(Insert controversial and attention grabbing title concerning evolution, creationism and god here)

Having spent considerable time reading several of the threads in this forum from start to finish, and several more part of the way through, I have found - albeit not to my surprise - that a great many people differ quite radically from me where it comes to evolution.

Knowing this is not enough for me. I want to know how other people differ from me not only in their view of evolution, but in their understanding of what it entails. I could of course create a spreadsheet of everything anyone has said about it, and find some arbitrary scale for my perception of their acceptance of it as a concept before trying to work out the overall pattern but that would be time consuming and quite creepy, really, so I thought it would be easier to tell you - as briefly and as specifically as I can - and then ask the key questions that I have concerning your beliefs...



My understanding of evolution boils down to three central concepts (please note, I have only recently tried stating my understanding of evolution briefly, and so earlier versions of this in other posts do differ slightly):

1) Organisms have variable traits

2) At least some of the variation in trait is heritable (passed from one generation to the next)

3) Not all organisms reproduce as much as one another.

The three of these, together, indicate to me that the frequencies of different variations of a trait will not be uniform across generations, which I take to be evolution. For evolution to continue indefinitely, a fourth point is required:

4) new heritable variations are generated over time

Which is effectively saying that I think mutation happens. Because I believe that evolution by natural selection is a major force in, well, nature, I also include two more

5) A level of variation in reproductive output between individuals is as a result of selective pressures imposed upon individuals

6) Variation between individuals leads (in at least some cases) to differences in susceptibility to selective pressures.

So, basically, an animal that dies prematurely for any reason - or is in any other way reproductively hindered - will reproduce less than an animal whose life continues uninterrupted, and some animals are better at avoiding death (by predation, disease, starvation etc) - for whatever reason - and aspects of this are heritable.

And finally, for divergence of populations (I have stated elsewhere why the concept of species - and thus the concept of speciation - is flawed, and would rather not go into it here. I will if forced, though), a seventh point:

7) variations may not affect reproductive output in the same way across a selective gradient

Which basically means that the "fittest" organism in a population will not stay the same if you move the population to a different environment. (e.g. a bird that is white would be very well camouflaged on snow, but very easy for predators - and prey - to spot in a forest or on a grassland).


My Questions

a) Do you believe that evolution occurs? (Please don't say something like "micro-evolution, not macro" because then I will have to explain why the concept of a species is flawed, thus making the concept of speciation flawed, thus meaning that the division between micro and macro evolution has no basis in biology)

b) If no, which of the above numbered points - please be specific - do you disagree with, and why?

c) Do you (regardless of your stance on evolution) feel that the above points do not accurately portray the concept of evolution, and if so, which ones do you disagree with, and why?




Thank you for your time and attention,

TheWill

PS - I recognise that this is based on the same premise as Romantic_Rebel's What are your views on Evolution, but as my interest is more in the specifics, I felt the need to start a new thread.

PPS - please note, everyone, that this is not about Darwin, or Hovind, or what anyone else has said concerning any specific evolutionary hypothesis. This is about what I think, what You think, and where we differ. So please answer as such.

PPPS - as much as it is not my intent to belittle other people's beliefs, I am naturally argumentative. I will try to suppress this, but views that differ radically from mine are likely to attract my particular attention. If your post does attract my particular attention, please note that it is not my intention to offend.

Great post S+F, I too want to know why people find it so hard to believe that over time organisms change. It seems the most logical.

A)My views are YES EVOLUTION, in fact we still are evolving (micro) which will lead to a much larger change later down the line (Macro). How can one conceive otherwise. If your religious why can you accept god can change things.

B) N/A

C) Number 5 is worded kinda funny in my opinion. Another thing is adding : the mutation rate per trait per organism varies based on complexity of the trait and its expression.

reply to post by TheWill


Havent really discussed my views on evolution here...I mean, we share something like 99.99% of the same DNA as a chimpanzee, but we also share more than 90% of our DNA with a field mouse....I feel there is a much more metaphysic aspect to our being the top of the tier on planet earth...I mean, generation after generation will change in slight ways but nothing noticable to those living...

I'll just leave this Russian Experiment right here...

The domesticated silver fox (marketed as the Siberian fox) is a domesticated form of the silver morph of the red fox. As a result of selective breeding, the new foxes not only have become tamer, but more dog-like as well. The result of nearly 60 years of experiments in the Soviet Union and Russia, the breeding project was set up in the 1950s by the Soviet scientist Dmitri Belyaev.

Forty genes were found to differ between the domesticated and non-domesticated farm-raised foxes, although about 2,700 genes differed between the wild foxes and either set of farm-raised foxes.

It only took 60 years to create what is virtually an entirely new breed from a wild animal...It exhibits behaviors entirely distinct from its feral cousins.

So clearly there is something to the accepted theory of evolution. But there has to be an unexplained aspect of this when it comes to human beings, I guess that's all I'm trying to say

reply to post by TheWill


A) Why yes, I believe evolution occurs
B) N/A
C) I would have provided some citations to back up your claims. I can dig some up if you want, because I'm sure they're going to be asked for.

Otherwise, damn good job.

