Evolution, Creationisim, Abiogenisis, etc.

[Dr. Paine]

Before you continue, please read this.

 

This is a discussion and debate thread. For the sake of everyone participating, and the mods, please try to abide by the following guidelines.

• Know that, by entering in this discussion, your opinion will probably be challenged. This isn't being mean, this is just natural curiosity about how other people think. If you post one or two sentences of 'I think x', and fail to provide any reason for why you believe 'x', don't freak out if a few people ask why and pose other questions. It's how we learn. Or, in short: be prepared to back up your opinion.

• On the other hand... don't dogpile newcomers/particularly heated posts. If one or two others have already addressed the person, please refrain from jumping on that particular train until they have answered. As others in GD have noticed, this behavior tends to drive away many people, and give a rather negative impression of the regulars. For the good of all of us, just exercise a little bit of restraint.

• While Creationism/Intelligent Design will likely be brought up in this thread, please keep any religious discussion/debate to how it relates to evolution. If it starts drifting away from that, it's highly encouraged you move the discussion to the Religion thread.

• Remain respectful. Don't personally insult people for what they believe in. If someone is intentionally trying to rile others up, just report it and move on. It's not good for your health or sanity getting too worked up over it.

• Tone does not carry over well in writing. If you're being extremely sarcastic, please, please give some indication- people have been warned or otherwise misunderstood because the tone just didn't carry! I doubt anyone here wants that. I'm not asking you completely avoid sarcasm, just... make it known when you are.

• Have sources! No matter which side you're talking for, sources are your friend! Wikipedia (even if it can be unreliable, it's still a good source for making a quick, unbiased point) and other educational sites will be your best bet, but as long as it complies to forum rules, it will be accepted.

• Discussion of abiogenisis/'where life first came from' is allowed. It comes up often enough, and honestly, I've always seen it as having some place in an evolution thread. So yeah- I know very little about it myself, but if people want to bring it up, I'd say the evolution of life from non-living matter is perfect game for here.

• TL;DR: Be mature, don't be a jerk, be ready to back up your opinion with some kind of source if people ask.

Okay, that's out of the way, on to the main subject!

 

Evolution, as defined by Wikipedia, is "any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins."

 

While it is commonly held that evolution is 'survival of the fittest', it is frequently misunderstood to mean 'only the strongest survive'. While this might be true in some cases, in others, the opposite is the case- take a look at the commonly held K-T extinction event. Dinosaurs were wiped out, while smaller creatures survived and eventually took over the ecological niches left by the dinosaurs.

 

Another misconception is that evolution has some higher goal. In terms of pure biological evolution, this just isn't true. The only 'goal' evolution serves is to allow a species to pass on its genes and survive, usually by adapting to whatever environment it's in. An ape is no 'lesser' than a human, a giraffe, a platypus, or even a venus flytrap- it just had a niche to fill, and it filled it well enough to remain relatively unchanged while other species adapted to other conditions. More extreme examples are the likes of coelacants, which are believed to have remained unchanged for around 400 million years. On a related note; no, evolution in a species does not mean all 'bad traits' are weeded out. Such traits may not impact survival too badly, allowing carriers to reproduce. Some traits might prove useful and eventually become more common.

 

But wait! Evolution is only a theory! From Wiki:

A scientific theory is a set of principles that explain and predict phenomena. Scientists create scientific theories with the scientific method, when they are originally proposed as hypotheses and tested for accuracy through observations and experiments. Once a hypothesis is verified, it becomes a theory.

It's a bit trickier than that, but there's the basics. A scientific theory is not the same as the everyday theory built on pure guesswork- there has to be some verifiable, observable, documented facts before a scientific theory is accepted.

 

That's about all I've got to say at the moment. There are others here significantly more knowledgeable than myself on this subject, and I look forward to what they have to say. All I can say on why I accept this, is that the evidence I've seen on either side lead me to believe that evolution is the best, least-flawed answer to where various species come from. It's not perfect, of course, humanity doesn't know everything yet. But more progress is being made every day, and the basics of it make sense.

Edited January 23, 2012 by Dr. Paine

[Chiaki]

Great thread and something I feel very strongly about being a Biologist myself.

 

I think the biggest thing that gets me is that people do misunderstand what scientists mean by the word 'theory'. It has to have substantial evidence and be widely excepted within the scientific community to be classed as a theory. And let me tell you, for anything to be widely excepted within that community means a lot.

