evolution

[Bartman]

I was thinking earlier today about evolution. Specifically if we could force evolution. What i mean by this is, for example, if you bred silkworms (i believe they come from warm climates). If you bred them and lets say kept the enclosure or incubation at the norm temps their used to. Then lets say over 60 years you droped the temp slightly. Would they learn to adapt over 60 or so year?

just a thought..maybe someone could educate me

[northernsnake]

I think you are thinking to much! lol thats what winter will do to you! but now you got me thinking to Hmmmmmmmm 60 years why so long how many generations would that be. I dont know.

[~Suntiger~]

I think in a species that breeds like crazy, such as fruit flies, you would be able to notice changes/mutations rather quickly in comparison to other types of creatures. By manipulating the environment I think it could be possible, depending on the species.

[northernsnake]

Originally posted by ~Suntiger~
I think in a species that breeds like crazy, such as fruit flies, you would be able to notice changes/mutations rather quickly in comparison to other types of creatures. By manipulating the environment I think it could be possible, depending on the species.

You know I still have thows dam frut flies in my house

[chas*e]

The more basic the genome the faster mutations can be recognized.....if you expose some species of fruit flys to radiation(ultra and above) there are genetic changes that occur in the population...A good example is Bacteria or Viruses,whole populations can be genetically different from their original in 1 day, if under stress....The key is Stress....populations evolve due to their enviormental stimuli(stress)......Your question is possible but over many generations

[Bartman]

I think you are thinking to much! lol thats what winter will do to you!

sheesh i know im sooo bored!!!!! haha

You know I still have thows dam frut flies in my house

try it!

[Crotalus75]

"Specifically if we could force evolution."


Yes. Humans can cause what is called "artificial selection" also called BREEDING. This is a human guided selection similair to Darwinian natural selection except that humans select the traits that they want to see in their animals instead of the environment selecting the most fit specimens. We have been doing this since the dawn of civilization. Domestic plants, dogs, cats and horses are a perfect example. Remember evolution is defined as a change in the allele (gene) frequency within a population over a period of time. If all of the breeds of domestic dogs were released into one breeding pool (thus relieving human selection pressures) these animals would probably all eventually revert to a single "wild dog" like appearance similair to what is seen in many urban areas of third world countries.

[golfsk8er]

I think that Like most things it would climatise (sp) it self through generations. Just my thinking!
matt

[Zoe]

Also, it should be noted that there is a difference between ADAPTION and EVOLVING. I can only explain it in french, so I'll give you examples to understand:
Say there is a population of light grey butterflies, and they live on trunks of trees that are the same colour. Therefore, they are camouflaged and survive better. Now let's say that there are a few darker individuals of the same species - their numbers stay low, because they are easily spotted on the light trunks and eaten.
Now, a certain factor (for example polution) gets into the environment and the trunks turns dark brown over a few months. The pale individuals will diminish in number because they can no longer blend with the trunks, and the darker butterflies will reproduce and many of their offspring will survive because they are camouflaged. There are, of course, still a few light ones left, but not nearly as many.
Just to further the example, let's say that years later the trunks turn pale again (because the polution was eliminated). Most of the dark ones would die and the pale ones would again take over.

THAT is evolution.

Now, let's say that when the trunks turned dark, the butterflies developped more melanin and the same individual that used to be light was now dark, to blend with the trunks - that is Adaptation.



If these silkworms grew accustomed to the cold, that would be adaptation, even if it happened over a few generations. If certain individuals had, say, a mutation that lessened the effects that the cold had on them, and if the temps went down they survived and 'took over' the population, that would evolution.

I hope that made sense, I know it isn't completely relevant to the idea but I just thought I would mention it.

Zoe

[Crotalus75]

Adaptations are produced through evolution by process of selection. But, I think that what you are saying is that if the original individuals were able to "adapt" without "evolving" and passing the surviving resistance genes through generations then that would simply be adaptation within an individual in the present generation to a given situation. I think I may see what you are getting at....But this type of "adaptation" would also have to have been something that would have been inherited thus it is still evolution at work (hypothetically speaking).

Some of these hypothetical silk worms would survive the temp drop and some would not. The ones that survived had to have by chance recieved genes that just so happened to give them a slight advantage and render them more resistant to the lower temperature.

[Zoe]

Adaptations are produced through evolution

Actually, it's the opposite. Following enough adaptations, there will be some form of evolution, be it macro (larger scale, occuring over geologic time and resulting in a new taxonomy) or micro (smaller... such as a new subspecies).
Adaption isn't produced through selection, either. It's simply a trait that asserts itself (or disapears) in a single generation or over a few, following an environmental change of some sort. In one respect, it is selection, because the weaker individuals - those incapable of adaption - will die. But it's not selection in the same sense as the natural selection that occurs during evolution.

If these silkworms were to evolve, there would have to be formation of a new species or subspecies (or the one species might separate into two). Otherwise it's just adaption.

I think that evolution is a term thrown around too easily, sometimes where it isn't supposed to be placed. Like here:

But this type of "adaptation" would also have to have been something that would have been inherited thus it is still evolution at work

I would think it would be the opposite (I know, I'm splitting hairs ) it's more like the eventual evolution that would come of a large-scale adaption would be adaptation at work.

But the question remains the same - will silkworms be able to deal with the change in temperature. IMO, probably not. If it happened over a few centuries maybe, but I don't think 60 years will produce enough generations to adapt to such a severe change in temperature. Other, more versatile species, perhaps, but silkworms are really stuck in their niche and I don't see them exitting it (alive) anytime soon!

Zoe

[CDN-Cresties]

Originally posted by Zoe
But it's not selection in the same sense as the natural selection that occurs during evolution.

Zoe,

Are you saying that natural selection causes evolution????


-Steve-

[Crotalus75]

I hear what your saying, but the definition of evolution is quite simply "a change in allele frequency within a population over a period of time". Adaptation (whether it be a light sensing structure such as an eye or a degree of resistance to fluctuation in temperature or some other type of advantage for the organism) is a result of certain genes being selected for or against by the environment.

It sound like you are speaking of speciation (the evolution of a biological species).

Splitting hairs is what science is all about!

[Zoe]

Yes... natural selection is evolution (it can also be adaptation). According to Darwin, natural selection is the process of animals more suited to their environments surviving and those less suited or less capable of adapting and evolving dying off.

This is a pretty good link for info on it: http://www.biology-online.org/2/10_n..._selection.htm

[Zoe]

Depending on where you look, the definition of evolution can be significally more complicated: "Change in the genetic composition of a population during successive generations, as a result of natural selection acting on the genetic variation among individuals, and resulting in the development of new species."

I suppose that in the end, evolution can be classified as a large, era-scaling adaptation.

Zoe