How does the Theory of Evolution explain the migratory pattern of the monarch butterfly?

The Monarch butterfly migrates thousands of miles from Mexico to Canada every year -- it takes three generations to make it to Canada, and a final fourth "super generation" to fly all the way back to Mexico. Where did these monarchs get their instinct from, so that generations never having flown to Canada or Mexico, know exactly where to go, and what to do? How is this genetic encoding attained, based on the process of evolution...?|||scientists have discovered that many animals migrate using the magnetic field of the earth. Birds, amphibians and turtles are some examples. instinctive behaviors are governed by fixed action patterns, which are neural networks, or a group of neurons that fire in a fixed sequence to activate different muscles of the body. An example of fixed action pattern is vomiting. Vomiting is not learned behavior, and infants are born with the ability to vomit. Once started, a fixed action pattern cannot be interrupted and will only proceed to completion. Therefore we cannot stop ourselves from vomiting even when our brains may try to interrupt it.



The monarch butterfly's instincts are probably similarly encoded in their DNA. A magnetic map of their migratory route can probably be stored in the DNA and/or fixed action patterns that result in migratory behavior can be stored in their DNA. Even though instinctive behavior is not learned, it still requires an appropriate stimulus or stimuli to be triggered. For example, we do not (thankfully) randomly start to vomit. We do not suddenly vomit while sitting in a restaurant, at our dinner table, or while we are kissing our loved ones, for example. Something needs to trigger the vomiting behavior, such as a finger inserted into the throat for example.



Therefore not every generation of monarch butterfly will exhibit the same behavior, or a behavior that is not appropriate for it. For example, those born in the nothern United States will not fly north as if they were in Mexico. By requiring that a particular instinct will only be triggered by the appropriate stimulus, the monarch can store several sets of instincts, but only the appropriate set will be triggered by the appropriate stimulus/stimuli. That could result in the observed behavior of multiple generations seemingly knowing what to do as soon as they are born.



Of course, Murphy's law states that if something can go wrong, then it will. In every generation, perhaps a few individuals may have a genetic defect, and these individuals may have the inappropriate sets of instincts triggered by the wrong stimulus. they will likely perish. If by chance, their "wrong" behaviors confer them an advantage because the environment has changed, then these individuals would perhaps be the only survivors, and there could be an abrupt change in the behavior of Monarchs. Therefore natural selection will constantly monitor and refine the behavior of monarchs to make sure each generation does the "right" thing. Of course, the possibility of extinction is always present. Natural selection cannot eliminate that possibility, but it will allow animals to avoid extinction if they can adapt to changes.|||I suspect you would get a better answer reading the works of the leading evolutionary biologists like Dawkins than posting here.


The forms of evidence that convince us so strongly of evolution don't always preserve a good record of behavior like migration, except for the wide swaths of area over which certain fossilized animals may be found and the ways that migration is seen in such a larger variety of related species today. So we may never learn the way specific migratory patterns emerged for each species.


We might look more to geology. Perhaps the butterflies simply continued flying a pattern that developed millions of years ago and as the continents drifted farther the butterflies simply added a few inches every century.


In the end, all evolution tells us is that if they do it, it must give them some benefit. Perhaps having such a wide range for their species helps prevent them from getting too reliant on a single food source, too devastated by a few predators or too disabled by local weather variations.|||If the shoe fits, wear it. Judging from your Yahoo name, I am guessing you are anti-evolution. However, one day for God is not necessarily one Earth day. So if God created the earth and the universe in six days, that may possibly be 12 billion years for Earthlings. Darwin and Genesis both agree that first the universe was formed, then the Earth, then plants appeared, then animals, and finally man. Why the creation/evolution debate? They are both the same theory (intelligent design.)|||A short explanation %26gt; http://www.brighthub.com/science/genetic鈥?/a>


More details %26gt;


http://scienceblogs.com/grrlscientist/20鈥?/a>


http://www.sciencedaily.com/releases/200鈥?/a>|||While I am not sure I suspect it could be due to some predatory issues. Perhaps that path contains the least predators so while others migrated towards certain death these one migrated in relative safety.|||%26gt;%26gt;%26gt;%26gt;%26gt;How does the Theory of Evolution explain the migratory pattern of the monarch butterfly?





Why would you use The Theory of Evolution by Natural Selection to explain butterfly migration? That would be ridiculous. This theory would be used to explain how and why allele frequency changes in populations of monarch butterfly over time but that's all.





%26gt;%26gt;%26gt;%26gt;%26gt;[blab blab blab...Where did these monarchs get their instinct from]


This question is not address by the theory of evolution. The theory of evolution addresses why allele frequencies change over time.





%26gt;%26gt;%26gt;%26gt;%26gt;[...]How is this genetic encoding attained


The genetic code refers to how codons are translated into amino acids. The question you are asking is how instinct can result for sequences of DNA.





%26gt;%26gt;%26gt;%26gt;%26gt;, based on the process of evolution...?


and for this, the answer is yes. Genes for different instinctual behaviors arose through natural variation. These variations have different consequences. Those organisms with genes that had deleterious consequences (inability to sense magnetic fields, a circadian cycle out of sync with the solar cycle) were less able to compete with butterflies that were good a sensing their environment.





Judging from your user name, I take this as an attempt to use the "god of the gaps" argument. Whenever there is a gap in understanding, invoke your favorite deity to supply an answer. This is a dangerous road to take for supernatural beings because it leads to diminished power over time for these magical beings as we learn natural explanations for phenomena that seemed supernatural.





Also, while "[your favorite god] did it" is a perfectly valid answer to any question, it is also a cop out answer. It tells us nothing more than not having that answer. We learn nothing about the world and we are just as helpless to try to figure out how things will behave in the future.