Pretty much the South was fighting *against *potential abolition, and the North was fighting against states rights in the form of states having a unilateral right to cecede.
IIRC, some early Christian theologians did dispute that the Earth could be round on theological grounds, but by the time of Dante Alighieri it was accepted the Earth was round. The myth is that people accepted church canon over the evidence of their eyes and common sense.
From the “dinosaurs were big clumsy lizards” school of paleontology. And that they became extinct because mammals came along and outcompeted them.
Oops, I seem to have taken sides after all. So what I’m wanting to say here is that, Blake, I think I agree with your conclusions, just not with that particular argument. And saying that food competition was the main driving factor doesn’t preclude either avoidance of predation, fighting, or sex (everything comes down to sex in the end, after all). And ed malin, I don’t think anyone is arguing that the giraffes sat down, had a conference, and said “Let’s all grow long necks, it’ll help us in this way…”. It’s a useful shorthand, that’s all.
The “junk” DNA is the DNA that doesn’t code for the RNA that will in turn code for proteins. But apparently RNA has other cellular functions as well.
And when I studied biology in the '70s, fungi were still considered part of the plant kingdom. (And even if they aren’t plants, their reproductive cycles provide an interesting example that bridges the gap between how algae reproduce and the simpler plants such as mosses.)
150kg? That sounds awfully light to me; **lions **average 150 kg and they hunt in prides. I grant you there is a mass where an adult herbivore is nearly immune to predation, especially if it’s a herd animal. Elephants definitely, rhinos almost definitely, buffalo and bison straddle the line between fighting back and running. As a rule of thumb I’d say if a herbivore’s survival strategy against predators is to run like hell, then it’s not immune to predation.
It’d work both ways but cats are ambush predators. They want to sneak up on their prey and kill it before it can figure out what’s happening, let alone defend itself. I’m not saying that’s why a giraffe would evolve a long neck but in this case if they can both see each other it’s an advantage for the prey species.
Wait, what? You mean someday we will be able to take photographs of atoms? Not imaging, we can do that already. You mean we will be able to photograph atoms when they are so much smaller than the wavelengths of visible light?
Funny, that’s pretty much what I was taught (over 25 years ago)…
From the sixth edition of Origin:
Granted, it was Wallace who first explicitly contrasted the adaptive origins of the giraffe’s neck, etc. with Lamarck’s “use and disuse” explanation. But Darwin most certainly had something to say about the evolution of giraffe necks.
Sure, that’s an advantage, but it’s very likely not the driving force behind the evolution of giraffe necks.
Mr. Darwin addressed this, as shown above – adaptations come into play primarily during times of duress. Similarly, the different beaks of Galapagos finches don’t really come into play until times are hard, and competition becomes fiercer. In times of plenty, everyone is more than happy to eat the low-hanging fruit, so to speak.
While it is true that fetal stages of any organism do not replicate adult stages of their ancestors, they do largely replicate fetal stages of their ancestors. Haeckel’s formulation was wrong, but there is a very definite link between ontogeny and phylogeny.
If you like black-and-white rules, or if you like having things work the way your common sense says they should, modern physics is definitely not for you.
you’re comments are very reasonable. getting back to the main theme of this thread, evolution is often taught as a cause and effect process based on suppositions about the benefits of adaptations. i did not seriously contend that giraffes had a conference to determine their future evolution, and i apologize to anyone who took my comments in that line seriously. but i have heard and seen written down many times, the conclusive statement, giraffes evolved long necks because there was more food available for them in the treetops. if that is shorthand, fine. but you are the first person to contend that this is a matter of definition, and if you understand how evolution works, and still want to use that shorthand, i have no objections.
PsyXe, the following comments are not directed at you. i’m sure you undertand this already. but, several times in this thread the contention is made that less competition for food in the treetops makes more food available there. one does not follow the other. it seems obvious to me that less food grows in the treetops (where giraffes currently live) than on the ground, if there were nothing eating it. unless scientific measurement shows that ground level competition exceeds this difference then the arguments about more food in the treetops are specious. maybe the evidence shows there is actually more food growing in the treetops before feeding. i never said it didn’t. i said that i have seen reasonable studies contending otherwise, so i don’t consider the more food theory indisputable. in addition, all of the arguments about current predators and current food conditions do not have any bearing on the evolution of giraffes unless you have some evidence to show what environment giraffes evolved in.
The sun burns hydrogen in the sense that it consumes hydrogen. Astronomers do talk about stars burning hydrogen (or helium, or whatever). But we know they don’t burn hydrogen in the sense of combustion with oxygen.
My 7th grade health teacher told the class that women should shave legs and underarms because of the bacteria that grows more on women than men. She was such a pretty little lady…a real cutie-pie that, luckily, many of us girls paid no attention to. It’s worse when it’s the actual textbooks that are wrong and not just a kooky teacher, but we have to remember, those books were written by regular people, too. Anyone seen those old, red, Communism hardback textbooks? Crazy stuff.
Well neither is chemistry. It definitely got “gisty” even when I was doing organic. (I mean I don’t remember any hard and fast rules about what was more neucleopholic than what, what species were a better activating group than another, etc.)
Yes, but when the phrase “the sun burns hydrogen” appears in elementary school textbooks, the students typically assume that means combustion with oxygen. And at least when I was in school, the teachers didn’t know better either.
