Evolution (quick) Masterclass

[ned flandas]

This just came up in a forum, but it seems that many of the Christians on here (me included) do not FULLY understand the basis of Evolution.

I can see how this stresses a lot of people out and many frustrated comments are flying about.

THIS TO ME IS A BLOCKADE TO HAVING ANY DECENT CONVERSATIONS AND JUST LEADS TO ABUSE.

Therefore... Let this thread be an explanation of Evolution where all of us can come and refer when we are about to blurt out some stupidity (which seems to be one of the gifts Christians have )

Is that ok??

 

[ranson]

http://talkorigins.org/

Start there.

 

[Darat]

This just came up in a forum, but it seems that many of the Christians on here (me included) do not FULLY understand the basis of Evolution.

I can see how this stresses a lot of people out and many frustrated comments are flying about.

THIS TO ME IS A BLOCKADE TO HAVING ANY DECENT CONVERSATIONS AND JUST LEADS TO ABUSE.

Therefore... Let this thread be an explanation of Evolution where all of us can come and refer when we are about to blurt out some stupidity (which seems to be one of the gifts Christians have )

Is that ok??

Why not start a thread in the "Science...." section outlining what you think is the theory of evolution and ask people to either correct any mistakes or affirm that you are right?

Personally in a format like the forum I've always found that a good way of learning about something e.g. "OK here's what I think... where am I right and wrong and why?" - go into it with an open mind and you'll find people can be very, very patient and very helpful.

 

[Tricky]

Do you mean biologic evolution, which is the most common usage these days, or evolution of all things, which essentially means "change over time"?

Be aware that biologic evolution does not address the origin of life.

 

[Mephisto]

Will biological anomalies and mutations be considered as well?

 

[c4ts]

The basis of scientific theory could also use coverage...

 

[drkitten]

This thread is a serious attempt at education, Iacchus. Don't ruin this one, too.

Is is possible/permissible for me to formally request that you moderate this thread strongly in an attempt to keep it on-track? I'm perfectly happy to try to have a serious discussion about evolution and a "serious attempt at education" -- but not if I have to dodge The Usual Inane Suspects whom politeness prevents me from naming directly....

 

[Darat]

I've tried to clean the thread up - please keep on the OP topic in future or the natural evolution of the discussion.

Replying to this modbox in thread will be off topic  Posted By: Darat

 

[drkitten]

I've tried to clean the thread up - please keep on the OP topic in future or the natural evolution of the discussion.

Replying to this modbox in thread will be off topic  Posted By: Darat

Thank you, Darat.

As I indicated earlier, Ned, I will be happy to help -- but "evolution" is a very broad topic, and it would probably be helpful if you could "prime the pump" either with an explanation of what you think evolution is, or alternatively what particular questions you have.

 

[Dr Adequate]

This just came up in a forum, but it seems that many of the Christians on here (me included) do not FULLY understand the basis of Evolution.

Hokay. The theory of evolution explains the origin of species "from a few forms or one" (Darwin) as a consequence of natural selection operating on randomly occurring germ-line mutations.

That was it.

However, there is a difference between knowing the theory and understanding it. By analogy, I could tell you Newton's laws of motion and gravity, but it would not be immediately apparent that they must mean that planets orbit in ellipses with the sun at one focus. To prove that takes work, even though it is logically implicit in those laws.

In the same way, you now need to ask: "What are the logical consequences of the laws of genetics and the law of natural selection? What does the theory predict that we should observe?"

This takes rather longer.

 

[ned flandas]

Do you mean biologic evolution, which is the most common usage these days, or evolution of all things, which essentially means "change over time"?

Be aware that biologic evolution does not address the origin of life.

I'm interested to learn more on the evolution of all things.

 

[ned flandas]

Thank you, Darat.

As I indicated earlier, Ned, I will be happy to help -- but "evolution" is a very broad topic, and it would probably be helpful if you could "prime the pump" either with an explanation of what you think evolution is, or alternatively what particular questions you have.

OK, here's what I understand by evolution in a nutshell.

If anything exists now, it means that it works the best in its environment for this moment in time.

Anything that has existed in the past buut does not exist today has failed.

 

[brodski]

I'm interested to learn more on the evolution of all things.

Unfortunately that is probably too vague a subject, and has very little to do with the specific processes, predictions and explanations which are relevant to biological evolution.

that "things change over time" is about the best I think you'll get asking such a wide ranging question.
However if you can give some specific examples of what you are interested in discussing, this thread will probably be more productive.

 

[drkitten]

I'm interested to learn more on the evolution of all things.

This is still a bit broad -- the word "evolution" is often used to describe any sort of change, especially change, over time. For example, people will talk about the "evolution" of the computer from its beginnings as a collection of vacuum tubes, through the era of individual transistors up to the modern ultra large-scale integrated circuits. I could do a similar discussion about the "evolution" of the automobile tyre, and how somewhere in that path it lost its inner tube.

