One of the wonders of life on planet Earth is the influence of sunlight. As winter fades away and summer approaches, we see all kinds of changes in life. As scientific research continues into the wonders of the animal and plant kingdoms, we see more carefully designed biological systems. Here are some examples of how sunlight affects life cycles:
COCCOLITHOPHORES: These are tiny phytoplankton plants that live in the ocean. As the season changes and the Sun warms the waters, those organisms increase their rate of reproduction. They would smother themselves with overcrowding except for the fact that they give off dimethyl sulfide. That chemical rises into the atmosphere and oxidizes into solid sulfate particles. For raindrops to form, there must be moisture, cool temperatures, and condensation nuclei. The solid sulfate particles provide the condensation nuclei, and the rising air cools the moisture from the sea resulting in clouds. The clouds block the sunlight, thus cooling the sea and slowing down the reproduction rate of the coccolithophores and avoiding a massive die-off. This phytoplankton literally manipulates the weather to ensure its own survival.
SALMON. These fish know when to return to the waters of their birth to spawn. Built into their bodies is a pineal gland that stimulates the pituitary gland, triggering an urge to spawn. Navigation tools designed into the salmon allow them to find the place of their origin where they spawn and die.
BEAN APHIDS AND OTHER ANIMALS. Bean aphids give birth when the length of the day reaches 14 hours and 55 minutes, assuring that the offspring will have warmth. Similar triggers by sunlight affects life cycles, allowing muskox to shed their insular undercoat, mallard ducks to shed their winter down, and snowshoe hares to change their color from white to brown before all the snow melts.
FROM FRUITFLIES TO HUMANS. Fruitflies shed their pupal husk an hour before dawn even when kept in the dark. Even when kept in total darkness, hummingbirds slip into torpor at dusk, allowing them to conserve energy. A poppy folds its petals at dusk, even in a dark box. Both the hummingbird and the poppy will resume operations at dawn, even in the darkness. Scientists are still researching what triggers these changes even without sunlight. Medical researchers are also studying how humans respond to a lack of sunlight, causing seasonal affective disorders (SAD).
Studying the incredible ways in which sunlight affects life cycles on Earth is a great way to grow in appreciation for the creation process. We marvel at the careful design built into all living things. David looked at himself and his world and remarked, “I will praise you, for I am fearfully and wonderfully made: marvelous are your works…” (Psalms 139:14).
Every summer and early fall, the newspapers start talking about how horrible mosquitoes are. Then I have to deal with questions of why mosquitoes exist. If there is a kind and loving God, why do we have to worry about the diseases that mosquitoes carry? I have heard some people give rather foolish answers to this question, and I don’t wish to over-simplify in discussing it. But why do we have mosquitoes?
Many years ago, one of my professors at Notre Dame was Dr. George B. Craig, whose specialty was mosquitoes. He was “an internationally recognized expert on the biology and control of mosquitoes” according to a publication of the National Academies of Sciences. As one of his students, I learned some fantastic things about mosquitoes. Mosquitoes are pollinating insects. Most species of mosquitoes pollinate plants and don’t “bite” anything.
The word “mosquito” is Spanish for “little fly” and there are some 3500 species of them. The larvae of the mosquito are a significant part of the diet of fish and other water creatures. The mutation which turned some of them into bloodsuckers seems to have come into existence in recent history. It appears they were not created that way, and certainly have not always carried malaria and other diseases. The fact that there were no mosquitoes in Hawaii until the white man came to the islands with water barrels containing mosquito larvae is another important point to consider. The question of “why do we have mosquitoes” won’t always get answered to everyone’s satisfaction, but at least we can raise some points to make people think.
The design of the various food chains on Earth is very complex. This is especially true in freshwater areas with unique problems. In Alaska, for example, the necessary minerals for plants and the food sources for bears come from the salmon runs that bring the nutrients. The soil is sparse and nutrient-poor, and much of the year, the cold prevents normal food chains from functioning. Insects provide a significant means of moving nutrients through the system, so they are the base of the food chain in those freshwater systems. Without mosquito larvae to feed the freshwater creatures, including the salmon, that life would not exist.
Over the years we have presented data on some amazing migrations. We have had several discussions about the Arctic tern and how it makes its incredible 12,000-mile journey. Research has shown that the Arctic tern uses multiple cues including magnetism, sight, smell, and even sound. We have also talked about whales, salmon, and sea turtles and the way they benefit multiple ecosystems by their migrations. Now we have a new migration that has just been discovered and is equivalent to 20,000 flying reindeer. It’s migrating insects.
According to the study, 2-5 million migrating insects fly over the United Kingdom each year. The study is reported in the December 23, 2016, issue of Science by a team headed by Jason Chapman. Tracking these arthropods involves the use of special radar designed to detect insects. The team estimates that the total biomass of these arthropods is 3200 tons which is 7.7 times more than the biomass of the songbirds in the same area. These are tiny creatures with some of them weighing less than 10 milligrams.
Chapman notes that these arthropods are not just accidentally caught up in the wind. Some of them climb to the top of a plant to launch their flight. Some stand on tiptoe and put out silk until the wind catches them and carries them away. The animals only launch when the wind is to the north from May to June, and in August and September, they launch when the wind blows to the south. Chapman concludes “these arthropods must have some kind of built-in compass plus a preferred direction and the genetics that change that preference as they or their offspring make the return migration.“