Poll: Do you believe in speciation?

[Mookie_Magnus]

a rare mid-working-week post from urprobablyright

I think speciation is quite believable.

Imagine if you will a working metaphor:

You drop a peice of playdough onto a large knife blade > the playdough splits in half > one peice goes into a hot environment; one peice goes into an environment of rollers and blasting gusts of air > the playdough in the hot environs quickly loses it's structural integrety and becomes liquid; the playdough going through rollers and gusts of wind eventually turns into a wide, billowing sale thing that floats around on hot pillars of wind > the two things end up completely different, but still based on playdough (or, in the case of life on earth, carbon/cells)

Some amoeba remained in the water - and developed their fish features further. Some amoeba took to land and flew off through their own gauntlet of evolutionary knife-blades. It's really quite easy to believe.

In the beginning, there was a single cell - almost like what u see in the egg of a fertilised human female for an instant before the cell splits - that cell split, it's clones went through hundreds of different knife-edges and ultimatly we all have a common ancestor in the cell - way back from gazillions of years ago - and in that we're all related to the trees, to each other (though which acceptable degrees of genetic difference so that it's not weird when we bump uglies)to monkeys, underwater freak-fish, murderers, ants and snails.

urprobablyright snaps his index finger like ali-G and screams "boo-yah kasha!"

That has to be one of the best metaphors for this that I have ever heard/read/

 

[Dando Dangerslice]

I'm not sure I understand. Individuals... evolving? Within their own lifetimes? Isn't that just... changing?

Exactly, there's no difference. Just superstitious skepticism.

Ha, I dig.

It's odd, I get the impression there's a fair amount of Americans in this thread (would make sense considering the ludicrous hour it is over here in England) but I actually don't know anybody in real life who doesn't believe in evolution.

As a city-boy I always think of myself as a switched-on, cosmopolitan kind of cat; but in a strange way it's kinda provincial and closed-off that I don't know anyone who even seriously doubts Darwinian theory...

Never thought about it before, just thought I'd share

 

[JodaSFU]

It's still the THEORY of Evolution. The THEORY.

Theory is the highest level of taxonomy in science outside of Math.

 

[Mookie_Magnus]

It's still the THEORY of Evolution. The THEORY.

This kind of ticks me off...

In science, a Theory is something has a large amount of proof behind it and is believed to be true. A law is something that is true and irrefutably so. Also, a scientific law states what happens, a Theory explains 'why' it happens.

Ex:
Law of Gravity: Things fall when you drop them.
Theory of Gravity: Things fall because they are being pulled toward earth because of the mutual pull between all objects.


... Get it now?

 

[Acid Armageddon]

It's still the THEORY of Evolution. The THEORY.

This kind of ticks me off...

In science, a Theory is something has a large amount of proof behind it and is believed to be true. A law is something that is true and irrefutably so. Also, a scientific law states what happens, a Theory explains 'why' it happens.

Ex:
Law of Gravity: Things fall when you drop them.
Theory of Gravity: Things fall because they are being pulled toward earth because of the mutual pull between all objects.


... Get it now?

Still, it's a THEORY and not a LAW.

 

[twistedshadows]

Is that really a changing of species though? your article
"The evolution of the peppered moth has been studied in detail over the last two hundred years. At first, many of peppered moths had light coloration, which made them camouflaged them against the light-colored trees and lichens which they rested upon. Due to the pollution during the Industrial Revolution in England, many of the lichens died out, and the trees that peppered moths rested on became blackened by soot, causing most of the light-colored moths, or typica, to die off from predation. At the same time, the dark-coloured, or melanic, moths, carbonaria, flourished because of their ability to hide on the darkened trees.[1]"

Isn't that more okay we have black and white moths, white moths get eaten so more black?

It isn't a new species its just a trait that became more prevalent.
Its not like the moth changed into a waterbug or beatle or something.

