The Instigator
iArgueForFun
Pro (for)
Winning
5 Points
The Contender
Happyreclusive
Con (against)
Losing
4 Points

Evolution did happen

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Post Voting Period
The voting period for this debate has ended.
after 2 votes the winner is...
iArgueForFun
Voting Style: Open Point System: 7 Point
Started: 5/14/2013 Category: Science
Updated: 3 years ago Status: Post Voting Period
Viewed: 2,045 times Debate No: 33712
Debate Rounds (4)
Comments (2)
Votes (2)

 

iArgueForFun

Pro

Definition for argument - Evolution - Change in the genetic composition of a population during successive generations, as a result of natural selection acting on the genetic variation among individuals, and resulting in the development of new species.

My argument - Evolution has occurred and did occur over many generations to create every living creature we see today.
Happyreclusive

Con

Since Pro makes a positive claim, I assume that the burden of proof lies wholly with him. Thus, I only have to show that he has not, or he cannot, prove that his conclusion is true.

First, as far as I can tell, his claim requires direct empirical evidence. So, I expect him to show examples where we have seen animals (or perhaps plants) evolve from one distinct species into another distinct species. Of course, he can show examples where some animals look like other animals, and he can claim this as a basis for knowing that evolution occurred. But the fact that one thing resembles another fails to prove a causal connection between the two.

Second, I assume we"re using a standard definition of "species." A species groups together animals or plants that are able to reproduce successfully. None from outside of that group can reproduce successfully with any in the group.

Third, I would like to see Pro develop a definition of "natural selection."

I hope that Pro realizes that although I am a man and that I am con, I am not a con-man.
Debate Round No. 1
iArgueForFun

Pro

Natural Selection - the process by which forms of life having traits that better enable them to adapt to specific environmental pressures, as predators, changes in climate, or competition for food or mates, will tend to survive and reproduce in greater numbers than others of their kind, thus ensuring the perpetuation of those favorable traits in succeeding generations.

Now, for my first bit of evidence I will point to the artificial selection of the samurai crab.

If I may take direct quotes from discoveries website.

"Many times a species is forced to make changes as a direct result of human progress. Such is the case with the peppered moth (Biston betularia). Up until the Industrial Revolution, these moths were typically whitish in color with black spots, although they were found in a variety of shades. As the Industrial Revolution reached its peak, the air in London became full of soot, and the once-white trees and buildings that moths used for camouflage became stained black. The birds began to eat more of the lighter-colored moths because they were more easily spotted than the darker ones. Over the course of a few months, dark moths started appearing in the area and lighter moths became scarce. Once the Industrial Revolution peak passed, lighter moths made a comeback." (Source at the end)

Here is a picture of the incredibly beautifully selected peppered moth.
http://www.empiricalzeal.com...

One more example from Discovery's beautiful list.

"Lactose intolerance is one example of natural selection. We are the only species that doesn't become lactose intolerant as we grow up. According to experts, this seemed to have happened when cattle became domesticated in Europe centuries ago [source: Broad Institute of MIT and Harvard]. Another example is the sickle hemoglobin gene, which occurs in people who live in certain regions of Africa and other areas where malaria is endemic. This gene mutation makes people who have it more resistant to malaria. While they can still contract the disease, they are less likely to die from it. The mutation probably happened over hundreds of generations as a result of the constant exposure to malaria and people contracting and surviving it [source: Harvard University]." (source at the end)

So as you can see, there is monumental evidence for the case of natural selection, small mutations that benefit a species can and will be more prominent among said species.

Now, the evidence for natural selection can also be seen in artificial selection.

Of course artificial selection is the selection of certain traits by humans, but it is not so different from natural selection.
In most cases of artificial selection, humans can be viewed as the guiding hand of an animals natural selection because we are the ones that determine whether said animal lives or dies.

Examples of artificial selection are seen throughout history, this is why we have a great abundance and different kinds of domesticated dogs. This is also why specially farmed cows have such great abundance and choice cuts of meat.
We have artificially selected many different kinds of cows to fit our needs, some cows are only good for giving milk, and some are only good for providing meat.

Here is a picture of primitive corn, compared to today's artificially selected corn - http://www.learner.org...

As you can see, there is more abundance of food on the artificially selected corn.

