The Evolutionary Hotseat

[Borodog]

Don't understand evolution? Have some questions? Think all of this couldn't have gotten here by "chance" ? Ask away! I will endeavor to enlighten*.


*While Borodog is not an evolutionary biologist, he plays one in his head.

------------------
Insert humorous sig here.

[Buzzsaw]

Hey, Boro! How's it going!?! Have you ever read Langdon Smith's "Evolution" poem?

Even if you aren't into poetry much, it's worth cking out.

[Orbiting]

Do you think that all actions are motivated by genetic/evolutionary pressures?

[Mr Nigma]

*puts on media badge, takes out pen and notepad, raises hand*

Is it true that we, and by 'we' I mean humans in general, are just survival machines for our genetic material? Or is this question more on the philosophy side than the scientific side?

------------------
I'm a figment of my imagination.
Cognito, ergo sum.

[Ghost Post]

If we are to evolve again in the near future, what step do you think will improve our bodies, to suit the enviroment in general?

[Fried Egg]

~ Steps up to assist Borodog in his defence of 'Evolution' ~

[Mr Nigma]

*scribbles in notepad, thinks of next question*

------------------
I'm a figment of my imagination.
Cognito, ergo sum.

[Internet Stranger]

What is the worst thing that evolution has done?

------------------
----------------------------------------------

"I didn't know she was your sister I swear!"

www.InternetStranger.com

[Ghost Post]

Gave us nose hair that looks ugly and grows to fast when your old.

[Fried Egg]

The Dodo.

[Bicho the Inhaler]

All right, I'll bite.

Advocates of "Intelligent Design" often point to lack of continuity in the fossil record as evidence against evolution: evolution predicts that there would be all manners of intermediate species between today's organisms and ancient ones we have fossils of, but apparently the fossil evidence for these intermediate organisms is somewhat lacking. What do you think of this?

Intelligent Design Creationists also point to irreducibly complex structures as evidence of "design"; for example, an eye is a complex of many functioning pieces, and removing any piece removes the functionality of the eye. How could such a thing have evolved gradually?

[Bicho the Inhaler]

Oh, and what mental image does evolution get when it sees Sofis's name

[HyToFry]

Why did we (as humans) give up the ability to breath under water?

[Fried Egg]

Bicho the Inhaler

[Logain]

Here's the documented theory for Hy's question...

[dethwing]

what's the worst thing evolution has ever done?

[Macros]

Hy

[Logain]

dethwing, did you mean with regards to human evolution or does that include the evolution of other species?

[Buzzsaw]

HyToFry.....

[Borodog]

Buzzsaw: How's it going!?! -- Good!?!
Have you ever read Langdon Smith's "Evolution" poem? -- No. I'm not into poetry much, but I'll check it out.

Orbiting: Do you think that all actions are motivated by genetic/evolutionary pressures? -- All actions? No. For instance, accretion in mass-transferring binary stars is not motivated by any genetic/evolutionary pressure.

In the biological world? No, although I think that all actions by biological entities can have genetic/evolutionary consequences. For example, did Hitler kill six million Jews because of any genetic or evolutionary pressure" ? No. But you will notice that because of that action (amongst others) his genes are no longer swimming in the community pool (of course that whole one testicle thing might have gotten in the way as well).

Mr. Nigma: Is it true that we, and by 'we' I mean humans in general, are just survival machines for our genetic material? Or is this question more on the philosophy side than the scientific side? -- No, it is not a question of "philosophy" rather than "science" (although look up what "philosophy" actually means; hint, there's a reason it's callaed a Doctor of Philosophy), and yes, we human beings, like all other forms of life on Earth, are survival machines for our genetic material. Whether or not we are "just" that is perhaps a questions for philosophers. Personally, I make my own purpose in life, that being to live, love, and understand. Virii are sets of coded instructions that say "Make copies of me." Elephants are mechanisms that contain sets of coded instructions that say "Make copies of me, via the circuitous route of first building more elephants." Human beings contain sets of coded instructions that say "Make copes of me, via the circuitous route of building more human beings."

johnnyFourFours: If we are to evolve again in the near future, what step do you think will improve our bodies, to suit the enviroment in general? -- None. We have already evolved the perfect adaptation to all environments: the ability to adapt the environment to suit our biology. This is not to say that we will not continue to evolve, we will, by definition.