No, but it shows how natural selection works, which is a keystone in evolution. Evolution depends of traits becoming more prevalent. The moths show how certain traits are passed along, and how others begin to die out. The traits that help a certain species live longer are those that are going to continue to thrive. Once enough new traits have been introduced (usually through mutation), and enough other traits that no longer help a species to survive have died out, the species starts to become genetically different from what it used to be. Like I said previously, it takes a very, very long time; it can take hundreds of years.

 

[mtk2a]

Evolution is obvious at this point.

Speciation is just a way of describing genetic drift. That is to say that if a population of one species is separated either by geography or by niche, their genetic makeup would begin to drift towards adaptations suiting their environments. Once those genes differ to the point where those two groups can no longer produce mixed offspring, then they have become a new species.

We are not talking about something that can be observed within one or two generations. This is why you don't 'see animals changing'. Small changes occur over hundreds or thousands of generations, and larger changes occur over millions of years. Changes occur more quickly when there is more intense pressure to adapt in order to survive. If the climate of a tropical island changed to an arctic one overnight, the mammals living on the island are much more likely to survive with thicker fur, for example.

 

[JodaSFU]

It's still the THEORY of Evolution. The THEORY.

This kind of ticks me off...

In science, a Theory is something has a large amount of proof behind it and is believed to be true. A law is something that is true and irrefutably so. Also, a scientific law states what happens, a Theory explains 'why' it happens.

Ex:
Law of Gravity: Things fall when you drop them.
Theory of Gravity: Things fall because they are being pulled toward earth because of the mutual pull between all objects.


... Get it now?

Still, it's a THEORY and not a LAW.

It will never be a law. Law only explains ONE secluded occurrence. If you drop a ball, the result will be the same every single time. Here it would fall with an acceleration of 9.82 m/s^2. A theory explains why it falls. Evolution can never be a law, because it explains biodiversity, it doesn't declare that it happens, we already know that biodiversity is a fact. The theory of evolution means, that we have a number of laws, observations, proofs etc. that can be explained with one unifying theory. It doesn't mean we are uncertain to the fact that evolution happens, theory simply means a unifying explanation to hundreds upon hundreds of pieces of evidence.

 

[twistedshadows]

It's still the THEORY of Evolution. The THEORY.

A true theory is a hypothesis that has been continually tested and has not yet been disproved. The term "theory" is often casually thrown about in everyday conversation in this day and age, but in regards to science, saying something is a theory means that way we have not come up with a scientific refutation to that idea. Many of the scientific ideas we believe to be necessarily true (such as gravity, the speed of light, etc.) are in fact theories.

 

[Alex_P]

Mutations usually don't get passed on to offspring IIRC, so they only last one generation. Mutations are just a scrambling of DNA and are generally non beneficial.

The amount in which everything has to work just defies my reasoning. Random chance for a genetic mutation+ random chance that this mutation can be passed on+ random chance that this mutation is beneficial somehow..... I mean randomly typing "evolution" the odds would be 26 raised to the 9ths power wouldn't it? thats 1 in 5,429,503,678,976 if i did it right on the cell typing 400 characters per minute that would take 226,229,319 minutes or 150,000(or so days) or 430 years. Just to type out a 9 letter word.

So to me the probability of random chance leading from single celled organisms to us is even greater. I mean how in the hell do you go from a single celled organism to something like humans? Yes it's possible but nowhere near probable.

It's not science it's speculation, and to accept it as a fact is insane to me.

This is where a background in something like computer science, discrete math, or information theory would really help you.

Your random search isn't an appropriate model of an evolutionary process.

You're searching the possibility space randomly, taking big steps and throwing away the history of past results. Evolutionary processes mostly involve small, localized changes.
Your generator: mash nine characters.
A more appropriate generator: start with a random combination of nine characters; at each timestep, pick a certain position in your word and "increment" or "decrement" the character (assume you just flip a coin to decide which).
That's a very simple approximation of a random but localized "mutation".

