Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Let's discuss evolution and instinct

  1. Dec 25, 2004 #1
    A couple of months ago someone left a kitten on the side of the road (it could not have been more than a week old, if that). Me being the push over that I am (even though I am not a cat lover) brought it home. On the way home I stopped by the pet store and got a litter box and the crap you put in it. I sat the litter box in the laundry room and filled it up while holding the cat. Went in the living room and the kids played with it for 30 minutes or so and fed it. After that the kitten ran into the laundry room, hopped into the litter box, pooped, covered it up, hopped out and ran back into the living room. Every since that time he has used the litter box. If we are outside playing with him, he will run inside to go to this litter box and use it.

    We will all agree that this must be due to instinct. Not taught by me or his parents. The question is how can this instinct have evolved??? How can this be passed down genetically. In my wildest imagination, I can see one of his parents or grandparents being taught and some how this being passed down. This has Lamarkian evolution written all over it. This trait must have been aquired and past down?????

    I know, I probably sound like an idiot here, but I thought I understood instinct in relation to evolution until I saw this.

    Anybody have any thoughts, explanatin, and/or other examples??? Surely, there is a simple rational explanation for this other than the passing of aquired characteristics, but what? There is no evolutionary advantage to this, although since man is the selector the cats, which do this would be selected. But, I just can not comprehend how this animal, which has never been around my laundry room, this litter box (or any other litter box), has probably never even been in a house before could instinctively do this. Like, I stated earlier, this cat was less than a week old, obviously had been left there for a couple of days (some neighbors had said they saw the cats there earlier) and I have heard of other cats doing this. So, whats is it???

  2. jcsd
  3. Dec 25, 2004 #2


    User Avatar
    Gold Member

    The simplest (and most boring) explanation that comes to mind is that in its first few days of life, it had seen its mother displaying the same behaviour and merely copied it.
  4. Dec 25, 2004 #3
    Loose-soil-pooping-and-flinging instincts

    Cat's seem to have an instinct to poop in loose soil and/or to fling loose soil between their legs after pooping. You might notice that sometimes a cat will miss when covering it up, and that when it does this it walks away afterward seemingly-satisfied just the same as if it had not missed. This might seem to imply that the covering-up motion (the flinging back of loose soil with the front paws - which is apparently very endorphin-releasing if you are a typical cat and you have just pooped) is what is instictive and whether or not the cat actually succeeds in doing it is peripheral to the reward mechanism of the instinct.

    If flinging loose soil between your legs directly after pooping released endorphins into your brain, do you not think you would go out of your way to do it every time you pooped, Nautica?
  5. Dec 25, 2004 #4
    Yes, that is definately simple - but like I said, I doubt this cat ever saw its mother run anywhere, much less inside a laundry room of my house.

  6. Dec 25, 2004 #5
    Yes, I understand this. I can realize that it is due to instinct, that is not difficult to see. But, I am looking for an evolutionary advantage. Could it be so simple that humans simply didn't breed those cats that did not poop appropriately. Would a tiger or lion kitten show similar behavior??? Would a female tiger not breed with a male tiger unless he displayed proper toilet etiquette???

    I guess man has selected on domesticated cat breeds for so long that any discussion of evolution is worthless when comparing to selection on the wild types by nature.

  7. Dec 25, 2004 #6
    A instinct doesn't necessarily have to be an advantage to survive the process of evolution. As long as it isn't a disadvantage there's really nothing preventing it from evolving.

    Although in the case of domestic cats there probably has been an great advantage for cats that have good "toilet etiquette". Cats have been domesticated for quite some time. Long enough to be shaped by selective breeding for sure. And selective breeding can accelerate the evolution of specific traits.

    Dogs don't naturally use litter boxes. So there is a fundamental difference there. Perhaps in the wild dogs ran around in packs bedding down at a different place every night. No need to worry about a poopie "house". :biggrin:

    Cat's on the other hand may have had specific dens where they bedded down quite often so they evolved to pay more attention to their poopie behavior so as not to dirty the den?

    That's entirely a guess because I never really studied the behavior of wild cats or dogs, but it is a suggestion of how these things could have evolved. The cats didn't necessarily have an advantage by bedding down in the same place often (or maybe they did). But my point is that some instinctual behaviors may not have had a clear-cut evolutionary advantages it might have just been something the animals did for perhaps some type of social reasons or whatever. That behavior would still become instinctual in the species.

