Earth’s Biodiversity Benefits All Life
Americans like options, lots of them. A visit to an American supermarket, a mall, or an online outlet like Amazon reveals a bewildering array of choices.
Diversity extends beyond shopping. We see it throughout creation. There are millions of different molecules and millions of different species of life. None of the billions of galaxies or billions of billions of stars are the same. And when it comes to our planet—in particular the variety of plants and crops Earth sustains—that diversity testifies to purposeful creation.
A History of Biodiversity
Our planet’s diversity of life is mind-boggling. It has steadily increased throughout life’s history, but grew exponentially since the end of the Precambrian 543 million years ago. The total number of families (a family is a taxonomic rank between a genus and an order) of life increased from just a few to 280 during the early Cambrian, rose to 450 during the Ordovician Period 485–444 million years ago, reached 650 by the end of the Permian Period 252 million years ago, shot up to about 1,300 in the late Cretaceous Period 66–60 million years ago, and exploded to 2,400 by the advent of humanity.1
The 2,400 families consisted of 6.5 million land species and 2.2 million marine species.2 These 8.7 million species include only the eukaryotic life-forms (life based on cells with nuclei), a number equal to the maximum theoretical carrying capacity of Earth.
The diversity of Earth’s life displays more than the implied extravagance of the Creator. Ecologists are uncovering multiple specific benefits of life diversity.
One recently discovered benefit concerns agricultural productivity. For centuries, farmers have presumed that crop specialization delivers maximum productivity. It is not uncommon, for example, to drive through Saskatchewan or Indiana and see family farms consisting of several sections of only wheat or only corn (one section = one square mile). Corporate farms typically are much larger and just as specialized. Such specialization has yielded more crops per hectare because the respective farmers need only to develop expertise on one crop.
However, two research studies have established that large-scale, intensified cultivation with crop specialization often results in soil and freshwater degradation, air pollution, excess greenhouse gas emissions, and ecosystem imbalances.3 In a recent issue of Science Advances an international team of seven biologists, environmentalists, and ecologists led by Giovanni Tamburini reported on their review of 98 meta-analyses that comprised 41,946 comparisons between multiple and single crop cultivation practices.4 They found that most of the analyses resulted in win-win solutions.
Tamburini’s team demonstrated that crop diversification in nearly all cases enhanced “biodiversity, pollination, pest control, nutrient recycling, soil fertility, and water regulation without compromising crop yields.”5 The enhancements were especially dramatic for nutrient recycling, soil fertility, and water regulation. Furthermore, Tamburini’s team showed that these win-win outcomes could be achieved at all farm
–size scales and on all regional scales, from local to global. Plus, the crop diversity supplies an insurance benefit. An environmental disaster might cripple the productivity of one crop, but it is unlikely that six or more distinctly different crops would all simultaneously fail.
An independent team of seven other ecologists led by Andrew Barnes presented another biodiversity study in the same issue of Science Advances.6 Barnes’s team compiled 487 arthropod food webs in long-duration grassland biodiversity experiments in North America and Europe. (Arthropods form an animal phylum that includes insects, spiders, scorpions, centipedes, millipedes, and crustaceans.) They showed that “plants lose just under half as much energy to arthropod herbivores when in high-diversity mixtures versus monocultures.”7 In other words, twice as many crops survive insect infestation when farmers diversify crops. Their studies revealed at least two of the reasons for the reduced arthropod herbivory (consumption by insects): (1) increased plant biodiversity reduced the average herbivore food quality, and (2) increased plant diversity provided more opportunities for predators of arthropods.
Biodiversity Philosophical Implications
Neither Tamburini’s nor Barnes’s team commented on the philosophical implications of their findings. The most obvious is that a high level of biodiversity is essential for maintaining healthy ecosystem balances. Another is that because of Earth’s extreme biodiversity we humans need not choose between what is maximally beneficial for sustaining our food supply and what is maximally beneficial for sustaining the rest of Earth’s life. The millions of diverse species of life presently on Earth mean that we can fulfill all of the biblical mandate to manage Earth’s resources for our benefit and the benefit of all other life.
It is compelling to consider that at humanity’s advent, Earth contained the maximum carrying capacity of different species of life. This means that we humans see God’s creativity to a degree that should leave no doubt to any human who takes the time to explore Earth’s life that an all-powerful, all-loving God must exist. The beauty and elegance we see in Earth’s life testifies of God’s love for beauty and elegance. As the prophet Isaiah declares, “He [God] did not create it [Earth] to be empty, but formed it to be inhabited (Isaiah 45:18).” And as the psalmist shouts, “How many are your works, O Lord: In wisdom you made them all; the earth is full of your creatures (Psalm 104:24).”
- Michael J. Benton, “Diversification and Extinction in the History of Life,” Science 268, no. 5207 (April 7, 1995): 52–58, doi:10.1126/science.7701342.
- Camilo Mora et al., “How Many Species Are There on Earth and in the Ocean?” PLOS Biology 9, no. 8 (August 23, 2011): id. e1001127, doi:10.1371/journal.pbio.1001127.
- B. M. Campbell et al., “Agricultural Production as a Major Driver of the Earth System Exceeding Planetary Boundaries,” Ecology and Society 22, no. 4 (December 2017): article 8, doi:10.5751/ES-09595-220408; Alison G. Power, “Ecosystem Services and Agriculture: Tradeoffs and Synergies,” Philosophical Transactions of the Royal Society B: Biological Sciences 365, no. 1554 (September 27, 2010): 2959–71, doi:10.1098/rstb.2010.0143.
- Giovanni Tamburini et al., “Agricultural Diversification Promotes Multiple Ecosystem Services without Compromising Yield,” Science Advances 6, no. 45 (November 4, 2020): id. eaba1715, doi:10.1126/sciadv.aba1715.
- Tamburini et al., “Agricultural Diversification,” p. 1.
- A. D. Barnes et al., “Biodiversity Enhances the Multitrophic Control of Arthropod Herbivory,” Science Advances 6, no. 45 (November 6, 2020): id. eabb6603, doi:10.1126/sciadv.abb6603.
- Barnes et al., “Biodiversity Enhances,” p. 1.