Should evolution be taught in schools?

[Cirdan]

Originally posted by jerseydevil
Very true - it wasn't as if the Sahara was at one time the same as the Amazon Jungle and just changed overnight into desert.

Plus there is no analysis as to whether the crocs posessed the adaptation from previous experience and it was maintained as a recessive passive trait. Remember that the environment changes are functuations and not permenet. An adaptation to a historical tendency of the environment to vary is a slow adaptation that occurs in spurts of reduction of the non-adapted genotype.

[Lief Erikson]

Originally posted by Cirdan
Plus there is no analysis as to whether the crocs posessed the adaptation from previous experience and it was maintained as a recessive passive trait. Remember that the environment changes are functuations and not permenet.

Good point. But wouldn't the first change have either killed them or forced them to migrate?

[Cirdan]

Originally posted by Lief Erikson
Good point. But wouldn't the first change have either killed them or forced them to migrate?

Migrate makes sense. Plus I think that as long as the crocs have been around they must have some pretty good adaptation skills. They outlived a lot of other less fortunate close relatives.

Edit: Plus it's not the only source of crocs. They should be able to repopulate environments that switch back.

[Lief Erikson]

But if they migrated, wouldn't that remove the need for them to adapt?

[Cirdan]

Originally posted by Lief Erikson
But if they migrated, wouldn't that remove the need for them to adapt?

The population would be enriched by those that might possess an adaptation. If the ability to survive erratic weather has been selected for over a long period then no further adaptation is neccessary. LIke BoPs example of losing melanin. Certainly somes died but the previously dormant ability to adapt responded to the environmental change rather quickly.

I was responding to your either or question without elaboration. My bad.

[Lief Erikson]

If the environmental shifts are predictable over a course of thousands of years, and a few of the crocs do gain the ability to adapt to their new circumstances (With strange speed), wouldn't this gene be rather overwhelmed? These creatures would be living in new environments with new circumstances for a few thousand years, and in that time many other genes to their new location would far take priority. Migrating back and forth until their gene becomes strong in them doesn't make that much sense to me, unless their new location became also bad for them in a quick space of time.

It seems much easier to believe that we are observing the same effect there that causes the fly to lose or gain a wing depending upon its environment, and that they can change to their surroundings.

Are you applying this principle of migration with the crocodiles to all of the species throughout time that have had to deal with the continually shifting environment?

One other thing as well: I'd like to bring up again my other question about the fossils. That is the question about the lack of intermediate species, even though the same species is found in several different locations. It is possible that we are finding only the predominate species, but if this is the case, that still doesn't dismiss the fact that there are many hundreds of unaccounted for species in between. I don't quite think that using a dominance slant quite removes the need for all of these other "lesser" species entirely.

[Lief Erikson]

Also, after the species have migrated away, there is little incentive for them to migrate back unless the new place that they live also becomes too hostile for them to any longer endure. And in that event, there is only a random chance that they might return to their original home.

“The transitions are sharp,” deMenocal said in an interview. “Climate changes that we thought should take thousands of years to happen, occur within a generation or two.”

Isn't that too fast, by the current evolutionary model, for them to create new genes?

[Cirdan]

Originally posted by Lief Erikson
If the environmental shifts are predictable over a course of thousands of years, and a few of the crocs do gain the ability to adapt to their new circumstances (With strange speed), wouldn't this gene be rather overwhelmed? These creatures would be living in new environments with new circumstances for a few thousand years, and in that time many other genes to their new location would far take priority. Migrating back and forth until their gene becomes strong in them doesn't make that much sense to me, unless their new location became also bad for them in a quick space of time.

Less focus on migration except that there would certainly be crocs in other locations that are the most conducive to the crocs. These would mingle with the crocs possessing the gene that helps them adapt. The gene is shared passively by all the crocs in the unstressed areas. It is the gene that would do most of the migrating. The selection only kills of the unadapted crocs. After a while all crocs have the adaptation. There must be stress to remove the unadapted crocs from the pool. I think water-borne creatures would have very little problem moving around places with water.

It seems much easier to believe that we are observing the same effect there that causes the fly to lose or gain a wing depending upon its environment, and that they can change to their surroundings.

Except your expecting a population to change genetically, in isolation, and in unison before they die. This seems harder to believe. Mutations are different than weight gain. Remember if they have the gene passively already they have adapted and no migration is neccessary.

Are you applying this principle of migration with the crocodiles to all of the species throughout time that have had to deal with the continually shifting environment?

Like a dog with a bone. Lose the migration thing. Population mixing is more likely than migrations, but they occur as well.

One other thing as well: I'd like to bring up again my other question about the fossils. That is the question about the lack of intermediate species, even though the same species is found in several different locations. It is possible that we are finding only the predominate species, but if this is the case, that still doesn't dismiss the fact that there are many hundreds of unaccounted for species in between. I don't quite think that using a dominance slant quite removes the need for all of these other "lesser" species entirely.