    I have two cats, and if they stopped pooping in the kitty potty and started pooping all over my house they would quickly become two Schrödinger cats (i.e. their probability of survival would become controversial). So it's definitely a survival advantage at my house. :wink:
  8. Dec 25, 2004 #7
    "Cat's on the other hand may have had specific dens where they bedded down quite often so they evolved to pay more attention to their poopie behavior so as not to dirty the den? "

    This is a good point, one which I did not think of. So, possibly this instinct had already evolved to a point and man accelerated it.

    Instinct still amazes me. How it generally evolved is not that hard to grasp, but once again, the fact that this cat took the initial step, at such a very young age to run to the laundry for this specific purpose and "act like a cat" is.

    I am trying to paint a picture in my mind of a specific nucleotide sequence working alone or in conjunction with other sequences, which provides information, which hard wires the connections in the brain, which in turn directed this cat to do the same thing that its predassesors have done for 1000's of years. And, also, the fact that this appears to be tied to the inheritance of an aquired trait, which I believe almost everybody after Lamarck and Darwin has dismissed.

    I am not only amazed, but I guess I am searching for an answer which will not be answered within the near future, at least not directly.

  9. Dec 26, 2004 #8
    I'm not a biologist. Although to be fair, I should mention that I took just about every major undergraduate biology course available, including genetics and cell biology. Both of which I found fascinating.

    I'm a rebel radical who refuses to believe anything merely because it's "traditionally accepted". None the less, I do believe that evolution was the mechanism that created everything we see around us. Not just the biological things, but the principle of non-genetic evolution also occurs in non-biological things. Such as the evolution of the geology of the earth, and in particular the composition of its atmosphere and oceans, etc. Of course I didn't stop there. I actually majored in physics (in a more 'real' sense) and I have studied the evolution of our solar system, our galaxy, and even our universe (at least to the extent where current theories suggest).

    In any case, I stand in awe at the biological evolution of instincts just as you do. There are however some things that help me to understand it better that aren't often taught in standard courses on biology. I'll list some of those concepts here,….

    1. A trait does not need to be an advantage to evolve (as long as it's not a disadvantage it can still evolve)

    The important thing to take from this is that traits or instincts don't need to have any obviously "reason" or "purpose". Evolution operates by chance, and by chance, any trait can be carried on through the process if it's not a disadvantage.

    2. The time scales involve in evolution are quite literally incomprehensible. I mean, we can talk about numbers, but humans only live for less than 100 years typically. So to even speak in terms of a mere thousand years is totally removed from any human's experience. To talk about tens of thousands, or hundreds of thousands, or even millions of years is really totally outside the scope of human comprehension. We can toss the numbers around, but we have no direct experience of what they mean. So to truly understand just how much time these processes had to work is really not possible.

    3. The whole is greater than the sum of its parts

    This one is probably the least understood in biology. Biologists are always looking for a gene that's responsible for this, or a gene that's responsible for that. But many of the large-scale traits of a living breathing creature may actually not be the work of any one gene, or even a handful of genes. It may just be the result of the completed biological machine. Heck, even man-made machines have individual personalities, if you will, that were not designed into them specifically. These individual personalities are a result of how all of the individual components work together to combine the whole. Biological machines being infinitely more complex than man-made machines would display this phenomenon infinitely more profoundly. (note: the word infinitely here is meant to imply a huge increase in ideas, and does not necessarily adhere to any formal mathematical definition of infinity.)

    Here's a topic in evolution that has always left me stumped,…

    There exists a spider (I think it's native to Australia, but not sure about that), that builds a net instead of a web. It hangs from plants waiting for some prey to come along and then pounces on the prey wrapping it up in the sticky net. This behavior is so totally outside of the scope of what most spiders do. Yet it is an instinctual behavior for this species of spider. Why did some spiders evolve to build webs to wait for prey to get caught in them, yet this other spider decided to build a net to catch its prey by hand? And how could such an elaborate behavior have "evolved". Who was the first spider to do this? And how did the urge to do this get passed down in genes?

    This net-casting almost seems like a conscious engineering feat. Yet, if we think about it, even the web-building technology of more common spiders seems more like engineering than instinct. All the different species of spiders build different types of webs. It seems that the blueprint for the web is passed down genetically too. But is there actually a gene for web building? Or do spiders that are built a certain way just automatically have an urge to build webs (simply because the whole is greater than the sum of the parts?).

    I have no clue. And I honestly don't believe that biologists do either actually. :biggrin:

    http://faunanet.gov.au/wos/factfile.cfm?Fact_ID=88 [Broken]
    (It's kind of like the litter box thing,… Why do they do something like this that they've never been taught to do):
    Last edited by a moderator: May 1, 2017
  10. Dec 26, 2004 #9
    Interesting link. Thanks. So what about the the inheritance of aquired traits. All biologist "know" that this is not possible. But, when we speak of instincts it seems like common sense says that it is possible. Even though, we could come up with no mechanism to show its existance.

