Proof of Evolution?

[Fencerguy]

First off, thank you good sir for bringing us back to an intelligent discussion, not just the spouting of opinions. Kudos to you!

I think you misunderstood me here. The organisms existed, the term 'partially formed' does not.

Back to my question of how do only fully formed structures/organs/organisms lead to other fully formed structures/organs/organisms.....That is an awful lot of change that needs to occur in quite a symmetrical fashion...

They're still here. They live in us, in our DNA. Yes I'm being serious.
A lot of our genome (and the genome of other animals) contain the genes of past ancestors, which is how we can tell the closest living relatives of homo sapiens are chimpanzees. It is entirely possible for a biologist to manipulate the genes of a chicken embryo to give them features their dinosaurs ancestors have - tweak their DNA a little and you can create a chicken with claws and teeth because their dinosaur genes are still there.

inasmuch as the bases are the same? Or are you saying that every gene from the simplest organism on is present (not necessarily expressed) in Homo sapiens? I still wonder how all of that extra genetic information was acquired...

Sometimes genetics is like a giant history book. Certain human disorders are 'throwbacks' to an earlier age, such as restigial tails. All humans have the genes which give them tails, they're just switched off. Indeed that's how many disorders work. People born without arms don't have an 'armless' gene, they have mutations which tell the genes which create arms to switch off.

I would debate the conclusion that such malformations are automatically "throwbacks." Do genes being switched on or off necessarily mean that such switches are a historical throwback? I do not challenge the data, simply the conclusions.

Good question. After all fish have been living in the water much longer than whales have, and they are not directly related. Again it all goes back to anatomy, which is a good indicator of whether two different organisms are related.

My only further question to this point is does "related" necessarily connote direct ancestry? Because a proper creationist phylogenetic tree would relate organisms that have similar anatomy, without linking all of them by direct ancestry.

Another good question. Hmm, it' hard to say. Evolution is so wildly unpredictable that we may end up with a creature which looks nothing like either Rhodocetus or a dolphin. However as I said earlier it's possible (more in theory than in practice) to bring up the genes of an extinct animal in a mordern one.

But is such a process possible in reality....It would seem to me that it would have to be, or else how do we support macroevolution?

 

[Notedstrangeperson]

My only further question to this point is does "related" necessarily connote direct ancestry? Because a proper creationist phylogenetic tree would relate organisms that have similar anatomy, without linking all of them by direct ancestry.

If you mean they're part of the same family tree then yes, anatomy (and possibly DNA, although it's hard to get from fossils) would be a very good indicator. If you literally mean direct ancestry - this fossil is the great-great-great etc. grandchild of this fossil - then no, that would be very unlikely.

But is such a process possible in reality....It would seem to me that it would have to be, or else how do we support macroevolution?

It's possible but incredibly complicated. You'd have to build the entire rhodocetus genome, identify the genes which gave rhodocetus it's legs, turn on these genes to give the dolphin legs (and many other features - did rhodocetus have ears, whiskers, hair follicles?) ... and what for? All that effort just to see what it looked like? Like I said possible but very difficult.

I would debate the conclusion that such malformations are automatically "throwbacks." Do genes being switched on or off necessarily mean that such switches are a historical throwback? I do not challenge the data, simply the conclusions.

Certain disorders and deformities perhaps. There's a theory that during pregnancy the embryo / foetus goes through previous evolutionary stages - which is why very early embryos all look alike, and why even human have tails, webbed hands and feet and even a fur-like substance known as lanugo. These are features we sometimes see in the animals humans evolved from.

inasmuch as the bases are the same? Or are you saying that every gene from the simplest organism on is present (not necessarily expressed) in Homo sapiens? I still wonder how all of that extra genetic information was acquired...

We'll never really know what genes the very first organism had, but you might be interested to know that the human genome contains the entire DNA of a virus, without which we could not make placenta. So yes - almost.

thank you good sir for bringing us back to an intelligent discussion, not just the spouting of opinions. Kudos to you!

Cheers. I'm not sure I'll be able to answer many more of your questions though. I'm not an expert, just an internet dweeb.

 

[Jro]

And if we want him to learn perhaps it's better not to belittle him and thinking he is stupid for asking questions about evolution. Perhaps if we laugh at him long enough he'll stop being a creationist out of shame amirite?

Here are a few links which might help:

Theistic Evolution - Perspectives
Welcome to Evolution 101!
TalkOrigins Archive: Exploring the Creation/Evolution Controversy

I didn't mean to insinuate anything, beyond trying to explain why science may look dogmatic. Good links!

Creation scientists can make specific predictions as well, it seems that many evolutionists think that anyone who believes in creationism only thinks that it is "because God did it, that is all," and that is a straw man... but those in the evolution camp seem to never take them seriously regardless of how well educated they are....I assume then that you are among those who have a significant amount of education?

Where are these predictions and how are they tested? I've read an awful lot of creationist books and opinions, and I have yet to see them make progress on tangible research. When asked for explanations on the distribution of organisms through both the fossil record and geographically, or the nested hierarchy of both morphological and genetic traits, the best I've gotten is "Well you can't prove that God didn't do it that way, because maybe he felt like it." If you've got some first hand creationist research that I've overlooked, don't hesitate to share.