[Completely Different]

As a biologist, I find evolution to be one of the greatest theories in my field. It really unites all aspects, from the study of huge ecosystems to even the tiniest molecules. For me, the amazing thing about evolution is that its so simple; its logical and its backed by evidence.

[lightbird]

As a biologist, I find evolution to be one of the greatest theories in my field. It really unites all aspects, from the study of huge ecosystems to even the tiniest molecules. For me, the amazing thing about evolution is that its so simple; its logical and its backed by evidence.

Pretty much this.

Also, for those who try to debunk natural selection by claims of Darwin dismissing it at the end of his life - it doesn't matter if HE dismissed it, even as the author of the theory, since many, many researchers after him have shown that it works.

 

Also, The Greatest Show on Earth - The Evidence for Evolution is quite an entertaining book, possibly one of Dawkins' finest, even for me being a biologist and knowing many of the things that were described there before picking it up.

 

As for the emergence of life, I have little idea about that, abiogenesis sounds cool, but there is too much lacking evidence for that, including that of how monomers might have assembled into the energetically less efficient polymers, or how phospholipids (or... the other molecules that the Archea have, I've already forgotten) might have formed sheets that might have later become the membranes of primitive cells etc.

I quite like the warm deep sea vent theory, but, like said above it's still lacking in some steps.

 

So, yeah.

Evolution - yes, and I fail to see how it's a matter of belief when there's so much overwhelming proof.

Emergence of life - still unclear, but Creationism along the lines of "God laz0red up all the species on Earth at the same time" is a cheap copout for the wishful crowd.

Edited January 19, 2012 by lightbird

[RheaZen]

I really don't see how people can discount evolution when we can it happening in real time. Drug resistant bacteria, pesticide resistant pests, all that good stuff's just due to populations evolving. I tend to lose a lot of respect for people who are willfully ignorant about evolution and are steadfast in their denial of its existence.

 

As for emergence of life, what Dia said pretty much sums up how I feel.

[Princess Artemis]

The Banana video. Here, Ray Comfort uses a dessert banana as backing for intelligent design

Starting the thread out with this kind of mis-characterization isn't cool. I believe you are smart enough to know that the guy in this video is not saying a single word in support of Intelligent Design, and smart enough to know that saying he is doing what he isn't will color the thread a certain way for the rest of its existence.

 

ETA: Just in case it's not clear, the only accusation here is of intelligence; otherwise, I'm calling out less than careful wording or perhaps a poorly thought out addition to an otherwise good starting post.

Edited January 19, 2012 by Princess Artemis

[Daydreamer09]

I find the study of evolution fascinating. A while ago, there was a show on our local public TV station about the newest revelations in mapping genomes. Scientists have found chunks in unmapped portions of DNA that are common in different species.

 

Some newly discovered genes have been found to be switches for turning other genes off and on, while others tell those switches what to do. That's why there's so much diversity in the animal and plant kingdoms.

http://www.pbs.org/wgbh/nova/teachers/body...nes-on-off.html

 

My personal opinion about evolution is that it's something part of my Supreme-being-of-choice's master plan. He made the world and allowed things to change until it is what it is today. I do believe in evolution, but it is part of his grand design.

 

Also, to the OP, can you give a definition for Abiogenisis? I've never heard of it and I don't think it's a commonly known term.

Edited January 19, 2012 by Daydreamer09

[lightbird]

Definition from Wikipedia:

"Abiogenesis (pronounced /ˌeɪbaɪ.ɵˈdʒɛnɨsɪs/ ay-by-oh-jen-ə-siss) or biopoesis is the study of how biological life arises from inorganic matter through natural processes, and the method by which life on Earth arose."

 

http://en.wikipedia.org/wiki/Abiogenesis

 

 

[TikindiDragon]

Gotta say that while I think evolution is a bit of a given I'm afraid I just can't accept abiogenesis as it currently stands. It's mathematically practicaly impossible.

 

Also, incidently, homochirality is a major problem with it in my opinion. Synthetic production of ammino acids, without a chiral catalyst, produce a roughly 50/50 mix of 'handedness'... yet in nature we only see left handed ammino acids. No theories as to why this might be have been able to be tested to any depth.

