Defining and measuring biodiversity: case essay guide
Answer eight questions on biodiversity in a 2-3 page APA essay with descriptive subtitles, covering definition, benefits, measurement, extinction, the Endangered Species Act, your local area's most and least diverse species from Map of Life, one local insect, and what you can do.
Editorial process
Last reviewed · August 13, 2026
Genes, species, ecosystems — and why measurement differs
The background reading gives you the structure the definition question wants. Biodiversity is the totality of genes, species and ecosystems in a region, and those three levels are not interchangeable ways of saying the same thing: genetic diversity is variation within species, species diversity is the variety of species in a region, and ecosystem diversity concerns the communities those species form. The measurement question follows directly from that split, because each level is measured differently and with different confidence. Species richness is a simple count; taxonomic diversity weights how distantly related the species are, which is why an island with birds and a lizard is more diverse than one with three birds. Ecosystem diversity is hardest because the boundaries of communities are genuinely unclear. Saying that explicitly answers question three far better than naming an index and leaving the reader to work out what it captures.
Questions six and seven require you to actually use the Map of Life tool for your own area, copy in the species chart, and comment on whether the result surprised you, then choose one local insect and describe its importance to humans. These cannot be answered generically, and they are the questions that make the essay yours. Question five flags that the Act's economic consequences come later in the course, so describe what it does and note the tension without arguing it out. The formatting instruction is specific: use descriptive subtitles summarising each question, answer in complete sentences that relate back to it, and include a title page, introduction and conclusion with APA citations throughout. Direct quotation is to be limited and marked, paraphrase must be attributed, and the submission is run through Turnitin with the originality score visible to you before the deadline — so write the background sections from the readings rather than close to them.
Likely learning objectives
Inferred from the brief — check these against your own rubric.
- 01Distinguish genetic, species and ecosystem diversity as three levels of biodiversity.
- 02Explain why each level requires a different measurement approach.
- 03Describe current drivers of extinction and their relationship to human activity.
- 04Summarise the purpose and mechanism of the Endangered Species Act.
- 05Use an interactive biodiversity tool to report on a specific local area.
Read the full question
Review every instruction before using the planning guidance that follows.
Turn the brief into deliverables
- 01A definition of biodiversity covering all three hierarchical levels.
- 02The importance and benefits of biodiversity.
- 03An account of how biodiversity is measured, including richness and taxonomic diversity.
- 04Definitions of extinction and its current causes, plus the Endangered Species Act's purpose.
- 05Map of Life results for your local area with the species chart, and one local insect described.
- 06A statement of what you can do individually to slow biodiversity loss.
Eight questions, eight subtitles
The Definition of Biodiversity
Genes, species and ecosystems as three hierarchical levels.
Why Biodiversity Matters
Ecosystem services, resilience, food and medicine, with sourced examples.
Measuring Biodiversity
Richness, taxonomic diversity and the difficulty of ecosystem boundaries.
Extinction and Its Causes
What extinction is and what is driving current rates.
The Endangered Species Act
What it does and is meant to do, with the economic tension noted for later.
Your Local Area on Map of Life
Most and least diverse groups for a chosen area, with the chart and a reaction.
A Local Insect Species
One insect from the area and its importance to humans.
What You Can Do
Individual actions that plausibly bear on biodiversity loss.
Background readings, then the interactive map
Recommended databases
- IUCN Red List
- Convention on Biological Diversity
- IPBES
- US EPA
- Map of Life
- World Health Organization
Search sequence
- 1.Re-read the supplied Global Biodiversity Strategy extract for the three-level definition.
- 2.Check the IPBES global assessment for current extinction drivers and rates.
- 3.Use the IUCN Red List to source the status of any species you name.
- 4.Read the EPA summary of the Endangered Species Act for its purpose and mechanism.
- 5.Open Map of Life at your own coordinates, capture the species chart, and identify one insect.
Reference shortlist
These are authoritative starting points, not a ready-made bibliography. A qualified reviewer must confirm that each source fits the assignment and supports the claim beside which it is cited.
Nothing here is cleared for citation until you have read it.
- 01
Global Assessment Report on Biodiversity and Ecosystem Services
IPBES · 2019
The current evidence on extinction rates and their drivers, for questions four and eight.
- 02
IUCN Red List of Threatened Species
International Union for Conservation of Nature · 2025
Authoritative status data for any species named in the local-area or insect sections.
- 03
Summary of the Endangered Species Act
U.S. Environmental Protection Agency · 2025
What the Act does and is meant to do, which is exactly what question five asks.
- 04
Convention on Biological Diversity
United Nations · 2025
The international framing of biodiversity levels and targets, supporting the definition and benefits sections.
- 05
Map of Life Platform
Yale University and University of Colorado Boulder · 2025
The interactive tool questions six and seven require you to use for your own area.
- 06
Biodiversity
World Health Organization · 2025
Human benefits of biodiversity, including medicine and nutrition, for question two.
Review before submission
Common mistakes
- Defining biodiversity as the number of species, which collapses three levels into one.
- Answering the measurement question by naming an index without explaining what it captures.
- Skipping the Map of Life work and describing biodiversity in general terms instead.
- Arguing the economics of the Endangered Species Act, which the prompt defers to later.
- Writing continuous prose without the descriptive subtitles the instructions require.
- Copying the whole United States map instead of only the species chart for your area.
Submission checklist
- All eight questions are answered, each under its own descriptive subtitle.
- The definition covers genes, species and ecosystems.
- Measurement is explained per level, including why ecosystem diversity is hardest.
- The Map of Life species chart for your chosen area is included.
- One local insect is named and its importance to humans described.
- Title page, introduction, conclusion, APA in-text citations and a reference section are present.
Use this guide to plan and review your own work. Follow your institution's rules and read our academic-integrity policy.

Written by
Aaron Bishop
MA, Education
assignment interpretation and research-methods coaching across disciplines
Aaron leads the EssayCrackers editorial desk. He works on how assignment briefs are read — what a rubric is actually asking for, and where students most often answer a different question than the one set.

Reviewed by
Dr. Nathan Cole
PhD, Rhetoric & Composition
Argumentation and thesis development
Nathan teaches first-year composition and directs a university writing center. He reviews EssayCrackers guides for argumentative soundness and citation accuracy.