I'm about midway into my edumacation and am starting my own research on evolution. If the theory's wrong, it ain't gonna work

 

[Fencerguy]

If you mean they're part of the same family tree then yes, anatomy (and possibly DNA, although it's hard to get from fossils) would be a very good indicator. If you literally mean direct ancestry - this fossil is the great-great-great etc. grandchild of this fossil - then no, that would be very unlikely.

Not as in a genealogy, but does the fossil record really show the process of ancestry from one species to another, or is the ancestry a conclusion that is applied to the data from the fossil record?

It's possible but incredibly complicated. You'd have to build the entire rhodocetus genome, identify the genes which gave rhodocetus it's legs, turn on these genes to give the dolphin legs (and many other features - did rhodocetus have ears, whiskers, hair follicles?) ... and what for? All that effort just to see what it looked like? Like I said possible but very difficult.

Not just to see what it looked like, to provide data that can verify the hypothesis that macroevolution is plausible....If organisms can change in one "direction" (i'm using the word geometrically, not saying that natural selection has "direction"), is it not just as likely, given the proper set of circumstances, that they could evolve in the opposite "direction?" If they retained all of their genetic material--didnt lose any genes--or gained more genetic material (still need a mechanism for how), would it not be equally as plausible that the organism could "evolve back"?

Certain disorders and deformities perhaps. There's a theory that during pregnancy the embryo / foetus goes through previous evolutionary stages - which is why very early embryos all look alike, and why even human have tails, webbed hands and feet and even a fur-like substance known as lanugo. These are features we sometimes see in the animals humans evolved from.

That example about embryos was disproved quite a while ago: While the features are there in a human embryo, it is not really accurate to say that the human embryo goes through "preevolutionary stages" during development...

RECAPITULATION
JSTOR: An Error Occurred Setting Your User Cookie
Recapitulation theory - Wikipedia, the free encyclopedia

We'll never really know what genes the very first organism had, but you might be interested to know that the human genome contains the entire DNA of a virus, without which we could not make placenta. So yes - almost.

It still remains to find a mechanism that can explain the uptake of new genetic material....

If we found the correct genes and could get them properly expressed, could humans have wings like the guy in the X-Men?

Cheers. I'm not sure I'll be able to answer many more of your questions though. I'm not an expert, just an internet dweeb.

Cheers to intelligent discussions without condesention and namecalling!

 

[Hespera]

As opposed to how easy it is to get well educated, scientifically grounded individuals to actually consider alternate explanations to the data from which they have gathered their sacred dogmas.....Again the problem that so many of you view yourselves and your theories as above reproach....You are all just as dogmatic as you proclaim me to be...

thing is you make up so much stuff, like the above. all made up all false.

 

[Notedstrangeperson]

at example about embryos was disproved quite a while ago: While the features are there in a human embryo, it is not really accurate to say that the human embryo goes through "preevolutionary stages" during development...

I'd be careful about that first link, creationist websites seldom note the differences between genuine hoxes and valid theories they happen to disagree with. As far as I know recapitulation is considered true. Even dolphin embryos have 'leg buds' [marked h--]

If we found the correct genes and could get them properly expressed, could humans have wings like the guy in the X-Men?

Humans were never descended from birds (both birds and mammals come from two very separate lines of reptile, and birds evolved much later) so this wouldn't be possible.

If organisms can change in one "direction" (i'm using the word geometrically, not saying that natural selection has "direction"), is it not just as likely, given the proper set of circumstances, that they could evolve in the opposite "direction?" If they retained all of their genetic material--didnt lose any genes--or gained more genetic material (still need a mechanism for how), would it not be equally as plausible that the organism could "evolve back"?

Yes they can, it's called 'devolution', in which organisms revert back to an earlier evolutionary stage. This actually makes sense - it's far easier to 'switch on' genes they already had but were no longer using, rather than try to evolve the same features over and over again.

There's a argument called 'Dollo's Law of Irreversibity' which states that an organism can never evolve backwards, but this has now been proven wrong. The New Zealand short-tailed bat for example which insted of catching insects in mid-air, simply swoops to the ground and eats them off the forest floor. It's wings are much thicker and heavier than other bats and their claws are bigger, suggesting they are slowly losing their ability to fly.

Devolution however has been misused quite a lot and has even been used to support racism. It does NOT mean becoming slower, stupider, less adapted etc., rather it means going back to features they once had, which are now useful once again.

 

[Fencerguy]

I'd be careful about that first link, creationist websites seldom note the differences between genuine hoxes and valid theories they happen to disagree with.

Most of the creationism-oriented discussions I have seen revolve around hoekel (sp?) and his phony diagrams...
The other objections that I have seen are related to the fact that recapitulated structures generally stay within the major types of organisms that they come from.....and that has a little more validity in my mind than human embryos having structures like fish or frogs or whatever..... See this section of the Wikipedia article:

• The backbone, the common structure among all vertebrates such as fish, reptiles and mammals, appears as one of the earliest structures laid out in all vertebrate embryos.
• The cerebrum in humans, the most sophisticated part of the brain, develops last.

If a structure vanished in an evolutionary sequence, then one can often observe a corresponding structure appearing at one stage during embryonic development, only to disappear or become modified in a later stage. Examples include:

• Whales, which have evolved from land mammals, don't have legs, but tiny remnant leg bones lie buried deep in their bodies. During embryonal development, leg extremities first occur, then recede. Similarly, whale embryos have hair at one stage (like all mammalian embryos), but lose most of it later.
• The common ancestor of humans and monkeys had a tail, and human embryos also have a tail at one point; it later recedes to form the coccyx.
• The swim bladder in fish presumably evolved from a sac connected to the gut, allowing the fish to gulp air. In most modern fish, this connection to the gut has disappeared. In the embryonal development of these fish, the swim bladder originates as an outpocketing of the gut, and is later disconnected from the gut.
• In bird embryos, very briefly fingers start to develop. After a short time, they partly disappear again, partly are fused with the handbones to form the carpometacarpus.

