Problem 11 - Biology Today and Tomorrow with Physiology

Question

An ______ species has population levels so low it is at great risk of extinction in the near future. a. endemic b. endangered c. indicator d. exotic

Step-by-Step Solution

Answer

The correct answer is b. endangered.

Step 1: Understand the Term 'Endemic'

An endemic species is one that is found only in a specific geographic location and nowhere else. It isn't necessarily at risk of extinction just because it is limited to a particular area.

Step 2: Understand the Term 'Endangered'

An endangered species is one that is at a high risk of extinction in the near future due to its low population levels among other factors. This directly matches the description given in the question.

Step 3: Understand the Term 'Indicator'

Indicator species are used to assess environmental health as they are sensitive to changes in their environment. This does not relate to population levels or risk of extinction.

Step 4: Understand the Term 'Exotic'

An exotic species is one that is introduced to an area where it does not naturally occur. This does not necessarily imply anything about its population levels or extinction risk.

Step 5: Choose the Option

Based on the definitions, the term 'endangered' (Option b) perfectly matches the description of having population levels so low it is at risk of extinction in the near future.

Key Concepts

Endemic Species

Endemic species are unique to specific geographic locations. They are found exclusively in a particular area and nowhere else in the world. This geographical restriction could be due to various reasons such as evolutionary history, habitat preferences, or physical barriers like mountains or rivers.

For example:

• The Lemurs of Madagascar
• Koalas in Australia
• Galápagos tortoises endemic to the Galápagos Islands

Endemic species are not automatically at risk of extinction simply because they are localized. However, they can become threatened due to habitat destruction, climate change, or invasive species. Their restricted range makes them more vulnerable to these threats, as they lack the option to relocate to new environments.

Conservation efforts for endemic species often focus on protecting their natural habitats and maintaining ecological balance within their locality.

Indicator Species

Indicator species play a crucial role in environmental science. They are species whose presence, absence, or abundance reflects a specific environmental condition.

These species are highly sensitive to ecological changes such as pollution levels, temperature shifts, or habitat alterations. For example:

• Amphibians are considered good indicator species for environmental health because their permeable skin makes them sensitive to pollutants.
• Lichens are used as indicators of air quality, as they are sensitive to air pollutants like sulfur dioxide.
• Mayflies indicate clean water as they cannot survive in polluted waters.

Indicator species are important tools for scientists to monitor the health of an ecosystem. By observing changes in the population of these species, environmentalists can gain insights into the broader ecological health and identify areas that may require restoration or further monitoring.

Exotic Species

Exotic species, also known as non-native or introduced species, are organisms that are introduced into an area where they do not naturally occur. This introduction can be intentional, such as planting non-native crops, or accidental, through processes like global trade and travel.

Once established, exotic species can have various impacts on their new environment. They might:

• Compete with native species for resources, sometimes leading to the decline or displacement of native species.
• Become invasive, meaning they spread rapidly and cause ecological or economic harm.
• Integrate without major problems into the new ecosystem.

A well-known example of an exotic species becoming invasive is the introduction of cane toads in Australia, which were brought in to control pests but ended up proliferating and causing damage to the local ecosystem. Managing exotic species often involves monitoring their spread and implementing control measures to protect native biodiversity.