In artificial selection, humans are the guiding hand, in natural selection, nature is the hand that guided every species for millions upon millions of years. Those that survive, breed, and the only ones to breed are the strong (either in mind, or physical strength).

I've given a few examples, and there are many more. Just search "examples of natural selection" and there really would be no argument.

Now, I assume your next argument will be about how life comes from non life. To that, I say look at this page on abiogenesis (how life can arise from simple organic compounds). Link: http://en.wikipedia.org...

Sources
http://dsc.discovery.com...
http://www.learner.org...
Happyreclusive

Con

Not so fast, my fine-feathered friend. You claimed that new species occur by evolution through natural selection. And, remember that my challenge is "to show examples where we have seen animals (or perhaps plants) evolve from one distinct species into another distinct species." Nothing you say shows any instance where one species became or produced a different species. Yours and Darwin's burden is to show me the new species.

The oft-cited moth example shows at most that a species of moth changed color. But the dark moth never became a species different from the white moth. It's not hard to imagine that individuals change within a species; the difficulty is finding and explaining how one species produces another.

Now my principal objection is that you've failed to produce an example of what you claim happened. I turn now to some minor points.

You say, "Lactose intolerance is one example of natural selection."

First, a great number of people become lactose intolerant in their later years. There is an entire industry built around it. So if our species maintains its tolerance for lactose, that adaptation hasn't taken hold, yet.

Second, you fail to show it is an example of natural selection. Do you suppose that early humans did become lactose intolerant in adulthood, and so lactose tolerance developed over time, such that those who were lactose intolerant were unable to mate as easily as those who were tolerant of lactose?

Third, how does being lactose tolerant, or not, help our species overcome what life-threatening environmental problems?

You appeal to the example of the sickle hemoglobin gene. The gene seems to help people survive malaria. Then your source claims: "The mutation probably happened over hundreds of generations as a result of the constant exposure to malaria and people contracting and surviving it. If some people contracted malaria and then survived the disease, before the existence of the gene, then obviously they didn't need the gene. If they didn't need the gene, neither does anyone else, and so there is no biological explanation for the gene's coming into existence.

You claim "the evidence for natural selection can also be seen in artificial selection," which I"m afraid is utterly false. Even the most adamant Creationist acknowledges that artificial selection occurs. No one, and I mean literally no one, denies that human beings cause changes in animals through artificial selection. Over the millennia, there is not a single instance where artificial selection produced a new species. Not one.

If you could provide examples of new species through artificial selection, then that would help your case for natural selection. Often science reproduces a result in the lab and that opens our understanding of a natural event. If we could produce a new species from artificial selection, maybe could understand how one species produces another.

You say, "Of course artificial selection is the selection of certain traits by humans, but it is not so different from natural selection. . . . In artificial selection, humans are the guiding hand, in natural selection, nature is the hand that guided every species for millions upon millions of years. Those that survive, breed, and the only ones to breed are the strong (either in mind, or physical strength)."

I don't want to argue about the phrase "not so different," but the differences between the two are interesting if not substantial. First, human beings intend changes through artificial selection. Nature has no intentions. It works willy-nilly and often, I suspect, without any purpose at all. Second, natural selection supposedly aims at improving a critter's ability to survive and thrive. Artificial selection has no such purpose. We did not breed dogs so they will survive in the wild better; in fact, that is precisely what we don't want in new breeds, lest they eat the baby. The purpose of artificial selection is to improve the critter for our benefit. Often the improved plants and animals fare far worse in the wild after we're done with them. Thus, there are two major differences between natural and artificial selection.

The ball's in your court.
Debate Round No. 2
iArgueForFun

Pro

"Not so fast, my fine-feathered friend. You claimed that new species occur by evolution through natural selection. And, remember that my challenge is "to show examples where we have seen animals (or perhaps plants) evolve from one distinct species into another distinct species." Nothing you say shows any instance where one species became or produced a different species. Yours and Darwin's burden is to show me the new species."

Well, I guess you were asking how different species form, I just thought you didn't believe in evolution.

One species can form and the species that it came from can remain, this is because the animals of the same species can break into different lineages.

