Thread: How do you prove evolution?

How does one go about proving evolution?
The one and only method that I have learned in school, the method that science uses to prove something, is the "scientific method".

How does one apply the scientific method to satisfy the hypothesis that
"given enough time, one species of creature is able to "evolve" or change into another species?"

Sure, it is possible to prove that over time, creatures develop different traits and characteristics through "mutations" and inheritance of traits...

But this only proves the existence of mutation and traits that are inherited.

It is not viable to just simply assume that...
"through these small mutations and inherited traits and given enough time, one species can transform into a different species"
This would have to be proven..... after all, its not it is not unheard of for a creature to mutate one trait and mutate again and lose that trait...

It is totally impractical to conduct a scientific experiment that spans millions of years to observe whether or not a a create can "evolve" into another "species" of creature... (unless someone unlocks the secret to immortality)

A bird with a bit larger beak then another birds does not qualify to be a totally new species...
Similar to how a person who is taller then average is not considered non-human.

So, how is evolution using the scientific method?
If it isn't, then how is it proven?

and if evolution is not proven using scientific method... why is it considered "science"?

First and foremost, get the notion of "proof" out of your scientific thinking and vocabulary. Proof is for mathematics only.

What you want for something to be scientific is that it is both predictable and demonstrated. (These things may not happen at the same time. It took almost a hundred years for Arrhenius's calculations on CO2-led climate change to show up conclusively in the data.)

A bird with a bit larger beak then another birds does not qualify to be a totally new species...

But birds which accumulate enough changes do become different species. This little video is a beautiful illustration of how speciation occurs. Ring species -- the abridged version - YouTube

It is totally impractical to conduct a scientific experiment that spans millions of years

Of course it is. The problem is your idea of "experiement" is too confined. It's quite possible to measure change over the course of millions (and longer) years and that's exactly what science does by looking at fossils, geology etc. It applies those observations of the "experiement," with other observations and checks for constitency (a softer form of prediction) with the hypothesis. Using these methods made a very compelling case for evolution by mid 20th century (some would argue 50 years earlier). Now with the incredible power of genitic analysis the evidence is overwelming--hence why it's called a theory which is the highest pssible level of certainty.

Dr. Carl Sagan said that "the core of science is prediction."

By this he meant that any ideas in science must be tested, and the testing process uses 'testable predictions'.
If you have an idea, which you hope to be scientifically acceptable, you have to be able to generate a prediction that can be tested by an experiment or a novel observation.

This is true for evolution. When Darwin wrote his book : "Origin of Species" about evolution by natural selection, he made a testable prediction, which is there in the book. Darwin predicted that fossils would be found, which would be dated and found to show a progression of changes from one species to another over time, something that had not been done in Darwin's time. Darwin's prediction has been tested numerous times since, and there are wonderful progressions of changes in fossils over time in many text books for all to see.

Some of these progressions show species changes over a short time period, such as foraminifera.
Evolution, Foraminifera
Some are long term progressions, and show major changes such as the movement from fish to amphibian.
http://www.earthhistory.org.uk/trans...h-to-amphibian

Do people think every animal that ever lived leaves a fossil behind once they die? Perhaps that misconception should be cleared up. The other concept that's difficult for some people to grasp may be huge expanses of time. The Earth hasn't exactly remained unchanged since day 1.

Your question is skeptical, which is a good thing. Just don't let it trend toward indignant or it will cloud your judgement.

You're looking for proof, but so-called soft science like biology is rooted in theory. We cannot write an evolutionary law in the same manner a physicist can write a gravitation law. Biologists rely on observation and experimentation in order to craft a theory that explains the mutations and adaptations of a life form over time. That having been said, if we lived during the era of the dinosaurs, no biologist could have realistically proven that they would same day evolve into birds. That isn't the nature of biology.

Just to expand on the point about "proof" ... science never proves a theory true, but it can prove a hypothesis or theory false.