    We know that germ lines are set before we have life experiences to change these. We pass genes, which have supposidly been unaffected by the life of the person who passes them (unless of course radiation or something has specifically affected the sperm or egg cells or organs which produce them). But, what if it is possible? What if the life experience of say this cat or spider, which you mentioned, somehow mutates the germ line.

    I know it is far fetched and I know for over 50 years 1000's of scientist have studied this and concluded that this is not possible. But, I have alway bought into the notion that if there is several different explanations for a phenomemon that the simpliest is usually correct and it just seems simple to me that this "aquired trait" has been passed.

  11. Dec 27, 2004 #10
    I'm inclined to agree with you to some extent.

    I personally believe that there is something more than just genetic biology going on here, but since I have no scientific evidence for that I'll refrain from going into that speculation. (or at least wait until the end of the post to mention it)

    First, I would like to speak to the issue of "acquired traits".

    Just when did the net-casting spider, for example, acquire the ability to create and cast a net? I asked in my previous post, "Who was that first net-casting spider?". Well, the answer is most likely that there was no individual spider responsible for this stroke of engineering genius.

    Instead what most-likely happened is something along the following lines. Let's assume that some species of spider failed to inherit the web-building instinct. So that species of spider, and its offspring, was actually at a disadvantage. This probably resulted in a lot of spiders that didn’t live very long thus they didn't pass on their deficient genes. However, some of those spiders may have had an instinct to use its sticky silk to help capture its food. The spiders that inherited that instinct tended to live a bit longer and thus propagate the genes that carried this instinct. So most of its offspring would inherit this instinct or urge. Over time, (lots and lots of time), the offspring that had the greatest ability to use sticky silk to capture its prey survived the longest, thus giving rise to offspring that carried this same instinct.

    Over many millennium only the spiders that were the most efficient at this technique survived thus weeding out the ones that didn't inherit this instinct. In other words, there were probably a lot of really crude net-casting spiders in the past that didn't live very long.

    But the main point is this,… Just where in this chain of events was the trait "acquired"?

    There wasn't any particular individual that was born without this instinct and then acquired it after birth thus passing it on to its descendents. In fact, in my make-believe scenario, this actually could have come about due to spiders that, for whatever reason, didn't inherit the more common web-building instinct. So this new ability was kind of acquired over time via the process of natural selection. Spiders that had a strong instinct to use their silk to catch prey survived to pass on that instinct. The spiders that had the best ability to do this passed on their genes, and the best one of that litter passed on their genes, and so on. Given that spiders often have literally hundreds of offspring, and given that this could have taken millennium there could have been a whole lot of failed spiders to achieve the efficient ones that we see today.

    Of course, getting back to your kitty litter question. There really doesn't seem to be any good reason why cats with poor poopie habits wouldn't have survived. Unless they were socially rejected from other groups of cats thus leaving them to fend for themselves with lesser chances to mate. I dunno.

    An unscientific aside,...

    Just for the record, I believe that there is something more to the whole mystery of life. I believe in reincarnation to some degree. That would explain how instincts are propagated (i.e. they are carried in the consciousness of the underlying spirits)

    Of course, I'm not sure how reincarnation would work. It would seem to me that spiders would need to be reincarnated into more spiders, and cats into cats, and humans into humans, etc. At least at some level. Maybe we all move up through a chain of reincarnations that start out as simple living organisms (maybe even plants!). Then after spending so much time being reincarnated in one life-form we move on to a higher species. There's no scientific evidence for any of that, but it would explain a lot about how instincts are propagated :biggrin:
  12. Dec 27, 2004 #11
    On a completely unrelated note, is it true that cats always land on their feet when they get thrown out the window?
  13. Dec 27, 2004 #12
    Yes, I agree. This is a completely unrelated note. :biggrin:

    But, I figure since Neutron brought reincarnation into to the thread it will come to an abrubt halt anyway. :biggrin:

  14. Dec 27, 2004 #13


    User Avatar
    Science Advisor

    Nautica, NeutronStar, interesting thread you have going here. I'll put in my thoughts. As far as burying behavior, I always considered it part of the predator/prey relationship. The predator may avoid detection by burying or masking its scent/presence in the area and thus achieve a better kills/attempt ratio than one that does not "use the litter box". This may be especially apparent in cats since I would think they have smaller home ranges than say dog packs that must hunt over more ground by necessity to feed the pack (someone please correct me if I'm wrong and lions may be the feline exception being group hunters, do they bury feces?). The trait may have simply carried over into domestic life like so many other predator traits, although as you say contemporary humans would surely "select" for this characteristic. Which brings me to an agreement with NeutronStar's approach to advantage vs disadvantage, if the trait isn't actively selected against then it could be passed on, even with no obvious benefit. Whether that is the case here remains to be proven.

