How is evolution a science if we can't directly test it?

Question

I understand the differences between micro- and macro-evolution but am hesitant in my support of evolution as a scientific theory. How can we experimentally test and prove evolution (could you cite me some experiments)?

I understand that many of the experiments are based off of micro-evolution and extended to macro-evolution but is this sound science? Please inform me as to how macro-evolution is testable and therefore a science and not a philosophy like Intelligent Design.

Answer 1

Of course we can directly test it!



And I don't mean the mechanisms (natural selection, genetic drift, gene flow, mutations) for microevolution ... these are obviously testable. The domestic breeding of animals and crops that is the backbone of the invention of agriculture, would not be possible if differential reproduction didn't create heritable change.



I also mean that what creationists (inaccurately) call "macroevolution", including the concept of common ancestry between living species, is also "directly tested" every day.





To see this, we need to understand what "test" means in science.



A "test" in science is a *predicted observation*.



An observation does NOT have to be in the form of an "experiment". For example, the entire science of Astronomy is not based on "experiment", but purely on *observation*.



The only requirement is that the predicted observation be in the form "if this prediction is not verified, then this disproves the theory."





I'll give an example from physics, and then an equivalent one for evolution.



When Einstein posited the theory of relativity, it *predicted* that light would be affected by gravity. The *test* of this prediction was to carefully observe a distant star just to see if its position appeared to "shift" as its light passed within the large gravitational field of the sun. We had to wait for a solar eclipse to do the observation. If there is no shift, then the prediction fails, and the theory fails its test.



But the predicted observation was verified ... so that aspect of the theory of relativity was *tested* ... and passed.





With evolution, one of the *predictions* of the claim that humans and apes share a common ancestor, is that there would be signs of chromosome fusion in human DNA to explain why the other apes have one more pair of chromosomes than we do. The *test* of this prediction was to look for tell-tale signs of chromosomal fusion in our chromosomes ... such as telomeres (DNA code normally at the tips of chromosomes) in the middle of a chromosome. If there are no signs of fusion, then the prediction fails, and the theory fails its test.



But the predicted observation was verified (we found markers of fusion in Human chromosome #2) ... so that aspect of the theory of evolution was *tested* ... and passed. [1]



For more, consider fossils. Evolution *predicts* that certain fossils representing certain developments, would appear in certain layers, and certain geographical locations. This is precisely how fossil-experts KNOW WHERE TO LOOK for these fossils. This can range from knowing there won't be trilobite fossils in the same layer as a T. rex, to knowing were to look for the first fishes transitioning to land, or feathered dinosaurs, or certain hominids with certain bipedal structure and brain capacity. The discoveries of tiktaalik, archaeopteryx, D. masillae, A. afarensis, and hundreds of others were based on these *predictions*.



So EVERY SINGLE NEW FOSSIL DISCOVERY is a *test* of evolutionary theory! One trilobite in the wrong layer ... one hominid in a Devonian layer ... one dinosaur in a Cambrian layer ... and evolution *FAILS THE TEST*.





So of course evolution can be directly tested! It is tested every single day!



---- {edit: Response @Questioner} ----



First, notice that he does not actually refute my Chromosome #2 or fossil examples ... he just dismisses it a "sanitized fan-boy story". But then IN THE VERY SAME SENTENCE accuses others of just "sweeping things under the rug".



[Edit: He later added a "rebuttal", saying "All that it shows (at most) is humans in the past had 24 pairs." ... as did the apes, and still do! That's a "rebuttal"? But more importantly, do you think he noticed that he used the phrase "in the past" in a conclusion we might draw from evidence? Oops.]



But second, and most amusingly, he seems to be answering both yes and no to your **question** ... is evolution "testable"? At first he seems to be arguing that evolution is not testable ("Any argument or idea that makes claims about the unrepeatable past requires belief.") ...



... but then immediately after arguing that evolution is not testable, he gives a long list of "tests" that evolution has supposedly failed!



The fact that I can rebut every one of his "tests" (if my answer were not already too long) ... and in fact they have been rebutted over and over again [2] ... is not my point.



It's that his mere eagerness to engage in arguments about evidence in the first place, means that Questioner admits that evolution is "testable" after all!



{edit} He even links to a creationist web site that actually uses phrases like "predicted by" and "should be found if" in reference to evolution.



So YES, EVEN CREATIONISTS ACCEPT THAT EVOLUTION CAN BE TESTED. They are admitting this every time they make statements of the form "if evolution is true, then we should see X."



---

Answer 2

There is no difference between macro and micro evolution. it's an artificial distinction based on the fact that Creationists have no choice but to give some ground in the face of the mountains of evidence for evolution. Seeing as how evolution occurs and can actually be shown to occur in a laboratory environment it is simply a matter of gathering the physical evidence of the vast number of lifeforms no longer extant and to trace the ancestry of the lifeforms that currently populate the Earth.



Gather up an example of every rodent on Earth. Observe the near seamless transitions across species of rodent with regards to size, diet, teeth, eyes, hair habitats and climates. Is it so hard to grasp the fact that on the scale of hundreds of millions of years that enough variation is possible that combined with founder effect and geological isolation that new species are absolutely going to arise. The theory of evolution, or more properly, the theory of natural selection that explains the fact of evolution explains all the variation in the flora and fauna that exists today. This theory did not come about in a vacuum. It's the most supported scientific theory we have....

