The Pensive Biologist

Our current culture is so rich that we live in a hyper-rich bubble unique to all of human history. We no longer suffer the great diseases and famines of the past. We travel vast distances and have cell phones that give us access to all human knowledge. But we lack the intimate knowledge of hardship and death that our ancestors saw in their villages and in Nature all around them. Safe within our bubble, we just don't understand Life in the raw, Life unfiltered. Evil causes death. It was a clear cause and effect relationship that our ancestors understood. Animal sacrifice was regarded as something that could reverse this inevitability. Perhaps the death of an animal would cover over human evil. Furthermore, those who sacrificed themselves could, in certain situations, protect the entire village. Though it's becoming harder for us hyper-rich people to see, the sacrifice of Christ is best viewed within this framework of our impoverished ancestors. It is the death of the obedient son to erase evil and grant life to others.

We have seen from our previous podcasts that the world appears to be cruel, brutal, and downright crazy. But can I make such a judgment call? Isn't my desire for mercy, morals, order and justice simply genetically-programmed? These sorts of traits are evolutionarily adaptive for social animals. I think worrying about the mechanism for how a particular trait got into us is a distraction. God can move through evolution to place such "cosmic-level" values in us so that we can communicate with God. So I do have freedom; freedom to make the call that something is off-kilter with this world. Freedom to yearn for something different. 

Herbivores like cows and sparrows have eyes on the side of their heads. This enables them to see predators from nearly 360 degrees. Herbivores live in constant fear of violent death. Carnivores, such as wolves and big cats, regularly detect key information from scents laid down by other carnivores. Even predators must continually stay on top of threats. An ecological “landscape of fear” has been postulated where animals withdraw in the presence of predators. The fear of death is not due to a lack of courage; rather, it is natural, sensible, and evolutionarily adaptive. 

A corpse is a rich source of nutrients for a diverse range of organisms. A straightforward way to consider our own mortality is to study the organisms that will decompose us in the final stages of our existence. Flies (maggots) are first on the scene, followed by beetles (grubs), but it is bacteria that do the bulk of the decomposition (no, you'll really love this episode!). In the end, it is dermestid beetles and two genera of fungi that eat the now dried remains. 

Plants create soft, sweet fruits for animals to eat in order to disperse the seeds. Fruits are plant organs that dissolve their own cells to become desirable. Deciduous trees in Autumn form beautifully colored leaves. These leaves are acutally in the midst of dying, evacuating their own chemical resources to the roots (and therefore turning colors). Both of these processes are evolutionarily favorable, bringing advantages to the plant. But why is Death a necessary evil in this world we live in?

In my yard, I build garden walls with limestone blocks full of fossils. Each block is really a memorial in stone of a community of organisms that had their own busy little lives 90 million years ago. Similarly, our human communities bond us together as we live our own busy little lives. Communities give us meaning and purpose. And yet communities die just the same as individuals. Communities become forgotten graveyards and then forgotten civilizations. They hold no refuge for us.

What do our bodies do with an infected cell? Or a cancerous cell? We must mark that cell for destruction for the greater good of the body. Why must lethal force be used continually to keep the body functional? Apoptosis, or cellular suicide, plays an essential role in the developing anatomy of the fetus. Why must suicide be essential to the generation of life? Could life have taken a different evolutionary path, one without death or violence or famine?

Our skin consists of cells, migrating upward to the surface, becoming hardened and waterproofed, and then dying to protect us from abrasion, chemicals, and pathogens. As the skin cells absorb this abuse, they are lost over time and must be continually replaced. Our own cells, with our own DNA, a part of who we are; these are daily on a journey to death. Death is the norm even at the cellular level.

Most organisms on Earth live very short lives and reproduce rapidly. We view them as "food for important species". Even at the top levels, most predators don't live to see adulthood. In an empty sort of way, some conclude that "it is the way it is", but let's actually think and ask why Life is so brief and so cruel.

The first episode in my module exploring Death from a biological perspective. Other than chemoautotrophs like plants, every creature on this planet, even herbivores, must eat another creature to survive. This brings the philosophical question: why is Life so completely dependent on Death?