Evolution and instinct. How does it work?

[murraybiscuit]

Right, so I'm not exactly an evolution buff. But I get the gist of it.
I started thinking about instinctual behaviour and can't figure out how certain behaviour is inherited without learning.
For example various insects which migrate, breed, die and then their offspring migrate back and repeat the cycle. Or certain insects which have extremely complex symbiotic rituals involving plants, pollination, and the larvae eating the resultant fruit for example.
Sorry about the inarticulate ramblings, but my question is really: how does the offspring repeat the same behaviour without being shown beforehand what to do and where to go? Is this something that can be genetically inherited?

 

[porchrat]

Innate behaviours (instincts) involve all sorts of things. The ones that are the easiest for us to comprehend are the simple repetitive behaviours in response to easily identifiable stimuli. Things like when a dog shakes itself to rid it's coat of water when it is wet. This is something all dogs know how to do innately, in other words they don't learn it from their elders, it is in their DNA.

Instinct doesn't have to involve conscious thought. Reflexes are another sort of easily observable instinct. When a human being (regardless of age) puts his/her finger on a hot stove plate an instinctual reflex arc results in response to that stimulus and the finger is rapidly pulled away. This arc involves a nervous impulse that moved from your sensory neurons into your spinal column and straight back out through your motor neurons to pull your arm away. At no point is your brain involved at all. You literally don't know you have moved your hand away until after it has happened. Again this isn't something we learn, we all do it instinctively. This is a direct result of our neurophysiology and hence must be genetic.

The survival advantages of the 2 above-mentioned instincts are obvious, dogs must keep their coat dry or it will no longer insulate them effectively and a human being that didn't respond to instantly to intense heat could suffer serious injury perhaps resulting in death. Animals usually migrate to find areas more suitable for mating, raising of young, depositing of eggs, moving with foodstocks etc. Just like with the dog's shaking and the human being's reflex arc, you would be hard-pressed to find an instinctive behaviour that isn't in some way beneficial to the organism's survival.

Lets look at how it could be possible for instincts to evolve:
The specific example you provided was migration patterns. In the beginning the organisms that exhibited or began to exhibit the innate desire to perform these migrations would be the ones that were more likely to survive to reproduce as they would have a readily available supply of food or their young would have ideal circumstances in which to develop relative to the members of the population that didn't migrate. As more of the migration-prone individuals survived and less of the non-migratory individuals survived so the population as a whole would tend towards migration as a behaviour.

Note that I'm not an Evolutionary Biologist. This is just my understanding.

 

[jboyx989]

I'm really glad this thread was started, I've been pondering the same thing myself. Having touched on more simple things like migration, I am lead to wonder about how more complex behaviour evolved, like weaver birds having the knowledge and skill to weave a consistently shaped nest for example. Other examples would be honeybees constucting a honeycomb, or a spider spinning a complex web.

 

[murraybiscuit]

yeah, the example i was reading about was the yukka moth.
http://www.lvrj.com/news/joshua-tree-yucca-moth-evolution-fascinates-researchers-119987234.html

first, they find a suitable host flower and, through scent, detect whether another moth has laid there already. they adjust their egg laying according to how many moths have already left a scent. then they deposit a number of eggs into the yukka flower's ovaries and pollinate the stamen with pollen from another bush which they have collected in their mandibles. it's not bee-like pollination involving hairs on the back legs which inadvertently deposit pollen on another flower. they purposely collect foreign pollen with the intent of fertilising the plant. once done, they rub their abdomen on the flower as a calling card for other moths. the hatched worm feeds off the fertilized fruit, and finally emerges. it then spins a thread to the ground below, crawls into the sand where it completes metamorphosis and repeats the same sequence of events.

clearly for i.d. proponents how this all works is clear as day. however, goddidit doesn't really satisfy an inquiring mind, so i want to know at a neural and genetic level, how such detailed information is stored, triggered and processed. it blows my mind.

for me, it raises the following questions:
1. is complexity (complex behaviour) necessarily related to animals capable of higher mental processing? possibly not.
2. if a moth is capable of this, then what of humans? how much of our behaviour is hardwired/genetically encoded? how can we determine what isn't hardwired?
3. when we talk about complexity and complex behaviour, what does that mean? surely what we interpret to be complex is relative, subjective and peculiar to our human (biological) viewpoint?

 

[Nerfherder]

The trick is to remember its all about survival.... the ones who survive breed, the ones who don't die out.

Some behaviors are learned... some are instinct. Most behaviors are a mix of both.

Also... things don't evolve over night, small changes in behavior happen each generation. That change will either help or hinder the species, if it helps the species it will survive and breed.

 

[abandonallhope]

however, goddidit doesn't really satisfy an inquiring mind

Keep at it, at the rate of practical and tangible explanations nerfherder and porchrat are going your inquiring mind will soon truly be satisfied.