Your only check is "Am I done?" Real selective pressure doesn't operate that way. It's more like (roughly speaking) "Is this better?"
Your fitness function: is my word "evolution" yes? if so, stop.
A more appropriate fitness function: for each letter, calculate how far it is from the desired letter, then sum these values together to get the word's total "suckitude"; try to minimize "suckitude" -- if the new word you made is better, keep it, otherwise, throw it out and keep the old word.
Selective pressure is always acting on a population (though, in reality, it can change over time), so this is a condition that you check at each iteration.

So, a very crude estimate of how long something like this takes to turn "argtuewii" into "evolution" is roughly 26 (options to search for each letter -- worst case) * 9 (number of letters) * 2 (since every time you pick a letter, there's about a 50% chance you'll "improve" it -- slightly-better-than-average-case) = 468. Roughly five hundred steps, on average, to go from any random nine-letter gibberish word to "evolution" using a simple change-one-letter-at-a-time search process. Not that bad, huh? And this is just a really naive search algorithm.
 

Now, I'm ignoring something else here -- natural selection isn't about producing (for example) tigers, it's about producing an animal that can fill a tiger's ecological niche. That animal needs to be a large pouncy predator with certain well-developed senses and natural camouflage. But it doesn't need to be orange, it doesn't necessarily need whiskers, it doesn't necessarily need to have a tail, it doesn't need to have icky smelly urine, it doesn't need adorable little white ear spots, and it doesn't necessarily need to roar.

-- Alex

 

[twistedshadows]

Mutations usually don't get passed on to offspring IIRC, so they only last one generation. Mutations are just a scrambling of DNA and are generally non beneficial.

Actually, genetic mutations can be passed to offspring.
Something that happens during a person's lifetime cannot be passed on (if my ear were to be cut off, my child would not be born with only one ear), but the mutation of a gene can be passed to the person's offspring (there's a 50/50 chance, which is actually quite substantial).

This is where a background in something like computer science, discrete math, or information theory would really help you.

Your random search isn't an appropriate model of an evolutionary process.

You're searching the possibility space randomly, taking big steps and throwing away the history of past results. Evolutionary processes mostly involve small, localized changes.
Your generator: mash nine characters.
A more appropriate generator: start with a random combination of nine characters; at each timestep, pick a certain position in your word and "increment" or "decrement" the character (assume you just flip a coin to decide which).
That's a very simple approximation of a random but localized "mutation".

Your only check is "Am I done?" Real selective pressure doesn't operate that way. It's more like (roughly speaking) "Is this better?"
Your fitness function: is my word "evolution" yes? if so, stop.
A more appropriate fitness function: for each letter, calculate how far it is from the desired letter, then sum these values together to get the word's total "suckitude"; try to minimize "suckitude" -- if the new word you made is better, keep it, otherwise, throw it out and keep the old word.
Selective pressure is always acting on a population (though, in reality, it can change over time), so this is a condition that you check at each iteration.

So, a very crude estimate of how long something like this takes to turn "argtuewii" into "evolution" is roughly 26 (options to search for each letter -- worst case) * 9 (number of letters) * 2 (since every time you pick a letter, there's about a 50% chance you'll "improve" it -- slightly-better-than-average-case) = 468. Roughly five hundred steps, on average, to go from any random nine-letter gibberish word to "evolution" using a simple change-one-letter-at-a-time search process. Not that bad, huh? And this is just a really naive search algorithm.
 

Now, I'm ignoring something else here -- natural selection isn't about producing (for example) tigers, it's about producing an animal that can fill a tiger's ecological niche. That animal needs to be a large pouncy predator with certain well-developed senses and natural camouflage. But it doesn't need to be orange, it doesn't necessarily need whiskers, it doesn't necessarily need to have a tail, it doesn't need to have icky smelly urine, it doesn't need adorable little white ear spots, and it doesn't necessarily need to roar.