Internet Stranger: What is the worst thing that evolution has done? -- Nothing. Evolution does not see "good" and "bad". It just is. What's the worst thing gravity has done?

Bicho the Inhaler: Advocates of "Intelligent Design" often point to lack of continuity in the fossil record as evidence against evolution: evolution predicts that there would be all manners of intermediate species between today's organisms and ancient ones we have fossils of, but apparently the fossil evidence for these intermediate organisms is somewhat lacking. What do you think of this?

First, there is a misconception in your set up. Typically, "Intelligent Design" is not inconsistent, in terms of it's prediction and interpretation of the fossil record, with evolution. Intelligent Designists acknowledge that evolution took place. They differ from Darwinists in what the mechanisms of evolution were. Were as Darwinists see the machanisms of evolution as mutation, natural selection, genetic drift, etc., IDists think that the mechanism of evolution has been the intervention of a unnamed Intelligent Designer (reference to the divine is scrupulously avoided, but plainly implicit).

The second half of your question seems more aimed toward Special Creationism, or just plain Creationism. Creationism has a number of flavors: Old Earth Creationism, Young Earth Creationism, etc. There are some Old Earth Special Creationists who believe that they see a fossil record inconsistent with Darwinian gradual evolution. They are incorrect. Firstly, it is a peculiarity of biological nomenclature that an animal (or fossil) can belong to one, and only one, species. This is by definition. You will never find an animal that is half of one species and half of another! However, intermediates at higher taxonomic levels are abundant, for example the evolution of modern the whales, the evolution of modern horses, the evolution of early mammals from reptiles, and human evolution are all well documented with abundant "transitional" forms, although animal each by definition was a member of exactly one species. No animal ever made a living being "transitional." It either lived and functioned fully well in its environment, or it didn't, taking it's genes with it.

As for the fossil record being "sparse" when it comes to "transitional forms," a) this is false, as we mentioned above there are plenty of transitional lineages very well known, b) one expects to find a spotty fossil record. Fossilization is a notoriously unlikely event. The vast amjority of dead animals (or plants) do not fossilize. Further more, new species are likely to evolve in small, geographically remote populations over brief (in geological terms) periods of time compared to the lifetime of species. Therefore you are simply much more likely to find lots of samples of a perent species and the daughter species, with few example of "transitionals" (although again, this is just a general rule, plenty of transitionals are known).

Bicho the Inhaler: Intelligent Design Creationists also point to irreducibly complex structures as evidence of "design"; for example, an eye is a complex of many functioning pieces, and removing any piece removes the functionality of the eye. How could such a thing have evolved gradually?

Citing a biological structure as "too complex to have arisen via evolution" is equivalent to saying "Well, if I personally can't think of a way that it could have happened, well then it couldn't have!" This is the argument from incompetence, or the argument from arrogance, depanding on how one views it. Either the IDist in question is simply to incompetent or lazy, or more likely lacks the understanding of evolution, to imagine an evolutionary pathway (which is usually the case, as every example I've ever heard has a relatively simple and plausible Darwinian pathway proposed), or because he personally can't think one up, that means that it can't possibly have happened, and therefore God, uh, I mean the "hypothetical Designer," must have majicked it into existence.

As for the example of the eye, would you have me believe that a slightly worse eye than yours would not still be useful to an organism? Would it then not follow that your eye would be a slight improvement over the slightly worse eye? Would it then not follow that an animal carrying the ever-so-slightly-improved eye would have an ever-so-slight advantage over the population in general? Would not that advantage eventually lead the frequqency of ever-so-slightly improved eyes to increase in the population? Can you not imagine a series of eyes, each advantagious to its owners above the last in the chain?

