pseudobug

Hello unworthyone and welcome!

First, I wanted to provide you with a "layperson's" explanation of natural selection. It is short, easy to read and communicates the basics of natural selction with some oversimplifications. However, it is a good starting point for the general conscepts w/o becoming overwhelmed by the terminology. The link is:<a href="http://www.bitesizebooks.co.uk/evolution_by_natural_selection_i.htm" target="_blank">Evolution by Natural Selection</a>. Reading just chapter 1 will give you a general idea of the concept of natural selection and will be a good starting point for the slightly more technical material in the TalkOrigins links provided by Rufus Atticus.

Two things to keep in mind with your initial reading. First, natural selection is the mechanism by which evolution occurs. Second, random mutation is the "raw material" which allows natural selection to work.

As to your question regarding evolution being "true"; it is within the context of a scientific theory and the "facts" or data supporting it--whether those facts are from inferences drawn from historical observation or those drawn from laboratory experimentation. If you are somewhat confused about what the differences are in a scientific theroy and that of "normal" usage, the first link Rufus Atticus provided does a good job of clearing that up.

There certainly are, as you intimate, extrapolations made from historical observations which cannot be reeplicated. However, we do know, and have observed, falsified and repeated the genetic mechanisms responsible for both random mutation and natural selection in the laboratory. Additionally, speciation has been observed in the lab and practiced by man via selective breeding--particularly in horticulture--for many hundreds of years. Moreover, evidence from comparative molecular genetics between both living and extinct species provide support for the descent different species from a common ancestor.

I'll cut out for now and watch. There are many other people in this forum more adept than I at answering your questions. Don't, however, be afraid to ask. Remember, the only dumb question is the one that is not asked.

Have fun and enjoy your visit!

Automaton

You obviously don't know very much about the topic you're dealing with. But I'll give you a famous specific example that appears to be what you want:

In 1860, the American species of cordgrass (Spartina alternifloria) was introduced into Europe, which grew alongside the European variety (Spartina maritima). Ten years later, a hybrid (x townsendii) was discovered. A mutation allowed polyploidy, thus the hybrid had 122 chromosomes starting from alternifloria's 62 and maritima's 60. This hybrid was sterile and could produce no seeds, and spread very slowly via vegetative propagation. Then, in 1890's it speciated yet again to a fertile variety (anglica) with 124 chromosomes. It was more vigorous than the original two and spread much quickly. This change has also been confirmed experimentally.

Automaton

You're right, but not in the way you think. Random mutation is what creates new characteristics. Natural selection is a logically necessary situation once you have biological variation in any environment - the traits that mean better survival/reproduction capabilities will mean the organism will indeed survive and/or reproduce better.

unworthyone

Thats why I'm here. But thanks for your re-affirmation.

How do you know the different species weren't always there or better yet created by someone like they did in the experiment?

[ April 05, 2002: Message edited by: unworthyone ]</p>

Valentine Pontifex

As has been already been pointed out, mutation is also involved.

Mutation can indeed produce new genes. And it is something that has been observed many, many times. The most common way is for a type of mutation that duplicates a section of DNA. The moment this happens a new gene has been created: where once was n genes there are 2n genes. Repeat, this is commonly observed.

Once this happens, further mutations can result in the new genes having an altered function. There are numerous families of genes that look EXACTLY like this how they formed. There are a number of hypothesises that can be formed from this observation. We can go over some of them if you like.

Full genes are not the only thing that can be duplicated. Sometimes segments of genes can be duplicated and aranged by mutation. For example <a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=985999 1&dopt=Abstract" target="_blank">this paper</a>. Others can be provided as well.

You quote:
Have you actually read this news item? If you have not, you need to give the actual source that you copied the quote from. It seems that most creationists debating on this and other boards are unaware that failure indicate that the quote was not obtained in the original is a form of plagiarism. It is also a big source of inaccuracy in the quotes and loss of context. What often happens is that person A quotes the article from the original. Then person B quotes that quote and its citation without giving credit to A. Then person C takes the quote from B, and so on. A game of telephone is formed. Eventually typos accumulate and context is warped.
(And this is assuming that A did not quote out-of-context to begin with as is such a big problem with creationist quote miners.) Also bear in mind that if you give a citation with no indication that the quote came from a secondary source, you have assumed moral responsiblity for its accuracy and have exposed yourself to charges of deception.

Automaton

On the former; you'll notice that I said the fertile species (anglica) could spread much more rapidly than the others, outcompeting them. If it was already present in the population from the beginning, that means long ago it would have already outcompeted the others and be strikingly present. How likely is it that, by chance, a new species with both the original chromosomes of the standard variety and the imported variety, just happened to only be discovered ten years after the imported variety arrived? Extremely slim.
On the latter; the equipment and means to do the experiment were certainly not around in the 19th century! It was only much later that the reported speciation incidents were reproduced in the laboratory.

unworthyone

Awesome well that means that any form of evolutionary evidence you find could not be deemed yours because you did not collect the physical evidences yourself and have exposed yourself to charges of deception.

unworthyone

Who says they always did rapidly reproduce. They may have very well been much slower at one time? Is that what qualifies a new species? The capability to reproduce quicker? Because if it is then I must be a species like no other.

Lizard

quote:
As for your question of observations of speciation, there are a few, but not many. Almost by definition, evolution is a slow process, and not likely to be directly observed during a human lifetime. For the most part, evolution is indirectly observed, so every species that exists (or ever existed) would be considered an example. There are some directly observed examples with species that reproduce quickly, however, and I hope someone here can provide a detailed reference.

Me:
"Ring species" are an example of macroevolution which is observed within human lifetimes. Look it up on Google.

unworthyone

Okay ring species sound cool. (ie the american herring gull) But how is this "macro"?
Changing a few colors and getting smaller offspring are typical things that happens in humans too. But that doesn't mean it was macro-evolution does it?

I mean some people are dark some are white, some are shorter and some are taller. This is genetic. How are these birds qualified as different species then the Alaskan or Siberian gulls?