Spider Brains

In recent years the arrival of six grandchildren was helpful in keeping their grandfather young in body, heart, and mind. The grands arrived in two cycles. Two older grands are currently becoming ensconced in athletics on their home turf as competitive high school sports commands their attention. This is a normal and desirable progression. We only hope their explorations and experiences during early visits to their grandparents’ “Driftless Area” home in extreme northwest Illinois may remain pleasant, instructional memories as soccer and swimming replace some of their earlier interests. Included in the former were observations of little black ants, digger wasps, and detailed experiences with monarch butterfly life cycles—all four stages from egg to adult. We fondly recall a few astronomical experiences such as meteor watching, observing Planet Venus set while positioned just above the crescent moon, and later identifying the stars of Ursa Major (the Big Dipper) in a dark sky to name just a few.

Our second cycle grandchildren are all less than age 7. We must now devise additional science experiences to strengthen their awareness of the Designer and Creator of all things. Our 9/7/18 post described how the orb-weaving barn spider on our back deck provided affirmation of remarkable arachnid intelligence:

http://jasscience.blogspot.com/2018/09/wonders-of-orb-weavers.html

The challenge was how to communicate the lesson of our back deck orb-weaving spider to our grandchildren who live two hours away. No orb-weavers have yet demonstrated their engineering skills at their house. Absent the opportunity to observe a real, living barn spider, on our next visit to their home we settled for the next best thing—YouTube videos on the computer screen. On virtually any science topic many animal behavior videos are available using ordinary search criteria. For example, a search of “orb-weaver videos” yields a wealth of resources. After watching a number of YouTube videos on spiders, our grandson, age 5, announced he planned to search his neighborhood for spiders in the future. The YouTube sessions generated meaningful discussions.

Included in our spider discussions with three grandchildren were questions such as, “What is the spider thinking? Where does his knowledge come from? And how does he accomplish his precision web-building feats?” Grandpa recalls pointing to the children’s foreheads in several past discussions with the news that their tough cranium protects an important body organ—the brain. We announced, “The brain is where you think!” We have discovered that such discussions with young children are more fruitful than we might expect. Information on arachnid anatomy, especially the nervous system, is potentially more than a mere esoteric diversion. Spiders have the same basic bodily systems as humans, but they don’t work the same way, and they are arranged differently in their bodies. Their body systems—nervous, muscular, circulatory, excretory, and digestive—are wonder-provoking miracles of design and function.

The tiny poppy-seed-size spider brain is less elaborate than the human brain. But it is capable of processing considerable information from reception of the mechanical stimuli of sound, light, touch, pressure, and body part location sent to its brain from the spider’s sensory organs. These signals, in reality minute electrical spikes known as action potentials, pulse through the spider’s body through neural passageways at exceedingly rapid speeds. Finally the tiny spider brain “integrates” the information and the animal responds. There is evidence that the spider possesses some ability to learn and remember. Complex skills such as species-specific web building are intrinsically locked away in the miniature spider brain as are many other behavioral traits. Species-specific web building may be considered a manifestation of the mysterious trait of consciousness. 

Spiders, many other arthropods, and animals in other phyla manifest the phenomenon of consciousness. (Check the reference to consciousness in the 9/7/18 post linked above.) Scientists are baffled by consciousness phenomena in living creatures. There is no adequate reductionist explanation. We should not substitute elaborate descriptions for true explanations. Consciousness is one of the most overwhelming mysteries of science. Well known consciousness guru David Chalmers describes consciousness as “the most mysterious phenomenon in the universe.” 

Explanations for wonderful conscious abilities of humans and many lesser creatures including spiders is a secret only known fully to the God of Creation. He implants unique abilities, characteristics, and functions in living creatures. For these gifts we bow in worship of the Creator.    