The theory of evolution proper only describes the evolution of biological organisms. At its very basic level, it simply notices that children are not like their parents,.... and that some children appear to be better fit for surviving and reproducing than other children. The children that are better at surviving survive, while those that aren't die. In turn, this means that the inheritable traits that make children better at surviving will be passed down preferentially to future generations, and as such, the "traits" that are common to all organisms of a given type will change very slowly over time.

 

[gnome]

OK, here's what I understand by evolution in a nutshell.

If anything exists now, it means that it works the best in its environment for this moment in time.

Anything that has existed in the past buut does not exist today has failed.

If I am correct in my own understanding, your first statement is untrue, and the second statement is generally true, but not very interesting, unless you have a definition for "failure" that "ceasing to exist" doesn't fall under.

Regaring the first... I believe that what exists now simply has adequate survival and reproductive ability... the "best" tend to populate more successfully, but they are hardly the only ones around.

A proper understanding of evolution would be better geared to the mechanisms of natural selection.

 

[brodski]

OK, here's what I understand by evolution in a nutshell.

If anything exists now, it means that it works the best in its environment for this moment in time.

Anything that has existed in the past buut does not exist today has failed.

presuming that you are talking about life,
I would rephrase that second point as
"If anything exists now, it means that it works in its environment for this moment in time. "
All that means is that those things which are here, are here because their ancestors successfully reproduced, evolution effectivly removes those that are unable to successfully reproduce.
When resources are scarce, those that have a comparative advantage over their competitors are more likely to reproduce (and n greater numbers), and their traits are passed on to their offspring.
evolution does not predict that things will be "the best" just that they are "good enough".

 

[drkitten]

OK, here's what I understand by evolution in a nutshell.

If anything exists now, it means that it works the best in its environment for this moment in time.

Anything that has existed in the past buut does not exist today has failed.

In very broad terms, yes. (Possibly misleadingly broad). A good example of this would be the dodo (technically Raphus cucullatus), which managed to live a long and happy predator-free life on a few islands in the middle of the Indian ocean.

In an environment that didn't include predators, there's not a lot of point in wasting time and energy looking for predators. However, when humans discovered the islands in the 1600s, all of a sudden there were predators -- with the changed environment, the idea of "don't waste time and energy looking for predators" failed, with tragic consequences for the dodo.

However, the process of extinction takes time, so there are things that exist now that are on their way to being driven extinct.... Similarly, there are also traits that don't appear to be either good or bad (for example, blue vs. brown eyes). Similarly, evolution isn't very good at doing global-level optimization, so it may not find "the best" solution to a problem (the blind spot in the human eye being a good example), but it usually finds something that is good enough to let the creatures reproduce.

 

[LordoftheLeftHand]

Let’s start with natural selection:

I’ll give you a personal account of natural selection (although in this case it was not very natural).

When I was in high school biology we each bred our own strain of fruit flies. Before we started we were given a handout detailing the different physical characteristics of fruit flies. We each chose different characteristics we wanted our personal strains to have. I chose wingless and eyeless.

On the first day of the experiment we were each given several random fruit flies. I sorted my flies into these groups:

1 flies with wings and eyes
2 flies with no wings and with eyes
3 flies with wings and no eyes
4 flies with no wings and no eyes (there were 0 flies in this group).

I destroyed all of the flies in group 1. I put the survivors into the same jar so they could reproduce. A few weeks later the next generation was ready.

Again I inventoried my stock. This time I had 4 different types:

1. Lots of flies with wings and eyes
2. Some flies with no wings and with eyes
3. Some flies with wings and no eyes
4. A few flies with no wings and no eyes

Again I destroyed the flies in group 1. I also destroyed several flies in group 2 and group 3. I returned the survivors to the jar and let them breed again. A few weeks later we had a new generation.

This time there was more of group 4. I destroyed every fly not in group 4. We did several generations after this and each time I destroyed every fly not in group 4. Each generation I got less and less of groups 1-3 and more and more of group 4.

In my experiment; having no wings or eyes was a beneficial trait. The flies did not change to meet my demands. My demands eliminated those without beneficial traits.

Organisms do not see an advantage in the environment and evolve to fill it. The environment is more likely to kill organisms that do not have an advantage, leaving the organisms which do have an advantage. Much of my population of flies was decimated by the sudden change in the environment, but eventually the survivors (with the beneficial traits) reproduced and repopulated the environment.

I guess an advantage could be described as any trait that makes a creature more likely to produce offspring (or more likely to produce more offspring).

LLH

 

[jimlintott]

Evolution 101

This site has a very good and easy to understand explanation.

OK, here's what I understand by evolution in a nutshell.

If anything exists now, it means that it works the best in its environment for this moment in time.

Anything that has existed in the past buut does not exist today has failed.

A good rule of thumb (that I use) when trying to understand evolution is avoid terms like best and advanced. There might be life forms that are better suited to survival on earth than currently exist. Evolution is about gene pools surviving and has nothing to do with life forms becoming advanced or best. If it was about life forms becoming advanced then some of the very basic life forms like nematodes wouldn't still be around.

So I might change your first statement to:

If anything exists now, it means that it works well enough in its environment for this moment in time.

 

[ned flandas]

I destroyed all of the flies in group 1.

and you say God is barbaric.


sorry