There are variations within the species and sub-species. It the the biologist that determines were to draw the line. I would still like and example of these hundreds of missing fossils. It sounds like heresay. Some species show many intermediates. Simpler organisms are very easy to track because the changes are simple. Mollusks are easier because they live in the sediment that becomes the rock so they are preserved at a much higher rate. Their population densities are great as well. A few stray teradactyls are harder to track changes in, but they are not evolutionarily significant anyway.

[Forge315-Halfling]

Sorry for the delay.

Do you have a shred of evidence this happened?

Go see these verses, Gen. 1:6&7, Psalms 148:4 and II Peter 3:5.

Oh, we're familiar with it. I have a whole degree based on it, if it helps. It seems that YOU are not familiar with how natural selection works.Would you care to explain it to us? Yeah, I thought not.

I wasn’t talking to you, the speech is catered to the ready. I don’t have degree in natural selection, but I understand it well enough.

When will you provide evidence of evolution creating a ‘new’ species?

The WORLD?? COVERED??? My god this is ignorant. I said earlier that the glacial maximum of the Neander time period ONLY occured in the European continent!!! And an 'Ice Age' does NOT cover things with an ice shield!!! It is just a colder period in time. Due to the frigidity of the atmosphere, the water levels are lower, and land bridges are formed due to ice and exposed land.

Perhaps it would be better said that a canopy of water surrounded the earth. See the first verses.

Oh and seems the whole earth was submerged by water, see this verse, Psalm 104.

I don’t have more time today but I’ll be back Tuesday, and look into the founder affect too.

[Rían]

jerseydevil - thanks so much for the cool F15 pic! Sorry I didn't get back to you sooner, I've been out of commission with an awful cold. No, I wasn't looking for an avatar, but I enjoy pictures - thanks again.

and COMPLETELY off the thread topic, but on the F15 topic and rather interesting- my dad, who was in airborne radar and a project manager on the F15, was talking to an Israeli fighter pilot trying to see which a/c he preferred - F15 or F16 (the pilot was qualified to fly both, which is rather unusual). The pilot talked about the pros and cons of both, but my dad wanted a definitive answer, so he finally asked the pilot: "ok, you're sitting here and the alarm goes off. You run out to the tarmac where there is an F15 and an F16 sitting there, both ready to go. Which one would you choose?" The pilot's answer? "Doesn't matter! The MiG will go down either way!!" (typical pilot answer! )

Also, my dad said that most American pilots preferred an F15, since the missile range is greater. The F16 is more maneuverable, but the F15's strategy is to keep getting off shots and staying out of the F16's range. Of course if you go up and the F16 is right there, that's a different story!

[jerseydevil]

Originally posted by Forge315-Halfling
Sorry for the delay.

Go see these verses, Gen. 1:6&7, Psalms 148:4 and II Peter 3:5.
....
Oh and seems the whole earth was submerged by water, see this verse, Psalm 104.

Sorry, but verses from the Bible do not stand up to scientific scrutiny. That is like me writing something on a piece of paper and saying that it's true because it says so. No one knows who wrote the Bible - you may believe it's the word of god - but that doesn't make it true.

[BeardofPants]

Originally posted by Lief Erikson
A slow evolution enhances the species, but I have trouble with the environment issue. If a swamp creature is slowly changing into a forest creature, then you have to assume that the environment is changing at an equal or even slower rate than the creature is in order for the genetic changes to be selected. However, if the environment changes too suddenly, then the creature, which is unable to adapt, will have a lot of trouble in the new surroundings. How could evolution keep up with environment? Is environment observed to change at such a slow rate?

This will have to be short and sweet, as I have had a rough day, and I'm feeling very much the worst for it.

Evolution is not about enhancing the species, but about selecting for the best possible fitness. The environment (and hence, natural selection) is a big part of this process. Going into basic genetics, do you remember the terms phenotype and genotype? Well, the genotype is the coding part of DNA, and the phenotype is the observable phenomena (expression of a trait) of what the genotype coded for (basically.) So you could say that, the Environment + Genotype = phenotype. Thus, it is not really about the process of evolution keeping up, per se, but more that they go in tandem with one another. The environment is a powerful 'force', if you will, and goes hand in hand with natural selection. Also, environmental changes are very seldom sudden. They tend to be cyclic, and gradual. One of the key theories postulated for early bipedalism is one of semi-arborealism; the reason? - a gradual change in environment from densely wooded forrests, to sparsely wooded forrests, to open savannahs. As the trees thinned out (due to rising temperatures (and drier climates)), hominids were forced to travel greater distances between trees due to areas of open land, and hence, greater exposure to predators. Nobody is quite sure how exactly this lead to bipedalism, as at that stage, quadrupedalism would probably have been faster, but there may have been some reason that they needed to free up their hands... carrying food, or young? Anyway, what I'm trying to say, in a rather rambling fashion, is that although these early primates showed traits that lead us to believe that they were bipedal (slight funneling of the rib cage, longer femurs, a change in the line of balance angles, a "platform" in the metatarpal/tarpal region, etc), there were still arboreal adaptions (long arms, divergent big toe, etc.) So, from one environment to another (wooded forrests to open savannah) there is evidence that while new traits were being picked up, some of the old ones were being retained. Gradualism is the key word here.

