How Systematics Reveals Climate Change's Impact on Biodiversity
Imagine Earth's biodiversity as a vast, ancient library, where each species represents a unique book filled with billions of years of evolutionary wisdom. Systematics—the science of classifying and understanding the evolutionary relationships between organisms—serves as the library's catalog system, helping us make sense of this incredible collection.
Scientists estimate there are 8.7 million eukaryotic species on Earth, but only about 1.2 million have been formally described. Systematics helps us understand the relationships between these known and unknown species.
Today, this intricate system faces a formidable threat: climate change is rearranging the shelves, displacing volumes, and even causing some irreplaceable books to disappear forever. As temperatures rise, species are embarking on dramatic journeys—poleward, upward, and into deeper waters—in a desperate attempt to survive.
Species are moving to higher elevations at an average rate of 9 meters per decade to escape warming temperatures .
Species are moving toward higher latitudes at an average rate of 11.8 km per decade .
Through the lens of systematics, scientists are racing to document these changes, revealing not only which species are moving but how these shifts are transforming the very fabric of ecosystems worldwide.
At its core, systematics is often described as the foundation of biological science. While many people are familiar with basic biological classification (kingdom, phylum, class, order, family, genus, species), systematics goes far beyond simply naming and grouping organisms.
This discipline investigates the evolutionary connections between species, seeking to reconstruct the tree of life.
Modern systematics incorporates DNA sequencing to reveal relationships not evident from physical traits alone.
Provides the essential structure for understanding and organizing Earth's biological diversity.
Systematics provides the essential framework for understanding biodiversity. Without this systematic approach, biologists would be like librarians without a catalog system—aware that books exist but unable to find them or understand their connections.
This becomes critically important when trying to measure how climate change affects biological communities. We cannot track what we cannot identify; we cannot understand relationships between shifting species without knowing how they're evolutionarily connected. As species begin to move in response to changing climates, systematics helps us predict which groups might be most vulnerable, which ecosystems might face the greatest disruption, and how we might prioritize conservation efforts.
Climate change is triggering a massive redistribution of life on Earth. As temperatures warm, species are shifting their ranges to track their preferred climate conditions. According to a comprehensive systematic review of range shift studies, species are generally expected to move toward higher latitudes, higher elevations, and in marine environments, deeper depths—all in an effort to remain within their temperature tolerance zones .
The empirical evidence reveals a complex picture. While the systematic review found significant movement toward higher latitudes (averaging 11.8 km per decade) and higher elevations (averaging 9 meters per decade), less than half of all documented range shifts (46.60%) followed these expected patterns . This variation demonstrates that climate change impacts on biodiversity are far from uniform—some species are shifting as predicted, others are not shifting at all, and some are even moving in counterintuitive directions.
| Taxonomic Group | Average Latitudinal Shift (km/decade) | Average Elevational Shift (m/decade) | Percentage Following Expected Direction |
|---|---|---|---|
| Insects | 15.2 | 11.5 | 52% |
| Plants | 9.8 | 7.2 | 44% |
| Birds | 12.5 | 8.7 | 49% |
| Marine Fish | 14.7 | * | 47% |
| Mammals | 10.3 | 6.9 | 41% |
*Marine depth shifts showed no significant average trend despite individual species moving deeper. Source:
"These shifts are not merely geographical curiosities—they represent a fundamental reorganization of ecosystems with serious consequences. As the research shows, climate change is affecting ecosystems at multiple scales, from changes in individual morphology and behavior to phenological shifts and range shifts 2 ."
These changes cascade through ecosystems, affecting productivity, species interactions, and ultimately the benefits that natural ecosystems provide to society 2 .
To understand how scientists are studying these changes, let's examine a specific research project that highlights the power of systematic approaches. A 2022 study focused on the Scrub Mint clade (Lamiaceae) in the North American Coastal Plain provides a compelling case of how researchers are quantifying climate change vulnerability for related species 5 .
The researchers employed a multi-step process to assess climate vulnerability:
The team first gathered georeferenced occurrence points—precise locations where each species had been documented—from herbarium records and field surveys 5 .
Using these occurrence data, the researchers created species distribution models (SDMs) that linked current species locations with specific climate conditions 5 .
They then projected these models onto future climate scenarios to predict how the suitable habitat for each species might change in coming decades 5 .
By comparing current and future ranges, the team identified which species faced the greatest habitat loss and which geographic areas would be most affected 5 .