As far as I know recapitulation is considered true. Even dolphin embryos have 'leg buds' [marked h--]

well adult dolphins have pelvic bones and small bones that appear like hind limb bones, I would expect the embryos to have those too.....But I still don't know if that really shows an ancestry of terrestrial mammals?

Humans were never descended from birds (both birds and mammals come from two very separate lines of reptile, and birds evolved much later) so this wouldn't be possible.

But if we have all the DNA of certain viruses within our genome, is it not conceivable that we could have bird DNA sequences in there as well? I know that we did not evolve from a virus, so why would that DNA be in our genome (unless it was added to our genome exogenously, as many viruses do, so not so much evolution as symbiosis)

Yes they can, it's called 'devolution', in which organisms revert back to an earlier evolutionary stage. This actually makes sense - it's far easier to 'switch on' genes they already had but were no longer using, rather than try to evolve the same features over and over again.

So I am still stuck with where new genetic information comes from, since many forms of microevolution involve the loss of genetic information (rather than just the inactivation of genes), where would organisms acquire genetic information that they did not already have?

There's a argument called 'Dollo's Law of Irreversibity' which states that an organism can never evolve backwards, but this has now been proven wrong. The New Zealand short-tailed bat for example which insted of catching insects in mid-air, simply swoops to the ground and eats them off the forest floor. It's wings are much thicker and heavier than other bats and their claws are bigger, suggesting they are slowly losing their ability to fly.

Do you think that we will see a time where these bats become....mice...again? (not exactly mice, but i think you get my meaning?)

Devolution however has been misused quite a lot and has even been used to support racism. It does NOT mean becoming slower, stupider, less adapted etc., rather it means going back to features they once had, which are now useful once again.

Such as the peppered moth changing colors?

 

[Jro]

Most of the creationism-oriented discussions I have seen revolve around hoekel (sp?) and his phony diagrams...
The other objections that I have seen are related to the fact that recapitulated structures generally stay within the major types of organisms that they come from.....and that has a little more validity in my mind than human embryos having structures like fish or frogs or whatever..... See this section of the Wikipedia article:

I'm not sure what you're saying here (sorry if I'm butting in). What do you mean recapitulated structures generally stay within the major types of organism (what are the major types for that matter?). Human embryos do have gill slits at one point in their development.

well adult dolphins have pelvic bones and small bones that appear like hind limb bones, I would expect the embryos to have those too.....But I still don't know if that really shows an ancestry of terrestrial mammals?

You're right to be skeptical. That one fact alone doesn't prove that the whale came from terrestrial mammals, however, it is one piece of evidence that supports the conclusion that they did. Other forms of support include other morphological features (teeth, mammary glands, skeletal structure, etc.), genetic similarities to closely related mammals such as hippos and the fossil record which has extensively documented the evolution of whales.

http://www.corante.com/loom/archives/Thewissen2002whaletree.gif

But if we have all the DNA of certain viruses within our genome, is it not conceivable that we could have bird DNA sequences in there as well? I know that we did not evolve from a virus, so why would that DNA be in our genome (unless it was added to our genome exogenously, as many viruses do, so not so much evolution as symbiosis)

Not so much. Viruses have a nasty little habit of inserting their DNA into cell machinery so that the cells build more copies of these viruses.

So I am still stuck with where new genetic information comes from, since many forms of microevolution involve the loss of genetic information (rather than just the inactivation of genes), where would organisms acquire genetic information that they did not already have?

Genetic information can be added in a number of ways. One of these is gene duplication, where sections of DNA are just kind of duplicated. The duplicated section of the genome is then basically junk DNA, so it can and does randomly evolve without affecting the phenotype of the organism too much. It can however lead to new developments of different bits.

Another thing is that you don't necessarily need to change that much of the genome to drastically change the organism's shape. There are these genes called HOX genes which are basically body-building genes. They coordinate cells during embryonic development to do things like "PUT ARM HERE" or "TURN ON HAND GENES NOW" (my understanding of these genes is obviously limited- for a good, easy to understand book on HOX genes and their role in evolution, Sean Carroll's "Endless Forms Most Beautiful" is a great book). Alterations in these genes can produce drastic changes in an organism, with only a few mutations.

Do you think that we will see a time where these bats become....mice...again? (not exactly mice, but i think you get my meaning?)

I'm guessing everything in New Zealand is probably on a one way track to extinction, but who knows!

 

[Fencerguy]

I'm not sure what you're saying here (sorry if I'm butting in). What do you mean recapitulated structures generally stay within the major types of organism (what are the major types for that matter?).

I am referring to the major types of organisms at the level of...say the Phylum or Class level....The structures that seem recapitulated don't just randomly show up on an embryo from a completely different phylum....They are only indicative of other organisms that are similar.....

Human embryos do have gill slits at one point in their development.