Answer 3

Not everything in science is testable, contrary to the popular Popperian theory of science. Evolution as a theory, has plenty of testable elements (you can test selection, drift, kin selection, sexual selection, mutations, etc.), but I will agree that as a whole you don't really test evolution. You can google (especially in scholar) evolution studies or evolutionary biology and you can get scores of experiments studying evolution.



But this is really an epistemological question of "what is science?"



Personally, I take a naturalist view. Science never invokes the supernatural. Evolution provides an explanation for how there is a great diversity of life and how it came about without invoking a supernatural creator. I.e., it does so within a naturalist framework. Intelligent design does not do this.



That said, a naturalist view of science is hardly the only view of science. It is certainly a broadly accepted modern view, however. There was a couple of pieces written recently in the NYTimes on this very discussion.

Answer 4

We shouldn't have direct remark of the life of the supercontinent pangaea, however you'll be able to nonetheless placed the outlines of the continents in combination, take observations of plate tectonics and seismic recreation over small distances and arise with a well, forged thought. You too can make predictions situated in this knowledge and if it maintains to help the idea, it is a well one. That's what evolutionary technological know-how does too. Makes predictions that for those who dig to a specific layer of the earth, any fossils will own exact attributes, situated at the thought that as we're all traditionally descended, spouse and children of a equivalent age and place will need to be equivalent in a predictable method. The equal at the molecular degree, the genetic degree, in embryology, and so forth. And it maintains to paintings after being continuously demonstrated - that is why we have by no means discovered bunnies dated again to the Pre-Cambrian. ^_^

Answer 5

First, there's no such thing as micro-evolution versus macro-evolution. Those are terms largely used by Creationists and ID advocates who don't want to concede the fact the Theory of Evolution is correct, but know they have no way to defend their position except to change the goalposts.



So, they redefine the basic framework of the Theory of Evolution to make it out to suggest things it does not suggest, and then insist what we have observed isn't "evolution," but "micro-evolution," and "macro-evolution" has never been observed. Then they usually throw in something about that making the Theory of Evolution a religion because they have redefined the word "religion" as well.



After they do all that, Creationists and ID proponents usually throw out some bit of nonsense such as "there's no way to increase the information in a genome" and "mutations are always harmful," while babbling something about irreducible complexity.



The trouble, of course, is every bit of that is complete nonsense and we know it. That's what separates Creationism and Intelligent Design from the Theory of Evolution. The Theory of Evolution is constructed from the facts at hand. If the facts change, so does the logical framework of the Theory. Creationism and Intelligent Design, on the other hand, begin by positing several things which are not only unproven, but which can never be proven, and grounding their thinking in them.



As for whether we can test evolution, the answer is "of course we can". What do you think our agricultural industry is based on? We've been using the underlying principles of the Theory of Evolution for thousands of years. We weren't aware that's what we were using, but it doesn't change the fact we were able to use it to change this:



http://www.anticaerboristeriaromana.it/prodotti/tinture_ita/Brassica%20oleracea.jpg



Into this:

http://eatlocal.files.wordpress.com/2008/10/broccoli.jpg

http://www.watchmyfoodgrow.com/wp-content/uploads/2009/04/9808-broccoli-detail-photo.jpg



And this:

http://www.juicingbook.com/_images/cauliflower.jpg



And this:

http://craftsanity.com/wp-content/uploads/2008/06/kohlrabi.jpg



And this:

http://0.tqn.com/d/chinesefood/1/0/Y/1/bokchoy2.jpg



And these:

http://images.teamsugar.com/files/upl1/1/15259/03_2009/7d3af43fba4003db_Brussels_sprouts.preview.JPG



And transform this:

http://enrin.grida.no/biodiv/biodiv/national/romania/wolf2.jpg



Into these:

http://www.typesofdogs.org/images/AmericanCockerSpaniel.jpg

http://www.deepglamour.net/.a/6a00e553bc52568834011168581515970c-800wi



We have observed genes being transferred from one species to another (google "NDM-1" and "elysia chlorotica") even across different kingdoms of life. We can provide clear chains of "irreducibly complex" systems at different points in their development, demonstrating how it was possible for them to develop (google "evolution of the eye", "opsin gene", and "blood clotting cascade").



We have observed species evolving new structures ("Croatia Italian wall lizards"), species making the jump from unicellular to multicellular ("Boraas Chlorella"), and have excellent fossil records that account for the transition of several lifeforms from prior, more primitive ancestors to their current forms (look up the whale, horse, and our own ancestry). There are multiple examples of evolution taking place in our own bodies (the most well-known examples being the wisdom teeth, but google also "sixth lumbar vertebrae", "palmaris longus muscle", and "thirteen pairs of ribs").



I could easily go on (finch 5110, endogenous retroviruses, etc), and that's not even getting into its importance in the field of medicine.