A light senstive cell - a cluster of light sesitive cells - a cluster of light-sensitive cells backed by a layer of opaque cells - a cluster of light sensitve cells back by a cluster of opaque ceels, covered with a protective transparent layer - a cup shaped cluster of light-sensitive cells backed by a layer of opaque cells, covered with a protective transparent layer - a deeper cup shaped cluster of light-sensitive cells backed by a layer of opaque cells, covered with a protective transparent layer- a deep cup shaped cluster of light-sensitive cells backed by a layer of opaque cells constricting to a narrow hole at the front, covered with a protective transparent layer - a deep cup shaped cluster of light-sensitive cells backed by a layer of opaque cells constricting to a narrower hole at the front, covered with a protective transparent layer - a deep cup shaped cluster of light-sensitive cells backed by a layer of opaque cells constricting to a pin hole at the front, covered with a protective transparent layer - a deep cup shaped cluster of light-sensitive cells backed by a layer of opaque cells constricting to a pin hole at the front, covered with a rounded transparent layer - a deep cup shaped cluster of light-sensitive cells backed by a layer of opaque cells constricting to a pin hole at the front, covered with a rounded transparent lens . . .

Hytofry: Why did we (as humans) give up the ability to breath under water? -- "We" didn't, as humans. Our ancesters, and those of all amphibians, reptiles, and mammals, lost that ability several hundred million years ago, with the advent of a little thing called the "lung." Interestingly, all of these (including us) develop and then loose gill-like structures during embryonic development; a legacy of our evolutionary past.

dethwing: what's the worst thing evolution has ever done? -- Nothing. Evolution doesn't know "good" and "bad". It only knows, "lives" and "does not live".

Buzz: . . . explain to the class what convergent evolution is. -- Convergent evolution happens when unrelated species (for the purposes of the characteristic in question; all species are distantly related) develop similar structures (or behaviors) independently, most likely because they make their living in a similar way. Examples would be the unrelated western and eastern hemisphere weakly electric fish, dolphins and icthyosaurs, unrelated african and south american ladder spiders, mammals wolves and the marsupial Tasmanian "Tiger," various unrelated "hedgehogs," various unrelated "anteaters," birds and bats, many types of unrelated gliding squirrell-like animals, etc.

------------------
Insert humorous sig here.



[This message has been edited by Borodog (edited 07-08-2002 02:59 PM).]

[extropalopakettle]

Are you aware of any work in the area of mathematical models of evolution that would allow one to draw conclusions about how long one might expect it to take for life as it exists today to evolve from one-celled organisms given some particular frequency of random mutation?

Put another way: Suppose, for the moment, that there were some supernatural intelligent force which willed every mutation to happen in a particular way, so as to cause a world such as ours to evolve from one-celled organisms as quickly as possible. Presumably, it would happen much more quickly that way than it would with random mutations (assume in both cases a similar rate of mutation, but a difference between deliberately chosen versus random mutations). Is there a mathematical model of evolution that could tell us that, yes, the world we see about us is consistent, given the time frame of 4 billion years or so, with that model?

[HyToFry]

[Antrax]

I think I speak for the entire male population on the GL, when I say: "Ow."
Antrax

------------------
I'm cool, really

[Eilonwy]

Am I the only one that has a problem with "evolving gradually?" I was under the impression that evolution was mostly long periods of near stagnancy (if that is a word), interspersed with short, extremely volatile periods of huge evolutionary leaps. The leaps are caused by phenomena such as huge temperature changes, meteors hitting the Earth, etc.

This would cause both a spotty fossil record and quick evolution of complex structures.

[Antrax]

That's the newer evolutionary theory. The idea that instead of one gene changing slowly after the other, you have many mutations in inactive parts of the DNA code. Then, one mutation activates that part, and suddenly your creature has 3 hands.
Antrax

------------------
I'm cool, really

[Borodog]

Extro: I don't have the references at my fingertips, but yes, that sort of study has been done, and yes it is entirely consistent.