    The spider scenario is also very interesting. Web building strategy is extremely variable across species, from those that don't use webs at all to capture prey to those that build elaborate orbs or huge multi-spider colonies. As far as molecular forces driving such behavior I would submit an example I read about some years ago in Nature:
    Eberhard, W. G. 2000. Spider manipulation by a wasp larva. Nature Vol. 406. 20 July: 255 - 256. (having problems with hyperlink, sorry)
    The article summarizes the relationship between a spider host and a parasitic ichneumonid wasp. The short story is that the parasite influences the host spider to dramatically alter its web design just prior to killing the host so as to create a web more suitable for the larvae to pupate in. This alteration of the spiders behavior is believed to be initiated by chemicals released by the larvae and speaks to "fine behavioral details [that] are independent units"
    and controllable by external influence. Whether this can be taken down to a specific proteomic/genomic substrate....?
    Further points on web spinning come from:
    Venner et al. Web-building behavior in the orb-weaving spider Zygiella x-notata: influence of experience. Anim. Behav. 2000 58(3): 603-11,
    which addresses the impact of information gained from prey capture on web building and how spiders "learn from experience".

    I'm not sure if any of my points get to the bigger issues of 'inheritance of aquired characteristics" but hopefully they shed a little light (dim or otherwise) on the seemingly limitless potential for organisms to adapt and evolve.
  15. Dec 27, 2004 #14
    http://www.museums.org.za/bio/spiderweb/manip_wasp.htm" [Broken]

    Very interesting. :approve:
    Last edited by a moderator: May 1, 2017
  16. Dec 27, 2004 #15
    More unscientific mumbo-jumbo

    Unfortunately the idea of reincarnation automatically conjures up ideas of mystical intervention for most people. :frown:

    However, it doesn't necessarily need to imply that. It could be that our universe maintains a separate dimension of consciousness that has evolutionary properties just like everything else. (i.e. this could be imagined to exist without invoking a higher power or controlling deity) In other words, it could be seen as just another dimension of the universe.

    I admit that this is an unscientific idea in the sense that it can't be directly proven. However, in light of the so-called science of String Theory where they talk about 11 hidden dimensions and multiple external universes in the form of branes. Well, wtf? If they can call that science it seems to me that one little assumption of an added dimension of consciousness deserves a little place in science as well. o:)

    However, since most people would automatically associate the idea of reincarnation with theological ideas I suppose I should have never brought it up. :yuck:

    Anyhow, I hope I didn't ruin your thread with that little tid-bit of an idea. :biggrin:
  17. Dec 27, 2004 #16
    I am running out the door and just logged in. I didn't have time to read the last couple of post, but I did notice this statement. And, no you did not ruin my thread. I am looking for all ideas from everybody. Be it scientific or not. I am not saying that I agree or disagree, but I am interested in everyones opinion.

  18. Feb 6, 2009 #17
    This is an old discussion so I'm not sure anyone is reading any more. But the topic interests me. The kitten covering urine and fecal matter is a variant of a powerful and very adaptive instinct, aversion to such substances which carry disease and perhaps other undesirable substances. Long before kittens ancestral animals which avoided contact with wastes the body had eliminated lived longer, were healthier and thus were more likely to reproduce. The animal registers aversion/disgust through smell that becomes offensive. Once a behavior pattern enters the genetic structure it can and usually does acquire other uses. There is more aversion to contact with other's potentially disease carrying waste matter than one's own, so an animal can use these to mark its territory. Other animals will notice the offensive smell. The pattern may become attached to behaviors associated with dominance and submission. The more dominant animal is in a position to register its aversion to the submissive animal's waste, the submissive animal's survival and well being depends on being more careful to avid giving offense. A tiny kitten knows, by instinct, it must cover its fecal matter. Domestic cats are living with beings stronger than itself, although some adult cats may push the matter by being less careful, or perhaps even deliberately offensive, about where they defecate. Cats being solitary hunters are, by instinct, more careful about cleanliness generally, probably those who in the past carries less odor were better able to sneak up on prey and thus healthier and better able to reproduce.
  19. Feb 8, 2009 #18
    This is alot of speculation - like to see the basis.