Human embryos have Pharyngeal Arches, not gills. Don't give me a misrepresentation of human development in an attempt to validate ToE....Pharyngeal arches in the human embryo bear only a visible similarity to gills, never do they function as gills...
Development of the Pharyngeal Arches
The human embryonic pharyngeal arches don't even give rise to any respiratory structures:Laryngotracheal groove - Wikipedia, the free encyclopedia
The Laryngotracheal Groove is where lungs begin to develop.

You're right to be skeptical. That one fact alone doesn't prove that the whale came from terrestrial mammals, however, it is one piece of evidence that supports the conclusion that they did. Other forms of support include other morphological features (teeth, mammary glands, skeletal structure, etc.), genetic similarities to closely related mammals such as hippos and the fossil record which has extensively documented the evolution of whales.

The fossil record has extensively documented many organisms that seem to be species in between whales and terrestrial mammals, it does not show obvious ancestry. And also, common design does not indicate ancestry, it indicates common design....

http://www.corante.com/loom/archives/Thewissen2002whaletree.gif

Nice diagram, what organisms are at the points where all the species branch off from? Do we have records of those species? or of the one organism that all of them sprang from? The problem with this diagram (and many phylogenetic trees that come from the ToE proponents) is that the only documented organisms are the ones out at the end of the tree, and those all seem to be quite diverse.....Where are the ones at the base of each branching? And where is the one at the very first branch?

Not so much. Viruses have a nasty little habit of inserting their DNA into cell machinery so that the cells build more copies of these viruses.

Yes, I believe that I mentioned that as well....So that is how humans have complete viral DNA in their genomes, it is placed there exogenously, not through evolution..... So should i expect to see the genes for say, lemur structures in my DNA?

Genetic information can be added in a number of ways. One of these is gene duplication, where sections of DNA are just kind of duplicated. The duplicated section of the genome is then basically junk DNA, so it can and does randomly evolve without affecting the phenotype of the organism too much. It can however lead to new developments of different bits.

Development of bits....But bits aren't good enough if they do not result in complete and functional structures.......Even gene duplication cannot explain the large expansion of genetic material seen between the levels of organisms along the fossil record, that would require a huge amount of gene duplication, along with a huge amount of rearrangement of the DNA (into useable forms only, such as would lead to functional structures). It seems rather difficult, to put it mildly...

Another thing is that you don't necessarily need to change that much of the genome to drastically change the organism's shape. There are these genes called HOX genes which are basically body-building genes. They coordinate cells during embryonic development to do things like "PUT ARM HERE" or "TURN ON HAND GENES NOW" (my understanding of these genes is obviously limited- for a good, easy to understand book on HOX genes and their role in evolution, Sean Carroll's "Endless Forms Most Beautiful" is a great book). Alterations in these genes can produce drastic changes in an organism, with only a few mutations.

This brings me back to an earlier question, shouldn't the fossil record be littered with organisms who were changing and evolving, but didn't get it quite right? Why don't we see whale intermediates with one diminished limb and two or three regular terrestrial limbs? Bc it would seem quite easy to me that one HoX gene could switch off, or be inhibited somewhat, but not all of them at once....So wouldn't the fossil record have untold swarms of organisms like this, that did not successfully adapt and change to match a changing environment?

I'm guessing everything in New Zealand is probably on a one way track to extinction, but who knows!

That's too bad, Where will they shoot the rest of "The Hobbit"?

 

[Jro]

I am referring to the major types of organisms at the level of...say the Phylum or Class level....The structures that seem recapitulated don't just randomly show up on an embryo from a completely different phylum....They are only indicative of other organisms that are similar.....

This is kind of similar to what you'd expect actually. Organisms that are very distantly related will have more differences than animals that are more closely related. Yes there are huge differences, but there are still similarities between phyla (deuterosomes and whatsumcalleds).

Human embryos have Pharyngeal Arches, not gills. Don't give me a misrepresentation of human development in an attempt to validate ToE....Pharyngeal arches in the human embryo bear only a visible similarity to gills, never do they function as gills...
Development of the Pharyngeal Arches
The human embryonic pharyngeal arches don't even give rise to any respiratory structures:Laryngotracheal groove - Wikipedia, the free encyclopedia
The Laryngotracheal Groove is where lungs begin to develop.

Ha, good catch. Still, we wouldn't expect gills to develop into lungs, as lungs are modified swim bladders. Lungfish, gar and bichir have all adapted to use their swim bladders as air breathing apparatus. There's a reason we share homologies like this in our organs with fish and not with birds. Although it would be completely cool to have unidirectional air flow.

The fossil record has extensively documented many organisms that seem to be species in between whales and terrestrial mammals, it does not show obvious ancestry. And also, common design does not indicate ancestry, it indicates common design....

It doesn't show direct ancestry, but it does show obvious ancestry because we can look at homologies. Common design is an insufficient explanation because it does not predict the pattern of homologies. Why would a whale fin be more anatomically similar to a human hand than to a fish fin? Etc.

Nice diagram, what organisms are at the points where all the species branch off from? Do we have records of those species? or of the one organism that all of them sprang from? The problem with this diagram (and many phylogenetic trees that come from the ToE proponents) is that the only documented organisms are the ones out at the end of the tree, and those all seem to be quite diverse.....Where are the ones at the base of each branching? And where is the one at the very first branch?

What you're asking for is equivalent to someone saying "Well you filled in one missing link, but now you've got two more gaps to fill!" All species that we find are going to be at the terminal end of a branch, because they are separate species. Most organisms, 95% or so, go extinct. Not all of them leave any descendants and most of the species don't even fossilize.