It is also important to understand that the concept of species is rather "fuzzily" defined. There are several ways of defining species; they are all man-made conventions though.

As noted, new species arise by accumulation of small changes. Occasionally we can observe this happening, either directly or indirectly.

This page has a good summary of the problem of defining species and some examples of observed speciation: Observed Instances of Speciation

And I just found this, which I hadn't seen before: Birth of New Species Witnessed by Scientists | Wired Science | Wired.com

Ow jeez, does another person doubt evolution again, or asks how to prove it... Why not create a sticky to explain this, before the question arises.

We prove evolution, looking at the past, up to now, where at all times the fittest were able to survive, and those who didn't fit died out. Random changes that occured slowly divides up species. This dividing usually implies that the random mutation that increases the chances of survival or offspring wins from the Wild type.

Dinosaurs, who are warmblooded (probably), need huge amounts of energy, they need the perfect environment for this, herbivores need LOADS of plants, and carnivores need LOADS of meat. Take away most plants, herbivores die, carnivores die, and only scavengers and omnivores survive, as they are better suited to this imperfect environment.

As noted by others the objective of science is not prove anything, but to arrive at the best explanation possible at the time. Evolutionary theory, Dawinism, the Modern synthesis, call it what you will, does this more effectively than any alternative explanation. And it does so in an internally consistent manner, with validation from genetics, developmental biology, zoology, botany, microbiology, biochemistry, anatomy, palaeontology, etc. There simply is no alternative that is even on the table as a plausible explanation.

Science doesn't prove what works, it eliminates what doesn't and says whatever is left over is the best choice at the time.

Yeah, your right @Flick & Galt, but i hoped to explain it more definitive. As sometimes i'm bothered why all questions are about this subject. How to prove evolution.. Your saying it can't be done. I say it can, with a reasonable certainty. Maybe not 100%, but all proof ever gathered in law, is unusable when questioning things on this level. There are points you simply must say, i have seen enough evidence, you MUST be the culprit. You'll go to jail for a long time... Evolution you...

There is also the fact that, as soon as you understand the basic mechanisms of inheritance and how this affects the physical form (and then how this interacts with the environment) it seems impossible for evolution not to occur.

Of course, we go on to discover even more complex ways in which genetic material is expressed and modified, organisms interact with the environment and each other, the importance of symbiosis, and other many other complicating factors. But none of this negates the inevitability of evolution, just makes it a more complicated process.

I don't require more complexity in life, i just want to understand it all... is that to much to ask for??

I think maybe we can at least prove that the concept (the concept of evolution) works by using computer simulation? the simulation may not be able to simulate life completely, but for simple stuff like artificial intelligence for board games: evolution seems to work. Basically what evolution do is just doing several thousand of trial & error and told the computer to save only the good results... hardly a controversial idea.

We can not imput all the parameters, plus we will get different results anyway..

To make science incapable of being able to prove anything you have to think of science in a very abstract manner and invoke all sorts of reality-bending scenarios to justify the claim. I think people conflate science in general with scientific theories. Part of the problem here may be that what science does often doesn't match up with how philosophers such as Popper described it - for example, much of science is observational and descriptive rather than hypothesis forming and testing. The idealised version of science often doesn't mirror what actually happens in the lab. Isn't it more correct to state that scientific theories can't be proven, rather than science can't prove anything at all?

Does the earth spin? Can science prove that? Someone might say no, because all of reality might be a lie or you might have just dreamt the whole observation up. That's the sort of lengths one has to go to to make science unable to prove anything (I agree, but see it as pointless quibbling). The spin of the Earth is an observation. Fact. Observed. "Proved" (intentional scare quotes). Why it spins on its axis might be described by some theory. That theory can't be proven, while many failed theories that attempted to explain its spin can be disproved. Some might argue that observation is not science. Do observations not count as science? Some say no and will happily dismiss much of astronomy, chemistry and biology from the realms of science. Others might claim that it is only our senses and instrumentation that see a spinning Earth, and thus the answers we get are only subjective and can't be verified objectively without reference to yet more instruments or senses.