"The biologists reasoned that diversity in a particular ecosystem is a result of three processes: local origination (which adds to diversity by generating new lineages), local extinction (which removes diversity by wiping lineages out in a particular area), and immigration (which adds to diversity through new migrant lineages from other areas). So the tropics might have high diversity because they have high origination (the "cradle" hypothesis), low extinction (the "museum" hypothesis), high immigration, or some combination of these factors."
(source at the end)

So, if a group of two animals (one of the groups had to migrate) went their separate ways, even though they were the same species, they would be in different parts of the world and equally different ecosystems. This is where the change in two of the species would take off, the groups of the same species would be in different ecosystems and face different environmental needs. The process of natural selection would take over, and over many generations the difference in the two would be drastic. However, the two variations of this species would be able to mate. Now, over an even longer time the two groups of this one species might develop different ways of reproducing (changes in seminal fluid or anything else) that would disable the ability of mating with the long lost group that is apart of a different ecosystem.

Now, you're probably thinking, "well why would the animals split from their species anyway?" Well, it happens all of the time, with reptiles this isn't rare, refer to this article http://news.nationalgeographic.com...

The animals of the same species developed different ways of birthing their young, because one group of the same species split off.

"One species does not "turn into" another or several other species -- not in an instant, anyway. The evolutionary process of speciation is how one population of a species changes over time to the point where that population is distinct and can no longer interbreed with the "parent" population. In order for one population to diverge enough from another to become a new species, there needs to be something to keep the populations from mixing. Often a physical boundary divides the species into two (or more) populations and keeps them from interbreeding. If separated for long enough and presented with sufficiently varied environmental conditions, each population takes its own distinct evolutionary path. Sometimes the division between the populations is never breached, and reproductive isolation remains intact purely for geographical reasons. It is possible, though, if the populations have been separate for long enough, that even if brought back together and given the opportunity to interbreed they won't, or they won't be successful if they try." (source at the end)

Now, if you were to ever look at the branching rows of evolution you would be able to see the evolution of new species, even though the last remains alive. This has happened with the many different kinds of humans. Refer to this image.
http://www.pbs.org...

Now as you can see, even though one species of humans evolved into another, doesn't mean that the original species isn't on earth anymore. This is because early humans (like many other species of animals) were nomadic.

As you can see, variation (and immigration) within a species can lead to a completely different species.

"Diversity= origination - extinction + immigration"

Sources:
http://www.pbs.org...
http://evolution.berkeley.edu...
http://news.nationalgeographic.com...

He shoots!...
Happyreclusive

Con

You write: " . . . I just thought you didn't believe in evolution." It's unfortunate you guess what I am thinking instead of reading what I write. You've tried to guess what I am thinking three times and you're mistaken in all cases. I encourage you to read what I wrote and try to respond to that.

I challenged your assumption that lactose tolerance came from natural selection. You made no response. I made the same challenge about the hemoglobin gene example. Again, you remain silent. I explained that your moth fails to prove your claim because no new species came into existence. Again, nothing from you. I had to explain the difference between artificial and natural selection because it seemed from what you said that you didn't understand the difference.

I am not sure how to get your attention. You claim that evolution produces new species through natural selection. I continue to point out that you have no proof of that claim. Your response is to copy and paste things you find on the internet. I wouldn't mind except that none of your quotes solves the problems I've set out.

Briefly, you claim that new species occur through evolution. I ask for proof. Want to know how to prove it? Show me one single instance where we observed a new species coming into existence. For instance, show me a population that separates into two groups. Show me how they became so different from each other that they could no longer mate successfully as they once did. Of course, I don't expect you to traipse through the woods looking for such, but I do expect you to find such an example online or wherever, or to confess that your belief in evolution is without proof.

Your example of the skink is interesting. The author claims that evolution is at work, but he assumes that evolution occurs. Did you notice that he never said anything about either population turning into a new species? If he showed proof of that, you'd be home free.

You quote: "The biologists reasoned that diversity in a particular ecosystem is a result of . . . ." Notice that these biologists already assume that evolution occurs and they are trying to explain some of its mechanisms. You and I do not assume that evolution occurs because you set out to prove it.

You say, "Now, you're probably thinking . . . ." There you go again, trying to figure out what I'm thinking. And you're wrong again.

You say, "Now, if you were to ever look at the branching rows of evolution you would be able to see the evolution of new species, even though the last remains alive." Showing a picture fails to prove your point. If I drew a picture of God zapping animals into existence, would you say, "Oh well, there's a picture, so he must be right"? (Resist the urge to guess again, what I think about God. You'll just be wrong again, that topic is outside the bounds of this debate, and you have enough problems with your argument.)

