By Chelsea Jandreau
Midsummer is a time for flying insects. They can be found deep in the woods and flitting around ponds and rivers, but wherever they may be, they have to land eventually.
Recently, a few other people and I were floating around in a small bay on a river. Dragonflies kept landing on our heads as if we were some sort of extra small island or perhaps a rock in the midst of the water. Occasionally another small, long-bodied flying insect landed on one of us or a nearby buoy. Those were the damselflies.
Damselflies are similar in shape and size to many dragonflies, and scientifically they are in the same order, Odonata. However, at some point in history, these two types of animals diverged enough to become two different suborders. As time moves on and different traits are prioritized, many living things very slowly begin to change to better adapt to an area or fit an underutilized niche.
For damselflies and dragonflies, it is likely they evolved from a different ancestor and began to diverge somewhere down the line into the two recognizable animals we have today. If you are looking to figure out which one you are looking at, there are some characteristics you can use. Dragonflies are usually larger than damselflies and have larger eyes. If you wait for one to land, you might get a clear view of how they hold their wings. Generally, dragonflies hold their pairs of wings directly out to the side like an airplane preparing for flight, whereas the damselflies usually hold their smaller wings folded together above their body.
Much of life on earth is quite likely a story of divergence. Plants, animals, fungi, and even bacteria have historically had to survive changing climates and continental movements, mass extinctions, and just the simple march of time over thousands and thousands of years. With changes in their habitats, food sources, and predators it makes sense that things will begin to split off into different families and species. Some of these living things continue to live in the same area, while others split off and slowly adapted to climates in entirely different parts of the world.
One of the classic examples of this involved finches in the Galapagos Islands. Each species of finch had a slightly different beak structure to help it eat a specific food. These birds did not have a lot of competition, so they were able to spread to different islands and fill a variety of niches, even though they came from the same common ancestor.
Animals and other living organisms are full of examples of divergence as things slowly drift apart, but they are also full of examples of convergence, where two entirely unrelated species develop similar traits simply because they are in the same habitat.
Birds and bats both fly which helps them survive by allowing them to escape predators and find food. Despite this, they are not closely related. Even within birds, things that look the same are not always the most closely related, at least down to their DNA. I am still regularly baffled by the fact that Rose-breasted Grosbeaks are in the same family as cardinals, but Evening Grosbeaks are actually in the finch family. This is one of those examples of when we used to categorize just by appearance. As technology evolves and scientists continue to learn more, the classification of living things has changed as well.
The divergence and convergence of traits is something that will likely continue to be necessary for the survival of many living things. Things sure look a lot different now than they did several thousand years ago, and I’m sure the organisms around today will continue to change into something different in the future. As organisms continue to change, they will find commonalities that work for multiple species, and they will also find that they have to take their differences and run with those to have the best chance of finding the things they need to survive.
Audubon Community Nature Center builds and nurtures connections between people and nature. ACNC is located just east of Route 62 between Warren and Jamestown. The trails and outdoor facilities are open from dawn to dusk. The Nature Center is open from 10 a.m. until 4:30 p.m. daily except Sunday when it opens at 1 p.m. More information can be found online at auduboncnc.org or by calling (716) 569-2345.
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