How do sea urchins think if they don't have brains?
117408
Jelly fish don't have brains either yet they are capable of actions that to a human observer seem to be caused by thinking. Likewise cells act and do not have a brain. The DNA inside it contains instructions for what to do. Also insects only have a ganglia, no real brain, which just handles motor skills only, not thought. So how do they do it? In actuality they are not thinking and then doing, just doing based on instinct. An observer may notice a small pause in the actions of say a jellyfish that to a human supposes thinking about what to do. Not so. The external stimuli isn't correct yet for the action to be taken is all, and when it is correct, it acts. Clams also have no brains. Nor a Venus fly-trap yet when a fly lands there it closes the trap. It's simply cause and effect.
108081
Sea urchin belongs to a group of animals called: echinodermata (among them: starfish, brittle star and sea cucumbers). All echinoderms have a water-vascular system, a set of water-filled canals branching from a ring canal that encircles the gut. The canals lead to podia, or tube feet, which are sucker-like appendages that the echinoderm can use to move, grip the substrate, or manipulate objects. These tube feet are extended and retracted by hydraulic pressure in the water-vascular system. Pedicellaria are small, snapper-like skeletal elements that are used by the echinoderm to keep small organisms from settling on its body.
390820
Like your mind or something..\nLike when you think? Make sense?\n\nWhen you do things without thinking you're stupid.\nBut you use that little friend (your mind) to help you. :)
244571
Actually wouldn't he first have to have a brain to get brain damage?
1051180
They think in a different way than women . They were given a brain and a weenie but the blood count is a little low to keep both functioning at the same time.
424033
Drink plenty of water.  \nDon't watch too much TV - your brain and the ability to think is like a muscle.  Use it or lose it.
677863
Jellyfish don’t have brains, and they aren't the only creatures that lack them. Sponges and a few other odd groups of animals also lack anything like a brain.\n\nJellyfish don't have brains because they don’t have any front or back. They represent a very early evolutionary experiment. At that stage animals had no front or back, instead the developed along the lines of a ball or disc. That body plan is very simple to construct, but balls and discs don't have any front or back.\n\nOther animals evolved brains because they have one part of the body that ALWAYS contacted food first as the animal moved around. That was the front end. And because there was one end that always came into contact with food first that end evolved the highest concentration of sense organs, and the highest concentration of nerves. That high concentration of nerves in turn evolved into a brain. Because they have no front or back jellyfish also never had the potential to develop a brain in the front end. \n\nI guess the question you need to ask is, if a jellyfish did have a brain where would it be? Since any part of a jellyfish has equal chance of can coming into contact with food there is no obvious place for a brain to evolve. Instead jellyfish have nerves scattered more or less evenly across the body, so all body parts are equally able to respond to stimuli.\n\nSo no, animals don't need brain to function. A brain is just a concentration of nerves. It is only useful if you can concentrate those nerves where most of the sensory input is going to arrive. For humans our eyes, ears, nose and tongue are all located in the head, providing a massive amount of sensory input, so it makes sense to have the processing nerves for those organs in the head too. The sense organs of jellyfish are scattered all across the body so it makes sense to have the nerves scattered too, and that is exactly what we see.\n\nNot having a brain hasn't prevented jellyfish and their relatives from being successful, and they have filled a great many ecological niches and evolved every major sense including hearing, smell, balance and even eyes.
689428
i like the way u think...who are we to know GODs plan when we are mere humans who thinks with no brain
1035185
They do in a developing embryo, but not in a fully developed animal/person.\n\nWhat brain cells CAN do is create connections between each other, creating more neural pathways that aid in recollection.  But if you damage your brain enough, it won't recover.
1094493
Instinct my dear...\nINSTINCT\nYeah what sorta zoo puts its deer in the lions cage for feeding, I never heard of that one?\nAnyway, we as humans are so BLESSED with brains though obviously some never use them...\nAnimals are blessed with INSTINCTS- oh we get stuff from our ancestors too like FIGHT OR FLIGHT--Addrenaline.\nOr our temperment,size,you know...how we think, feel, react to certain things.\nBut the ANIMAL KINGDOM, since their brains for most of em are so small, They have to go on INSTINCTS from their PARENT, and their parents and their parents,parents,parents...lol\nYou get the picture?
