Evolutionary Biology fails as a "theory"?

I was talking with a friend about the Polio vaccine, when he said to me that evolutionary biology has a major problem because you cannot do experiments in it because there are too many variables. His example was, if you have three bears in a snowy environment, one black bear, one brown bear, and one white bear, you cannot do tell which one will live the longest because there are too many variables. The black bear could be stronger than the white bear and brown bear, etc. Sure, the white bear could blend in into the snowy environment, but that's not necessarily an advantage to it's survival because it could just as easily be killed by something else.

His other example was with opposed thumbs. Is it possible for the thumb to become too opposed, so opposed that it no longer is a benefit to survival or to the specimen the thumb inhabits, and at what point did thumbs become a survival mechanism?

It got me thinking.

 

Log in or Sign up to hide all adverts.

If you do an experiment, obviously you have to limit the variables. As far as predicting the fate of any particular creature, all you can go on is probability based on previous statistics.

On the thumb question, no it's not possible to evolve something that doesn't benefit the life form in terms of reproductive success. Thumbs are useful for gathering food in some animals. They are so useful that pandas evolved something like a thumb even though it isn't a true digit.

 

Log in or Sign up to hide all adverts.

How would experiments in evolutionary biology be done then? Doesn't that either lead to either too few variables to bring a valid conclusion or too many variables that you can't do an experiment on it in the first place? His bears example seems a bit flawed because it's a hypothetical. Probability based on hypothetical situations that are probably unlikely given the circumstances isn't a good way to prove a point.

 

Log in or Sign up to hide all adverts.

Often experiments in evolution are done in a laboratory with animals that reproduce quickly like fruitflies. That way you can know the genome of the animals you are working with. I've heard of other experiments like one with lizards where a certain species of lizard were introduced to an island devoid of lizards. Then scientists would go back to that island periodically and examine lizards to see how they have changed on average over time.

 

You have to have decent numbers of replicates for each combination of variables, and decent phenotypic variance in the system. It's just a question of replication and power. Old news. To answer your friend back: you don't just use one bear of each colour.

 

Evolution occurs in populations. If you have a thousand of each bear over many generations, you would see trends. It wouldn't necessarily default to the white bears, he is right about lots of variables in play, but you will see changes that result from environmental pressures as well as other factors. But it would take a long time with bears. Not so much with bacteria, insects, and other organisms that have quick population turnover.

 

So we have no possibility of theory in geology, astronomy, meteorology, oceanography, or any other field in which we cannot do full scale replicable experiments?

 

I suppose that will be bad news for the many thousands of evolutionary biologists around the world who spend their careers performing research into evolutionary biology. To be put out of a job like that so easily will be hard to stomach.

Please Register or Log in to view the hidden image!

Here are some answers:

http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1420-9101

http://www.biomedcentral.com/1471-2148/

http://mbe.oxfordjournals.org/

http://www.pagepress.org/journals/index.php/eb/issue/current

http://www.hindawi.com/journals/ijeb/contents/

 

Pfft

I'm tempted to say hell no, that isn't science, but in point of fact you clearly can. Sampling is sampling.

 

Regarding the original idea of "brown bear, black bear, white bear in a snowy environment" - I'd agree with your friend. Not much information about evolution could be pulled from that structure - random chance would as likely over-ride any genetic advantage.

However, this is only an issue because data is noisy. If you manage that random chance by looking not at three bears, but at bear populations in the realm of thousands over many years, you can find trends in how various bear populations do in snowy climates as the amount of snow varies from decade to decade. Track changes in territory and number of individuals, color variations within the populations, etc.

*That* would provide useful data.

 

What is a Good Study? Questions You Can Ask

Written by Kyle Hill
Thursday, 15 March 2012 09:00

In becoming a science-based person, I can imagine a process that involves three tiers. First, you decide that you are going to get your information from reputable sources like scientific journals and then decide that any other claims that you find should have a similar backing. Second, pushing past the veneer of scientific legitimacy, you decide to look into the claims for yourself. This involves not only getting your information from sources based on scientific journal articles, for example, but also going through the study yourself to determine whether it is a “good” study. Lastly, after having navigated scientific sources for some time, you are able to evaluate claims base on methodologies and procedures that you would expect the offered evidence to have if it were indeed credible. Because most of us are not scientists and find it hard to invest in the education it would require to reside comfortably in the third tier, I will try to offer some help with the second.
If you ever would consider a career as a science writer or science journalist, there are a few basic techniques that you must master or at least become proficient at. Among them are learning statistics and how to interpret them, interviewing scientists to get the best information, and how to translate sometimes complex and technical scientific information into something that the lay audience can digest. Another fundamental skill that you must wield effectively is being able to confidently answer the question, “What is a good study?” To this end, what follows are some basic questions that you should ask yourself when trying to determine the validity of a scientific study. You would find these kinds of questions in any introductory level science-writing textbook, and they will become a valuable tool in your skeptical arsenal.
Keep in mind that when you are evaluating a study, the more of these questions that you can have answered, the better off you are. However, if you find yourself questioning every single procedure, method, and ethical choice in a study, this may be a red flag in itself. As a properly skeptical consumer of scientific information, a good place to start at is what is called the null hypothesis. That is to say, assume that a new medical treatment or physics experiment won’t work. Without being downright cynical, greet every claim with this assumption. Your new motto when faced with a claim in a study or elsewhere should be “show me.”
Is the study large enough to pass statistical muster?

Is the study designed well? Could unintentional bias have affected the results?

Did the study last long enough?

Are there any other possible explanations for the findings or reasons to doubt the conclusions?

(For medical claims) Does a treatment really work?

Do the conclusions fit other scientific evidence?

Do I have the full picture?

Have the findings been checked by other experts?

What now?

