ps418

Well, the fitness of artificially selected organisms often does increase. Once a desirable trait has been bred in a crop, say tomato plants which yield giant tomatos, farmer John can plant all his tomato patch with this new variety of tomato plant, and other farmers will want to propagate the new tomatos as well, at the expense of other varieties. Thus the new tomato line will be more successful at getting its genes into the next generation, and its fitness will have improved as a result of artifical selection. In this case, the plant's environment includes the breeder/farmer -- a strong selective agent, if ever there was one!

Patrick

Tara

hah, clever. I was thinking of humans/breeders as separate from the environment, but obviously we're nature too. Only, artificial selection is adaptation to human's needs/wants/whims, a little different than an organism's adaption for survival in a non-domestic environment, but none-the-less still adaption I guess.

Dr. Rick- interesting article. I see for sure how evolutionary theory will change overtime. But I believe it's very doubtful that 50 or 500 years in advance we'll have discarded evolution as an explanation of the origin of life altogether! It's sentiment like this that I'm encountering from a fundie christian (but otherwise intelligent) friend. :banghead:

I know I previously had the notion, which I had never questioned much, that males (of all species) are more "ardent and promiscuous" than females... but upon actually thinking about it , it's clear that’s really not likely the case... Seems Darwin may be partially (largely?) to blame for that rather widely held misconception.

Peez

How the evolution affects humans is, in a sense, irrelevant to the evolution of the plant (in fact, the interplay can be quite complex and certainly relevant in the long run). The point is that some plants are more reproductively successful than others, regardless of the reason, and the descendants of these plants will therefore tend to predominate in the following generations. You can think of it as a mutualistic relationship, similar in some ways to the algae and fungi that make up lichens.

Peez

SULPHUR

The word is symbiosis

Peez

No, but thank you for the suggestion. From Biology, Sixth Edition (Campbell and Reece, 2002, Benjamin-Cummings):Thus, a person and their tapeworms are in a symbiosis as much as the two organisms in a lichen, but a farmer and his/her crops are not. In fairness, "symbiosis" is popularly used, at least some of the time, to refer to a mutually beneficial relationship (this is the third of three definitions for "symbiosis" in the Webster's dictionary that I have).

I should also point out here that I have used "mutualism" a little too liberally. When I checked the same text, I found Thus, although the relationship between farmer and crop may be mutually beneficial, since it is not a symbiosis it cannot be a mutualism. My apologies for the mistake.

Peez

Tara

What if we genetically engineer new plants? Still adaptation?Genetically modified plants will be more successful, but the reason is a little unusual, historically, at least.

SULPHUR

The relationship between algae and fungi in lichens is held as a prime example of symbiosis

ps418

Sure. If the engineered trait leads to increased reproductive success, it is an adaptation, I would think. The only difference between genetic engineering and old-fashion evolution is that in the former the changes are being made deliberately in a targeted manner. Breeding is itself a form of genetic modification, as is chemical and radiation mutagenesis, only it works through the selection of phenotypes. But fundamentally, all organisms are genetically modified versions of their ancestors.

Patrick

Peez

It is also a "prime example" of a fungus and an algae, so what? I pointed out that one might think of the relationship between a farmer and her/his crops as a mutualism, then provided lichen as an example of a mutualism. The fact that lichen is also a symbiosis, and is also a fungus and an algae, and also terrestrial, and also involves eukaryotes, is irrelevant. Lichen was provided as an example of a mutualism, so that one might better understand what I meant when I called the relationship between a farmer and his/her crops a mutualism. Your comment clearly implied that I should have used the term "symbiosis," which would have been incorrect.

Peez

SULPHUR

If you make an example please use the right words. Your simplistic approach is disturbing.