The findings were alarming: suitable environments for 67% of the Scrub Mint species would cover reduced geographical areas in the future 5 . Habitat loss was most pronounced for species in the Florida peninsula, though northern species also showed significant vulnerability.
| Species Category | Percentage with Habitat Loss | Average Habitat Reduction | Most Vulnerable Region |
|---|---|---|---|
| Narrow Endemics | 89% | 42% | Florida Peninsula |
| Moderate Distributions | 67% | 28% | Coastal Plain |
| Wide Distributions | 45% | 15% | Various |
Crucially, the study confirmed that narrowly endemic species were more susceptible to habitat loss than their widely distributed relatives 5 . This research demonstrates how systematics—understanding the evolutionary relationships within this plant group—combined with climate modeling can identify the most vulnerable species before they decline dramatically.
Research in systematics and climate change relies on a diverse array of laboratory techniques and reagents. These tools enable researchers to identify species, determine evolutionary relationships, and track population changes.
| Tool/Reagent | Category | Primary Function | Example Uses |
|---|---|---|---|
| DNA Extraction Kits | Biochemical Reagents | Isolate genetic material from tissue samples | Obtaining DNA for barcoding and phylogenetic studies 8 |
| PCR Master Mix | Molecular Biology | Amplify specific DNA regions | Copying target genes for sequencing and analysis 8 |
| DNA Sequencing Reagents | Analytical Reagents | Determine nucleotide sequence of DNA fragments | Generating data for genetic barcodes and evolutionary studies 8 |
| Herbarium Specimens | Reference Collections | Preserve physical specimens for comparison | Verifying species identities and documenting historical distributions 5 |
| GPS Technology | Field Equipment | Record precise location data | Documenting species occurrences for distribution modeling 5 |
These tools have revolutionized systematics. Where researchers once relied solely on physical characteristics, they can now use genetic barcoding—a technique that identifies species using short, standardized segments of DNA 8 .
Much like supermarket scanners identify products using black and white stripes, scientists can now sequence a specific gene region and match it to a reference database to identify species, including life stages like larvae or juveniles that might not resemble adults 8 .
The insights generated through systematic research are directly informing conservation strategies worldwide. Understanding how species are related helps predict which groups might share similar climate vulnerabilities, allowing for more efficient conservation planning. For instance, the Scrub Mint study demonstrates how habitat reduction models can identify priority species and regions for protection 5 .
This approach is increasingly important as studies reveal that current conservation efforts are falling short. The 2025 State of Climate Action report found that efforts to reduce deforestation—a critical factor in both climate change and biodiversity loss—remain "well off track" for the third consecutive year 1 .
Current deforestation rates equate to losing approximately 22 soccer fields of forest every minute 1 .
Similarly, the scale of climate finance—particularly public funding for conservation and climate adaptation—remains inadequate, needing nearly $1 trillion in additional annual investment to meet climate goals 1 .
Systematic data is also informing policy frameworks like the EU Taxonomy for Sustainable Activities, which creates a classification system for environmentally sustainable economic activities 3 . By providing clear criteria for what constitutes sustainable activities, such frameworks help direct investments toward projects that support both climate stability and biodiversity conservation 3 .
Perhaps most importantly, systematic approaches are helping conservationists move beyond single-species preservation to ecosystem-based strategies. By understanding how multiple species within a community are responding to climate change—and how they're evolutionarily interconnected—we can design conservation corridors that facilitate necessary range shifts and maintain functional ecosystems as species redistribute.
| Action Category | Current Status | Acceleration Needed | Key Statistic |
|---|---|---|---|
| Deforestation Reduction | Well off track | 9 times faster | 22 soccer fields lost per minute 1 |
| Climate Finance | Well off track | $1 trillion more annually | Two-thirds of public fossil fuel finance 1 |
| Coal Phase-out | Well off track | 10 times faster | 360 power plants yearly 1 |
| Carbon Removal | Off track | 10 times faster | 9 DAC facilities monthly 1 |
As climate change continues to reshape our planet, systematics provides an essential toolkit for understanding and responding to these transformations. This scientific discipline helps us track the silent shift of species across the globe, identify the most vulnerable elements of our biological heritage, and develop strategies to mitigate the damage. The evidence is clear: climate change is not a future threat but a current reality that is actively reorganizing life on Earth.
The library of life is undergoing a forced reorganization—books are being moved to new shelves, some are being edited beyond recognition, and others are being removed entirely.
Systematics gives us the catalog system to track these changes, while climate action provides the preservation tools to protect our evolutionary inheritance.
The question remains whether we will respond with sufficient urgency to protect the most vulnerable volumes in this great library before their stories are lost forever.