You write, "As you can see, variation (and immigration) within a species can lead to a completely different species." Still not a proof.

He shoots! And misses.

P.S. I am beginning to think you're just now learning about evolution. I don't mean that unkindly, but I suspect you don't yet have mastery over the subject. By the way, you need not give me references to read on evolution. I assure you that I have read a great deal on the subject.
Debate Round No. 3
iArgueForFun

Pro

"Of course, I don't expect you to traipse through the woods looking for such, but I do expect you to find such an example online or wherever, or to confess that your belief in evolution is without proof."

This is where you have gone completely wrong. If your claim that you read a lot about this topic is true, than you should know that it takes too long for a species to branch into another.

Now, I can give you many examples of where two different species have split, but those would JUST be PICTURES, even though the practice of taxonomy can be traced back to actual observable fossils.

Now, I did provide you with HOW speciation has occurred, but I guess you just want to dismiss that.

One thing that I forgot to add, however, was that when the two different group's DNA becomes too different, the act of mating does not work.

This is because of new courtship rituals among the other group. Also, the different group might not find the other attractive, which would cause problems with mate selection among the two groups.

Now, since there is a barrier between them, evolution is still in place and at full force. Over many other generations the groups will become so different that they cannot mate, because their DNA just doesn't work together.

However, animals that are in the same genus can sometimes mate ( for example, donkeys can mate with horses). But over an even longer period of time, since the two groups face different environments, the two species may become too different to mate (I can't stress this enough).

So, there is an ever growing barrier between the two separate groups, which ultimately stops them from mating with one another. Over generations of not mating with the other group, the animals become too different to mate. (because animals find their same species attractive, usually)

Also, since hybrid animals do exist, it shows that two different species can mate, because they both share a close common ancestor (their DNA make up isn't too different to make mating impossible). The ancestor, however, isn't gone, the ancestor's DNA lives within one of the two groups. Meaning, the split group that immigrated would be the different species from the ancestor, not the original whole group.

Oh, there's really no need to be anal about everything, I'm trying to have a simple and fun debate (that's why I joined this site).

"You quote: "The biologists reasoned that diversity in a particular ecosystem is a result of . . . ." Notice that these biologists already assume that evolution occurs and they are trying to explain some of its mechanisms."

That's a funny sentence, they don't assume that evolution happens, it does.
It's just a fact that the fittest animal survives and reproduces, that's all natural selection is.

I've explained how two species can come from one perfectly now, and how the barrier of mating is made.

Formation of five new species of cichlid fishes which formed since they were isolated less than 4000 years ago from the parent stock, Lake Nagubago.
(Test for speciation in this case is by morphology and lack of natural interbreeding. These fish have complex mating rituals and different coloration. While it might be possible that different species are inter-fertile, they cannot be convinced to mate.)

Mayr, E., 1970. Populations, Species, and Evolution, Massachusetts, Harvard University Press. p. 348

Rapid speciation of the Faeroe Island house mouse, which occurred in less than 250 years after man brought the creature to the island.

(Test for speciation in this case is based on morphology. It is unlikely that forced breeding experiments have been performed with the parent stock.)

Stanley, S., 1979. Macroevolution: Pattern and Process, San Francisco, W.H. Freeman and Company. p. 41

Even though the mice were introduced by man, the speciation occurred naturally.

I'm incredibly sorry if you thought I was trying to avoid the lactose intolerance and the hemoglobin things. I just didn't want to waste the round by explaining all of that, I would rather jump to higher places than argue over simple occurrences.

Of course I am not a master over the subject, I just enjoy reading about it.

You get the last say, good debate.
Happyreclusive

Con

Suppose I declare that I can prove Santa Claus exists. You ask for proof. On Christmas morning, I take you around town to
show you all of the presents under trees. You object, explaining that presents under the tree fail to prove that Santa Claus put them there. You ask again for proof and again I show more presents under more trees. You want to watch Santa Claus fly in his sleigh, land on the roof, slide down the chimney, and put presents under the tree. “Oh,” I say, “I can’t show you that, so let me show you more presents under trees.”