 

[porchrat]

clearly for i.d. proponents how this all works is clear as day. however, goddidit doesn't really satisfy an inquiring mind, so i want to know at a neural and genetic level, how such detailed information is stored, triggered and processed. it blows my mind.

Look up DNA transcription, RNA, tRNA, mRNA, reading frames, codons, transcriptase etc.. You will quickly discover that the amount we know about the regulatory mechanisms of gene expression is staggering. You could literally write multiple books on this stuff.

for me, it raises the following questions:
1. is complexity (complex behaviour) necessarily related to animals capable of higher mental processing? possibly not.

Depends on what you mean by "complex".

2. if a moth is capable of this, then what of humans? how much of our behaviour is hardwired/genetically encoded? how can we determine what isn't hardwired?

Some stuff, like the reflex arc, is clearly hardwired. Now that I think about it I would argue that the vast majority (if not all) of your behaviours are hardwired at least in part.

3. when we talk about complexity and complex behaviour, what does that mean? surely what we interpret to be complex is relative, subjective and peculiar to our human (biological) viewpoint?

I think everything is relative to our particular viewpoint.

 

[Elimentals]

The trick is to remember its all about survival.... the ones who survive breed, the ones who don't die out.

Some behaviors are learned... some are instinct. Most behaviors are a mix of both.

Also... things don't evolve over night, small changes in behavior happen each generation. That change will either help or hinder the species, if it helps the species it will survive and breed.

Also what we sometime call instinct is just behavior reaction to something that simulate some sense.

For example, a cat that loves it to be scratched along the outer edge of the lower jaw, where pheromones glands are located to mark its territory and other information vs a dog that don't.

 

[Chevron]

Right, so I'm not exactly an evolution buff. But I get the gist of it.
I started thinking about instinctual behaviour and can't figure out how certain behaviour is inherited without learning.
For example various insects which migrate, breed, die and then their offspring migrate back and repeat the cycle. Or certain insects which have extremely complex symbiotic rituals involving plants, pollination, and the larvae eating the resultant fruit for example.
Sorry about the inarticulate ramblings, but my question is really: how does the offspring repeat the same behaviour without being shown beforehand what to do and where to go? Is this something that can be genetically inherited?

well yes. It's the same way girls are still attracted to guys with muscles. Thousands of years ago muscles were good for catching wild animals. No I get meat from the butcher, yet girls still have insticnts for muscular guys.

Obviously there are exceptions to everything.

Even most people fear of the dark is also instinctual. Thousands of years ago, a dark cave could have had a tiger or bear. So we were wired to be scared of the dark.

That actually is part of the fear of the unknown. It's why religion does so well. People are wired to be scared of not knowing where they came from or where they will go when they die

 

[porchrat]

What is considered attractive by society changes as society evolves though. I'm sure there is some conditioning in who you find attractive. You can't just chalk it all up to genetics.

 

[Techne]

Right, so I'm not exactly an evolution buff. But I get the gist of it.
I started thinking about instinctual behaviour and can't figure out how certain behaviour is inherited without learning.
For example various insects which migrate, breed, die and then their offspring migrate back and repeat the cycle. Or certain insects which have extremely complex symbiotic rituals involving plants, pollination, and the larvae eating the resultant fruit for example.
Sorry about the inarticulate ramblings, but my question is really: how does the offspring repeat the same behaviour without being shown beforehand what to do and where to go? Is this something that can be genetically inherited?

The way I see it, instinct is a natural operative power. You get different kinds of natural operative powers. For example, acquired and intrinsic. An example of an acquired natural operative power would be knowledge gained via experience. An example of an intrinsic natural operative power would be instinct. Instinct is thus an intrinsic faculty or capacity natural operative power of something that allows it to naturally desire or naturally have an appetite for something or naturally be attracted to something.

The concept itself (instinct) is irreducibly teleological as all natural operative powers are irreducibly teleological (don't confuse ID for teleology, it is a common mistake).

The are genetic and epigenetic elements to such behaviours are beginning to be understood and of course it is inherited or passed on from previous generations. Take the hypothalamus for example. It plays a role in regulating your body temperature. The Otp (Orthopedia) gene is a Hox gene that plays a crucial gene in specifying the neuronal cell linages that become the hypothalamus during development. Without the proper expression of this gene, secretion of neuropeptides such as somatostatin and thyrotropin-releasing hormone are not carried out in an appropriate manner. Temperature control cannot be carried as a result. Or to put it differently, the natural operative power of temperature control is dependent on a functioning Otp gene and this gene is inherited.

Obviously more complex instinctual behaviours have more complex genetic elements to them.

 

[Voicy]

What excites me about evolutionary instinct is muscle memory.

