The Key to Life
Earth is home to millions of species that interact with each other daily. Like pieces in a puzzle, each of these disparate species works together to
create a complete whole—the beauty of life on Earth as we know it.
So, what is the secret to how the environment works? Plant life, animal species, bacteria and other chemical compounds have all evolved in
specific ways that enable their survival in diverse, and sometimes even hostile environments. Think about a small part of an important process for a
moment: when a bee lands on a flower to help spread its pollen. Let’s say a bee lands on a flower in search of nectar (a sweet plant secretion), and some pollen
attaches to its body. As the bee flies around looking for even more nectar, it distributes pollen along its flight pattern, almost accidentally, and
ensures that the pollen from the first plant is distributed to the second plant, thereby acting as a middleman in flower reproduction. In this example, we see that
there are at least three organisms at work: plant 1, bee and plant 2. The existence of this system, with three organisms working together to ensure the mutual
survival and propagation of each other, is a product of biodiversity.
Biodiversity is a general term that describes diversity among plant and animal species in a given environment or ecosystem. Ecosystems are very
delicate. Think again about a puzzle: if one piece is slightly too big or too small, it will have consequences for the puzzle as a whole, and the ultimate
picture will not be complete. Biodiversity in ecosystems ensures that all of the pieces of the puzzle fit together.
A worthwhile thought experiment is to consider how biodiversity works in the ocean. If you have ever snorkeled or gone on a scuba diving
expedition, you know that it is possible to see a complex and complete underwater ecosystem if the ocean is clear and clean. When examining the shallows
of some parts of the ocean, it is possible to make out bright corals, waving sea anemones and many different kinds of fish all living together. Sometimes, an eel
will swim past; sometimes you can see a low-swimming rockfish. Close to shore are tide pools, which are pockets of biodiversity in themselves: these are areas
of the beach that are sometimes underwater, depending on how high the tide is when you visit.
In these underwater ecosystems, coral is often the most recognizable organism. A sponge-like substance, coral can be a variety of different hues—
sometimes they are green, sometimes brown, sometimes even blue or pink. Algae, a type of water-based bacteria, causes coral to become brown, while
other coralline pigments cause coral to have brighter coloration. The algae that causes coral to turn brown lives inside and feeds off the coral. Without the
coral, it would be unable to survive. This type of interaction is known as symbiotic because both organisms are affected by their interaction with each other.
When they are healthy, the interaction is predictable and understandable. Due to the nature of the relationship between coral and algae, and how reliant
they are on each other, if, say, the algae is unhealthy, it will negatively affect the coral, and vice versa.
Aquariums and zoos attempt to mirror the complex ecosystems that have evolved in nature. If you visit a zoo in North America, you can see a lion
living in a manmade habitat that reflects the ecosystem of its natural habitat in Africa or Asia. In the habitat, there will be plants and trees also native to
Africa, as well as rock formations (like caves) that replicate a lion’s natural surroundings. Similarly, if you visit an aquarium, you can look through thick panes
of glass to shark tanks, complete with large swimming turtles, rays and other fish that live peacefully among sharks. These are attempts to reproduce the
conditions in which the animals we see on display evolved—in so doing, they highlight biodiversity.
Biodiversity becomes especially important when an unexpected event takes place. A problem in the 21
st
Century is the fear of oil spills off the
coast of North America. For decades, companies have extracted oil from deep below the earth’s surface (mostly from areas deep in the ocean), where it was
produced centuries ago by natural processes. Oil is a very useful chemical compound we have to thank for most of modern technology, like the
gasoline we use to power our cars, and the electricity we need to see at night. With any extraction from the earth’s natural resources come certain risks, and
one of the risks of extracting oil is that it is likely to spill into the water. Oil, much thicker than water, can cause fish and other ocean-based mammals, and plant
life to lose access to light and oxygen, their main sources of nutrients. If you think about it, oil spills cause a breakdown of the biodiversity in an ecosystem—by
clogging up access to oxygen in the water, plants cannot photosynthesize (their growth system), fish lose their source of food, and oceanic organisms cannot
breathe.
As you can see from everything discussed above, an ecosystem’s biodiversity is the foundation for the lives of the organisms that inhabit that
ecosystem. Plant life, aquatic life and terrestrial life would be impossible without the delicate balance of each piece of the puzzle. If something goes wrong in
an ecosystem—like if all the bees that pollinated one flower species died—scientists will look to the biodiversity (that is, all of the organisms that live in
an ecosystem) of that meadow in which the bees were found, in order to assess what happened. For all parts of an ecosystem to have a mutually
beneficial relationship, the mechanisms that have evolved over a period of many thousands of years must be intact.
1. What is biodiversity?
A all the differences among the living things in an environment or ecosystem
B the underwater environments where algae, coral, and other oceanic organisms interact
C the process by which bees spread pollen from one flower to another
D unexpected events that take place and disrupt the way that an environment works
2. What does this passage explain?
A This passage explains photosynthesis by listing a series of steps.
B This passage explains zoos by using the point of view of a lion.
C This passage explains biodiversity by giving examples.
D This passage explains oil extraction by discussing an oil spill.
3. Different organisms in an environment interact with each other. hat evidence from the passage
supports this statement?
A Aquariums and zoos try to recreate the complex ecosystems that have evolved in nature.
B A bee flies from flower to flower in search of nectar, distributing pollen as it goes.
C Coral is an underwater organism that can be green, brown, blue, or pink.
D Oil is a useful chemical compound that helps power cars and other modern technology.
4. What could happen to an ecosystem if an unexpected event causes its biodiversity to reak down?
A The ecosystem could be harmed.
B The number of animals in the ecosystem could increase.
C The number of plants in the ecosystem could increase.
D The ecosystem could increase in size.
5. What is this passage mainly about?
A what an oil spill is and how it can harm an ecosystem
B what zoos are and how they recreate animals’ natural habitats
C what biodiversity is and why it is important
D the different ways that bees and flowers interact
6. Read the following sentence: “As you can see from everything discussed above, an cosystem’s biodiversity is the foundation
for the lives of the organisms that inhabit hat ecosystem.”
What does the word organisms mean in the sentence above?
A shallow parts of the ocean
B unexpected events
C chemical compounds
D living things
7. Choose the answer that best completes the sentence below.
In an ecosystem, different kinds of organisms interact with each other,
A such as
B although
C before
D instead
coral nd algae.
8. How do oil spills cause a breakdown of biodiversity in an ecosystem?
9. Based on the passage, why are bees important to flowers?
10. Suppose that all the bees that pollinated a particular flower species in an nvironment died. Based on the information in
the passage about biodiversity, what ight happen in that environment? Support your answer with evidence from the assage.