[Nine]

I've always believed in evolution as a concept, theory, reality, etc. I was surprised when I found out there were those who did not believe in it, because to me it was as grounded into reality as gravity (lolol...get it?).

 

Misconceptions about human evolution get me the most though; you know, that humans evolved from chimpanzees, humans were born to hunt and use tools, 'missing link', we've always had a bigger brain and all that. Most of it's from media-vomit and circulation of false info, so I don't blame people too much for not knowing the truth. Plus nobody listens to Anthropologists-- not when they could be looking at dinosaurs! Guilty as charged =o

[Daydreamer09]

I've always believed in evolution as a concept, theory, reality, etc. I was surprised when I found out there were those who did not believe in it, because to me it was as grounded into reality as gravity (lolol...get it?).

 

Misconceptions about human evolution get me the most though; you know, that humans evolved from chimpanzees, humans were born to hunt and use tools, 'missing link', we've always had a bigger brain and all that. Most of it's from media-vomit and circulation of false info, so I don't blame people too much for not knowing the truth. Plus nobody listens to Anthropologists-- not when they could be looking at dinosaurs! Guilty as charged =o

Well, if you consider that the whole creationism vs. evolution debate really hit the fan back in the 30s-40s-ish with it being taught in schools, it's not too surprising that there are still people who don't believe in evolution. Many of those individuals who lived during that time are still alive today. There's also the fact that with each new generation, we learn more and more about our genetic structure and newer generations become more well informed than the old. I think, give it time and there will be less individuals who believe that evolution is a lie.

 

Really interesting fact is that part of the reason that we have a larger brain, some experts believe, is we have a genetic disorder in a strand of DNA for our muscles. The muscles around our cranium, particularly those that allow us to chew, are much smaller and weaker than those of other primates. But with smaller muscles, there's more room up top for our brains to develop.

Edited January 19, 2012 by Daydreamer09

[Vixonstar]

Misconceptions about human evolution get me the most though; you know, that humans evolved from chimpanzees, humans were born to hunt and use tools, 'missing link', we've always had a bigger brain and all that. Most of it's from media-vomit and circulation of false info, so I don't blame people too much for not knowing the truth. Plus nobody listens to Anthropologists-- not when they could be looking at dinosaurs! Guilty as charged =o

Actually, humans are not decended from ANY of today's apes, all of us (that's the apes too) are decended from various older species that went extinct before we knew anything about them. Different species of ape are just branches off of the main evolutionary track. (Okay, lecture over. Sorry.)

[philpot123]

I really don't see how people can discount evolution when we can it happening in real time. Drug resistant bacteria, pesticide resistant pests, all that good stuff's just due to populations evolving. I tend to lose a lot of respect for people who are willfully ignorant about evolution and are steadfast in their denial of its existence.

 

As for emergence of life, what Dia said pretty much sums up how I feel.

There is a distinction made to a creationist between microevolution and macroevolution. Microevolution is "evolution" or adaptation within a specific kind that theoretically requires no additional genetic information. An example would be a population of rabbits in a snowy area. Any brown rabbits would slowly be weeded out by any predators because of their visibility, and as a result, the remaining white rabbits would be dominant (silly example, but it's to the point). Macroevolution would be an evolution between species, and following the Theory of Evolution, an evolution to a HIGHER species. A fish growing legs and becoming a lizard, an ape evolving into a more advanced species of ape, etc, that theoretically requires additional information to evolve into a higher order of animal. I don't think you'll find an informed person in the world who denies the existence of adaptation, but it's not necessarily a proof for evolution from lower animals into higher animals.

[lightbird]

...what constitutes a higher and lower animal in your opinion?

 

Genome size by its own is in no way an indication of the complexity or the age of evolutionary emergence of an organism.

Edited January 19, 2012 by lightbird

[Completely Different]

There is a distinction made to a creationist between microevolution and macroevolution. Microevolution is "evolution" or adaptation within a specific kind that theoretically requires no additional genetic information. An example would be a population of rabbits in a snowy area. Any brown rabbits would slowly be weeded out by any predators because of their visibility, and as a result, the remaining white rabbits would be dominant (silly example, but it's to the point). Macroevolution would be an evolution between species, and following the Theory of Evolution, an evolution to a HIGHER species. A fish growing legs and becoming a lizard, an ape evolving into a more advanced species of ape, etc, that theoretically requires additional information to evolve into a higher order of animal. I don't think you'll find an informed person in the world who denies the existence of adaptation, but it's not necessarily a proof for evolution from lower animals into higher animals.