Given the amount of evidence we've accumulated, of such a diverse and thorough nature, I'm not sure how much more evolution could possibly be (or needs to be) proven correct before it can be considered science rather than philosophy.

Answer 6

There are different forms of "testing" in science, and some of it consists simply of looking at the evidence at hand and making predictions based on it. An archaeologist can't return to ancient cultures to see what they looked like, but that doesn't mean he can't learn about them by looking at what they left behind. But if you want to know how to test or observe it directly, it's easily done, by looking at species with much shorter life spans than humans. One example is the biological arms race going on between rattlesnakes and ground squirrels. Some rattlesnakes, such as the Mojave rattlesnake have a neurotoxin in their venom. Others, such as the Northern Pacific don't. However, ground squirrels have been evolving gradually, developing an immunity to the venom of the Northern and Southern Pacific rattlesnakes. As a result, rattlesnakes are evolving as well -- neurotoxins are beginning to show up in the venom of the Southern Pacific rattlesnake. This is an evoloutionary change happening over only decades. Evolution is also beginning to affect rattlesnake behavior as a result of human predation. Rattlesnakes are becoming less likely to rattle, which leads some people to think they're just more relaxed, but in reality, rattling gets the attention of humans (the main predator of rattlesnakes), so snakes with less tendency to rattle are more likely to survive to pass along their genes.



If you have trouble with the idea of evolution, think about what it really says:



1. There exist differences between individuals, and some of those differences are the result of genetics (you look different to your friends, but you probably bear some resemblance to your parents).



2. In any generation, there are more offspring born than survive to reach reproductive maturity



3. Individuals with genetic profiles that are conducive to survival are more likely to survive to reproductive maturity than individuals with genetic profiles that are not conducive to survival, and therefore are more likely to pass on their genetic profile by producing offspring.



Ask yourself which of those principles you don't agree with, and I suspect you'll find that evolution isn't a hard idea at all to support.

Answer 7

The debate is often described as “creationism vs. evolution,” as if the “ism” should not apply to “evolution.” But, this isn’t accurate, because believing in evolution, like believing in creation, requires acceptance of a certain presuppositional dogma and it requires placing one’s faith in a story about the unrepeatable past. To accept that worldview, you must have faith in a professor or textbook—or yet another secondhand source and that secondhand source’s interpretation. After all, not a single person was alive to see how life began or the supposed evolution of life on earth. Any argument or idea that makes claims about the unrepeatable past requires belief. We may have reasons (right or wrong) to believe what we believe, but we cannot go back in time to see if that belief is right.



Most of the time, people just give examples of natural selection and assume it points to microbes-to-man evolution. Even young-earth creationists believe in natural selection and "speciation." Take a look at these:

http://www.answersingenesis.org/home/area/RE2/chapter4.asp

http://www.answersingenesis.org/get-answers/topic/speciation



============



Apart from the sanitized fan-boy story told by secretsauce, there are plenty of anomalies that just get swept under the rug. They are constantly having to explain away things like:

-The “Cambrian Explosion” (where we have the sudden appearance of all these diverse and fully formed animals in the fossil record, with no evolutionary ancestors).

-Or fossils too low or too high in the geologic column.

-Or polystrate fossils (fossils that extent through several layers of strata). They have found polystrate tree trunks and even polystate animal fossils.

-Or sedimentary strata found in the wrong stratigraphic order.

-Or missing strata.

-Or thousands of feet of strata that is bent and folded without cracking or signs of melting (which must have happened while it was all still wet).

-Or strata that lacks any erosion features with smooth lines between the layers.

-Or the lack of plant fossils in many formations containing abundant animal fossils.

-Or strata that are supposed to be many millions of years apart that are inter-bedded.

-Or fossils of marine organisms found in high mountains, all over the earth.

-Or out-of-place human artifacts (although they have some strange ideas, Cremo and Thompson have done a thorough job of listing some out-of-place artifacts in their book, Forbidden Archeology).

-Or “living fossils” (animals and plants that supposedly lived tens and even hundreds of millions of years ago that forgot to evolve and look the same as they do today—despite significant shifts in their environments).

-Or Dinosaur soft tissue being found (as they first did in March of 2005); how could soft tissue and cells remain so relatively fresh for the tens of millions of years of supposed evolutionary history?

-Or the “150 million-year-old” squid that was discovered with an intact ink sac. As Dr. Phil Wilby of the British Geological Survey said, “It is difficult to imagine how you can have something as soft and sloppy as an ink sac fossilized in three dimension, still black, and inside a rock that is 150 million years old.”



When this kind of evidence is brought to light by creationists and ID advocates, they are simply ignored or vilified.



From what I've seen, here is the Darwin Party M.O.:

-Step 1: Assume evolution.

-Step 2: Observe a fact.

-Step 3: Make up a story to show how the fact might fit in with the assumption of evolution.

-Step 4: Attack, ridicule, and persecute anyone who doesn’t toe the Darwin Party line.



=============



And if the chromosomes were fused in apes, then you might have an argument for common descent. All that it shows (at most) is humans in the past had 24 pairs.



New Research Undermines Key Argument for Human Evolution:

http://www.icr.org/article/6089/

Answer 8

It depends..