 

The problem is although the process of change that life undergoes is well documented, the approach is so convoluted that thousands of experts only seem to be able to satisfy each others expectations, but never seem the fully satisfy the common sense requirements of the laymen. This is why this question comes up again and again and is never satisfactorily answered.

Darwin built this nice cottage (theory). As it expanded to include more ideas and opinions, the building process had no sense of long term order. The convoluted theory that evolved (random house) is hard to work with in terms of common sense predictions.

Let me outline a common sense proof of evolution, that allows one to make a prediction. The premise is, one aspect of evolution can be induced by the imposition of a singular boundary condition.

In this case, we will start with bacteria and add antibiotics. Since antibiotics will kill bacteria, the new boundary is simple. There is only one place for evolution to go; survival. The prediction is some bacteria will find the funnel hole and will develop a resistance to the boundary condition. This change is evolution. There is no other place it can evolve, since all other paths will end in death.

 

keep digging buddy, you'll find the truth, but only if you are honestly objective.

 

wellwisher

"Common Sense" in science often leads you astray. Relativity, for example, is far from common sense, yet it has passed every test so far. And meeting expectations of accuracy, rigor and logic is a bad thing how, exactly? The reason the question keeps coming up is that laymen often misunderstand the principles involved and there is active desimination of false information, often by theists, about the reality science shows to be true.

Darwin did two seperate things. He gathered evidence that showed that Evolution is indeed a fact, and he proposed a theory(Natural Selection)to explain that fact. By the way, he was right in both things.

Absolute non-sense, the opposite is the truth. There is nothing at all convoluted about survival to reproduce, nor is it not common sense that traits that allow an increased chance of survival will tend to survive more, becoming more likely to survive in the genome. Those traits that are detrimental to survival tend to get eliminated from the gene pool. If you can't understand something so simple it is not the fault of the system, if you just won't(due to preconceived notions from ancient texts), ditto.

Individual bacteria do not "develop" new traits, it is just that some bacteria have a higher resistence already in their genome(due to mutation). Since the bacteria that do not have that trait die without reproducing the only ones that DO reproduce already have that resistence, so do all of their progeny. THAT is Evolution. If such traits do not exist within the genome they will not spontainiously arise and extinction occurs. Almost all lifeforms to ever exist on Earth are now extinct.

Grumpy

Please Register or Log in to view the hidden image!

 

Grumpy,

Thanks - now what you write is indeed not just common sense (it is that) but also empirically verifiable.

 

What Darwin built was a collection of specimens, illustrations, studies, notes, articles and books that reflect years of effort, during his travels around the world, and for years thereafter, which have contributed to scientific understanding of the natural world with huge ramifications for advancing the biological sciences. To ridicule this reflects a mean, envious, small-minded and foolish kind of ignorance.

The refinements to Darwin's original statements on evolution are minimal, and do not reflect an expansion as you may imagine. Your perception that people have inflated Darwin's ideas is absurd. What has happened is that countless studies have corroborated evolution by natural selection, period. It is this repeated confirmation -- from the culturing of microbes to the recovery of fossils to the sequencing of genomes -- that has given Darwin such celebrated status.

Contrast your foolishness with this:

http://www.smithsonianmag.com/science-nature/What-Darwin-Didnt-Know.html#ixzz1pW4TQyT4

and this, by Jesuit Teilhard de Chardin:

The only thing convoluted is your own ideation which takes some of the best most elegant concepts from science and twists them with contempt and a deluded sense of self importance. Your use of the term "random house" is another convolution, born of a reluctance to learn what Darwin said about the random nature of mutations within a species, further explained by Mendel, whose work you are also ignoring. You continue to ignore the meaning of "random mutation".

Contrast your convolutions to this:

Theodosius Dobzhansky [pioneering geneticist], “Nothing in biology makes sense except in the light of evolution.” The American Biology Teacher, March 1973.

You are not expressing common sense nor are you proving anything except your own fallacies. As for predictions, Darwin said in Origin: "In the distant future I see open fields for far more important researches". The predictive ability lies in Darwin's work, not yours. Look again at the first cite above, note the phase: Yet his original theory has encompassed all these surprises and more.

Hogwash. You alone are imposing boundaries and conditions.

This is an example of your convoluted reasoning. You seem to be wrestling with the notion of natural selection. It is clear that if you kill all the bacteria, nothing happens next. What you are missing is they are not all killed, because they are not all exactly the same. Some are more resistant that others. This is what Darwin realized a century and a half ago, in part from the work of Mendel, but which you have not yet attempted to understood. Here is where you only need to learn the actual theory instead of twisting it to suit your personal opinion. The prediction is this: resistance is attributable to random mutation and to inherited traits; both of these code the DNA; those with greater antimicrobial resistance will tend to survive and their genes will be handed down, whereas the non resistant cells will die without reproducing. And this is observed.

You continue to fail to acknowledge the way evolution relates to the evolutionary niches. This again from Theodosius Dobzhansky:

Until you learn what the the theory actually says, your attacks are utter nonsense.

 

@Shawn
Can you see now why three variants competing is not a good model of how evolution works?
A bit of feedback for the people who have tried to explain it to you would be appreciated.

 

This is the classic argument from incredulity: "I do not understand how evolution works, so there must be a fundamental flaw in it."

Correct. That is the only place evolution ever goes.

Yep. With the caveat that not only does that cause death, many other things do as well. Harmful mutations. Overpopulation. Failure to reproduce. Etc etc. One more factor has been added to that mix - resistance to a given antibiotic. The few bacteria that survive all that get to reproduce.

 

evolution is about which biological entity has the ability to survive compared to its equivelent

the famous moth situation in England before and after the industrial age

the genetics of the species didn't change just which was better suited to survive in this enviroment , before , middle , and after