    Let's review the assumptions. On what data doe we see health and reproduction favored among those that avoid contact with wastes?
    Just how does a behavior pattern "enter the genetic structure"? Mind giving us an example? and hoe does such a pattern become "attached" to a behavior? Why are "solitary hunters" instinctively (genetically?) more careful about "cleanliness (whatever that means in this context)?
    I'll be especially interested in understand how that translates to sneaking up on prey - as if the prey only smelled feces.
  20. Feb 8, 2009 #19
    JorgeLobo, You raise a number of questions. What data suggest health and reproduction are increased when animals avoid contact with wastes? It is well known that wastes carry disease. David McCulloch in his book 1776 discusses the huge number of deaths from disease of Washington's soldiers, who did not regularly established latrines (digging ditches to bury waste) and many fewer diseases among more disciplined British soldiers who did establish latrines. To take another example, disease took more of a toll in the middle ages among Christians whose management of body wastes was lax, to say the least, than among Jews who more adhered to standards of cleanliness. There is a reason that fecal matter smells bad not just to us, but animals generally act as if there were some such aversion.

    How does a behavior pattern "enter the genetic structure"? This sounds like the discredited theories of Lamarck, the question originally posed about the kitten only a few days old using the litter box. This is not, however, Lamarck. Just for the sake of argument, suppose that cats not defecating in places offensive to more powerful beings was just a matter of cats doing what is pleasing to humans. (I don't think it is just this, but suppose it were.) I believe cats have been living with humans for about 10,000 years. Over these many years, those who defecated people's beds or tables would probably be more often drowned, or at least evicted from the house and not fed, than those who refrained from such behavior. Genes promoting restraint would be more likely to be passed on to future generations, a genetic structure lacking this restraint would more likely be extinguished. Not Lamarck here but pure Darwinean survival of the fittest. Richard Dawkins in his many works (especially, maybe, The Blind Watchmaker) has written about this most eloquently, but others have as well.

    How does such a pattern become "attached" to a behavior? A pattern, once established, acquires other uses. Thus with patterns governing physical structures. Feathers apparently first evolved in beings that did not fly. Maybe they helped conserve heat? Once feathers existed, they proved very adaptive to beings that started gliding and then flying, so that animals with those particular patterns of genes proved superior in competition with most other gliding or flying animals. This is an example of a physical structure acquiring other uses. You're right, probably, to point out my sloppy language, but one might say (sloppily) that the genetic pattern (feathers) becomes associated with a new behavior (gliding or flying). Genetic patterns that are behavioral can acquire other uses. Among mammals, the mother animal obviously provides some care, nurturing and protection to offspring. Among some mammals, then, adults may provide care, nurturing and protection to one another, not just offspring. Once the pattern exists it can be used for other things.

    Why are solitary hunters more careful about cleanliness? Those that depend on stealth, such as cats, will be more successful if prey do not detect their presence until it is too late. Cats can walk very quietly. They move slowly and duck down or otherwise hide when they are sneaking up on prey. They will be more successful hunters (thus live longer and reproduce more) if prey are less likely to detect their presence by smell. Prey do not smell only feces, but feces do have a particularly strong odor, so it would be adaptive for cats to be especially careful about feces. Cats are not only careful about feces but also spend considerable time and energy licking themselves which helps keep their fur clean.

    Thanks for the interesting questions.
  21. Feb 8, 2009 #20
    In the wild, only secondary cats bury their waste to protect their trail from predators. The dominant feline will actually display his or her feces prominently. This sends a strong message of dominance. In the world of house cats, you are the dominant animal and the house cat chooses not to offend you. They will carefully bury their feces to eliminate interfering with what they perceive as the natural order.

    that was from: http://www.sniksnak.com/cathealth/whydo.html

    i got that from a topic on yahoo where someone was asking why their kitten would not cover up after.

    i think this means we have to keep neutronstars point on looking at something as a whole in mind. clearly there is personality involved in this, otherwise there would be no dominance and then the question is, would they all cover their waste or would they all not cover it? but their is personality and so that means (if we think of it like a computer program) the instinct is: IF i am the alpha THEN i do not cover my waste; IF i am the beta THEN i do cover my waste.

    but........... if the definition of instinct is:
    a largely inheritable and unalterable tendency of an organism to make a complex and specific response to environmental stimuli without involving reason b: behavior that is mediated by reactions below the conscious level.

    how can this be an instinct if they have the a psychological choice to not do it? it seems more like cats have inherited knowledge available to their conscious mind. or perhaps they evolve as individuals much more quickly than we comprehend in association with ourselves. they live much shorter lives, so perhaps the 'fog of infancy' wears off in a matter of days or even hours and their mother communicates this behavior to them. there are many forms of communication, who says it has to be a visual demonstration.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook