How is instinct possible?


by KAckermann
Tags: dna, instinct
yerpo
yerpo is offline
#19
Jan16-09, 02:49 PM
P: 24
Quote Quote by The Dagda View Post
What instincts do all humans share?
All of them, by definition.
The Dagda
The Dagda is offline
#20
Jan16-09, 02:52 PM
P: 266
Quote Quote by yerpo View Post
All of them, by definition.
?
baywax
baywax is offline
#21
Jan16-09, 04:47 PM
PF Gold
baywax's Avatar
P: 2,215
Quote Quote by The Dagda View Post
?
Just google the question you're asking... here's what I got from the infamous Wikipedia

Instincts in humans can also be seen in what are called instinctive reflexes. Reflexes, such as the Babinski Reflex (fanning of the toes when the foot is stroked), are seen in babies and are indicative of stages of development. These reflexes can truly be considered instinctive because they are generally free of environmental influences or conditioning.

Additional human traits that have been looked at as instincts are:
sleeping,
altruism,
disgust,
face perception,
language acquisitions,
"fight or flight" and
"subjugate or be subjugated".

Some experiments in human and primate societies have also come to the conclusion that a sense of fairness could be considered instinctual, with humans and apes willing to harm their own interests in protesting unfair treatment of self or others.[1][2]
http://en.wikipedia.org/wiki/Instinct
turbo
turbo is offline
#22
Jan16-09, 05:11 PM
PF Gold
turbo's Avatar
P: 7,367
I'd like to add here that there are physiological reactions that are inheritable - not instinctual. For example (probably due to some Native American heritage on both sides of my family) I cannot be poisoned by mushrooms. I am acutely sensitive to the taste of alkaloids and experience a most revolting gut-wrenching bitterness at exposure levels that most people can't detect. I found this out when participating in a genetics program as a biology student. While undergoing genetic screening with a whole bunch of other "guinea pigs" we had to file through a station at which you were told to touch a piece of blotter paper to your tongue, and write down your impression. Every single person in front of me (that I could see) simply went through the station and shrugged (or less) and wrote something on their clip-board. When I tasted the paper, I retched and thought I might puke - it was that bad.
baywax
baywax is offline
#23
Jan16-09, 05:43 PM
PF Gold
baywax's Avatar
P: 2,215
Quote Quote by turbo-1 View Post
I'd like to add here that there are physiological reactions that are inheritable - not instinctual. For example (probably due to some Native American heritage on both sides of my family) I cannot be poisoned by mushrooms. I am acutely sensitive to the taste of alkaloids and experience a most revolting gut-wrenching bitterness at exposure levels that most people can't detect. I found this out when participating in a genetics program as a biology student. While undergoing genetic screening with a whole bunch of other "guinea pigs" we had to file through a station at which you were told to touch a piece of blotter paper to your tongue, and write down your impression. Every single person in front of me (that I could see) simply went through the station and shrugged (or less) and wrote something on their clip-board. When I tasted the paper, I retched and thought I might puke - it was that bad.
Conversely, although the firstnation people had developed a genetic warning system with regard to certain foods, they were totally new to booze. Consequently, this was taken advantage of... along with their lack of anti-bodies that fight Small Pox... to the point of diminishing what was once quite a large North American population.

Personally, I must have genes that regulate my gag reflex to "Cherry Jack"... (some kind of sick winey kind of booze)
kingdomof
kingdomof is offline
#24
Jan16-09, 11:39 PM
P: 97
Well, considering this is a pressing issue in the Neurodevelopmental Biology community that has yet to be answered, I suggest to you that you will receive no simple answer as to how an instinct is coded for. To begin with Neurodevelopment is dependent on plenty signaling mechanisms that code for the massive amount of differentiation in the CNS. I'd hypothesize, as I really don't know a lot about the subject, that instinctual behaviors, such as FAPs, are resultant of the intrinsic nature of the neural network of an organism. Neural development is not exactly replicable in the sense of one hundred percent spatial conservation across individuals in a population, but it is similar in a sense, for instance cells regulate the amount of synapses of different types of neurons that connect to them, in terms of overall surface area. So I'd expect that these genes are responsible for the overall development of the organism's instincts would be those that code for the signaling proteins in the pathways that would control cytoskeletal elements, or the other large number of pathways that may be implicated by my previous very blanket-like statement.

Genes do code for instincts, but not in a very 1:1 type of way. For instance, look at autism, specifically Fragile X. The loss of a single protein causes major defects in physical appearance, retardation, problems with blood glucose regulation, and I'm sure, much more which has not been yet elucidated or that I'm forgetting.
The Dagda
The Dagda is offline
#25
Jan17-09, 01:28 AM
P: 266
The brain uses DNA methylation to store memories, so that they can be copied as well. That is probably the basis of fear instincts as well in our more primitive brains.

DNA methylation is a type of chemical modification of DNA that can be inherited and subsequently removed without changing the original DNA sequence. As such, it is part of the epigenetic code and is also the most well characterized epigenetic mechanism.[citation needed] Because Methylation is a common capability of all viruses for self non-self identification the epigentic code could be a persistent remnant of ancient viral infection events.[1]

DNA methylation involves the addition of a methyl group to DNA — for example, to the number 5 carbon of the cytosine pyrimidine ring — in this case with the specific effect of reducing gene expression. DNA methylation at the 5 position of cytosine has been found in every vertebrate examined. In adult somatic tissues, DNA methylation typically occurs in a CpG dinucleotide context; non-CpG methylation is prevalent in embryonic stem cells.[2][3]

In plants, cytosines are methylated both symmetrically (CpG or CpNpG) and asymmetrically (CpNpNp), where N can be any nucleotide but guanine. Some organisms, such as fruit flies, exhibit virtually no DNA methylation.