We can't show that any of these fossils or these species directly led to the evolution and origin of modern species, but we can place them within the framework of descent by examining the evidence. What we're doing is looking at footprints, but even though the trail is old and elusive, we can still follow the trail.

Phylogenetic trees are hypotheses, informed by both genetic and morphological data. Many of them are quite possibly wrong, and there are lingering debates between the crotchety taxonomists and the new fangled molecular biologists as to whether genetic similarities or morphological similarities are more important in determining relationships, but the interesting thing is that most of the time they wind up agreeing.

Yes, I believe that I mentioned that as well....So that is how humans have complete viral DNA in their genomes, it is placed there exogenously, not through evolution..... So should i expect to see the genes for say, lemur structures in my DNA?

You share quite a bit of genetic material in common with lemurs actually, exactly as predicted by evolution. Want to hear something REALLY mindblowing? You can even look at the DNA of the invasive viruses and compare them between different species of Apes to show relatedness. Not only is our genetic code more similar to lemurs than to snails, our invasive viral DNA is more similar to the DNA that invaded say, chimps, than it is to lemurs.

Development of bits....But bits aren't good enough if they do not result in complete and functional structures.......

What you're talking about is phenotypic integration. Remember, we aren't dealing with individuals, but with populations, which means that several mutations can happen at the same time and spread through the species all in the same generation.

Complex functional structures, like, say wings take time to develop. Despite that, they've evolved at least 4-5 times in vastly different groups (Do flying fish count? They should!). They require a high metabolism and dedicated muscles to power flight, etc., etc. We can look at the evolution of these traits in the characters of other species. It turns out half a wing can be very advantageous for an arboreal critter, just as a high metabolism can be advantageous for other reasons besides powering flight.

Even gene duplication cannot explain the large expansion of genetic material seen between the levels of organisms along the fossil record, that would require a huge amount of gene duplication, along with a huge amount of rearrangement of the DNA (into useable forms only, such as would lead to functional structures). It seems rather difficult, to put it mildly...

Yup, there's evidence that there were several complete genome duplications. Wheat has SIX copies of its own genome right now. There was also a genome duplication event in (sigh, my favorite) actinopterygia.

This brings me back to an earlier question, shouldn't the fossil record be littered with organisms who were changing and evolving, but didn't get it quite right? Why don't we see whale intermediates with one diminished limb and two or three regular terrestrial limbs? Bc it would seem quite easy to me that one HoX gene could switch off, or be inhibited somewhat, but not all of them at once....So wouldn't the fossil record have untold swarms of organisms like this, that did not successfully adapt and change to match a changing environment?

Yes and no. Even modern organisms exhibit transitional characters. For example the nautilus has no lens over its eye. Their eyes still work perfectly fine for them though! Genes also don't have to work the way you're thinking either. One gene can control all four limb lengths for example. And the fossil record DOES have swarms of organisms that failed to adapt and went extinct. Shoot, that's basically all the fossil record is.

That's too bad, Where will they shoot the rest of "The Hobbit"?

Which part of him did they shoot first?

 

[Fencerguy]

This is kind of similar to what you'd expect actually. Organisms that are very distantly related will have more differences than animals that are more closely related. Yes there are huge differences, but there are still similarities between phyla (deuterosomes and whatsumcalleds).

Yes I would expect this, but my creationist reasoning for why the differences are similar only in related types of organisms wouldn't make the evolutionist types happy....lol

Ha, good catch. Still, we wouldn't expect gills to develop into lungs, as lungs are modified swim bladders. Lungfish, gar and bichir have all adapted to use their swim bladders as air breathing apparatus.

The problem with the "gill arch" fallacy is that the pharyngeal arches don't lead to any respiratory structures whatsoever....So anyone trying to defend evolution by citing vestigial structures and these recapitulated "gillslits" in the human embryo are doing exactly the same thing that they accuse the creationists of doing.....Changing the facts to suit their agenda....

There's a reason we share homologies like this in our organs with fish and not with birds. Although it would be completely cool to have unidirectional air flow.

You're not kidding!! lol

It doesn't show direct ancestry, but it does show obvious ancestry because we can look at homologies. Common design is an insufficient explanation because it does not predict the pattern of homologies. Why would a whale fin be more anatomically similar to a human hand than to a fish fin? Etc.

If the fossil record does not show direct ancestry, why do so many evolution proponents act as if it does.......Obvious ancestry is still too strong of a word for me, because it implies jumps that seem too large for any microevolutionary mechanism that I know of.....A logical question arises regarding whale ancestry: other organisms such as otters and crocodilians thrive in aquatic environments, but they have retained four limbs that are fully functional in both the land and the water...Why have these organisms not lost their hind limbs due to their aquatic habits?

The only explanation off of the top of my head (and this truly is a wild guess, I am merely thinking practically) would be that since a whale has such greater mass than most fish, they would need greater support in the structures that provide locomotion, hence a bone structure more similar to a hand than a fin?

What you're asking for is equivalent to someone saying "Well you filled in one missing link, but now you've got two more gaps to fill!" All species that we find are going to be at the terminal end of a branch, because they are separate species. Most organisms, 95% or so, go extinct. Not all of them leave any descendants and most of the species don't even fossilize.

Pardon any unintended impertinence, but saying that most species don't fossilize seems awfully convenient for the evolution proponents....If all species we find are going to be at the terminus of a branch on the phyologenetic tree, then do we or can we really know for sure which organisms gave rise to which? If there are no examples of the organisms that are found at the bases of the branches, then how do we know that they were ever there to begin with?