I doubt we notice evolutionary adaptations in modern day homosapien, seeing that it takes 100 of 1000s of years for it to ingrain itself and we change our behaviour too rapidly.

For example, for argument's sake ... if technology comes to a stand still for the next 50,000 years, will our kids be born with the instinct of being able to drive - considering that it's a skill that would be developed and passed down in every generation. Obviously this is a bad example, considering the way driving skills change in accordance with the technology of cars associated with it.

However, it intrigues me that with enough practice and duplication of genes, actions could be hard wired.

It's also important to differentiate between what is instinct and what is intuition. Will a weaver bird who was separated from other weavers at birth still have the instinctive knowledge of how to build a nest identical to those of free weavers or does it copy the design from observing those who came before it?

Migratory birds may have magnetic navigation instincts, but do they know where to fly to or do they use it to fly back to where they were guided to the year before?

 

[sanimoyo]

Wow interesting questions, have never thought about it that way, I would assume the migratory birds use magnetic navigation to go where they have been guided to before, would be great to carry out an experiment though and a theoretically one, what would happen if they were placed on a different planet altogether (different magnetic field and that)

 

[agerbon]

Most articles/books I read trying to answer such a question end up asking for the person to assume too much. In other words it usually comes with a stench of pseudoscience.

However one of my favourite explanations as to be Rupert Sheldrake's theory on morphic fields. Ofc it's got the overtone of pseudoscience.

I feel that biological science still runs on the Newtonian view of our universe and that quantum physics hasn't really been applied to biological science maybe when this happens we can get a real answer.

http://en.wikipedia.org/wiki/Rupert_Sheldrake

 

[murraybiscuit]

didn't see the follow ups on this. thanks porchrat and techne.
i've been trying to avoid getting into genetics, but i think i may need to delve a bit deeper into it.
the terminology alone makes my head hurt.
/damn i wish i'd done bio in high school
/also, i wish i'd never found mybb. curse you all to heck.

 

[zippy]

Most articles/books I read trying to answer such a question end up asking for the person to assume too much. In other words it usually comes with a stench of pseudoscience.

However one of my favourite explanations as to be Rupert Sheldrake's theory on morphic fields. Ofc it's got the overtone of pseudoscience.

I feel that biological science still runs on the Newtonian view of our universe and that quantum physics hasn't really been applied to biological science maybe when this happens we can get a real answer.

http://en.wikipedia.org/wiki/Rupert_Sheldrake

Which Newton view are you referring to ?

 

[CoolBug]

We will always have to learn how to drive just like animals have to learn how to hunt and kill, they learn it from their mother as well as playing with siblings. I'm sure you've seen a mother lion give her cubs injured prey to play with.

If you take a cub away from its mother at a young age and reintroduce it to the wild, it probably won't live very long.

The difference is that if we fail we just take the test again if they fail, it usually means death.

 

[Elimentals]

We will always have to learn how to drive just like animals have to learn how to hunt and kill, they learn it from their mother as well as playing with siblings. I'm sure you've seen a mother lion give her cubs injured prey to play with.

If you take a cub away from its mother at a young age and reintroduce it to the wild, it probably won't live very long.

The difference is that if we fail we just take the test again if they fail, it usually means death.

Kind of why they say its next to impossible to bring an extinct species back to "life" again.

Sure we can keep DNA from different groups to enable em to breed again, the real loss is not the DNA but the knowledge that species held. Like what to eat and what to avoid, even minor things like if they suppose to mark territory or travel in packs will be unknown to the clones.

 

[CoolBug]

Kind of why they say its next to impossible to bring an extinct species back to "life" again.

Sure we can keep DNA from different groups to enable em to breed again, the real loss is not the DNA but the knowledge that species held. Like what to eat and what to avoid, even minor things like if they suppose to mark territory or travel in packs will be unknown to the clones.

Yeah, these clones would of course have to live in a zoo of some sort.

Did you guys hear about the T-Rex like creature discovered not too long ago that had feathers?

Interestingly, feathers developed to keep warm not for flight, then apparently these creatures had less chance of dying when falling from trees and so they were naturally selected according to flight capability. Their bones became hollow and flight became one of the best forms of survival.

What draws me to evolution is interesting theories like this that's about a million times more interesting than a sky daddy waving his wand to make everything in their current form.

http://www.bbc.co.uk/news/science-environment-17612354

 

[Chevron]

didn't see the follow ups on this. thanks porchrat and techne.
i've been trying to avoid getting into genetics, but i think i may need to delve a bit deeper into it.
the terminology alone makes my head hurt.
/damn i wish i'd done bio in high school
/also, i wish i'd never found mybb. curse you all to heck.

Watch the vids on this channel:

http://www.youtube.com/watch?v=CBezq1fFUEA