-- Alex

You, sir, just made my day.

 

[Lord Monocle Von Banworthy]

Now, I'm ignoring something else here -- natural selection isn't about producing (for example) tigers, it's about producing an animal that can fill a tiger's ecological niche. That animal needs to be a large pouncy predator with certain well-developed senses and natural camouflage. But it doesn't need to be orange, it doesn't necessarily need whiskers, it doesn't necessarily need to have a tail, it doesn't need to have icky smelly urine, it doesn't need adorable little white ear spots, and it doesn't necessarily need to roar.

-- Alex

You started out great with refuting the old thesis that evolution is "random," (it's not, it follows rules), but then you ended with another teleological assertion. Evolution isn't about producing ANYTHING. Things change over time. That is the FACT of evolution. The THEORY tries to describe a mechanism for it, and the mechanism is elegantly simple. You did a great job describing it too. Random mutations are usually fatal, sometimes neutral, and rarely beneficial, where beneficial means "more likely to produce reproductively viable offspring." That is all. There is no goal there.

 

[Alex_P]

You started out great with refuting the old thesis that evolution is "random," (it's not, it follows rules), but then you ended with another teleological assertion. Evolution isn't about producing ANYTHING. Things change over time. That is the FACT of evolution. The THEORY tries to describe a mechanism for it, and the mechanism is elegantly simple. Random mutations are usually fatal, sometimes neutral, and rarely beneficial, where beneficial means "more likely to produce reproductively viable offspring." That is all. There is no goal there.

Correct. I'm presenting a lightly anthropomorphized oversimplification. I find that's helpful when trying to explain searching a possibility space.

-- Alex

 

[Ghouly0104]

I've noticed that some people are misusing the words 'Theory' and 'Proof' as they are used in a scientific context.

Saying that a scientific theory is unproven is a meaningless statement because when your only tools are empirical observation and mathematical modeling it is impossible to 'Prove' anything in the mathematical sense (as in being able to say definitively 'If A Then B' every time without fail). The only thing we can actually do is disprove things (I can prove that things sometimes fall to the ground on earth by dropping a stone, but all this says is that that particular stone fell that time, it says nothing definitive about gravity as a whole)

Gravity is an unproven theory, the model we have of the blackbody radiation curve (the origin of the "science... it works bitches" quote) is an unproven theory. The only 'Proof' that we have for them is that when we apply them to what we see around us, they work.

In this same vein, speciation will never be proven any more than Maxwell's Equations, and the value of speciation as a theory (or any theory for that matter) is entirely independent of this. The value of a theory lies in its ability to fit the data that we have as close as possible with the fewest (or easiest to justify) assumptions possible.

To this end, we have a huge number of species on earth today, and we know that they had to come from somewhere. If separate species cannot share a common ancestor then why are 97% of our genes identical to those of a chimpanzee? Why can we find genetic similarities between a chicken and a T-Rex (remember this next time you eat chicken, and know fear)? These genetic similarities point toward SOME relation between separate species. From a scientific perspective it is entirely permissible to assume speciation is incorrect, so long as you can point out specifically where it fails to fit the data.

As to the age of the earth/universe, we can measure this using other unproven theories. For example, Relativity is unproven, but we have taken tons of data that says that it matches reality pretty well. So if we assume a constant speed of light (which falls out of Maxwell's Equations, another theory that fits the data really, really, well) we can then measure the distance from the earth to some distant stellar body (for how this is done visit http://www.astromart.com/articles/article.asp?article_id=229) and use the fact that light travels at a constant velocity in vacuum to say how long it took that light to reach us, and thus get a lower bound for the age of the universe (the universe has to have been around long enough for that light to reach us).

This will give an age of the visible universe that is certainly greater than a few million years, and this is not anywhere near 'infinite time'. A better idea of a really, really, long time (preposterously long) is to look at room filled with air and calculate how likely it is that the air will condense is a corner and not fill the room, which is a possible state given that the molecules in the air are just moving about randomly. The amount of time it would take for this state to be likely is so long, however, that it greatly exceeds our estimates on the age of the universe (greatly meaning many, many orders of magnitude).

