Paralith

right you are. my mistake.

But have I not provided some evidence that the data Lomborg is using is incorrect, at least to a certain degree? That if he corrected for extinction debt, he would find that deforestation does indeed seem to correlate with high levels of extinction? Lomborg's examples don't seem to be that clear cut themselves. In the quotes you provided he's merely talking about percentages of forest lost to percentages of species lost. Where is the data showing that of the species that did go extinct, or that are severely endangered and are on the brink of extinction, habitat loss played no significant part in their situation? (And I'm talking about species living in areas where habitat loss occurred.) That some other factor was irrefutably the cause? Clearly these are difficult questions to answer, and I'm not saying that the data I provided answers them while Lomborg's does not. I'm merely saying that Lomborg's data is not infallible, and that at this point I don't know if we can firmly say yay or nay to his conclusions.

I have a question for you. I agree with what's quoted here - but I have also heard that certain genes may have physical qualities then enable them to be passed on to the next generation more than other genes; e.g., the genes are competing between each other at the molecular level to get passed on, and in that case the genes themselves are actually the objects of selection. I don't know much about this, though, it's mostly vague memories from my genetics class several years ago. I'm curious if you've heard about it, and/or what your opinion of it is?

I concur with Lucaspa. Neotony refers to the maintenance of a younger developmental form, instead of continuing on to the more adult developmental form. Think of toy dogs; adults bred to have more of the cutesy, younger characteristics of puppies. I suppose at a stretch you could say that "molecular neotony" means using simpler, more primitive molecules instead of more complicated molecules, even if the ability to make those more complicated molecules is present, or something along those lines.

Well, it may or may not take total destruction to drive a given species or two to extinction. Enough combined factors, one among them being reduction of habitat, that drive their populations below a minimum viable number may be all it takes. And with effects like extinction debt, it may be a while until the real ramifications of such situations are realized. Also, I wasn't using the howler monkeys as an example for extinction, just an example of fragmentation preventing migration. The monkeys being studied by my professor are actually hybridizing, and she thinks isolation within fragments may be a cause of it.

eep - definitely have to refer to the neuroscientists on this one. /^^ very interesting question though, I agree.

well, i think your visual cortex doesn't do much more than process the information that it's supplied with by the area of your brain that holds memories. just as you don't really see what your eyes take in until its processed by your visual cortex. If supplied with visual information of some kind or another, the visual cortex just does its thing. Probably the neuroscientists in the crowd can do a lot better job explaining this than I can.

Well, the question is if clear cutting a forest and reducing its size will cut "survival needs and food supplies," as you put it, to the extent where the habitat loss itself is a major contributing cause to the extinction of species. (I'm going with what I've taken to be Lomborg's stance on habitat loss, given the quotes provided by SkepticLance.) A big problem with this is fragmentation. Most animals need a corridor of habitat where they can safely move from one spot to another, and they simply don't have it. A professor of mine worked with howler monkeys suffering from this phenomenon - they would get trapped in the fragments, and be far too afraid of dogs and people and other predators to make the trip of who knows what distance over land. Probably if they can't visibly see the next patch of forest, they're not going to leave the one they're in. These are species that spend their lives travelling through the upper canopy. Land travel just isn't how they roll, as it were. They're not smart enough to make the connection, and I think we can all agree that the Land Before Time dinosaurs were highly anthropomorphized as regards their intelligence.

I know the abstract I quoted is a little dense, but if you read it closely it says this at the end: Unfortunately I can't access the article itself (the part I hate the most about not being a current member of an organization with journal subscriptions >_<), but I think it's safe to assume that the authors have actual numerical data within the paper, and it is summarized here in their abstract. If you have the proper access, I included all the relevant information in my first post so that you should be able to locate the article and read it in its entirety if you would like. Edit: I've tried to find another concrete example or two. Several of the studies I came across use simulations, which supported the existence of an extinction debt, but it depended on the life history of the species, which makes sense. Then I found this article by Mark Vellund et al, 2005, in Ecology: Vol. 87, No. 3, pp. 542–548, entitled EXTINCTION DEBT OF FOREST PLANTS PERSISTS FOR MORE THAN A CENTURY FOLLOWING HABITAT FRAGMENTATION. Again, the abstract:

the input, in this case, comes from your stored memories. these memories activate your visual cortex, enabling you to "see" yourself at the beach.

I think that it's actually more likely that Lomborg is understimating extinction rates. From: http://rainforests.mongabay.com/0908.htm This is the abstract from an article from Conservation Biology (Volume 16 Issue 3 Page 666 - June 2002), by Ilkka Hanski and Otso Ovaskainen, entitled "Extinction Debt at Extinction Threshold."

If you would like to disagree with the premise of this thread and provide concrete examples of contributions creationists have made to science for us to discuss, then please do.

I don't think he's saying that they have the same kind of reproduction; rather, both E. coli reproduction and human reproduction are dependent on the human staying alive and healthy; they both require the same thing in order to propagate.

I think Sayonara is making an important point about the ecological complexity of extinction. We may never find an example of habitat loss being the one and only reason for an extinction, except maybe in cases like Sayonara's example of a sudden volcanic eruption simply wiping out all life on an island. Let's talk about a hypothetical example. The snuffles are a big cat that live in forests. It starts with the forest area being severely reduced, which in turn reduces the number of snuffles that can be supported at any given time. After sighting snuffles for the first time while cutting down the forest, people start poaching them for their beautiful coats. Then as a result of their reduced and continually shrinking population size, they suffer more from effects like demographic stochasticity (too many males and not enough females are born) and environmental stochasticity (a drought reduced the prey density), which even further reduces their population size, sending them into an extinction vortex. So what is to blame? Had the forest not been cut, would the snuffles have been able to survive occassional culling by poachers? Had there been no poachers, would the higher ratio of males to females have been such a big deal? Would they have been able to squeak past even given the lower prey density? Is it the final blow or the first blow that counts? What if the poaching came first, then the drought, and then the habitat loss? Few species live in such a bubble that they will not suffer mutliple "attacks," as it were, as their population size shrinks for one reason or another.

hmm. I don't know a whole lot about stem cells, but after looking at that website, I would advise your girlfriend's parents against it. Just dumping a load of stem cells into your body doesn't mean suddenly you'll be healthier. It takes proper regulation/stimulation/etc for a stem cell to differentiate into a specific type of cell, and I don't think having them simply circulate in your bloodstream means they will somehow know where they're needed and differentiate accordingly.

