Myth 2: Life is Fragile and Cannot Adjust Easily to Change
Myth 2: Life is Fragile, Requires Specific Conditions, and Can’t Adjust Easily to Change
Reality: Life is robust and capable of adjusting to change; life has persisted for at least 3.5 billion years, and as a group has greatly changed Earth’s surface and atmosphere.
Persistence vs. fragility: not every species can endure every condition, but life as a whole endures and adapts over time.
How life persists through change (in real time):
Some species adjust rapidly to short-term change.
Mechanisms of adjustment: behavioral, physiological, and, if necessary, evolution.
There are limits; large environmental changes may require biological evolution, which can be slow for long-lived organisms.
Debates continue about whether most species can adjust fast enough to rapid global warming.
Evidence of rapid adjustment in real populations:
Great tit, Parus major: a 47-year study showed females began laying eggs earlier as caterpillars emerged earlier due to warming; populations appeared to be doing fine.
IUCN notes population trend for Parus major appears to be increasing, not approaching Vulnerable under population-trend criteria.
Long-lived grasses and sedges in Britain showed little effect from thirteen warming years, illustrating real-time adjustment.
Three ways life can adjust to environmental change:
Behavioral: move or shift timing (e.g., earlier breeding like Parus major).
Physiological: adjust body function to cope with temperature or moisture changes.
Evolution: populations adapt genetically when needed.
Limits and time scales:
Short-term adjustments can occur quickly; long-term, substantial changes may require evolution, which can take decades to centuries for some species.
Recovery vs. change:
Some species recover slowly from changes, but many recover or persist via refugia, rapid evolution, or migration of genes/seeds.
Recovery and Real-Time Adjustment in Trees and Species
Refuges during climate change: sparse populations of tree species persisted during last glacial maximum (glacial refugia), allowing rapid post-glacial growth when habitat opened.
Rapid biological evolution: documented in wild organisms; invasive species have shown rapid evolution after arriving in new habitats.
Migration routes via seeds/pollen: trees don’t migrate themselves, but their propagules do.
Tree migration example (post-glacial):
Hemlock reached Massachusetts ~9,000 years ago (earlier than beech by ~2,000 years).
Hemlock reached the Upper Peninsula of Michigan ~5,000 years ago and moved west toward Lake Superior; beech is still migrating west, with its western boundary in the middle of the Upper Peninsula.
Hemlock population has faced pest pressures since ~1950 from an alien insect.
Biological Invasiveness Is a Major Factor in Life Persists
Biological invasions are a powerful means by which life persists and expands into new habitats.
Natural and human-assisted invasions:
Burmese python in Everglades; zebra mussels in North American waters; Melaleuca trees in south Florida as a pest.
Natural invasions (examples):
Surtsey Island (formed by volcanic eruption off Iceland): within weeks, a sea rocket appeared; soon mosses and grasses followed; demonstrated rapid natural invasion after new habitat creation; long-term monitoring began.
Cattle egret: native to Africa; expanded to South America, then North America (Texas to New England within a few decades); later spread to Australia and New Zealand.
Ecological invasion: invasion of an entire community via ecological succession.
Mount St. Helens eruption (May 18, 1980) destroyed forests and streams; life returned rapidly via pioneer species (e.g., fireweed) followed by late-successional species; soil stabilization and nitrogen fixation aided rapid recolonization; elk and steelhead returned in substantial numbers within years.
In the Past 2.5 Million Years, Few Species Are Known to Have Gone Extinct
Workshop (2007) examined extinctions during the last 2.5 million years; surprisingly few species went extinct despite major climate swings.
Notable exceptions in Europe and North America were linked to geography and migration barriers:
Europe’s north-south mountain barriers limited southward tree migration during ice ages, contributing to higher local extinctions of some tree genera.
North America’s north-south mountain ranges did not present the same barrier, affecting mammal extinctions differently.
The overall message: the capacity to adjust to climate change has been greater than some forecasts imply; extinctions have been fewer and more regionally dependent than assumed.
The Cost of Saving Endangered Species
Current scope:
About 1.5 million species are known and named.
US Endangered/Threatened: 1,209 endangered + 359 threatened = 1,568 total.
IUCN (2014): 7,678 vertebrates, 10,584 plants, total 22,413 species threatened.
Forecasts by some researchers: up to 15 to 37 percent of species extinct by 2050 in some regions (high-importance forecasts that influence policy and funding).
Cost examples (illustrative, not precise projections):
Snow leopard program (GSLEP) projected cost ~150 to 200 million over the first 7 years; condor conservation in the US cost ~5 million per year, about 100 million over two decades.
If the high-end forecast of 225,000 to 450,000 species were “fragile” and needed saving by 2050, costs could reach:
At roughly 100,000,000 per species: 22.5 trillion to 45 trillion over 35 years, i.e. about 643 to 1,286 billion per year.
Compared to the US annual budget (~3.7 to 4 trillion), this would be a substantial fraction (roughly one-sixth to one-third of annual spending) if applied broadly.
If costs were 10,000,000 per species per year, total long-run costs would be 2.25 to 4 trillion over 35 years, i.e. 64 to 129 billion per year, similar to major budget areas like education.
Core takeaway: while there is cost to conservation, projecting enormous, universal extinction risk can lead to misallocation of resources and overestimation of what can be saved; many extinctions are not inevitable, and resources must be allocated to prioritize where they matter most.
What Difference Does It Make If We Believe This Myth?
Believing that species are inherently fragile can mislead policy and funding decisions:
Underestimates the difficulty and cost of saving endangered species; some extinctions are beyond our control.
Risks overcommitting resources to save all species, which may be impractical or impossible.
Highlights a bias toward charismatic megafauna; many lesser-known or less charismatic species may be neglected.
The goal is to inform decisions about which species to prioritize and how to allocate resources effectively, balancing practicality with the desire to preserve biodiversity.