We can't show that any of these fossils or these species directly led to the evolution and origin of modern species, but we can place them within the framework of descent by examining the evidence. What we're doing is looking at footprints, but even though the trail is old and elusive, we can still follow the trail.

I applaud your honesty good sir, but this begs the question of why one conclusion based on the trail is so far superior to another? No one dropped a map along the trail of biodiversity, so how can we know for certain that all of the organisms we observe came from one single ancestor? Why is the creationist idea that multiple generic "kinds" of animals were created, and then evolved--within their "kinds"--to show the diversity that we have today? Why is that creationism so invalid?

Phylogenetic trees are hypotheses, informed by both genetic and morphological data. Many of them are quite possibly wrong, and there are lingering debates between the crotchety taxonomists and the new fangled molecular biologists as to whether genetic similarities or morphological similarities are more important in determining relationships, but the interesting thing is that most of the time they wind up agreeing.

Would anyone consider this phylogenetic tree acceptable?

Which part of him did they shoot first?

The movie.....They have shot all of the Lord of the Rings movies in New Zealand.....If New Zealand went extinct they would have no place sufficiently epic to finish the Hobbit movie......

 

[Jro]

Yes I would expect this, but my creationist reasoning for why the differences are similar only in related types of organisms wouldn't make the evolutionist types happy....lol

Feel free to give it a try, but yes, it will probably get criticized. Criticism isn't necessarily a bad thing, I can't tell you how many of my ideas have been ripped apart.

The problem with the "gill arch" fallacy is that the pharyngeal arches don't lead to any respiratory structures whatsoever....So anyone trying to defend evolution by citing vestigial structures and these recapitulated "gillslits" in the human embryo are doing exactly the same thing that they accuse the creationists of doing.....Changing the facts to suit their agenda....

Again, we wouldn't expect gill arches to lead to respiratory structures in terrestrial organisms, because that's not the evidenced path of lung evolution. The fact that pharyngeal arches arise AT ALL should lead you to ask why. This isn't the only homology we share with fish either. For a really easy read on our similarity to fish, and probably one of the most modern iconic stories of evolution, check out Neil Shubin's "Your Inner Fish."

If the fossil record does not show direct ancestry, why do so many evolution proponents act as if it does.......Obvious ancestry is still too strong of a word for me, because it implies jumps that seem too large for any microevolutionary mechanism that I know of.....

I can't tell you what most evolutionary proponents are telling you- there's a lot of misinformation out there. We have many records of microevolution leading to speciation, new morphological structures, new enzymes, etc., etc. in modern time. Time + adaptation can cause surprising changes, and some of these can be quite fast. The microevolution vs. macroevolution is a weird dichotomy that I don't really like anyway.

A logical question arises regarding whale ancestry: other organisms such as otters and crocodilians thrive in aquatic environments, but they have retained four limbs that are fully functional in both the land and the water...Why have these organisms not lost their hind limbs due to their aquatic habits?

It could be a variety of reasons. One important thing is that evolution is not directed. If the necessary mutations never happen, a species can't motivate itself to evolve in a certain direction. Crocodiles have moved to the ocean in the past (observe the mosasaur), but legs seem advantageous for near shore living.

The only explanation off of the top of my head (and this truly is a wild guess, I am merely thinking practically) would be that since a whale has such greater mass than most fish, they would need greater support in the structures that provide locomotion, hence a bone structure more similar to a hand than a fin?

Nope, whale sharks and ocean sunfish (the two largest fish that are as big as some whales) still have fins based on their respective ancestry. Look at the different wings of the pteranodon, the bird and the bat. Ask yourself why does a bat have a hand that's more similar to a monkey and to a whale than it is to a pteranodon or a bird. Then ask why all three of these critters have bones that are more similar to each other than they are to insect wings.

There is a pattern to these homologies that cannot be explained by 'common design.' Something you might expect from common design is, for example, Russian wagon wheels to be the same as Chinese wagon wheels. Wagon wheels have largely the same purpose, so it wasn't necessarily that they were copying each other, but that they came by the same solution to the same problem. Wheels gotta roll, yo. You see evidence of this in the natural world as well, for example, sharks, icthyosaurs and dolphins have similar body plans. They found the same solution for how to catch fish at high speed in the ocean, but it doesn't imply any relationships between them. What you wouldn't expect is seeing wagon wheels used as airplane wings, which is what we've seen in the natural world. We don't see this pattern in isolated cases, we see it spread through the entire natural world.

Pardon any unintended impertinence, but saying that most species don't fossilize seems awfully convenient for the evolution proponents....

Hey, that's a good question. I like good questions. But it's also just the truth that most things don't fossilize and there's been a LOT of species. There are species living today where we can only tell them apart based on genetic testing. Fossilization requires a very particular set of circumstances that just won't happen in many parts of the world. Unfortunately some of life's history is just lost forever. Oh for a time machine.

If all species we find are going to be at the terminus of a branch on the phyologenetic tree, then do we or can we really know for sure which organisms gave rise to which? If there are no examples of the organisms that are found at the bases of the branches, then how do we know that they were ever there to begin with?