This is a bit of a side-track, but I've never really liked using the terms "higher" and "lower" organisms. It gives the sense that there is some type of evolutionary level, that mammals are intrinsically greater than fish. That's really a misconception; fish and mammals are equally good for the environments and conditions they live in.

 

I'm not necessarily saying you don't know that, or anything; I just find that terms like that spread a lot of misconception around, which is something this field needs less of.

[lightbird]

I'm not necessarily saying you don't know that, or anything; I just find that terms like that spread a lot of misconception around, which is something this field needs less of.

This, too.

 

Preferably, I'd compare organisms as being more or less "primitive" by their age of origin/being genetically closer/farther from the supposed protobiont/universal ancestor of all species - unless it is proven in the future that life originated on several separate occasions, however, one should always keep in mind that the same function/ability can be gained or lost several times during the species'/clade's existence, depending on the environmental and genetic changes... though I'm not very well-versed about how that happens, herpaderp, beyond saying "It's natural selection!!!11!

Edited January 19, 2012 by lightbird

[philpot123]

...what constitutes a higher and lower animal in your opinion?

 

Genome size by its own is in no way an indication of the complexity or the age of evolutionary emergence of an organism.

I'm (clearly) not a biologist, so my opinion doesn't count for much. But I was referring to the typical "upward slant" of evolutionary thought, small organisms evolving into water dwelling creatures evolving into land dwelling creatures etc. The mental "fish crawling out of the pond" picture if you will. Obviously that's not scientific by any means

 

Preferably, I'd compare organisms as being more or less "primitive" by their age of origin/being genetically closer/farther from the supposed protobiont/universal ancestor of all species - unless it is proven in the future that life originated on several separate occasions, however, one should always keep in mind that the same function/ability can be gained or lost several times during the species'/clade's existence, depending on the environmental and genetic changes... though I'm not very well-versed about how that happens, herpaderp, beyond saying "It's natural selection!!!11!

 

That is what I was referring to. The concept of ancestors evolving into new creatures. In theory that would take added information that is not necessary with adaptation or "microevolution." So disagreeing with the Theory of Evolution is not rejecting that an observable form of something that could be CALLED evolution exists, it is to reject the theory that all (most?) complex creatures are descended from a common ancestor.

[lightbird]

Actually, the study of evolution includes many smaller theories about various mechanisms.

 

The thing is, there isn't really an upward slant, so to say, just progression of whatever changes are more useful for a certain kind of organism under certain environmental changes = there is no ultimate goal in evolution. Technically, the most evolutionary successful group of organisms are Bacteria - they may not have hopes and dreams like we do, but they're the most numerous and faster-changing group of living organisms that we know of.

Either you change with the environment, or you die (sniff, Trilobites, may you rest in peace). Which explains why some species of generally land-inhabiting groups, such as mammals, have "reverted" to bodies that are suitable for life in water, such as dolphins/whales etc., but I'm just throwing arounf factoids here. /flails

Edited January 19, 2012 by lightbird

[Dr. Paine]

In theory that would take added information that is not necessary with adaptation or "microevolution." So disagreeing with the Theory of Evolution is not rejecting that an observable form of something that could be CALLED evolution exists, it is to reject the theory that all (most?) complex creatures are descended from a common ancestor.

Wouldn't that 'additional information' come in by way of various genetic mutations that would arise over the millenia? Obviously, not all would be useful, but many were.

 

Take feathers- it's now widely held that some dinosaurs were feathered, but couldn't fly. They were still useful though, as it would help regulate body temperature, attract mates, and maybe even provide camouflage. Over time, some mutated to become much larger, allowing smaller, lighter dinosaurs to glide for short periods of time. This would help them avoid predators and possibly catch more prey, meaning they would be the ones to pass on their genes. These mutations stacking onto each other would eventually give rise to the first feathered dinosaurs capable of flight, and eventually, modern birds.

 

... I probably managed to fudge some things there, but that's my basic understanding of how it works. Macroevolution is... well, microevolution over millions and billions of years. Eventually, the change is just so great that the end creature is a different species.

[Completely Different]

Exactly as Lightbird described.

