I Should add one more thing about the hatching of eggs. When, say a chicken, starts to lay eggs, say one or so a day, they will not sit them until they have a full clutch. The eggs, during this time, do not develop much. Once she is done laying, she sits on the eggs and they hasten to develop such that eggs laid over a period of many days hatch within one or two. This is another instinct necessary for survival of their species. Farmer Hardalee
Consider what humans experience involving the sensations of the rectum and anus. Not only can humans sense if something present is gas or feces, but also if the feces is of normal consistency or watery diarrhea. What we call "instinct" refers to the wired behavior that leads to survival. Most animals, including humans, have instinctive behavior that increases the survival of the individual, and thus, the survival of the species. If a bird guards its feces and not its eggs, the survival of its offspring/descendants is much less likely, and thus, this instinct won't propagate as well into future generations. We see guarding behavior in fish, other marine animals, etc.
Not when your are over 50. I was told once when you are over 50 that you "Should never trust a fart." I have found it to be too true.
She got the information from her sensory nerves. She does it because chickens that distinguish between poop and eggs pass on their genes; chickens that leave their eggs in the forest for predators do not.
I would recommend reading the Selfish Gene as it's quite a good starting explaination without all the scientific jargon and it's available in most book shops. Game theory is also worth putting some effort into knowing. When you get a feel for evolution it will really blow your mind. You begin seeing the world like Neo sees the Matrix. This world is more than skin deep. As for your question, you already have the answer from spider but now you need to understand the answer (see what I did there - spooky).
////////////////////////////////////////////////////////////// By the way adoucette the fellow with the fish convinced me more of a probability of programming exist , Since I was thinking about chicken , but he in an innocent way , protection of a female to eggs exist in fish also, that tells me that the instinct was implanted millions years before the dinosaur extinction. By the way I do not contribute to Richard Dawkins bank . I am aware of evolution and I think it is real.
Exactly, but the selection pressure for this particular event is timeless. The chicken would be as active in the preservation of the behaviour as the dinosaur just as any ancestor with a small clutch of eggs that came before it. However, if all the chicken's predators disappeared, the time wasted on finding a safe place to lay her eggs and nest building might be a negative behaviour and natural selection would favour the hen that laid her eggs in the most convenient way (like birds on some islands). Over time that "safe laying" habit might be overruled. For interest sake, did you know that a group of scientist say there is a good chance they can regress a chicken into a dinosaur? http://www.ted.com/talks/lang/eng/jack_horner_building_a_dinosaur_from_a_chicken.html A bit scary but quite interesting. Not sure what you have against Dawkins; that book was written over 30yrs ago and the content has proved to be quite robust. Perhaps then, John Maynard Smith would provide a guilt free read but he's quite maths heavy.
Even this behaviour can evolve: From New Scientist AS IT floats through the air, a spore of the fungus Ophiocordyceps camponoti-balzani seems benign. But when it encounters an ant its true nature is revealed. First, it punches its way through the insect's exoskeleton. Once inside, it begins to grow, consuming just enough of its host's tissues to leave it weakened but functional. Finally, when the fungus reaches sexual maturity, it releases chemicals into the ant's brain. Under their influence, the hapless insect makes its way to a popular ant meeting place, climbs a plant and clamps its jaws onto the underside of a leaf, just as the parasite consumes its brain. Days later, elaborate fungal reproductive structures shoot out of the insect's corpse, spores rain down onto the unsuspecting ants on the forest floor, and the cycle begins again. The method used by the parasitic barnacle Sacculina to perpetuate itself is even more fiendish. Its free-swimming larvae infect crabs and, once inside, develop into a structure on the animal's abdomen that resembles a regular egg sac. If the infected crab is female, the presence of the false egg sac and the fact that the parasite releases hormones mimicking the ones that make her broody cause her to care for the barnacle as if it were her own offspring. Manipulation of males is more cunning still. Hormones released by the parasite change both his morphology and behaviour: the abdomen becomes wider and flatter, resembling a female's, and he becomes sterile and develops egg-caring behaviours to nurture the barnacle.
