Evolution: plausible or proven? What causes the genetic variation?
#1
Posted 2009-January-28, 18:07
I am consistenly awestruck when I find out the multitude of ingenious ways in which organisms make the most complicated of problems at a cellular level seem trivial. With none is this more the case than the wonderful notion of "evolution", which not only is extremely elegant in its own design but allows everything to fall into place.
As a result I can get agitated quite easily when people dismiss the notion of natural selection and evolution without even considering it and admiring the extent to which is allows us to make some sense of a microscopic world of which we, in the end know relatively little about. However, it is also my opinion that the scientific community is very much lopsided in its opinion regarding a hypothesis that has not been proven as a fact at a fundamental level (to my knowledge anyway). And as much I endorse the ideas behind evolution, I can get easily irritated when people simply look down on others when they do not believe in evolution (Yes, I know I am a difficult person ).
As I understand it, evolution has been "proven" as a fact regarding genetic change in organisms through generation, but it has NOT been "proven" with respect to the reasons as to why genetic change arises. I'll try and convey my thoughts on this and why I myself can't accept it as "fact".
The general reasons as to why variation arises seem to be the following:
- Combination of parental genomes
- Recombination
- Random mutation in germ line cells
Combination of parental genomes: This is not as much as a source of genetic variation as it is a way to randomly distribute the existing gene pool. I believe it can most certainly act as a means to propagate the "natural selection" of favourable traits, but I think that is a far cry from generating an eye from one generation to the next. And no, it does not make sense to start with part of an eye and then gain more and more bits of it through subsequent generation because accumulating "partial eyes" would challenge the very theory of natural selection that supposedly drives it.
Recombination: Shuffling DNA sequences may result in wonderful new DNA sequences, identical ones, different ones with same function or damaging ones. However, the truth remains that the chances of favourable change are extremely remote and the chances of damaging ones are orders of magnitude higher.
Perhaps a more intruiging point is that even though most organisms reproduce sexually and employ the above mechanisms, it seems to be an inferior form of reproduction when compared to parthenogenesis. Perhaps these processes do not have the exact functions that we thought them to possess. Recombination for instance has been considered a way for sexual organisms to bypass problems associated with Muller's ratchet. Parental recombination clearly functions much better to transfer naturally selectable traits than to actually form them.
Random mutations in germ cell lines: Notwithstanding the exhilarating notion of standing and admiring everything around me and being able to attribute it to randomness, it seems a little farfetched. It basically boils down to getting randomly mutated DNA becoming so incredibly beneficial that it will get selected over other mutations. Realistically I don't think this is very likely. Firstly the mutations in coding DNA are so rare and secondly, for every beneficial mutation, dozens of harmful ones will occur. The gene pool would be cluttered with damaging mutations and could not be selected against because then they would be selecting against the beneficial mutations too.
The biochemical world is full of anomalies that random mutation can not account for: gastrulation, endosymbiotic theory or even flagella suddenly appearing on bacteria at some point in history can not be explained by a couple of "lucky mutations". It seems to me, that the scientific community is overzealous to embrace an idea because it explains so much of what we see, feel, touch, hear and smell around us.
You might be thinking that I am just somebody who likes to criticise others without giving any alternatives myself. Well, I do have one, I think that genetic variation arises through regulated mutation, something along the lines of intragenerational selective gametogenesis. Anyway, I'm curious to hear what you think about this.
#2
Posted 2009-January-28, 18:15
#3
Posted 2009-January-28, 18:17
EDIT: I got link to the other thread O.o
#4
Posted 2009-January-28, 18:19
Little Kid, on Jan 29 2009, 03:07 AM, said:
I think that it would have been a much better use of your time googling the words
bacteria
flagellum
evolution
and reading the litany of materials on these topics rather than generating a long ignorant post...
#5
Posted 2009-January-28, 18:35
Little Kid, on Jan 28 2009, 07:07 PM, said:
It seems to me, that the scientific community is overzealous to embrace an idea because it explains so much of what we see, feel, touch, hear and smell around us.
<snip>
Isn't that the entire basis of religion and creationism? IMO religion was created to explain the things we saw or didn't understand. (See mikeh's and jdonn's posts in the other thread which btw are exactly my opinion also...). Googling this might also help, although there are some heavily biased blogs/webpages to stear clear of...
#6
Posted 2009-January-28, 18:53
Read The Blind Watchmaker, or Climbing Mount Improbable. Even if you are a bigot who discounts the opinions of a scientist because the scientist is also an atheist, as is Dawkins, I would hope that you would recognize that his evolutionary views are not unique to him, but are built upon and respected/accepted by a myriad of workers in the field
#7
Posted 2009-January-28, 18:54
jdonn, on Jan 29 2009, 12:15 AM, said:
That's exactly what I though as well
#8
Posted 2009-January-28, 18:56
mikeh, on Jan 29 2009, 12:53 AM, said:
Yeah don't read Dawkins, he is the atheists prophet lol.
#9
Posted 2009-January-28, 19:01
Fluffy, on Jan 28 2009, 07:56 PM, said:
mikeh, on Jan 29 2009, 12:53 AM, said:
Yeah don't read Dawkins, he is the atheists prophet lol.
