Today is the International Day of Biological Diversity, which was created in 1993 by the United Nations to promote discussions about issues of biodiversity. Biodiversity means that there is diversity among and within plant and animal life in a particular environment. There is no question that biodiversity is an important environmental issue. Each year scientists discover new wonders within the natural world, but there are also many animals (and plants) that are on the verge of extinction.

Any discussion of Jewish ideas on biodiversity includes, almost by default, a conversation about Noah’s ark. To protect the world that had been endangered by humankind’s corrupt behavior, God devised a plan for preserving the original biological diversity that He had created in the world. The Torah makes it clear that Noah’s task was to include all of the animals of the world because all species are important to the Divine plan of creation.

The story of Noah is one of the primary sources in the Bible that encourages diversity. But, it is not the only way in which Judaism expects people to take care of the world. There is, for one, the prohibition against destroying fruit trees, which provide sustenance for all levels of life.

There is also a prohibition against cross-breeding species. One might not immediately see the restriction on cross-breeding as a promotion of biodiversity. From the perspective of Jewish tradition, however, it is a safeguard that preserves the natural order of the world. Even seemingly benign alterations in nature can, though not always, have devastating effects on the environment. Just think of the stories of foreign flora or fauna that have wreacked havoc because the new environment had no natural predators for that species. This does not always happen, and one can certainly point to improvements made by such scientific engineering, but the Torah sees greater benefit in protecting the specific integrity of all of God’s creations and teaching the world’s inhabitants to protect and appreciate nature as it is.

Note: While the act of cross-breeding a species is prohibited, however, once a new species has been created, such as the Ugli fruit, one may partake of it.