Discussion of everything related to the Theory of Evolution.
I used to breed and study some egg-laying fish, and some live-bearing fish.
I have listened to a variety of speakers dealing the topic of evolution and creation. However, I have found too much of it(on both sides) to be rooted in various methods of fallacious ratiocination, presumptions, invalid inference, a misunderstanding of each side; and a desire to prove that the other side is incorrect, rather than discovering the truth of the matter.
For the moment, I have only two questions:
1: What amount of evolution has not been observed?
2: What amount of evolution has been observed?]
Circumstances permitting, I hope to return soon.
1. not observed - nearly 100%
2. observed - next to nothing
Last edited by JackBean on Thu Oct 20, 2011 6:31 am, edited 1 time in total.
Reason: quotes fixed
Cat's response lacks scientific evidence.
1. Many experiments have been conducted that support that organisms, over several generations, are able to evolve in order to increase their fitness. Specific examples include the experiments conducted by the Grants at Princeton University on finches over a period of 30 years, experiments conducted on fruit flies by Diane Dodd at Yale University, and experiments by Cooper and Lentski on E. Coli at Michigan State University. Evidence supporting that evolution has occurred in the past exists extensively in the fossil record, and studies using artificial selection have shown an increase in fitness over several generations. Also, this page (http://www.gate.net/~rwms/EvoMutations.html) shows some interesting experiments that have been conducted. In addition, using data from experiments on abiogenesis, such as Urey-Miller, Fox, and Wachtershauser, several hypotheses have been proposed for the origin of life, with strong scientific evidence backing.
2. The reason why some are still arguing against evolution is because they haven't seen it occur with their own eyes. Obviously direct observation is not possible, as evolution occurs over a period of tens of thousands of years in nature to produce a significant degree of macroevolution. However, most of the evidence for past evolutionary change can be found in the fossil record. Also, the currently accepted phylogenetic tree of life is far from complete. There is much more evidence left to be discovered in order to correctly identify the evolutionary relationships between organisms.
Yes, Aptitude. Well said. But saying it differently does not change the facts...
1. "not observed - nearly 100%" = millions of years NOT observed (as evidence CAN be misinterpreted and wrong conclusions can be drawn even from the observed events)
2. "observed - next to nothing" - minute fraction compared to overall picture...
Lastly, I don't disagree with fact of evolution when it's defined as "change over time". But I disagree strongly with the underlying preconception that evolution is process of change toward something BETTER or more ADVANCED. As far as I know, there is no evidence of that at all...
but the evolution is not prograssing towards better or advanced. At least not on purpose. It's rather blind worker, who's trying to fix previous bugs. But since the more adapted survive, we say they evolve into higher level. But that doesn't mean that bacteria are less evolved. They were evolving for billions of years just as we did.
Cis or trans? That's what matters.
I agree with most of that assessment. However, there is a penchant to disregard the deterioration of the genome over time or to view it as something positive. As you do in a single sentence: “It's rather blind worker, who's trying to fix previous bugs”. It is blind process, but it’s NOT trying to fix anything. I will try to explain…
The way I see it:
1. Start with an organism at some point in time that is perfectly suited for the environment.
2. If environmental conditions remain fairly static there is no selective pressure.
3. Over time, organism accumulates errors, mutation, in its genome. This leads to diversity.
4. Natural selection takes care of the disastrous traits.
5. At some point, the amount of erroneous information made brings the organisms (variants of the original) to the edge of the extinction.
*That is the point at which the new is actually WORSE off than the original.
6. Now something happens to some of these organisms that create a new subset of “new originals” that cannot be called progeny of the old (something like genome duplication). And the process starts all over…
* At this point you cannot really compare the “new original” to the “old original”. It might be better or worse off…
I know that environment did not remain static, so that is unknown factor. I am just trying to explain my reasoning. Considering that we, humans, are have not been under natural for quite some time I think we might be heading toward the extinction…
Cat, I think only persons who are not familiar with evolution say that evolution drives organisms towards something "better". I think what can be said is that organisms tend to evolve towards direction that suits their current environment optimally. And since environments can change quickly, this may lead to a poor outcome in the long run.