For instance there's 10 million years, give or take, between humans and chimps (common ancestor 5 million years ago). That's about 1 million generations (give or take), and of the order of billions of individuals (note that we are ignoring the modern explosion of the Homo sapiens population) since we can presume each population was at least of order a thousand individuals at most times. Each individual human or chimp has around 3 billion base pairs. The human and chimp genome differ by around 80,000,000 base pairs. So that's a rate of change of 8 base pairs per year. Studies have sown that DNA mutates more or less at a rate of a few base pairs per billion per year. Of course, this has to be in the reproductively active cells, but that's no problem; it happens in ALL cells. This means that a single individual is adequate to explain the mutation rate. The population mutation rate is much higher, because of the thousands of individuals, but most of those mutations will be negative, and will be selected against. Maybe 1 in a thousand will be found advantageous by natural selection and increase in frequency. Poof, agreement.

Your milage may vary, but this has been done with many species and many different pieces of the genome (some places seem to mutate at faster rates than others), and it is has always been found to be generally consistent.



------------------
Insert humorous sig here.

[Agamemnon]

Do you think that Ted Levine went a bit too over the top with his character? Or did he blend well with Duchovny?

[Borodog]

"Am I the only one that has a problem with "evolving gradually?" I was under the impression that evolution was mostly long periods of near stagnancy (if that is a word), interspersed with short, extremely volatile periods of huge evolutionary leaps. The leaps are caused by phenomena such as huge temperature changes, meteors hitting the Earth, etc"

You've misunderstood a popular theory known as "punctuated equilibrium." This theory states that most species exist "statically" for relatively long periods of time, and then "rapidly" speciate to form new species. The key here is to understand "rapid." Rapid by geological standards. Rapid by evolutionary standards. By still many thousands of generations. Evolution proceeds gradually, with minute changes from generation to generation. Most speices once established do exist in a kind of "stasis," they have developed a kind of "genetic inertia" because they have a very large genepool that it is difficult to move. Small, isolated populations are more susceptible to natural selection and geneetic drift, meaning that most speciation takes place in small, geographically isolated places over RELATIVELY short periods of time (although still gradually).

Disastrous climatological changes, i.e. catastrophes like comet strikes, actually don't have anything to do with natural selection at all. They kill off large numbers of species precisely because life forms could NOT be "prepared" for them by natural selection. Natural selection works only with the environment you have, not the one you're GOING to have. Similarly, surving one comet strike can be argued as not really equiping any of your descendants to survive the next one, in another 26 million years. The killing off of entire fauna will leave open evolutionary niches, where there is suddenly no competetition, opening up "living room" for adaptive radiations by other groups. This is how the dinosaurs came to rise after the mass extinction of the dominant mammal-like reptiles 220 million years ago, and how the true mammals came to power after the mass extinction of the dinsoaurs 65 million years ago.

------------------
Insert humorous sig here.

[Borodog]

"Do you think that Ted Levine went a bit too over the top with his character? Or did he blend well with Duchovny?"

I haven't the foggiest idea what you're talking about. Is this some sort of vieled X-Files jab at evolution? If so, I don't get it.



------------------
Insert humorous sig here.

[StupidVisitor]

How do the intermediate critters survive? They look really silly.

Also: Do you think birds evolved from dinosaurs?

------------------
Chinese Valley Girl Torture:
"And then I was totally like 'No way!' and he was all like 'Yes way!' and it was totally sweet how he, like, got me all these, you know, roses and stuff. And..."

[Borodog]

StupidVisitor: How do the intermediate critters survive? They look really silly. -- How so? Remember, there is no such thing as an "intermediate critter". They are all fully functioning species.


Also: Do you think birds evolved from dinosaurs? -- Yes. There is ample anatomical evidence that birds evolved from small therapod dinosaurs.




------------------
Insert humorous sig here.

[extropalopakettle]

Platypus: reptile or mammal?

[Borodog]

Class Mammalia, Subclass Prototheria, along with the spiny anteater.



------------------
Insert humorous sig here.

[Coyote]

How do they tell which fossils are 'transitional'? For example, suppose Species A branches off into two very similar Species B and C. B dies out, but C further evolves into Species D. How can they tell that it's C, rather than B, that is the transitional step between A and D?

[Bicho the Inhaler]

OK, I admit, I don't know enough about eyes to say whether they're really irreducible. I read an article by a molecular biologist that said they were, but he seemed a little biased.

Looks like the punctuated equilibrium theory can also help account for "evolutionary gaps" in fossil records, where they may stand out or where people may perceive them.

