A common theme among many of the previous Sightings blogs is that natural laws (physics, chemistry and biology) govern the planet and universe and that life has evolved from the basic elements released during the Big Bang. Each organism is part of a population of similar organisms and an ecosystem made up of other plants, animals and inorganic features. They also evolved from a common ancestor living about 3.5 billion years ago.
Theologians spend years poring over every verse in their sacred books to better understand the creator. Another gauge of the creator’s true character can be seen in the genesis of the universe and nature. Natural laws and commonalities across species (DNA, reproduction, adaptation) are all mirrors of the creator’s artwork and the universe is the canvas.
Several features of nature cut across species and even non-living landscapes. A few are described below:
Similarities of Life
All life has a series of characteristics in common:
- Composition – cells form the basis of life and function to sustain an organism in its environment.
- Energy Use – all processes expend energy, but the source of energy may be different. Plants obtain their energy from sunlight while animals obtain their energy from feeding and the breakdown of glucose. Some bacterial life obtains their energy from sulfur.
- Response – plants and animals react to stimuli in the environment.
- Growth – most living organisms grow and change through cell division (mitosis). Unicellular organisms ingest nutrients, grow and divide into two new daughter cells.
- Reproduction – Organisms must reproduce either asexually or sexually. Asexual organisms make an exact copy of themselves, while multicellular organisms allow for the exchange of genes within the same species and this ultimately aids evolution through genetic adaptation to environmental conditions.
- Adaptation – All organisms adapt and evolve to a changing environment. Those that do not adapt successfully will become extinct.
There is an amazing similarity across many species during the embryonic stages of life. The development of an organism expresses some elements of the intermediate forms of its ancestors throughout evolution as shown in the figure below. Human embryos at various points of their gestation have gill slits, webbed feet and hands, and tails. In organisms that need these features they are retained, but where they are not needed they are eliminated by genetic signals causing the gills, web between fingers and toes, and the tail to be reabsorbed through a process called necrosis. These similarities suggest a common origin.
Similarities of Genes Among Species
If life comes from a common ancestor, then their genetic makeup would show evidence of this evolution. The table below illustrates that all species contain genes (genetic building blocks) that are similar to those found in humans. A human gene transplanted into another organism performs a similar function. We are most closely aligned with African apes which contain about 99 percent of the genes found in humans. This reflects our close relationship with our most recent ancestor and our origins on that continent two million years ago. Many other mammal species contain between 75 and 84 percent of genes comparable to humans. Drug development with these species is common and is used to find medicines that will function in humans.
It is then not surprising that we have similar genes in our makeup that are common to fish, insects and even plant species. Life all originated in the primordial ooze 3.5 billion years ago and evolved from that point to all the species that ever inhabited the earth, perhaps as the creator intended.
Common Patterns in Nature
Nature, both living and unliving, is filled with many common patterns which include:
- Symmetry – in many organisms the left side is a mirror image of the right side.
- Fractals – are never-ending patterns that remain indefinitely even as they are broken into smaller pieces. Spirals are common in living things, such as the horns of a sheep and a nautilus shell. Spirals can also be seen in hurricanes.
- Fibonacci patterns – Based on a mathematical formula known as the Fibonacci sequence and illustrated by branching in trees and leaves arranged on a stem.
- Tessellations – Patterns formed by repeated cubes or tiles and typified by the honeycomb formed by bees.
Ecosystems form the foundation for life on earth. They provide the life support and ecosystem services needed by humans and other life to survive. Nature has evolved over billions of years and has formed ecosystems that contain both living and non-living components that interact as a unit and perform many vital ecosystem services.
Many scientists suggest we are in the sixth mass extinction our planet has faced, but this time at the hands of man. Nearly 26,000 plant species, 1,100 mammals, 1,200 birds, 700 freshwater fish and hundreds of reptiles and amphibians are threatened with extinction according to the World Resources Institute. This represents a huge loss of natural capital and is contrary to one of the primary rules of ecosystem health: diversity.
The scale of negative human impacts is growing and accumulating to fundamentally affect the ability of nature to supply these services. Ultimately, we do not know how resilient nature is to absorb this damage. The fate of nature is our fate. In the words of Pope Benedict XVI, “the book of nature is one and indivisible.”
The next Sightings, An Earth-Centered Economy, will explore the ecological underpinnings of the planet and their relationship to a sound, sustainable global economy. Several specific ecologically-based strategies will be examined.