We can't ever prove that one organism was at the base of a branch for a couple reasons. 1) We can't infer that that specific organism gave rise to another. 2) Speciation doesn't necessarily lead to the annihilation of the progenitor species. Oftentimes species will persist long after they've split. 3) I'm not aware of any methods that could tell you the order of speciation, ie, who led to who, even with recently speciated organisms. 4) Because we can trace the evolution of characters within those species.

Think about it this way, let's say you and your relatives carry a mutant gene that make your eyes purple. Even though your family records were destroyed by a passing buzzard, you can still infer relations based on that character.

I applaud your honesty good sir, but this begs the question of why one conclusion based on the trail is so far superior to another? No one dropped a map along the trail of biodiversity, so how can we know for certain that all of the organisms we observe came from one single ancestor? Why is the creationist idea that multiple generic "kinds" of animals were created, and then evolved--within their "kinds"--to show the diversity that we have today? Why is that creationism so invalid?

Even if we were working only with modern organisms we could infer the trail of evolution. The fossil record is not necessary to infer common descent, but it does provide extensive evidence as to the route it took. Creationism isn't just a little off base, it's the equivalent of a hunter saying "Different animals made all of these tracks that are the same size, going in the same direction and I see the deer off in the distance, but that's probably a different deer..." The evidences that inform us of the relationship with, say apes, also inform us of our relationship with say, plants.

Would anyone consider this phylogenetic tree acceptable?

I mean, it's a valid hypothesis, but it was not supported by the evidence and other models were. The debates in taxonomy are not over whether there is common descent or not.

The movie.....They have shot all of the Lord of the Rings movies in New Zealand.....If New Zealand went extinct they would have no place sufficiently epic to finish the Hobbit movie......

I was kidding. :] Besides, the area might still look nice, it'll just be filled with non-indigenous species. Mourn the kakapo.

 

[Wiccan_Child]

I've been away for a few days and the discussion's moved on, so I apologise if I'm going over anything that's already been covered!

To this point I'm completely with you, why is it so outlandish to think that God created some generic Kinds of animals (such as "Lizard," "Mammal" and "Fly") to then reproduce and become more varied? That is exactly the kind of evolution that I can observe, and I don't see any problem with connecting this description with my Creationist beliefs...

Brilliant! Then your objection to evolution isn't theoretic, but empirical. If God could create 'kinds' that have since diversified, such as 'Mammal' that has since diversified into the many mammal species we see today - why couldn't God have created a single kind?

The problem arises with the rest of your discussion. I need to see the actual observable mechanism for such huge changes. The obstacle still exists: how is so much completely new genetic information acquired by the organism,

An organism inherits the vast majority of the mutations, and creates a few itself. Then, its offspring will have all the mutations of the parent, plus the new ones, and some even newer ones its created itself. That's how mutations accumulate and genetic information increases. Now, not all mutations are good, and those which are bad are weeded out by nature - malformed wings on a bird will inevitably kill it, as will lethal mutations to protein folding or digestive enzymes. Sometimes, however, an offspring is produced that has new mutations which improve the organism - slight changes to protein folding that just so happen to confer a benefit to the organism (it may acquire a more efficient way to digest, or to fight infection, or to change its colour, or to grow less dense bones, etc).

mutations can only allow for so much variation (that is beneficial) before it reaches its limit....

What limit are you referring to?

Mutation alone cannot physically result in such huge variations that would lead to the changes from one organism to another...

Why not?

What mutations have been observed that result in the acquisition of large amounts of previously nonexistent genetic material that are also beneficial to the organism?

Well, the fundamental principle in evolution is that no single mutation accounts for large change - rather, each small mutation is a small improvement on the last. Over thousands and millions of years, all these little mutations, all these single point insertion mutations, they all add up to massive quantities of genetic material. If you have a thousand generations, each adding chunks of DNA to the genome, you get thousands of chunks more on your genome that you would otherwise.

As for actual examples, we have seen bacteria that can digest wholly synthetic materials, such as nylon, or otherwise uningestable things, such as citrus, which attests to their ability to evolve large, novel traits and functions. The fossil record is replete with examples of lineages showing a smooth transition from A to B to C to D to E to F, even though A and F are superficially very different.

 

[Delphiki]

Would anyone consider this phylogenetic tree acceptable?

Not as long as there's genetic and morphological similarities between the living things at the base of the tree, no. There would have to be either nothing in common or at least enough in common to be considered coincidental - and the evidence does not show this.

Just some food for thought: We're 50% genetically similar to bananas.

 

[Willtor]

Would anyone consider this phylogenetic tree acceptable?

The trouble with that phylogenic tree is that it doesn't take into account all of the evidence. In actuality, there are smooth transitions between almost all living species. More than that, too, there has been a great diversity in the past that is not even reflected in living species.

I have augmented your graph to illustrate what I mean:

 

[Bombila]

Hey guys, this is one of the best creation/evolution threads I've seen in a long while, well done both sides.

Couple simple things I'd like to mention that were perhaps not emphasised, though briefly alluded to and seemingly obvious to most people with any kind of biology background, may help with understanding some concepts:

1. Sex: A mutation in an individual sexually reproducing animal does not get passed on to all of its offspring. The individual with the mutation of necessity will mate with an individual which does not have that mutation, and no more than half of the offspring in that first generation will have the mutation in question.

2. Wrt ancestor species still being around or even surviving after the extinction of a descendant species: I think it's important to remember that even when an advantageous change gets fixed in a descendant population, the ancestor population does not necessarily become extinct, so it isn't unexpected to come across fossil examples of ancestor species occurring later in the fossil record than the animals that are considered a descendant species.