Also, I like the metatitle, especially when I'm one of those that comes up with some controversial and attention grabbing titles.

What can I say? I'm a showman.

reply to post by HollowJacket


Ah, numbers. I like numbers.

The similarity between human and chimp DNA is actually 96%, this includes a difference in chromosome pair count, which is accounted for by human chromosome 2, a fusion of two other great ape chromosomes.

I'll let Ken Miller explain more on that.



There really isn't anything special about us genetically or biologically. We're simply...more intelligent.

Apologies for combining replies - I'm trying not to falsely inflate my own thread.

reply to post by Xiamara


Level five is worded funny - I struggled a bit trying to put that one in a way that showed that it incorporated only the first three concepts without referring to specifics. Obviously it got away from me a bit...

The rate of mutation being affected by complexity of a trait (oh how I love epistasis...) is very much a valid point. I would love to say that I thought of including it and didn't, but if I had thought of it, I wouldn't have included it in the starter for the thread because it is more about our current understanding of how inheritance and mutation work than about the basic underlying theory of evolution, and I was excluding other aspects of mechanism to keep the starting post as simple as possible.

reply to post by HollowJacket


Having read several of Belyaev's papers quite recently for my course, I have to say that as interesting as his silver fox study was, I'm not entirely sure how it goes against current evolutionary thought - the changes in behaviour were what was specifically selected for, if I recall correctly. The changes in appearance and reproductive cycle are more interesting genetically, because it begs the question as to whether the loci selected for in behaviour have been closely associated with loci involved in piebaldism, interruption of normal ovulation etc for a long period of evolutionary history (as they appear in a wide range of domesticated animals), especially as Belyaev was careful to avoid inbreeding.


reply to post by madnessinmysoul


I am hoping that this thread will be a "this is what I think, what do you think?" thread, but if you could point me in the direction of a couple of good papers that would provide ammunition if (when?) people start to turn it in to a "what you think is valueless, this is what you should think" thread, I would be grateful. It doesn't take long to walk to the library and go through the archives for any of the more classic studies, but I am always grateful for time saved.

I really like to know why you think speceation is flawed ? Maybe with an example ?

1, 2 & 3 Yes. Comment for 2 = Some ?

4,6,& 7 Yes

5

5) A level of the variation in reproductive outputs between individuals is a result of selective pressures imposed upon these creatures

Yes. Humans have , by pressure created selected trades to become better developed. But...

You should know that evolution does not have anything to do with selection or the fittest actually.
Although, evolution does happen because of. Selective is a big no no because it suggests there has been a plan.
There isn't a plan. It just is things change and those that survive the changes because of any biological advantage gets a better shot at passing its genes along.

reply to post by TheWill


Ahh that makes sense, I wasn't sure on your science backgrounds extent. I just love genetics, its my favorite part of science other than organic chemistry. There is a lot of new information to evolution that should be added in my opinion since I find creations die hards tend to neglect or ignore the new scientific data.

reply to post by Sinter Klaas

I really like to know why you think speceation is flawed ? Maybe with an example ?

This is my own personal reasoning, which I should have made clear in the OP, I suppose - Linnaeas came up with the concept of the species in his Systemae Naturae (I think that's what it was called), and while being creationist does not discredit him (and nor does describing amphibians and reptiles as loathsome creatures and stating - falsely - that the creator had seen fit not to make many of them. Everyone's entitled to their opinion, I just don't see the grounds for calling amphibians or reptiles loathsome), it did, at the time, involve considering each species to be variation not from an ancestral theme which had since diverged, but corruptions upon a "perfect" individual of that species.

This in itself does not make the concept of a species invalid, and nor does large the number of contrasting definitions of what a species actually is, in biology (From a life-history perspective, my favourite definition of the biological species is Meyr's, which defines a species as one or more populations of an organims reproductively isolated from related populations with which they would otherwise be interbreeding)

My problem with the concept of a species is that there can be no absolute point at speciation "happens", dividing two subspecies into species: the members of the genus Canis, for example, can interbreed freely, and are only reproductively isolated where they inhabit sufficiently different ecosystems that a hybrid cannot survive (and breed) in either. Equus (ferus) caballus and Equus (asinus) africanus can famously produce a single generation of hybrid that itself seems sterile, although I have heard (from a former biology teacher, so not a hugely reputable source because I also had a biology teacher that insisted that the earth was 6000 years old) that a reproductively capable mule can occasionally arise. Then of course there is that famous example of a ring species, in which a population spreads out and, once the two sub-populations leading the spread meet on the other side of the barrier that the populations are spreading around, sufficient mutations have accumulated to prevent interbreeding of individuals from the different populations - the famous example (invalid, I gather, but used here to illustrate a hypothetical situation) being the Larus gulls in the Arctic circle - two "species" which do not interbreed are found in the UK, but follow either species' interbreeding populations and subspecies around the Arctic circle and eventually you reach the other - under Meyr's concept, they would only speciate when one of the links in the chain of interbreeding populations goes extinct, and yet in the UK, the two populations are sufficiently distinct, genetically, to be incompatible.