    

   

   

Ecology and Environment

Ecology is a study of the interactions among living organisms and their environment. This discipline could involve one organism or species or all organisms in their living and non-living surroundings. The term ecology possesses manifold meanings and applications. For that reason, laypersons may shy away from pursuing an in-depth understanding of the subject. Ecology is sometimes called a science, a systematically organized body of knowledge. Therefore, we encounter the “science of ecology.”

The term had become popular in the second half of the 20th century. For centuries some writers introduced ecological principles as we understand them today, but there was never a unifying, rigorous, qualitative science associated with ecology. Two events helped heighten pubic awareness in the 20th century. One was the frightening onset of the atomic age. Another was the publication of a startling volume by Rachel Carson entitled “Silent Spring” in 1962. Atomic explosions and the impact of pesticides, especially DDT, affected ecological relationships and damaged the environment. In general we have become more aware that humans are capable of producing negative effects on our environment. 

The familiar term environment is sometimes confused with ecology. A brief definition follows: Environment consists of the surroundings or conditions in which an organism exists. The two terms are not synonymous. Sometimes people mistakenly state that certain events are “bad for the ecology.” Since ecology refers to interactions among living things, one cannot state that interactions are intrinsically bad or good. Some conditions we inflict on our environment, however, may be damaging.

Partly as a result of the two occurrences mentioned above, the first Earth Day was observed in 1970. Wisconsin Senator Gaylord Nelson was the prime mover for the Earth Day event. At the time, pollution problems were rampant, especially across our industrial cities. Earth Day affairs were held April 16-22. Famous CBS network commentator Walter Cronkite broadcast a comprehensive 15-part analysis of the nationwide Earth Day activities. The nascent movement has become mature in the last half century.

We recently viewed the entire Cronkite commentary series of the 1970 Earth Day. In my teaching district, I was blessed to have a wonderful teaching colleague—an environmental enthusiast who inspired teachers and students. My colleague combined Earth Day activities with a unique recov of local history. Our school was a short distance from the historical “Rockabye Railroad” which passed through the community of Brookside, NJ in the early 20th century on the way from Hunterdon County to Morristown, NJ. Summertime cargo consisted of peaches for the metropolitan area. In keeping with the goal of recovering history, his students recovered many railroad spikes and other artifacts from the original Rockaway Railroad bed which passed by our school grounds at a mere stone’s throw.

Earth Day clean-up events at my school are still etched in my memory. After viewing the Cronkite account of conditions in our country in 1970 we were reminded that government policies on air and water pollution were seriously deficient. It is difficult to recall that there were inadequate regulations on clean air, clean water, and endangered species. Soon there were government regulations on air, water, and endangered species. Studies in ecology and activism in environmental issues have sometimes morphed into weighty political issues. It has been difficult to find an appropriate balance between prudent environmental concern and the natural tendency of many citizens to actively propel their favorite movements or causes, often driven by personal politics.

Our blog attempts to strengthen personal faith as supported by knowledge of science. God’s reality is affirmed by investigating the beauty and order of His created works. In turn, God’s people are responsible for understanding, managing, and preserving the beauty of His created works. The mandate “rule over” of Genesis 1:28 implies utilizing our divinely implanted intellectual gifts to understand the dimensions of ecology and the blessings of our environment.        

               

Wonders of Orb-Weavers

Recently a new visitor appeared in a corner of our backyard deck. She was resting on a beautiful silken web. It was a barn spider. I made a mental note to instruct my young grandchildren on the wonderful diversity of spiders on our next visit with them. Perhaps we will need to convert them from arachnophobes to arachnophiles. Knowledge borne of patient instruction will be our educational goal. This easily spotted specimen was dark brown with a large, round abdomen about 3/4” long.  

What are spiders? They belong to a biological class of joint-legged arthropods, the most plentiful phylum in the animal kingdom by far. Arthropods include spiders and insects but spiders are distinct from the far more numerous insects. Spiders possess eight legs instead of six, only two body sections rather than insects’ three and they do not possess antennae or wings. They are carnivorous. There are over 45,000 spider species on the planet while there are well over one million different insect species. Of the 45,000 existing spider species there are 2800 orb-weaving spider species—180 of them in North America. Orb-weaving spiders make wheel or circular shaped webs.    They are the third most plentiful family of spiders in existence. One of the most well known capabilities of spiders, orb-weavers in particular, consists of their web-spinning designed to ensnare their life-sustaining meals. 