Regarding the OP: evolution is also an observation as well as a theory. There is a collection of hypotheses and theories (no doubt incomplete) that explain how we think evolution happens. It is conceivable that all those theories are wrong (by imagining some crazy scenario) but the observation of evolution will remain a fact (unless you want to view reality as being a dream or a lie). In some sense evolution is proved by the observation of evolution. Do you trust your senses enough to feel confident in claiming that when we see a population of viruses evolve that they actually did do just that?

In the real world science proves many things. It's only by breathing in the rarefied atmosphere inhabited by the philosopher that we can say that what we observe and measure might not be true. Accepting that the world may be a lie, or that supernatural forces interfere with our observations or that we may live in a weird bubble with it's own rules different from the universe at large, then sure, we can say that we can't prove anything. Let's go for 99.999999999% positive.

Originally Posted by Zwirko

...

That was one of those, "I wish I had said that" posts.

evolution is also an observation as well as a theory. There is a collection of hypotheses and theories (no doubt incomplete) that explain how we think evolution happens. It is conceivable that all those theories are wrong (by imagining some crazy scenario) but the observation of evolution will remain a fact

Good point, too often forgotten.

We don't need science to "prove" that gravity exists. We all know it does. We expect science to come up with useful explanations and quantitative descriptions of the mechanisms.

The same is true of evolution.

Good question, just because its is quite obvious that random mutation do happen and evolution does occur, it is quite another thing to make the wild claim that we all evolve from the same unintelligent goop. In fact they can not even prove that Africans, Asians, and Caucasians share the same ancestor. And that's just over a few thousand years, let alone billions!

Originally Posted by ttown

In fact they can not even prove that Africans, Asians, and Caucasians share the same ancestor.

Yes they can, in as much as anything can be "proved".

Originally Posted by ttown

And that's just over a few thousand years, let alone billions!

It's over hundreds of thousands of years, actually. And who mentioned billions? 95% of the animals on this planet evolved in the past 65 million years, after the last mass extinction event.

Originally Posted by SpeedFreek

Originally Posted by ttown

In fact they can not even prove that Africans, Asians, and Caucasians share the same ancestor.

Yes they can, in as much as anything can be "proved".

Originally Posted by ttown

And that's just over a few thousand years, let alone billions!

It's over hundreds of thousands of years, actually. And who mentioned billions? 95% of the animals on this planet evolved in the past 65 million years, after the last mass extinction event.

Wasn't the beginning of the last ice age (2,6 million years ago) the last mass extinction event?

Wasn't the beginning of the last ice age (2,6 million years ago) the last mass extinction event?

When we say mass extinction event we're not just saying lots of extinctions. The last event of the big 5 knocked out 95% of all species alive at that time. The last ice age knocked out a lot of critters, but nothing like 95% of all species.

Extinction event - Wikipedia, the free encyclopedia

Originally Posted by Zwolver

... Wasn't the beginning of the last ice age (2,6 million years ago) the last mass extinction event?

don't think mass extinction
think genetic bottlenecks where much (most?) of a species die off
there is also suspected to be one for us at @70,000 years ago, and another at the dawn of heidelbergensus, roughly 1-1.2 million years ago

The last mass extinction event is right now, and stretching back over about 15,000 years. The Polynesian expansion across the Pacific, for example, resulted in 2,000 species of island birds going extinct, mainly from the introduction of the Polynesian rat.

Probably the biggest mass extinction location is the Amazon rainforest right now. I lived there and noone seems to care about the environment.