Dawkins is excellent, I have read a few of his books... They are certainly recommeneded for anyone who hasn't read them .
#10
Posted 2009-January-28, 19:34
#11
Posted 2009-January-28, 19:44
Fluffy, on Jan 28 2009, 08:34 PM, said:
I wouldn't call myself a fanatic, but I'm an athiest in case you couldn't tell...
#12
Posted 2009-January-28, 23:58
Quote
Natural selection means that the process occurs wthout need for choice - it is a natural occurence.
#13
Posted 2009-January-29, 00:20
Let's assume that we can't travel back in time, and suppose that we can't assume some sort of divine intervention. Is there any sort of scientific evidence that will convince these folks that the biblical story of genesis is not true and that evolution is?
I suspect that there is no such possibility of evidence, and would say that this is what separates science from religion. It's also worth noting that the scientific case for evolution is now extremely solid (having been helped a lot by our greatly improving understanding of genetics).
a.k.a. Appeal Without Merit
#14
Posted 2009-January-29, 00:38
awm, on Jan 29 2009, 01:20 AM, said:
The argument against evolution is this:
1. My religion is incompatible with evolution.
2. My religion is correct.
3. Therefore, evolution is false.
All of the sophistry used against evolution aims to obscure the real argument. For those firmly dependent on such religious beliefs, no amount of evidence for evolution will suffice. Otherwise the existence of ring species would prove very convincing, to say nothing of all the other mountains of evidence for evolution.
If anti-evolutionists had the courage of their convictions, they would state their real argument up front and save everyone else a lot of trouble. They would also preserve some self-respect.
The infliction of cruelty with a good conscience is a delight to moralists — that is why they invented hell. — Bertrand Russell
#15
Posted 2009-January-29, 01:54
PassedOut, on Jan 29 2009, 01:38 AM, said:
1. My religion is incompatible with evolution.
2. My religion is correct.
3. Therefore, evolution is false.
All of the sophistry used against evolution aims to obscure the real argument. For those firmly dependent on such religious beliefs, no amount of evidence for evolution will suffice. Otherwise the existence of ring species would prove very convincing, to say nothing of all the other mountains of evidence for evolution.
If anti-evolutionists had the courage of their convictions, they would state their real argument up front and save everyone else a lot of trouble. They would also preserve some self-respect.
Well put.
#16
Posted 2009-January-29, 03:15
I ask this out of genuine curiosity to those who are knowledgable, what are the legitimate holes in the theory of evolution? What needs to be proven in order for it to evolve from just being a theory?
#17
Posted 2009-January-29, 04:52
http://www.ncbi.nlm.nih.gov/pubmed/1908172...Pubmed_RVDocSum
http://www.ncbi.nlm.nih.gov/pubmed/1908104...Pubmed_RVDocSum
#18
Posted 2009-January-29, 04:55
JLOL, on Jan 29 2009, 04:15 AM, said:
I ask this out of genuine curiosity to those who are knowledgable, what are the legitimate holes in the theory of evolution? What needs to be proven in order for it to evolve from just being a theory?
Hi,
I would not call it a hole, but scientific methods get adjusted over
time, because by using the method one learns to know the limitations
of a given method, an example follows below (1).
Another thing is, that there are still missing links, and the gap is
quite often bid with egards to the time, a gap of 1 mio years would
not be unheard of, an example followes (2).
I hope you got the idea: If you are looking for holes, you will find some,
and basically you have to decide for your own, if those holes are relevant
or not.
Basically you will never be able to prove a theory like evolution, but actually
this does not matter, as long as a theory gives useful answers for our /
your current life, it makes sense to assume that the theory is true (3).
With kind regards
Marlowe
(1) There is a lot of controversy around the topic, how to determine
the age of a given object.
A very popular method is the so called C14 method, which measure
the amount of C14 isotops.
The method assume, that a living being has a certain concentration
of C14 isotops, and the concentration goes down at the moment the
living dies.
The assumption was, that the concentration of the C14 isotops is
constant, it groven, that this assumption proven wrong.
(2) It is assumed that all living humans share one ancestor species, but
there is also a strong evidence, that several starting species did exists,
and it is unclear, what happend to the other species, when did they die
out, see for example the "hoppits" from the isaland flores (indonesia),
there is an discussion, if this is a different branch of the human species
or not..
(3) For a time, the Catholic church did not like the copernican world view,
which said, that the sun is in the centre (which is wrong, although only slightly),
but the catholic ship captains used the maps and methods based on the
despised theory anyway, because they came home faster and securer, and
the catholic church did approve the usage.
Uwe Gebhardt (P_Marlowe)
#19
Posted 2009-January-29, 04:57
#20
Posted 2009-January-29, 05:18
Little Kid, on Jan 29 2009, 01:57 PM, said:
The easiest way to show how random chance can lead to complexity is to look at the application of genetic algorithms for product design.
The following is a classic reference on the topic.
http://faculty.washington.edu/sundar/PAPER...uctDesignMS.pdf