You rightly claim that I’ve failed to prove that Santa Claus exists. I claimed to know the cause of the presents (Santa Claus), but all I ever show is the effects (presents under the tree). You and I both know that there are many possible causes of presents under trees, and to prove my claim I have to show Santa Claus climbing down chimneys. Our debate has been like this example.

You set out to prove that evolution produces new species. I ask for proof and you show me species of animals. You explain that a white moth turns dark. I argue that you’ve shown me an effect: a species of moth turns color, but you haven’t shown me the cause. (Indeed, the moth example is poor because there is no new species.)

I ask for examples where we’ve seen a new species come into existence. You say you can’t produce that evidence. But there
is no example even in artificial selection, where humans have produced many variations of plants and animals, where a new species came into existence. For thousands of years people used artificial selection and not a single new species comes from that practice. Add thousands of hours of people working in labs trying to make a new species. Still there is no new species.

You point to fossils and DNA as evidence that evolution occurred. The problem is that the argument is always “notice how similar these fossils are to those fossils; therefore, the older animal gave way to the newer species.” The same argument works with DNA. “My goodness, ape DNA is very similar to human DNA; therefore they must be closely related, they must be a new species that arose from a common ancestor.” But the fact that two things look alike proves no causal connection with a third thing. In other words, when you say, “They look alike; therefore they must be connected in some way,” you utter a fallacy where you completely invent something that isn’t proved. “My red barn looks like his red car, so they must be related in some way other than being red.” “My DNA looks like a chimp’s DNA, so we must have come from the same source.” The conclusion is completely invented with no proof of a connection.

The second problem with fossil and DNA “evidence” is that, once again, they are presents under the Christmas
tree. When you say, “This species came from that species,” you already assume or presuppose that one species can come
from another. Two fallacies occur here. The first is “begging the question” or “circular reasoning.” You assume the thing you’re trying to prove: “Evolution caused this species to become that species; therefore evolution occurs.” The second fallacy is “post hoc ergo propter hoc.” The fact that something occurred before something else doesn’t prove that the first thing caused the second thing.

Incidentally, my critique of your claims that lactose intolerance and the hemoglobin gene result from natural selection is quite telling. Your ignoring my critique of your examples of moths and lizards is surprising. Surely if you could rescue these examples, you would have tried to do so.

I’m glad that you think the debate was good. I don’t think we ever got off the starting block. I hoped to take this debate into more specific critiques of natural selection. Since you enjoy reading about evolution, and if you don’t object to critiques or your views, I recommend the following:

The Edge of Evolution, by Michael Behe. Behe is a biology professor.

What Darwin Got Wrong, by Jerry Fodor and Massimo Piattelli-Parmarini. By the way, these two authors are complete
atheists, if that helps you decide to read this book or not.

Debate Round No. 4
2 comments have been posted on this debate. Showing 1 through 2 records.
Posted by iArgueForFun 3 years ago
iArgueForFun
I've explained how, provided direct evidence of animals going through the process of speciation, and cited that evidence.

It's not like humans live long enough (4,000 years, in the cichlid fishe's case) to observe the gradual change and speciation of an animal. Fossil evidence, DNA evidence, and the processes that have been observed through the results of years of the study of nature seems to me sufficient evidence.

What we do know, is that natural selection works, it just does, so of course people studying will assume that it works and occurs in nature, because there is tons of observable evidence of it happening.

There is less direct evidence of speciation (there still is some as I have presented), as it takes a longer time to produce a completely new species from subtle mutations.

I will recommend reading the books that you have mentioned, thanks.
Posted by iArgueForFun 3 years ago
iArgueForFun
Oops, I was going to point to the samurai crab but my mind trailed off into the peppered moth.
Sorry.
2 votes have been placed for this debate. Showing 1 through 2 records.
Vote Placed by Skeptikitten 3 years ago
Skeptikitten
iArgueForFunHappyreclusiveTied
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Total points awarded:50 
Reasons for voting decision: Con's sources are all considered non-credible in the sciences.
Vote Placed by badbob 3 years ago
badbob
iArgueForFunHappyreclusiveTied
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Total points awarded:04 
Reasons for voting decision: The burden of proof was on pro. I was surprised to see him bring up the peppered moths as proof of common descent and con easily refuted that idea. I loved cons example of santa claus. It was great argument. I also give conduct to con because pro kept trying to guess what he was thinking instead of responding to the arguments. Con wins! Good debate on both sides.