Well, now we're getting into exactly what we mean by habitat. Correct me if I'm wrong, but I've always understood an animal's habitat to be the physical environment which it inhabits, including plant life. In this case, habitat loss can be actual removal of all the plant life and/or a change to the physical aspects of the area, such as pollution, aka the introduction of chemicals harmful to the animal or the habitat itself. But does habitat also include the other animals that live in that habitat, the whole community, in other words? Because if it does, then you're covering a lot more ground. Then habitats can become non-survivable if a new and effective predator (including humans) or competitor is introduced, or a viral or bacterial disease is introduced. At this point you can probably take almost any of the multiple causes of extinction and say that it somehow counts as habitat loss, the habitat having become non-survivable for a given species. If this is how we define habitat, I would have to agree with Sayonara - clearly Lomborg is wrong if nearly every cause of extinction can be attributed to this definition of habitat loss. However, if habitat is more limited to the physical aspects of a species' environment, then I would agree more with SkepticLance. While it seems obvious to me on an intellectual level that sudden removal of an animal's physical habitat would be more than enough on its own to drive a species to extinction (the one in which it was designed to survive, particularly if the animal is a specialist), I have to admit that I don't know of any clear cut obvious examples where habitat loss is the only (or almost only) contributing factor.

As was briefly discussed earlier, the large amount of allergies people suffer from these days may be a relatively new development, brought on by a change in lifestyle. It's still debatable, of course, but I'm inclined to believe it. In general the histamine response is good, it's your immune system at work. But we may have only recently created an environment for ourselves where it actually does more harm than good. Thusly, evolution hasn't had time to dump it yet. Especially since allergies like hay fever probably don't have a significant effect on fitness.

Probably not entirely, since not all of the symptoms of hayfever are due to the inflammatory response alone.

She. =) and yes, a good biology book ought to have explanations and diagrams. Though if you take the time to look you can find diagrams online as well.

google search for "parenchyma": first item to come up, wikipedia article on parenchyma. article links to this main article on plant ground tissues: http://en.wikipedia.org/wiki/Ground_tissue#Parenchyma Like I already said, these tissues are not limited a specific place in the plant. They are throughout the plant. So if you are looking for answers that tell you exactly where the tissues are in the plant, you won't find them.

I'm not an expert on the subject, but that sounds like a good idea to me. Touch down PCR uses a similar technique where you start the annealing temperature very high and slowly work it down, to make as much of the primer bind as specifically as possible to the template DNA. I really don't know how else you could increase the specificity, other than trying to avoid mixing up that many different sequences in the first place =p

i don't think a taproot is specific to a certain environment, especially since they're not all the same. Plants with taproots are usually strongly anchored in the ground. Some plants store nutrients etc in taproots. Desert plants can have very long taproots in order to reach deep ground water. The plant tissues are located throughout the whole plant, each performing certain functions. It should be easy to look them up and find a description of each one.

I apologize if this sounds harsh, but I think the reason you may not be getting a lot of answers is that this type of problem is a concept that is probably already explained in your textbook, and/or by your teacher, if this is for a class, which I'm assuming it is. Also, doing a google search for molarity or concentration chemistry problems will provide plenty of web pages that describe how to do these problems. This is something you should be able to handle yourself, and not just sit and wait for others to solve for you.

A pretty good case for habitat loss is Amur leopards - again, not extinct, but almost close enough. They used to range all throughout Russia and nothern China and India etc when it used to be all forest. Now they're restricted to remote Siberia and they number less than 50. Poaching has exacerbated their situation, but I think we can agree that the loss of a huge amount of habitat, for a predator that requires a large range, was the real killing blow. It's really kind of stupid to say habitat loss is a minor cause of extinction. Animals adapt to their environment, and many specialize to their specific habitat. And if that habitat is pulled out from under them in an extremely short amount of time? There's no way they can evolve quickly enough, unless we're talking about mice or something, but they're generalists anyway. Of course they won't survive, not well at least. And if they're competing with people? Psht.

one of your body's responses to the allergen is to release histamines - it's an immune response. your body's immune responses are what cause a lot of the normal side effects of colds or injuries - swelling, for instance, is caused by and increase of blood to the area. a fever is caused by your hypothalamus raising your body's temperature after detecting the presence of a pathogen. You take anti-histamines so stop your body's flow of mucus, aka to clear up a stuffy nose, etc. histamines are not cells to be attacked, they're chemicals. i think the whole "rise to cleaner living" thing does have some truth to it. after all, young kids who get out in the dirt and get sick and give their immune system excuses to build up, tend to not get sick as much as adults. I know I read a study somewhere about that, and anecdotally, my boyfriend is a living testament. As a kid he was always running around in the woods with his friends, and he got sick alot, but now he's healthy as a horse. Only been sick once in three years that I can remember. Allergies, I think, are from a substance that your body wasn't exposed to for a long time, and then was hit real hard once, and then every time after that it's exposed to the substance it has that same bad reaction. Again anecdotally, my boyfriend got stung by hundreds of bees once when he was a kid, and now he takes most insect bites pretty badly.