Evolution and speciation happen because there is always pressure towards some direction: the predator develops sharper teeth to bite through your thick skin. In turn, you can grow a thicker skin - or maybe a lighter one so that you can outrun the predator.
But what I disagree mostly with you is that you say humans are not under natural selection(?, a word seems to be missing from your sentence). We most certainly are! In our current environment things just are quite different from what it is in the nature. The pressure on us is eased on some traditional aspects, that would eliminate animals, such as: bad eyesight, bad back, bad knees, some autoimmune diseases etc etc. - these traits are quickly eliminated from wild animals, but not from the human gene pool. However, the essential question is whether we can create more offspring than there are deaths, and reaching the 7 billion mark right now I can assure you that we do just well - frighteningly well to be honest.
Now, all this, bad eyes and knees and such, can suddenly turn out to be very bad traits if our environment suddenly changes a lot and we end up living like cavemen. However, even then there are people with good eyes and knees who are likely to survive. And if the change in the environment is big enough, any species can go extinct. Think about dinosaurs as a famous example - they dominated the earth for millions of years after all.
Much of the mankind if bound with technology nowadays: bad eyes are fixed with glasses or laser, bad back with a surgeon's knife and diabetes with an insulin pen. We do well as long as we have these tools - just as hermit crabs do well only as long as they have their "technology" with them, the abandoned seashells. But neither of us, humans or hermit crabs, are likely to go extinct just because natural selection is not working. Trust me, it works (:
You cannot have it both ways. We rely on technology to avoid natural selection. In other words, we create artificial environment. If a significant part of our artificial environment was removed, a significant part of world population will die.
Consider several factors:
1. We live in societies that greatly depend on one another. With the exception of a very few people, most of us don’t know how exist without being part of the structure. Individual survival skills are disappearing. How many city dwellers know anything about farming or hunting?
2. Female infertility increases. Male Y chromosome gets shorter.
3. Our reliance on technology increases constantly. It seems that a few hundred years from now people will have no idea what pens and paper are. How many people under 40 know how to use a logarithmic ruler today?
Now, for the sake of the argument, let’s say tomorrow we permanently lose electricity (like in “The Day the Earth Stood Still”). Considering the factors above, could you describe what would happen? How about a few generations from now?
1. The idea of our superiority comes from the fact that our brain is larger than that of our ancestors and, thus, smarter.
2. Larger than normal brains have been linked to autism (http://www.ncbi.nlm.nih.gov/pubmed/16151044).
Considering evidence above, doesn’t that make just as likely that all of us are autistic when compared to our ancestors?
I do not disagree with the points you made. That is why I compared us to hermit crabs: both rely heavily on "technology" and could even go extinct if we would lose the access to it. However, technology (or seashells for the hermit crab) are an integral part of our environment, and our fitness is always compared to our environment - as long as we have the technology available and it eases the evolutionary pressure on us, we do fine.
Infertility increases in both men and women, but still, as long as we can reproduce more than we lose our numbers, we do fine. The very moment we fail to procreate efficiently enough, our numbers start to get lower and either there will be mutations that help to fix the problem or we just perish. Natural selection works for us just as it works for any organism: it gets rid of the genes of the ones that fail to have offspring. That is it.
All the scenarios you list: loss of electricity, no knowledge of farming, reliance on technology, they simply show how well we have evolved to utilize technology. If we lose that suddenly, then millions, if not billions, would die - and that precisely would be a grand demonstration of natural selection in action: technology-dependent organisms would perish, and the ones that have other means to survive would flourish...
I do not quite get this autism example: we quite obviously are not autistic, because we fail to fulfill the very criteria of autism we have determined ourselves (diagnosis of autism requires much more than just big brains).
I'll try to explain:
We define our mental abilities as normal, brilliant, or dull, etc. in comparison to each other. "Normal" is description of mental abilities exhibited by majority of today’s population. Others are comparative.
So, if our ancestors (in majority) were "brilliant" in comparison to our "normal", than, by definition, compared to their "normal", our mental abilities would be underdeveloped.
Who is online
Users browsing this forum: No registered users and 3 guests