monarch butterfly migration

[Socratic Spelunker]

The full time it takes for a monarch butterfly to complete its migration is longer than the life of the butterfly, meaning that when a monarch leaves a spot to migrate, it will never return there. It's offspring will.

My question is... How does the offspring know where the route is?

 

[origin]

The full time it takes for a monarch butterfly to complete its migration is longer than the life of the butterfly, meaning that when a monarch leaves a spot to migrate, it will never return there. It's offspring will.

My question is... How does the offspring know where the route is?

Actually that is not correct, the life cycle of the monarch involves 4 different generation in one year. The last generation migrates south to mexico or california and then returns back north to lay their eggs. Monarchs life cycle
Now, you are still correct that the 4th generation has never made the trip. How does it know where to go? It is instinct, which is a term I hate. I think that it is more accurate to say it is genetic memory. It is the same thing with bird nests, each robin make a nest that is like every other robins' nest. Essentially the robin just knows or 'remembers' how to make the nest.

I find this whole area of biology pretty cool. I think monarchs are amazing I almost drove into a ditch one time trying to avoid hitting one (which was really stupid).

edited to add: I misread your post; you were saying that the monach does not return to mexico or california which is correct - sorry!

 

[Socratic Spelunker]

Its interesting that this "instinct" is so accurate that they can return to the same grove or field year after year. Maybe it has something to do with the built-in GPS that some animals have.

Do we happen to know how this "genetic memory" stuff works?

 

[Walter L. Wagner]

Its interesting that this "instinct" is so accurate that they can return to the same grove or field year after year. Maybe it has something to do with the built-in GPS that some animals have.

Do we happen to know how this "genetic memory" stuff works?

Not yet. This continues to elude us. It likely has something to do with having a navigation system that follows certain types of land formations, but there are several monarch routes, and that probably doesn't answer all of it. Good question. Any physicists out there want to hazard a guess? It's a tougher question than what they ponder, I believe.

 

[Me-Ki-Gal]

Genetic disposition and yes humans have it too ! Talk about it until my face turns blue . Free will is an illusion. You all think you have shed your instinct like a snake sheds its skin . Wrong . Study the human animal for a while and see for your self if i am right our am i wrong ? Course I know I am right . Cause I been watching you little buggers for ever and you all act the same. Once in a while you get a Logan's runner . I don't know why that happens , part of evolution I guess , or it could be left over pioneer spirit of great human migrations to cover the earth . O.K. here is one you can sink your teeth in . The average person moves every 7 years ? or is it 5 years now . Not the point . The point is it is a fluctuating number based on habits as a whole. Habits determine outcome . It is an integral part of ritualistic human behavior . The addictive mind set of the human species. The past determines the future so to speak . The habits of the past pass to the next generation . Like your kid walking the same way you do . You can separate the child and the parent can have no contact what so ever and if the child got your walk well they got your walk cause they come from you .

Now recently I heard something startling . I don't know if it is factual yet or not . What I heard was that if a parent changes a habit the child will modify behavior even at a distance . I know it sounds hocus pokus , but I think there is something to it . I am also thinking if there is any truth to that then the parent can be affected by the child also . I think it occurs in family members more than friends and such , A blood tie of some type . That is just speculation , but I would not be surprised if it turns out to be true

 

[origin]

Its interesting that this "instinct" is so accurate that they can return to the same grove or field year after year. Maybe it has something to do with the built-in GPS that some animals have.

Do we happen to know how this "genetic memory" stuff works?

The term I used, "genetic memory" is probably a bad term, becasue it is used for several other ideas from evolution to paranormal stuff. The point is, I assume that there is someting in the DNA of the birds that 'hard wires' the knowledge to build a nest into their bird brains. Humans have areas of their brains that are primarily for sight, hearing and speech. Aparently there is a area in the brain for nest building - with a very specific configuration. Probably the same type of thing for the monarchs. I do not know of any research that has shown how this phenomena works. Generally it is just said that this type of behaviour is instinct - which is really lacking in my opinion. I will ask my daughter what she thinks, she in going to school for molecular genetics and is alot smarter than me.

I suppose the migration could be something less amazing (or maybe more amazing) like the mass of monarchs leave a long lasting pheromone on the tress that can guide the next years monarchs to those same trees.:shrug:

 

[Walter L. Wagner]

It is also present in humans. Here is a good starting point for studies of monozygotic (identical) twins raised separately (in different families):

http://www.collegetermpapers.com/TermPapers/Science/twins_and_genetics.shtml

 

[iceaura]

They don't need genetic memory of that kind - they can simply react to stimulus (lowering light, temps, sun angle, etc) appropriately, and follow each other.

They do cluster en route, and maybe in general toward evening (would increase the effectiveness of their warning coloration and/or scent) - a branch of a tree in my childhood back yard, in Minnesota, used to harbor clumps of monarchs in the early fall.

The California migration is different from the midcontinent one.

Not all monarchs end up at the best or same place, going or coming - even at the insect brain level, we have evidence of some freedom of will.

More accessible examples of similar but smaller scale behavior are available: whirligig beetles on midsized lakes, for example, huddle up in a few of the same small places along the shoreline during the day (after spreading out to forage the surface at night). This has many advantages for them, but the navigational problem they face, finding these little havens from the middle of a lake in the dark, seems insurmountable for a small swimming beetle. The way they do it turns out to be fairly simple.