Category Archives: Nature & Environment

The Epic Journey of the Monarch Butterfly

Monarch and flowerThe migration of the Monarch butterfly is one of the most incredible adaptations in the natural world. There is nothing that we observe in the delicate-winged creatures that would predict the immense journey of the butterflies. And yet, they will undertake a 4 generation migration, which will cover 2,000 to 3,000 miles (each way). The migration begins in a remote mountain range in Mexico, goes across America to Canada and back to Mexico again.

The Migration Route

After overwintering in Mexico, the Monarchs begin the migration to Canada. These butterflies are the 4th generation in the cycle, and they are unique. They have made the migration from Canada to Mexico, arriving in October. The following spring they will start the migration back to Canada. They begin the journey by flying to the southern United States, where they will mate and die. The 2nd generation will make it as far as the northern states; they to will mate and die (living only one month). The 3rd generation will settle in various locations in Canada and the northeastern United States (also living one month).

The 4th generation will make the trip to Mexico before winter comes again. They will live almost nine months, and make the epic journey from Canada to Mexico, all on their own. They will have to fly an average of 50 miles per day. On their way the butterflies will cross the Great Lakes, the Great Plains, hundreds of miles of deserts and the Sierra Madre Mountains. Starting from different locations in the northeastern U.S. and Canada, the Monarchs will find their way south and converge in huge flocks near Mexico. Millions of butterflies take part in the 2 month-long migration.

How do They do it?

Monarch migrationNaturalists are unable to explain how the Monarch butterfly accomplishes such an incredible flight. Each butterfly weighs less than one fifth of an ounce, and its delicate wings must withstand the journey. Also, a large amount of energy is needed to fly such long distances. A butterfly is built more like a helicopter than an airplane, thus it is not the most efficient flyer. There are, however, ways that they can maximize their energy. They only fly when the conditions are perfect. And they can take advantage of rising columns of air. This occurs when the sun heats the ground, causing the air directly above to become hotter. The hot air gets lighter and then rises, carrying the butterflies up. In this case their light frames are a bonus.

Perhaps the most puzzling question regarding the migration is: how do the Monarchs navigate? The 4th generation will begin the journey from a wide variety of locations, and find their way to a forest in the mountains of Mexico (a place they have never seen). Scientists can only speculate how they do it. Maybe they follow a specific angle of the sun or the earth’s magnetic field. Maybe they are guided by wind directions or follow landmarks. And why is the 4th generation more adept at flying long distances, and able to live much longer?

The Power of Multiple Generations

I find it particularly interesting that multiple generations are needed to accomplish the full cycle of the migration. It brings to mind a comparison with human life. In many ways, recent generations are special. We are special in the sense that we benefit greatly from the labors of past generations. Our modern life is the product of people who are no longer here. Like the Monarchs, each generation has passed on something to the next, and over time it has built up.

Today, humans can achieve great things, because we have been given great opportunities. Much of which we take for granted has come about through multiple generations. For example, democracy, human rights, technology, industry, agriculture and so on. Some challenges are so immense that it takes more than one lifetime to overcome them. We should also keep in mind that we will leave something to the next generation.

On personal note: I live in Atlantic Canada, and I have on occasion observed a passing butterfly. They are beautiful creatures, and seem to have a mystical quality to them. In addition to their vibrant colors and elegant flight, the thought of having come from a grounded caterpillar is remarkable. The transformation from caterpillar to butterfly is one of the most amazing transformations in nature. For me, the Monarch is the most familiar of the butterflies. And even before I knew of the migration, I would still pause in admiration when one flew by.

The story of the Monarch Butterfly is so incredible that if it had not been observed and documented, no one would believe it. In fact, the full extent of the migration was not known until 1975. There are Monarchs in other parts of the world, but only in North America do they migrate such great distances. The Monarch butterfly is clearly one of the most amazing animals on earth. And it shows us that very often nature is more creative than we are.