The better question is: can you devise an experiment that dis proves evolution? Evolution is based on about 4 ideas about how the world works, disprove any one and evolution is in deep trouble.
premis number one:"like begets like", cats have kittens, dogs give birth to dogs, chicken eggs hatch into chicks not turtles.
premis number two: premis number one is not perfect. Off spring are not perfect duplicates of the parent. There is variation within normal reproduction and "freaks" happen.
premis number three: not everything that is born successfully reproduces itself.
premis number four: if an individual inherets a trait which makes it unable to reproduce then it will not pass that trait on to its offspring.
Demonstrate that any one of those ideas is false and you will have reason to seriously doubt evolution.

Originally Posted by Sealeaf

premis number three: not everything that is born successfully reproduces itself.
premis number four: if an individual inherets a trait which makes it unable to reproduce then it will not pass that trait on to its offspring.
Demonstrate that any one of those ideas is false and you will have reason to seriously doubt evolution.

These 2 were interesting...On number 3, Apart from hive grown species, like ants of bees, all offspring will be able to reproduce itself (apart from the freaks who didn't get functioning genitals) I van't think of any other species that does this..

On number 4... There are cases where a freak who is unable to reproduce himself, can still pass on traits... A virus can...

Though a virus does not disprove evolution.

Originally Posted by adelady

When we say mass extinction event we're not just saying lots of extinctions. The last event of the big 5 knocked out 95% of all species alive at that time.

Correction: KT boundary number was 75%. The end Permian extinction, the really big one, got 95%+/- of marine species, but only 70% of terrestrial.

Edit: I've just noticed that you linked to the same site I used to confirm my quoted numbers! I shall make an entry on your term report card "Coud do better. Does not always pay attention."

Originally Posted by Zwolver

Originally Posted by Sealeaf

premis number three: not everything that is born successfully reproduces itself.
premis number four: if an individual inherets a trait which makes it unable to reproduce then it will not pass that trait on to its offspring.
Demonstrate that any one of those ideas is false and you will have reason to seriously doubt evolution.

These 2 were interesting...On number 3, Apart from hive grown species, like ants of bees, all offspring will be able to reproduce itself (apart from the freaks who didn't get functioning genitals) I van't think of any other species that does this..

On number 4... There are cases where a freak who is unable to reproduce himself, can still pass on traits... A virus can...

Though a virus does not disprove evolution.

Contrary to popular dogma, many if not most social hymenopterans are able to survive the death of the queen by either altering the development of a larvae, or by one or more of the adult females transitioning into a queen.

Originally Posted by Zwolver

Originally Posted by Sealeaf

premis number three: not everything that is born successfully reproduces itself.
premis number four: if an individual inherets a trait which makes it unable to reproduce then it will not pass that trait on to its offspring.
Demonstrate that any one of those ideas is false and you will have reason to seriously doubt evolution.

These 2 were interesting...On number 3, Apart from hive grown species, like ants of bees, all offspring will be able to reproduce itself (apart from the freaks who didn't get functioning genitals) I van't think of any other species that does this..

On number 4... There are cases where a freak who is unable to reproduce himself, can still pass on traits... A virus can...

Though a virus does not disprove evolution.

You are missing the point of premis three. it is just a statement of natural selection. In every generation there are some that don't make it to reproduce. They may die before maturity or may find no mate or just be so bad at some aspect of parenting that they fail at it.

Sealeaf, is the point of number 4 similar to number 3, just to provide a terminal node of the "family tree"?

Originally Posted by JoshuaL

Sealeaf, is the point of number 4 similar to number 3, just to provide a terminal node of the "family tree"?

Essentially, yes. But with emphasis. Inhereted traits that kill their pocesser do not get passed on. Yes it is self evident. That is the point of all four premises, they are so self evident as to be inarguable but they are the true basis of the theory of evolution. It rests on very basic ideas and remains solid unless those basic ideas are challenged.

I can think of one other thing that would be a serious challenge to evolution : the actual observation of an act of "poof" creation.

I have the same question. Did someone found anything?I have the same question. Did someone found anything?