Research has suggested that long term memories in humans may be stored via DNA methylation
http://en.wikipedia.org/wiki/DNA_methylation
kingdomof
kingdomof is offline
#26
Jan22-09, 05:27 PM
P: 97
Quote Quote by The Dagda View Post
The brain uses DNA methylation to store memories, so that they can be copied as well. That is probably the basis of fear instincts as well in our more primitive brains.



http://en.wikipedia.org/wiki/DNA_methylation
Is there any evidence for a DNA methylation based memory mechanism? I mean, I understand how methylation is implicated in long term changes of functionality in the brain in response to sensory information, but is it memory with respect to learning or is it a plasticity in functionality due to a stimuli? I understand the basis behind LTP and what have you, but I never heard of a methylation based mechanism. Please elucidate this concept!

Thanks.
yerpo
yerpo is offline
#27
Jan23-09, 12:59 AM
P: 24
If I had to guess, it influences the expression of genes that control axon formation.
The Dagda
The Dagda is offline
#28
Jan23-09, 02:50 AM
P: 266
Quote Quote by kingdomof View Post
Is there any evidence for a DNA methylation based memory mechanism? I mean, I understand how methylation is implicated in long term changes of functionality in the brain in response to sensory information, but is it memory with respect to learning or is it a plasticity in functionality due to a stimuli? I understand the basis behind LTP and what have you, but I never heard of a methylation based mechanism. Please elucidate this concept!

Thanks.
Sure.

http://www.newscientist.com/article/...-your-dna.html

Memories may be stored on your DNA

REMEMBER your first kiss? Experiments in mice suggest that patterns of chemical "caps" on our DNA may be responsible for preserving such memories.

To remember a particular event, a specific sequence of neurons must fire at just the right time. For this to happen, neurons must be connected in a certain way by chemical junctions called synapses. But how they last over decades, given that proteins in the brain, including those that form synapses, are destroyed and replaced constantly, is a mystery.

Now Courtney Miller and David Sweatt of the University of Alabama in Birmingham say that long-term memories may be preserved by a process called DNA methylation - the addition of chemical caps called methyl groups onto our DNA.

Many genes are already coated with methyl groups. When a cell divides, this "cellular memory" is passed on and tells the new cell what type it is - a kidney cell, for example. Miller and Sweatt argue that in neurons, methyl groups also help to control the exact pattern of protein expression needed to maintain the synapses that make up memories.

They started by looking at short-term memories. When caged mice are given a small electric shock, they normally freeze in fear when returned to the cage. However, then injecting them with a drug to inhibit methylation seemed to erase any memory of the shock. The researchers also showed that in untreated mice, gene methylation changed rapidly in the hippocampus region of the brain for an hour following the shock. But a day later, it had returned to normal, suggesting that methylation was involved in creating short-term memories in the hippocampus (Neuron, DOI: 10.1016/j.neuron.2007.02.022)...
stochastic
stochastic is offline
#29
Feb9-09, 08:10 PM
P: 61
first, in regard to the bird migration topic, i think we would have to know: if you took a bird egg and raised the bird for a couple years then released it (and it didnt join a group) would it still fly to the same spot as the rest of its species?

im sure that is known, but i do not. so, if the bird did not fly to the same spot, i think that would mean it has nothing to do with instinct, rather it is socially learned, in the form of following the old wise bird that followed the old wise bird that followed... and then the original old wise bird most likely figured it out from observing its environment, as in, movement and position of the sun in the sky. birds are very keen observers of the sun, they sit and stare at it during sunsets. hopefully someone here has studied birds and can shed some light on my speculation.

now for human instincts, i have thought about this a few times since a friend told me he had a college 'professor' that claimed we have no instincts. one i came up with that i think is pretty solid is: if a baby was born in a cave and it could see the opening where the light comes from, and you never let it see you leave or enter the cave, when left alone and able to move by itself it would surely move toward the light (energy) as opposed to into the dark cold cave.

the point im trying to make there is that for the sake of survival the baby moves toward warmth, not to mention our other many connections to light and the sun.

also, another one i just considered is, babies being able to swim, has this not been shown to be an instinct? i dont know. :)
Rustelee
Rustelee is offline
#30
Apr3-10, 08:42 AM
P: 1
Quote Quote by The Dagda View Post
I just googled that and it said on wiki that it's a common misconception that googling is an instinct?

Now I'm just confused?

Is it true that if you type Google into Google it can break the internet?
If you type Google into Google you will travel in time to the future at a speed and time comparative to your central processing unit.


Register to reply

Related Discussions
Let's discuss evolution and instinct Biology 81
PF PHOTO CONTEST - Animal Instinct (11/24-11/30) General Discussion 60
VOTE PF Photo Contest - Animal Instinct (Group 1/2) General Discussion 13
VOTE PF Photo Contest - Animal Instinct (Group 2/2) General Discussion 11
Question about origins of survival and instinct Biology 9