 

References:  Journey of the Butterflies, Aired November 30, 2011 on PBS


 

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The Abundance of Nature

wild flowersIn many respects planet Earth is a rare and unique place. This is partly due to the abundance of nature. There is abundant opportunity, quantity and diversity, as well as abundant time and space. No matter where we look, we will find that things come in large quantities. There is rarely just one of anything in nature; if there is, it probably won’t last for very long.

For our convenience, we separate and categorize the components of nature. Inanimate substances and living things make up two large categories, which are broken down into smaller subgroups. This is useful for us, but in reality the Earth is a living planet. What we consider as inanimate is shared and circulated to maintain all life on earth. For example: soil, water, air and sunlight are part of the living world (in a roundabout way).

Natural Selection and Exponential Growth

Natural selection, Darwin’s term for nature’s sorting process, has a subtle implication; similar patterns and forms are repeated over and over again. This is an unavoidable consequence of natural selection. In order for environmental conditions to serve as a shaping force, it must be favorable for numerous life forms. If only a few individuals are favored, then randomness necessitates that their genes will not be passed on in the long term. On the other hand, when selection acts positively on large numbers (of genes, individuals, groups or species), then the odds are high that they will prosper.

Success from an evolutionary standpoint means survival and replication. There is a constant competition for resources; there are always winners and losers. Once something gains an upper hand, exponential growth will lead to an abundance of that particular life form. It is similar to compound interest in a bank account. Of course, abundance does not entail permanent growth. All species will eventually decline or become extinct due to ever-changing conditions. Nevertheless, when anything survives the process it will do so in large numbers, otherwise it would not be here.

butterfliesFor example, if favorable conditions (such as a plentiful food supply, lack of predators and a temperate climate) are present for a particular species, then the numbers will likely grow. This may at some point lead to overpopulation and stress the survival needs of the species, which can create an opportunity for competing species. The growth of species will usually fluctuate; but most of the time a balance will develop, somewhat like the swinging of a pendulum. In the end the diversity of life will almost ensure that life as a whole will be plentiful.

Self-Organization, Order and Randomness

Both the living and non-living world has the ability to self-organize. That can partially explain how order emerges from a random and chaotic world. The process of self-organization in nature is messy, nothing like we organize our daily lives. With humans there is usually a clear direction or purpose when we make plans. But not all the time; humans also self-organize when groups of people act in a similar way, even if no one is in control.

In nature, the terms trial and error best describes how order and structure arises. There is a role for both order and randomness in this process. The order allows for stability, the random component creates opportunities for change. For example, if we think of how seeds from plants are dispersed, we can see that they fall to the ground in irregular patterns. There is no reason why any seed will come into contact with fertile soil. In fact, the majority of seeds will be wasted. Still, within each seed contains the information necessary to produce the plant. And due to the abundant production of seeds, by random factors alone some seeds will find a prosperous location.

treeFor instance, a mature tree can produce thousands of seeds, and yet, only a tiny fraction of those seeds will become trees. Looking at this process from an individual seed, it seems that the survival chance of a seed is extremely low. But if we account for all the seeds of a tree, there are bound to be seeds that are deposited in just the right location. This is just one example of many similar situations where the abundance of nature assures that life will go on and flourish.

 The Goldilocks Zone

The term Goldilocks Zone is often used to identify the location of the Earth. The idea being that our planet is just the right distance from the sun to support life. The Earth’s location allows for a narrow band of temperature variations (in relation to the universe), a range that can provide liquid water. For water to exist it cannot be too hot or too cold. For life as we know it to exist, liquid water is an absolute must.

At first glance the Earth’s precise location seems highly improbable; however, like the seeds from a tree, there are huge numbers of planets that can’t support life. Hundreds of planets outside our solar system have been discovered, and there are surely countless more. Thus far only a few exoplanets (planets outside our solar system) could be considered as earth like. Out of over 1800 that have already been found, most cannot support life as we know it.

Goldilocks Zones are applicable to situations on earth as well. All life is sustained by a narrow range of conditions. However, because nature allows for abundant opportunity, quantity and diversity something will always find the right location (or conditions). Clearly, from any perspective, there is abundance of every kind. This is what we observe when we examine the natural world. That is why in the grand scheme of things, nature always flourishes.