I've seen over the last several years that deviants and serial killers who have been otherwise normal have been suggested to be infested with toxoplasmosis, or some other parasite.

Now what I might find interesting about this is that what if eventually a species became immune to a parasite that had significantly altered its behaviour over time? That the structures for the alteration remained, the pathways in the brain, but the parasite itself was eventually conquered?

The difference between those who stayed and became chimpanzees, and those who for some reason had to follow the great herds? Those who followed the great herds had contracted a parasite from the herds, and had a need to follow them to continue the cycle.

edit to add: cool question OP.

"You can tell what a man is by what he does when he hasn?t anything to do." Anonymous

Originally posted by nii900
"You can tell what a man is by what he does when he hasn?t anything to do." Anonymous

Let me cite the butterfly.

Whilst in the chrysalis form from what I can research it is either ALL of the tissue of the caterpillar is broken down with the exception of 4 'imaginal disks' And these begin transforming this fluid into the butterfly.

Other descriptions say all of the muscles, tissue and many of the organs so I cannot get a definite the brain is also reformed but really for this we don’t need that to happen it would be helpful to this description if it indeed did.

So the instructions as it were are contained in these four 'imaginal disks'. the insects brain does not play a part in this and may in fact not be there to take part in it. (hopefully someone can answer this one way or the other).

Now this means that the information is stored in these 'imaginal disks'. I think from this we can show that in the butterfly at least its initial and given its life span ALL of its activities can be explained as instinctive and not learned.

The butterfly has an acute sense of smell and so this coupled with pheromones can account for the chemical driven responses. We are left with explaining flight. How some moths have developed an avoiding technique in response to bat echo location. How the site for laying eggs is chosen.

If we move a cabbage whites eggs to a different plant does the caterpillar still seek out the cabbage and if so why? Is this information also stored in the 'imaginal disks'?

So does this point towards the DNA. I think yes but my big question is then, HOW and WHERE? Does this begin to explain 'junk DNA'?

Thanks in advance for finally a debate at last. Long may it live.

Some more thoughts on the mechanics of behaviour – An evolutionary perspective.

I started to think about what behaviours we (humans) exhibit that could be regarded as Instinctive. Now this is quite a difficult task as, compared to most mammals we are born relatively immature.

Compared with a cat or dog (gestation about 70 days, life expectancy about 15 years) a human would be the equivalent of about 5 years old at birth, or an elephant (life expectancy 80 years, gestation 22 months) where a human would be equivalent of 2 and ½.

With this in mind, I am going to focus on behaviour that might not exhibit itself immediately at birth in humans, but could also be identified as nonlearned behaviour. (Sucking is far to obvious an example where failure to suck would prevent the offspring from surviving to reproductive age, although this is also instinctive behaviour)

When a human infant reaches a certain level of motor control, every object grasped is immediately put into the mouth. There’s a very good reason for this as the mouth, lips and tounge are the most tactile sensitive organs in the human body. (Freud has some interesting views on this stage of development)

An object placed in the mouth, compared to one held in the hand is perceived to have more distinct textures, sharper edges, rougher or smoother surfaces. The taste of an object gives an infant clues as to whether its edible, sweet things remain in the mouth whereas bitter, astringent tastes are spat out. (Usually with enough facial expressions to earn £250 for anyone filming it on camcorder)

So that could be seen as an example of a behaviour that is instinctive, i.e. not learned, and that aids survival. Baby doesn’t eat poison.

Omnivorous apes (chimps) exhibit behaviour that borders on a hunter gather lifestyle. For the most part, chimps will travel across the treetops, grazing the fruits on offer, but will also hunt small monkeys in co-ordinated, pack hunts.

It is the grazing aspect that I want to switch focus to at this point. (I promise to attempt to link this with the previous paragraphs)

When observing grazing chimps in the wild, (OK, I mean on Discovery) the behaviour appears to be totally autonomous and similar to that of the infant holding a new object. The item is grasped, placed into the mouth, and if unfamiliar, manipulated using the lips and then either eaten or discarded.

As with rats, I am not claiming to be an expert on chimp behaviour but I offer the idea that the chimp doesn’t wake up and rationalise that it needs to graze, it just does it because that’s what chimps do when they’re hungry.

What I have attempted to posit here is a link between the instinctive behaviour of an infant of one species and the mature behaviour of a closely related species, and you would be quite within your rights to ask why.
IF you understand and accept evolution, then you accept that all organisms on the planet have a common ancestor, and that some ancestors are more closely related than others. (This is why I chose the chimp rather than the cow, but for what I am about to propose, either would be suitable)

Again, if you are happy to accept that cross species similarities are due to kinship, then you might also be happy to accept the possibility that cross species behaviour is also due to kinship.

It could be argued that both similarities are due to the recent divergence from the evolutionary paths that each species took, the more recent the divergence, the more apparent the similarity, both in appearance and or behaviour. (Actually, the cause of the divergence would also have to be taken into account rather than merely the timescale)

Now the weird bit. (That I am seriously considering basing my thesis on)

Is there any evidence suggesting that humans still exhibit grazing behaviour? (from a psychological perspective rather than just eating cake for hours on end)

I believe there is!

I believe that grazing behaviour is a repetitive, autonomous task, entered into without thought or rational. I think that when a human has a”genetic throw back” and exhibits grazing behaviour it manifests as OCD (that’s “Obsessive compulsive disorder”)

For those that are not aware with the effect that OCD has, I ask this question.

Have you ever lay awake at night with a single phrase constantly going through your mind. ? Maybe a few words from the chorus of a song, or a single sentence from a presentation you’re going to deliver! The words mean nothing but for some reason you stay awake for hours just repeating them over and over and over. That is an example of OCD behaviour and in extreme case leads to physical manifestations such as turning lights on and off, opening and closing doors etc.

EDIT - Thank you for posting this thread, you may well have provided the question that answered MY needs.