 

Also- if you're interested, the way that organisms regain traits that they once lost is usually the same way they gain a completely new trait. So when whales developed fins again, it wasn't necessarily because they still had genes that were "turned off" for fins and the like. I believe there was a horse/hippo like creature that lived in swampy, wet areas. Creatures that could swim faster escaped prey from both land and the water. Therefore more streamlined, water adapted bodies propogated throughout the population until you had all the modern varities of today.

 

However, it is possible to switch on an "off' gene that's stopped being used for anything. I'm not sure how common this is in nature, but its certainly possible in a lab. For example; chickens have the majority of the genes their dinosaur ancestors had. Its possible to switch them back on when the chicken is still an embryo, and it will develop scales instead of feathers, and teeth, and a bunch of other dinosaur-like traits.

 

...I didn't really have any point to make there, except that its interesting.

 

Edit: Lol, this post fits in well with Dr. Paine's.

Edited January 19, 2012 by Completely Different

[Kestra15]

Evolution >> Creationism.

[Alpha1]

One piece of evidence that debunks YEC is the fact that all the isotopes with a half-life as long as or longer than plutonium-244 are present, and all those with a half-life shorter than that are absent unless they’re currently being produced in nature. If the earth is believed to be around 10,000 years old, you can extend the table to include nuclides with a half-life of 1000 years or more. It is virtually impossible for this to be a chance arrangement unless someone believes in a deceitful god.

 

 

More evidence:

 

Human Chromosome 2

 

 

 

Fossil Record

 

 

Endogenous Retroviruses

 

 

Nested hierarchy

 

 

Pangaea

 

 

Gotta say that while I think evolution is a bit of a given I'm afraid I just can't accept abiogenesis as it currently stands. It's mathematically practicaly impossible.

 

 

That’s why the statistics game doesn’t work.

 

Also, incidently, homochirality is a major problem with it in my opinion. Synthetic production of ammino acids, without a chiral catalyst, produce a roughly 50/50 mix of 'handedness'... yet in nature we only see left handed ammino acids. No theories as to why this might be have been able to be tested to any depth.

 

http://www.sciencedaily.com/releases/2011/...10119100204.htm

 

Here’s one hypothesis for the chirality problem:

 

“A wider range of asteroids were capable of creating the kind of amino acids used by life on Earth, according to new NASA research.”

 

“In the new research, the team reports finding excess left-handed isovaline (L-isovaline) in a much wider variety of carbon-rich meteorites. "This tells us our initial discovery wasn't a fluke; that there really was something going on in the asteroids where these meteorites came from that favors the creation of left-handed amino acids," says Dr. Daniel Glavin of NASA Goddard. Glavin is lead author of a paper about this research published online in Meteoritics and Planetary Science January 17.

 

"This research builds on over a decade of work on excesses of left-handed isovaline in carbon-rich meteorites," said Dr. Jason Dworkin of NASA Goddard, a co-author on the paper.”

 

[TikindiDragon]

A) I understand that abiogenesis is far more complicated than the picture on the left hand side. You, of all people, should know I'm not an idiot and do put a fair amount of research into my opinions.

Saying "It may have come from outer space" doesn't actualy answer the question. It just pushes it back further. Saying the left-handed bias came from meteorites doesn't even begin to explain how the left-handed bias occured on meteorites in the first place. Same problem, just in a different location.

 

Incidently I can't help but wonder about how chromasomes developed into having different numbers of pairs in them. This may seem rather silly... but geneticaly choromasome pairs of different length can produce offspring, but those are almost invariably infertile. Like Mules. Horses and Donkeys have different jnumbers of chromasomes. They can interbreed, but in 99.99% of cases the resulting offspring is infertile. And all recorded fertile offspring have been female which, when bred back to horses, only pass the horse DNA on.

[Kai]

You're right about pushing it even back further - at some point in the past, it must have happened. The only question is how. Same with homochirality.

 

Anyway, why is it mathematically impossible? Inevitably all these arguments end up making assumptions about what is the simplest possible form of life.

 

[TikindiDragon]

You're right about pushing it even back further - at some point in the past, it must have happened. The only question is how. Same with homochirality.

Now, see, that argument has precisely the same amount of proof for it as creationism. We're here, so it *must* have happened. Sorry, don't accept "we're here" as any kind of proof for anything.