Few people have failed to read or encounter the plot of E. B. White’s Charlotte’s Web, a 1952 top children’s fantasy classic about Charlotte, the barn spider, who helped save Wilbur the runt piglet from slaughter by weaving messages of support for preserving Wilbur’s life on her web. Woven into the plot of the story is the fragility of life, including the frequent mention of flies which are naturally caught in Charlotte’s web. Charlotte eventually dies, but not before her genetic line continues in the birth of new spiderlings. There are many more positive life lessons woven through the classic’s story plot.

The web of orb weavers is a startling marvel of strength. Hundreds of feet of organic proteinaceous silk is produced by the spider and distributed through the animal’s spinnerets—silk spinning organs. The material from which spider webs are made is a marvel of function designed by the Creator of all Things. The diameter of spider webs is 1/10 of human hair, but ten times stronger than steel pound for pound. It is flow tolerant—stiff, then stretchy, then stiff again.

Construction of the orb-weavers’ web is an engineering feat practically unmatched in the animal world. She begins by floating a web line into the wind with the goal of attaching the end to a location some distance away. The spider attaches another single web to the original line to form a “Y.” Other spokes are constructed from the center point. Hundreds of concentric strands are then built on these spokes toward the middle. They are precisely spaced and meticulously attached as the spider extends the silken web from his spinnerets and attaches the sticky strands one spoke at a time in a deliberate act of precision engineering. Details of the intricate process are documented in many easily accessed YouTube videos—a wonderful resource for both young people and adults fascinated by the instinctive, mostly unlearned behavior of animals in the natural world.

Our spider is ready to capture her next meal. While she needs no help from humans in her predatory exploits, children and adults have been known to fling captured flies into the webs to observe the exhilarating result. Orb-weavers have poor eyesight but rely on vibrations from insects entrapped in the sticky web. Spiders have tiny brains only as large as a poppy seed. It is not really a brain typical of mammals but rather a tiny mass of “nerve tissue.” Somewhat complex architectural decision making is possible along with ability to sense the location of trapped flies trembling with desire to escape.

What neurological wonders result in such fascinating, deliberate behavior? Bioscientists are unable to propose a reductionist explanation. How is this behavioral pattern “encoded by neural networks?” Neuroethologists are “scientists who study the evolutionary and comparative approach to the study of animal behavior and its underlying mechanistic control by the nervous system.” The foregoing definition uses evolutionary as an adjective which hopefully explains the astonishing behavioral characteristics and ability of one of the most remarkable animals on Planet Earth. Other science writers offer us no additional help, offering description as a weak substitute for true explanation. Orb-weavers appear to possess a consciousness which cannot be explained except by the Creator of life itself.

Wikipedia introduced their lengthy article on “Animal Consciousness” with this statement: “In 2012 a prominent group of neuroscientists signed the “Cambridge Declaration on Consciousness,” which “unequivocally” asserted that “humans are not unique in possessing the neurological substrates that generate consciousness. Non-human animals, including all animals and birds, and many other creatures, also possess these neural substrates.” (emphasis mine)

The term consciousness generates a lively interest from behavioral scientists to theologians and many experts in between. We have submitted several posts on consciousness in humans and animals in the past. Our current post travels somewhat farther into discussion of a lower form of consciousness, this time in insects. Consciousness in humans, of course, is far more highly developed in terms of sentience and executive control. Consciousness in lower creatures, however, is also a bestowment of the Creator of All Things. Here is a link to our past post “Consciousness in Animals”—living things lower than man:

https://jasscience.blogspot.com/2017/02/consciousness-in-animals.html