I'll also mention that I subscribe to the theory of punctuated equlibrium, which basically means that evolution occurs in fits and starts; periods of activity, followed by periods of stasis.

[Dunadan]

Originally posted by Methuselah
I am interested in your opinions. Do notions of truth, humility, and love have intrinsic meaning or do we just attribute meaning to fictitious concepts? If they have intrinsic meaning, do we learn about them because God has imprinted them into nature (ours or the world’s) in the form of design, or because some chance combination of molecules produces comprehension of these ideas?

So, either God exists or the world is just a chance combination of molecules. This is what I find depressing about Christianity: the idea that love derives from God, not from us. I also find it to be arrogant to relegate my most profound experiences to some bloke in a robe poking about in my subconscious.

Doesn't this externalise love, taking it beyond the individual? In turn, doesn't this process reduce the individual's responsibility in the matter of morality, thereby permitting the rank hypocrisy which has characterised the practice of religion throughout history?

[BeardofPants]

Originally posted by Forge315-Halfling
I don’t have degree in natural selection, but I understand it well enough.

I'm sorry, but I don't think you do. Care to disabuse me of this notion?

FH:
When will you provide evidence of evolution creating a ‘new’ species?

Have you studied the fossil record lately? Or perhaps you think that all species that currently exist have always existed. What about extinctions? They aren't all in the same time frame, and can not necessarily be explained way by catastrophism.

FH:
Perhaps it would be better said that a canopy of water surrounded the earth. See the first verses.

That doesn't work either.

I really would suggest that you read up on the subject matter a bit first, before posting on it.

FH:
Oh and seems the whole earth was submerged by water, see this verse, Psalm 104.

So it is as I remembered.

How is it that you are severely lacking in the theological dept as well?

It should be interesting to see how you warp the founders effect.

[Lief Erikson]

Originally posted by Cirdan
Like a dog with a bone. Lose the migration thing. Population mixing is more likely than migrations, but they occur as well.

I don't think you can. And I'll tell you in a moment why.

Originally posted by Cirdan
There are variations within the species and sub-species. It the the biologist that determines were to draw the line. I would still like and example of these hundreds of missing fossils. It sounds like heresay. Some species show many intermediates. Simpler organisms are very easy to track because the changes are simple. Mollusks are easier because they live in the sediment that becomes the rock so they are preserved at a much higher rate. Their population densities are great as well. A few stray teradactyls are harder to track changes in, but they are not evolutionarily significant anyway.

Thank-you, but that doesn't answer the question at all. Yes, there are (Quoting from the World Book) a few species which have the intermediates found for them. Not many at all though, and I'm certainly not warring with the existence of intermediates. But because I think a faster evolution happened, it makes sense that there aren't a whole lot of those found.

All that you basically said is that there are a few intermediate species. What does that prove? What I'm saying is that there are several different species found in many different locations. Why should these species appear in multiple locations while hundreds of intermediate species of all sorts of creatures go entirely unobserved. I think that we should be seeing less of the same creatures and more of many different species.



Now back to the environment question. Between 150,000 and 120,000 years ago, the Sahara/Gobi desert chains were all lush without any evidence at all of any desert life. Between 120,000 years ago and 9,000 years ago, this area became extremely arid, turning into a desert type region. Between 20,000 years and 18,000 years ago, this area became so hot, dry and impossible to live in that there is extremely little evidence of any creatures living in these regions. That period was the most difficult during that stretch for the desert inhabitants.

Then, between 9,000 years ago and 6,000 years ago, the climate changed again, and forest and grasslands spread all over the region, with only a few patches of desert left. The country then received 50 times as much precipitation as it had during the arid years before.

Then everything became desert again. I get these dates from the World Book Encyclopedia and an Internet article written by E. Lioubimsteva called "IMPACTS OF CLIMATIC CHANGE ON CARBON STORAGE VARIATIONS IN AFRICAN AND ASIAN DESERTS." You can reach it through a search at google.com.