3. It can happen that the ecological niche which a mutation allowed an animal to exploit to its advantage can degrade or disappear through climate change/habitat destruction, and that may happen quickly enough that it pushes the mutated population to extinction, while the ancestor population may have lucked out on a stable habitat/niche and survived.

Seems obvious, but I've seen creationists boggled by not thinking of this and evolutionists not notice that there are some basic concepts left uncomprehended.

 

[Fencerguy]

Not as long as there's genetic and morphological similarities between the living things at the base of the tree, no. There would have to be either nothing in common or at least enough in common to be considered coincidental - and the evidence does not show this.

Why do the genetic and morphological similarities disprove my phylogenetic tree? Why would the God who created the "kinds" of organisms at the beginning use a completely different genetic code for each kind? That would be tedious in fact make the concept of creationism a little too obvious.....Why would there have to be nothing in common between the created kinds? You are making an assumption about God's creating style that is not backed up by Scripture or science....What evidence shows that there was a single common ancestor?

Just some food for thought: We're 50% genetically similar to bananas.

And? How does this disprove my phylogenetic tree hypothesis? We are 98% the same as apes, and yet look how different we are in that last 2%

 

[Fencerguy]

Brilliant! Then your objection to evolution isn't theoretic, but empirical. If God could create 'kinds' that have since diversified, such as 'Mammal' that has since diversified into the many mammal species we see today - why couldn't God have created a single kind?

I'm not saying that God couldn't have started with a single organism, but from my standpoint (using the Bible as an authoritative historical/theological text), He simply didn't. The Bible says that God created the organisms that fly in the air, and swim in water, and walk on land, and that He gave them instructions (instincts? genetic instructions?) to reproduce after their kinds......so for me, I don't see the single ancestor hypothesis as holding water, and will need to see a LOT of data that confirm it beyond refutation...

An organism inherits the vast majority of the mutations, and creates a few itself. Then, its offspring will have all the mutations of the parent, plus the new ones, and some even newer ones its created itself.

not necessarily, the mutations are just that, mutations, they do not necessarily get passed on through the gametes.....They can, but that is not set in stone....

That's how mutations accumulate and genetic information increases. Now, not all mutations are good, and those which are bad are weeded out by nature - malformed wings on a bird will inevitably kill it, as will lethal mutations to protein folding or digestive enzymes. Sometimes, however, an offspring is produced that has new mutations which improve the organism - slight changes to protein folding that just so happen to confer a benefit to the organism (it may acquire a more efficient way to digest, or to fight infection, or to change its colour, or to grow less dense bones, etc).

But the progression that is seen in the fossil record involves additions of DNA that are larger and more complex than mutations (alone, as the mechanism) cannot physically account for....

What limit are you referring to?


Why not?

Because such large mutations (even ones that are beneficial on a small scale) would be much more likely to have a harmful affect on the organism.....Which is why no one can provide me with fossil evidence of a truly transitional organism (i.e. a terrestrial organism with three legs and one lobe-like fin).....If the mutations become too large, the organism is less likely to be able to function properly.....

Well, the fundamental principle in evolution is that no single mutation accounts for large change - rather, each small mutation is a small improvement on the last.

Then there are several people on here that need to get their stories straight, because I have had several of them tell me that even a small mutation can lead to large phenotypic changes....which is possible, but it seems like we both think that that is not how the evolutionary process works...

Over thousands and millions of years, all these little mutations, all these single point insertion mutations, they all add up to massive quantities of genetic material. If you have a thousand generations, each adding chunks of DNA to the genome, you get thousands of chunks more on your genome that you would otherwise.

But there are not that many types of beneficial mutations that actually add DNA to the genome......That would involve the evolution of wholly new genes, which seems too complicated for random chance, or even an infinite amount of time....

As for actual examples, we have seen bacteria that can digest wholly synthetic materials, such as nylon, or otherwise uningestable things, such as citrus, which attests to their ability to evolve large, novel traits and functions.

It depends on your definition of large.....because a homeostatic change or dietetic change is not "large" in my mind when evolutionists are saying that the bacteria became eukaryotic, and then multicellular, and then started developing other multicellular structures.....These seem much larger than the ability to adapt to a new food source....The data is still lacking for these "large" changes...

The fossil record is replete with examples of lineages showing a smooth transition from A to B to C to D to E to F, even though A and F are superficially very different.

The keyword here being "superficially"
Are you assuming then that the changes in lineage that we actually see (speciation, adaptation, microevolution) naturally follow into changes that there is not explicit data for (simple to complex organism, addition of wholly new genes, etc)

 

[Fencerguy]

The trouble with that phylogenic tree is that it doesn't take into account all of the evidence. In actuality, there are smooth transitions between almost all living species. More than that, too, there has been a great diversity in the past that is not even reflected in living species.

Which would be why not all of the branches go to present time......

What evidence does my phylogeneitc tree not take into account?

I have augmented your graph to illustrate what I mean:

What data indicate that there was a single common ancestor?
And how do most people explain the Cambrian explosion? That also seems more favorable of my phylogenetic tree than one leading back to a single ancestor.....
Your adendum to my tree also assumes that there were organisms before the creation......work with my diagram, don't change it into yours because you think yours is better......Your augmentation changed my graph into your single ancestor phylogenetic tree.....so we are no longer speaking of new ideas or hypotheses....

 

[CaliforniaSun]

I like this one better.