What all of this means to say is that speciation, as a model, gives a passable explanation of what we have around us today. To me, that means that it makes sense. The fact that macro-evolution/speciation seems to be a crazy-complicated process that (to some) defies logic does not matter to me because it fits with what we observe empirically. Is it any less believable than the idea that time slows down when you go really fast, or that our smooth, continuous world is actually broken up into little quantized bits of stuff (both crazy ideas that have since been born out by many experiments)? I don't think so.

 

[Lord Monocle Von Banworthy]

But I don't like even stepping down that road, Alex. Any kind of anthropomorphizing evolution leads people to wondering what its goal is, and then thinking that current species or especially humans are that goal, etc.

What if you reworked your analogy a little so that instead of printing a given word, your program's goal was say to play chess or the like using an evolutionary approach to rewriting itself by using random changes and then seeing if it's more likely to win? There have been some great programming analogies for evolution over the years, but I think it sets a bad precedent to use an analogy where an end is sought to teach the concept only to ask people to abandon that part of the explanation later once they've got it.

 

[Ghouly0104]

Also, noting the talk of theory vs. law above, there are no laws, only theories. The only distinguishing feature is that a law is accepted by almost everybody, it's still just a theory.

 

[asiepshtain]

I'd like to start off by saying several things.
First, if this has been done before, from this same perspective, I'm truly sorry and will let it die.
Secondly, don't look at it from a religious standpoint, but rather from a scientific one
Third, be scientific in your responses if possible, and no douchebaggery, please.

So since the beginning of my High School career, the great(terrible) educational system of the United States of America has been trying to ram this concept down my throat, that being evolution. I don't mean the part where a species changes over time, as that is quite evidently true, but rather that all species came from a common ancestor through the process of speciation. I quite frankly don't see how this could possibly make any sense. Even through billions of random mutations, I don't think bacteria could turn into something as complex as a human. Also, is it not true that because species can only reproduce with members of the same species that whenever a new species did arise through a mutation it would immediately die off as it had no other organisms to reproduce with, because no other organisms would have that exact mutation turning it into that species? And why don't we see any animals changing species today? You'd think that at least one or two should be crossing over around now. I don't know, it just doesn't make sense to me, and the fact that scientists blindly accept this as fact really grinds my gears. Every time i say something against it people immediately assume I'm looking at it from a creationist standpoint, when I really am not. I don't know if anyone else has opinions about this, but input would be very nice.

While your questioning attitude is a good one and we should always attempt to refute the current understanding (this process is after all what science is) It seems to me that your questions are mostly based in ignorance, thus leading to a knee-jerk reaction you've been getting. I recommend you pick up a few basics books on modern research in evolution, your questions are addressed and answered.

 

[Limos]

In short Yes

In long Yes you stupid stupid person.

Speciation is when enough evolutionary changes have added up that the two groups are no longer interfertile. This is observable fact. We know that things change over time, and we know that enough changes added up means they can no longer have viable offspring. This results in speciation.

Observed Instances of Speciation [http://www.talkorigins.org/faqs/faq-speciation.html]

The very idea that Anyone still clings to Creationism is shameful.

Anyway species do not just pop up in a single mutation. There is a transition period. Let's say you have species A, now Species A mutates and gains Mutation 1. Species A0 is interfertile with species A1, now the A1 population mutates again and we get species A2. A0 is not interfertile with A2, but A2 is interfertile with A1.

A0 fills a niche, A2 fills the niche A1 filled but is more successful. A1 dies out.

Now we have A0 and A2. The two species are no longer interfertile and you have just witnessed speciation.

 

[Lord Monocle Von Banworthy]

Are we actually seeing a non-religious victim of the Wedge Strategy here?