By the way, Borodog, I think the distinction between "intermediate critter" and "transitional form," if not imaginary, is rather nitpicky.

[Will]

Borodog When the dinosuars were wiped out by something like the comet or what ever you will say.Some scitsit say that all the land animals except small animals like the cockroach wasn't killed. After this the evolutionary line had to restart and make us. But why do you think that the evolutionary line made more reptiles when they failed to live through the extinction? Well i am trying to go somewhere with this post i just can't get it out k so let me think about it.

[Logain]

Borodog, one time I was in a friendly discussion/debate with some Creationists. Oddly enough, we were all chemical engineers, and I thought the majority of us were athiest evolution supporters *shrug*. They used the argument that since entropy is the universe's driving force and favors randomness and chaos, that evolution couldn't be true. If the universe is heading toward a random goal, how can evolution be the answer when it is based on selectiveness and an ordered being? How would you have countered their argument?

[Borodog]

Coyote: How do they tell which fossils are 'transitional'? For example, suppose Species A branches off into two very similar Species B and C. B dies out, but C further evolves into Species D. How can they tell that it's C, rather than B, that is the transitional step between A and D?

They can't. But it doesn't really matter. 99.999...9% of all organisms that have ever lived and died do not fossilize. This includes not just some entire species that go unrepresented in the fossil record, but most species. Still, you require surprisingly low resolution to put the puzzle together, in broad terms (and when you get lucky, fantastically detailed terms).

Bicho the Inhaler: By the way, Borodog, I think the distinction between "intermediate critter" and "transitional form," if not imaginary, is rather nitpicky.

That's the point. Saying that a certain fossil is "transitional" between two other species does NOT indicate that individuals of it's species were somehow "intermediate". At the time the animal lived, it was a member of a species. Period. From it's point of view, it wasn't "transitional". It is only with the benefit of hindsight that we can say thing like, "Ah, the ambulocetus was clearly transitional between the mesonichids and the archaic whales!" Go back in time and tell that to ambulocetus, and he would have eaten you. He wasn't "half" anything.

Will: Borodog When the dinosuars were wiped out by something like the comet or what ever you will say.Some scitsit say that all the land animals except small animals like the cockroach wasn't killed. After this the evolutionary line had to restart and make us. But why do you think that the evolutionary line made more reptiles when they failed to live through the extinction? Well i am trying to go somewhere with this post i just can't get it out k so let me think about it.

Try real hard to make that make sense, and I might answer it.

Logain: Borodog, one time I was in a friendly discussion/debate with some Creationists. Oddly enough, we were all chemical engineers, and I thought the majority of us were athiest evolution supporters *shrug*. They used the argument that since entropy is the universe's driving force and favors randomness and chaos, that evolution couldn't be true. If the universe is heading toward a random goal, how can evolution be the answer when it is based on selectiveness and an ordered being? How would you have countered their argument?

Ah, the old "evolution violates the Second Law of Thermodynamics" argument. I'd have countered it like this:

Bunk.

First, who knows what is meant by "entropy is the universe's driving force and favors randomness and chaos." In general the 2nd Law of Thermodynamics says that systems tend towards higher entropy (i.e. greater disorder) IN THE ABSENCE OF SOURCES OR SINKS OF ENERGY. If you look up in the sky tomorrow from around 6 am to 7 pm you might notice a giant, flaming thermonuclear energy source. It is called "the sun". It drives many, many, many, many, phenomena in the world "uphill" towards order. Disorderly water molecules get evaporated so that they can condense and become incredibly ordered snow flakes, for example. If they don't believe that order can come from disorder without divine intervention, tell them to supersaturate dissolved sugar into hot water, dangle a string in it, and let it set for a week. Then ask them if God came down personally from Heaven to make the beautifully ordered crystaline structure of the resulting rock candy.

------------------
Insert humorous sig here.



[This message has been edited by Borodog (edited 07-08-2002 09:36 PM).]

[Will]

Why did this so called evoultion decide to make more reptles when they were weak and couldn't survive very well?

[pikachamp]

quote:

---

If they don't believe that order can come from disorder without divine intervention

---

i thought the sun was divine