[Lief Erikson]

Now to continue my question posing. Between 150,000 and 120,000 years ago, you have a lush climate. This supports creatures that live in a beautiful and fertile land, and there is no evidence at this time of any desert life. This information is based upon pollen. The first question that this (if you accept the current methods and information) raises is: Where did the desert animals come from that filled the Gobi and Sahara desert regions? And where did all of the other animals that filled this enormous space of land (18,000,000 km., all the territory from the Atlantic Ocean and Sahara Desert to Northern China) go to? Did they all migrate or die? And the desert creatures, there was no evidence of desert life at all to our knowledge in these areas, even in minority. Yet they came from no where to spread out over enormous tracts of land, replacing the former inhabitants.

You have to assume the migration of enormous numbers of creatures if you're going to get anywhere. Let's say you do this. What then? You have these creatures migrating into already populated areas by other creatures, thus causing enormous conflict over the resources available. Predators would be encountering other predators and needing food just as the others did.

But enough of raising those issues, let's get back to the dates. Between 18,000 years ago and 20,000 years ago, there is almost no life recorded due to the enormously hostile environment in these regions. Then, between 9,000 years ago and 6,000 years ago, everything became lush again. You had grasslands and forests (Information taken from the World Book) in these regions. The desert creatures largely vanished. Migration, or death? Anyway, out of the blue in this period of time, we have Hippos, Giraffes, Elephants and many other species. These forementioned creatures cannot possibly have managed to live through the thousands of arid years and survived the extremely hostile period. They need, as I'm sure you know, water and foliage in large amounts in order to survive. The nature of the body structures of the creatures makes it impossible for them simply to have "adapted" over millions of years of the same events happening in structured pattern. They had to have migrated in; there's no other explanation by the current evolutionary standard.

Also in the Arabian peninsula you see no arid landscape at all between the last 9,000 and 6,000 years.

Then the desert took over again, and its creatures. This actually also helps to go against Natural Selection, which says that all the creatures best adapted to an environment are the ones that will survive. The desert creatures would be at a severe disadvantage during this period of 3,000 years, and would be easy prey to the new creatures which are so much better adapted to the climate.

If these sorts of drastic changes (Not influenced at all by man at that time) were happening over those periods of time, we cannot simply assume that it is only during the past million years or so that these things are happening. There isn't any reason why the time we're looking at now should be any different than that which has been since life on Earth first evolved. This implies that these enormous shifts we see today could easily have been happening during these older periods of time as well.

The main explanation that I can see is migration, but there is a difficulty with the migration theory. And that is that slow evolution theory assumes that creatures slowly evolve to their environment. The migration theory basically shoots that, for they no longer need to evolve that much (Although they still can, to some extent), they can simply migrate, and they have to migrate. Species built for plentiful food resources cannot survive in arid desert climates, however much you argue "adaptation due to experience."

And BeardofPants, jerseydevil, whoever out there has some knowledge of evolution and this kind of thing, I don't want to be holding a private conversation with Cirdan. I'd rather hear of your opinions on this as well.

[Cirdan]

Originally posted by Lief Erikson
I don't think you can. And I'll tell you in a moment why.



Thank-you, but that doesn't answer the question at all. Yes, there are (Quoting from the World Book) a few species which have the intermediates found for them. Not many at all though, and I'm certainly not warring with the existence of intermediates. But because I think a faster evolution happened, it makes sense that there aren't a whole lot of those found.

If the change is one genotype, how many intermediates would you expect to find? What do you consider "fast"? How many millions of years is fast?

All that you basically said is that there are a few intermediate species. What does that prove? What I'm saying is that there are several different species found in many different locations. Why should these species appear in multiple locations while hundreds of intermediate species of all sorts of creatures go entirely unobserved. I think that we should be seeing less of the same creatures and more of many different species.

The gaps in fossils only applies to large species were preservation is poor. What does the gap prove? No preservation? No intermediates doesn't imply fast unless you can find the before and after lying right next to one another. A lack of data proves nothing.

[Lief Erikson]

All that says is that a lack of data proves nothing. It doesn't answer my question.

[Cirdan]

There is no real problem with the changing environment unless you try to establish that all the species that were there had to leave and return and that all the species there were there before. If a species migrates to a compatible area from another then it simply populates. Look at any pacific island. They are populated by species that can fly or float. The air-born and water-born species of plants and animals are the paratroopers of nature. Coconuts are know to travel thousands of miles.

If the species that have existed for a long history are found in the new desert are you implying with fast evolution that they evolved from a grassland species? The problem arises when the identical creature is found elsewhere and at other times. Simple creatures adapt quickly. Larger or more complex species migrate.

Look at the impact of humans on native species. Humans destroy, cultivate, genetically select, and redistribute species. Human activity is shown to follow herds while hunting. Even passive distribution of organisms can be highly effective. The margins of the deserts moved and did not outpace the speed of the herds.

[Cirdan]

Originally posted by Lief Erikson
All that says is that a lack of data proves nothing. It doesn't answer my question.

You're trying to push "fast evolution" using lack of evidence. Do you have any evidence that it happens? You have yet to even define it. You're just dancing around your case without making it.