the case? Nope. There are major differences that separate the squid eye from the tuna eye even though they are adaptations for the same environment, and the same purpose.

Genetically, we can compare genes and find out if they match the predictions made by the same designer/same design hypothesis. For example, we can compare the cytochrome genes of placental wolves, marsupials wolves, and humans. Creationists would predict that the placental and marsupial wolves would have sequences that are closer to each other since they serve the same function. Evolution predicts that human and placental wolves will share more sequence, and be equidistant from the marsupial wolf. What do we observe? Exactly what the theory of evolution predicts, and the exact opposite of what the creationist argument predicts.

Yes, possibly, but what about genetics do you find weak and or makes you think twice?

 

[Notedstrangeperson]

But not fertile offspring, or not without human intervention. A horse and a donkey can have offspring, but mules are infertile. Lions and tigers can have offspring, but they never do so in the wild, only in captivity when kept in close proximity.

Fertile hybrids do occur (albeit rarely) in nature: one example would be "grolar" bears - the hybrid offspring of grizzly and polar bears. The few examples which have been tested have proved to be fertile, and they occur both naturally and in captivity.

IOW, the line between microevolution and macroevolution is gene flow. When you have different microevoutionary events accumulating in two independent populations, then you have macroevolution. Microevolution is change from one generation to the next in a population with unrestricted gene flow. Macroevolution is divergence over time due to microevolution in each of the populations and restricted gene flow between the populuations.

In many cases reduced gene flow does result in speciation, simply because if two populations cannot mate then eventually they become too genetically dissimilar to do so. But from what little I do know, there are certain cases where two related populations which, despite being genetically dissimilar, can still interbreed.

Humans and chimpanzees, despite diverging between 8-5 million years ago and being up to 98% genetically identical (depending on what you measure) cannot interbreed at all. Certain sub-species of fruit fly, despite diverging as much as 40 million years ago, can interbreed and have fertile offspring.

 

[PsychoSarah]

Fertile hybrids do occur (albeit rarely) in nature: one example would be "grolar" bears - the hybrid offspring of grizzly and polar bears. The few examples which have been tested have proved to be fertile, and they occur both naturally and in captivity.


In many cases reduced gene flow does result in speciation, simply because if two populations cannot mate then eventually they become too genetically dissimilar to do so. But from what little I do know, there are certain cases where two related populations which, despite being genetically dissimilar, can still interbreed.

Humans and chimpanzees, despite diverging between 8-5 million years ago and being up to 98% genetically identical (depending on what you measure) cannot interbreed at all. Certain sub-species of fruit fly, despite diverging as much as 40 million years ago, can interbreed and have fertile offspring.

Oh, the reason why humans and chimps can't breed is because the sperm/ova of humans are treated as foreign bodies by chimp sperm/ova.

 

[Notedstrangeperson]

Oh, the reason why humans and chimps can't breed is because the sperm/ova of humans are treated as foreign bodies by chimp sperm/ova.

There's probably more to it than that. Technically in humans the man's sperm is regarded as a foreign body by the woman's egg.

 

[PsychoSarah]

There's probably more to it than that. Technically in humans the man's sperm is regarded as a foreign body by the woman's egg.

I meant it isn't recognized as a reproductive cell.

 

[Notedstrangeperson]

I meant it isn't recognized as a reproductive cell.

How so?

 

[Loudmouth]

In many cases reduced gene flow does result in speciation, simply because if two populations cannot mate then eventually they become too genetically dissimilar to do so. But from what little I do know, there are certain cases where two related populations which, despite being genetically dissimilar, can still interbreed.

It is not a question of can they interbreed, but do they interbreed at a rate sufficient to spread alleles evenly across the populations. Also, the genetic dissimilarity is the product of macroevolution.

 

[DerelictJunction]

"A good number" could still be well within that 0.01%, though. Of the 7 billion people on the planet, 0.01% amounts to 70,000,000 apostates - that's more than the population of the UK, and could well be the actual number of apostates we see across the world. But this is pure conjecture - without hard data, I don't think we can safely say whether 99.9% is a fair figure or not.