124312
Invertebrates can manage this apparent degree of complexity because so much of their behaviour is instinctive. It is preprogrammed into their brains before hatching and is largely unchanging.  That method of storage is highly efficient because the macroscopic brain structure itself can be tailored to support it. This allows for very complex behaviours with relatively little brain mass. The downside is that the animals have little ability to learn and even less ability to respond to change.\n\nIn contrast mammals have very few preprogrammed behaviours, instead they learn most of what they need to know through experience. That makes mammals extremely flexible animals compared to most invertebrates because they can tailor all their behaviour to circumstances. The downside is that it requires a large brain to allow for all the possible circumstances the animal might meet.\n\nTo illustrate this, consider something like the ;structures’ that a spider builds. some species of spiders build complex silk baskets for their eggs. The basket consists of a ‘floor’ and a domed roof, complete with an escape hole for the hatchlings. They are very complex and very impressive without a doubt, but the spider makes them according to an inbuilt program. If that program is disrupted or indeed can not be initiated the spider simply can not cope. If a spider is disturbed just after it has constructed the floor of the basket it can’t simply start again. It has to complete the program cycle. It will spin the domed roof, then lay the eggs in there, and because there is no floor the eggs fall onto the ground an all die. \n\nCan you imagine a bird or squirrel that is disturbed hen it begins making its nest trying to build the sides of the nest on nothing? Nope, that’s because mammals and birds are flexible. The basic of nest building may be inbuilt, but the specifics are the result of learning and adaptations. \n\nAnd that is true of all invertebrate behaviour. An caterpillar will starve to death in a room full of food simply because the food doesn’t have any smell, or a spider that is prevented form spinning a web will starve even when given unlimited amounts of disabled but living insects because it can ONLY hunt when food is caught in a web. Bees will fight to the death to keep other insects out of their hive, but once they are inside the hive and acquire the right smell they will let other insects kill them and take no action at all.\n\nAnd the list of examples goes on and on. Bugs simply are not very adaptable creatures. If they experience something new they simply can not do anything about it at all. And although spiders, ants and so forth can learn their ability is extremely limited. They can exhibit complex behaviour in one limited way, but they can’t readily alter that behaviour. \n\nAnd that is why they can exhibit apparently complex behaviour with a small brain. The complexity is wired in, with no ‘waste’ space. But that comes at the expense of adaptability. In contrast mammals exhibit les complex behaviours but are infinitely more adaptable. Horses for courses.
653958
They have a water vascular system which is unique to echinoderms (sea urchins, sea stars, etc) since they have a digestive system but no circulatory system.  They have an opening called a "madreporite" through which water flows into their bodies.  They have a system of canals within their bodies, and the flow of water transports nutrients.  It is also used for movement and respiration.
206614
some animals were them on the outsied insects and lobsters.\ninvertabreas dont have a spine and some dont have any bones!
309101
They don't have a nervous system.  They do have chemical and tactile sensors, as well as chemical messengers that cause actions in response to stimuli.  For example, a mimosa plant will fold up in an attempt to protect itself if touch it with your finger.
931340
I saw on a National Geographic filler that ants don't sleep. \nAnts don't have large brains, they don't need them as they would be wasted.....brains are very expensive energetically to maintain so animals don't want more than is required. \nAnt colonies work on simple principles to maintain themselves. For example, when a forager ant comes across a prey item and goes back to the colony to recruit help the number of foragers is not determined by the colony but by the size of the prey item. \nWhen the prey starts to be moved by the ants it is a signal that no more recruits are required. This shows that no conscious effort or knowledge is required by the colony, ants therefore don't need intelligence to carry out what on the surface may seem like intelligent decision making....simple brains.
1165485
Ants do not have feelings.  Science has verified by functional MRI and earlier brain ablation studies, that "feelings" originate from distinct locations in the vertebrate brain.   It is known that ants do not have a centralized nervous system (aka: a brain).  Instead of a brain, they (along with other arthropods like spiders, scorpions, crabs and lobsters, for example) possess clumps of ganglia (a collection of neuronal cell bodies) which are distributed down the length of their bodies which integrate neuronal feedback from external receptors (chemoreceptors, for example, on their antennae).  They can communicate to other ants by chemical signals and can see light because they have photoreceptors within their compound eyes.  These signals get processed by the closest ganglia, and this is the extent of their neuronal function.  The mammalian brain, on the other hand, sends all of its signals to one distinct location- the brain- where they get processed and thus we have what we call thoughts and feelings.  Insects have a very primitive, less evolved nervous system than that of mammals, though.  Since they lack the physical machinery where thoughts/feelings originate from, they physically cannot produce thoughts/feelings, therefore.
549981
No...man loses his wisdom even thinking about it.  As soon as his little head starts to think - this can be many times in a day - all the energy is drained from his big head and is redirected into his little head. This is the point he  loses reason.  It's interesting to note, the recovery process is almost immediate after he leaves the specific area, drained. That's when he remembers he's married...or whatever