Does that make any sense? Basically it's a personal campaign against the word, which was why I used the word "divergence" instead (because speciation is a word for an unspecified level of population divergence).

1, 2 & 3 Yes. Comment for 2 = Some ?

Some because not all variation has a genetic basis - for example, people do have a tendency to put on weight at different rates, but a certain amount in the variation of body weight will also come down to environmental factors - starving people, regardless of their genetics, tend to be lighter than people with unlimited food. Phenotypic versus genotypic variation, and a general avoidance of making absolute comments.

5) A level of the variation in reproductive outputs between individuals is a result of selective pressures imposed upon these creatures

Yes. Humans have , by pressure created selected trades to become better developed. But...

You should know that evolution does not have anything to do with selection or the fittest actually.
Although, evolution does happen because of. Selective is a big no no because it suggests there has been a plan.
There isn't a plan. It just is things change and those that survive the changes because of any biological advantage gets a better shot at passing its genes along.

When I first read this, I thought I was being unfairly accused of applying teleology. Then I reread what I'd written, and saw why you would interpret it that way - I do know that variation doesn't arise because of selective pressure (i.e. evolution is blind), I was trying to say that the variation in how much an animal reproduces is affected by selective pressures. (Reproductive output varies at least in part because some of them are better at coping with the demands of the environment).

reply to post by TheWill


Check your messages, I've sent a little bit of stuff over there.

Also, I forgot to recommend something else, but I'll just say it for you.

This is a thread about the biological theory of evolution which explains biodiversity and nothing else.

Why did I say this?

Well, you'll get questions about the origin of life, the universe, and everything else if you don't.

One thing I would add is the theory of evolution starts with the premise; Living organisms were born suddenly out of non-living matter. Now I know you didn't state this in your op, but I think it's an important detail.

reply to post by addygrace


We still are individually made up of non living matter. Humans consist of :
1. Oxygen (65%)
2. Carbon (18%)
3. Hydrogen (10%)
4. Nitrogen (3%)
5. Calcium (1.5%)
6. Phosphorus (1.0%)
7. Potassium (0.35%)
8. Sulfur (0.25%)
9. Sodium (0.15%)
10. Magnesium (0.05%)
11. Copper, Zinc, Selenium, Molybdenum, Fluorine, Chlorine, Iodine, Manganese, Cobalt, Iron (0.70%)
12. Lithium, Strontium, Aluminum, Silicon, Lead, Vanadium, Arsenic, Bromine (trace amounts)

reply to post by Xiamara


That's pretty neat, but that doesn't begin to quantify how it's possible to turn non-living matter into life. This is one of the main problems I have with evolution theory. If they could somehow recreate this in a very strict test, It may validate the theory a little bit.

reply to post by addygrace


You might as well ask well do we get all the elements on earth? Its jut not logical. You need building blocks that develop and the right conditions. Why does suddenly having something magically become a complex multi-cellular organism make anymore sense?

reply to post by Xiamara


It's funny that you mention magic. This is usually used when we can't understand something.
Here is a good example of this by Leslie Orgel

"The self-organization of the reductive citric acid cycle without the help of 'informational' catalysts would be a near miracle...It is hard to see how any..[of the potentially self-replicating] polymers that have been described up to now...could have accumulated on the early earth...[It is] to appeal to magic."

reply to post by addygrace


No I don't understand creationism I understand evolution I'll believe in creationism when a drop dead gorgeous man appears because a creator created him there. Until that time I will enjoy living in the world of science and fact.

reply to post by Xiamara


So you understand how abiogenesis occurs? It would be great if you could explain that one, because we're all waiting to hear that.

Originally posted by addygrace
reply to post by Xiamara

 

So you understand how abiogenesis occurs? It would be great if you could explain that one, because we're all waiting to hear that.

Abiogenesis has nothing to do with evolution

reply to post by addygrace

No need to keep squabbling about this. Evolution is a theory explaining the origin (meaning: the cause) of variation, not the origin of life. It is entirely compatible with the idea that a divine creator formed the first living things out of inanimate matter.

The OP has very carefully declared the terms of the discussion. Surely the question of whether the theory of evolution must include a theory of abiogenesis is one for a different thread. If you want, I'll start it for you. It may do well; the assertion seems to be a popular one among creationists.

The distinction between living and nonliving matter is that the former is, for a time, able to resist entropy, maintaining its integrity and organization against it. It is, I agree, a very big difference for the matter involved; awesomely, almost mystically big. But in another way, it is trivial: life is just a temporary arrangement of nonliving matter. The potential to be living exists in all matter. Shall we return to the main discussion, which was so much more interesting?

Thanks to those who have already explained this, and:

reply to post by addygrace


Thank you for posting your thoughts, but I did have a fairly major reason for not including that point - my intention was to separate evolution from other - albeit related - scientific theories. Evolution does not make any assumptions as to how life started, it is more a comment on how it changes and diversifies. An understanding of evolution, then, can be based on life created on purpose or life created by happy chance.

With this understood, or if not assuming for my convenience that the origin of life is not an aspect of evolution, I would be interested to know what else you would you say to a), b) and c)?