Um....0.01% of 7 billion is actually 700,000. I know we've moved on but .... just sayin'.

 

[Wiccan_Child]

Um....0.01% of 7 billion is actually 700,000. I know we've moved on but .... just sayin'.

Quite right, I calculated 1% by mistake.

Welcome to CF, btw It's an odd first post, I'll give you that.

 

[Aman777]

Aman,

what you have written is a textbook example of an argument from ignorance.

Dear AEC, How do you know? God Bless you.

In Love,
Aman

 

[Aman777]

The first two points are also groaning under some misconceptions.

Dear Golden Yak, I don't understand. Where are the misconceptions? God Bless you.

In Love,
Aman

 

[PsychoSarah]

How so?

I said it doesn't recognize it as a reproductive cell. Our cells have proteins on their surfaces which fit with other proteins like keys; not enough of the chimp proteins match up with those on the surface of our cells, and visa versa.

 

[Aman777]

Read the OP again. You're off topic.

Dear Armoured, No, I'm not. I believe in the measurements of the changes in the allele frequency in a population over time. That makes me an Evol, technically, doesn't it? What you don't like is that my Faith is in Jesus and His Holy Word, and you would rather me Reject God's Truth. Right? God Bless you.

In Love,
Aman

 

[PsychoSarah]

Dear Armoured, No, I'm not. I believe in the measurements of the changes in the allele frequency in a population over time. That makes me an Evol, technically, doesn't it? What you don't like is that my Faith is in Jesus and His Holy Word, and you would rather me Reject God's Truth. Right? God Bless you.

In Love,
Aman

Out of curiosity, how old do you think this world is (since you consider the world Noah existed in to be different)?

 

[Aman777]

No, Aman, that is not correct, we can explain intelligence with evolutionary theory, and if you haven't noticed, people have been posting what they consider to be weaknesses in the theory, who agree with the theory, so stating that we will never say is blatantly false.

Dear PS, You are correct and I should never say never. However, your idea that you can explain How and When a concept, an idea, a measurement, changed apes into Humans, then post away. I welcome your correction of my uneducated ways. God Bless you.

In Love,
Aman

 

[PsychoSarah]

Dear PS, You are correct and I should never say never. However, your idea that you can explain How and When a concept, an idea, a measurement, changed apes into Humans, then post away. I welcome your correction of my uneducated ways. God Bless you.

In Love,
Aman

That is going to be a lot of reading on your part and a lot of writing on mine, you ready for that? Because there is only so much summarizing I can do without vital information being lost.

 

[Aman777]

Out of curiosity, how old do you think this world is (since you consider the world Noah existed in to be different)?

Dear PS, Our Universe is some 13.7 Billion years old in man's time. In God's time, since our world was made on the 3rd Day Gen 2:4 and today remains the 6th Day, Gen 1:27 it has been 3 Days/Ages ago in God's Time. This dates each of God's Days/Ages as being some 4.5 Billion years in man's time. The FIRST Day of the Creation was some 25 Billion plus years ago, in man's time.

Noah's world was made the 2nd Day. Gen 1:6-8 and placed in a massive amount of water which eventually destroyed it in the Flood. The date in man's time was some 18.2 Billion years ago, since Noah's world was made 4.5 Billion years before the Big Bang of our Cosmos. God Bless you.

In Love,
Aman

 

[PsychoSarah]

Dear PS, Our Universe is some 13.7 Billion years old in man's time. In God's time, since our world was made on the 3rd Day Gen 2:4 and today remains the 6th Day, Gen 1:27 it has been 3 Days/Ages ago in God's Time. This dates each of God's Days/Ages as being some 4.5 Billion years in man's time. The FIRST Day of the Creation was some 25 Billion plus years ago, in man's time.

Noah's world was made the 2nd Day. Gen 1:6-8 and placed in a massive amount of water which eventually destroyed it in the Flood. The date in man's time was some 18.2 Billion years ago, since Noah's world was made 4.5 Billion years before the Big Bang of our Cosmos. God Bless you.

In Love,
Aman

Wait, but you believe also that Noah's world was submerged in a body of water on this world, right? How did it get there if it was made billions of years before this world existed?