Myth 2: Life is Fragile and Cannot Adjust Easily to Change

Vocabulary flashcards covering key terms and concepts about life’s persistence, adaptation, invasion, ecological succession, and endangered-species economics from the notes.

Myth 2: Life is fragile

The belief that life cannot respond to environmental change; reality is life is robust and can persist by adjusting behavior, physiology, or through evolution.

Parus major (great tit) study

A 47-year British study showing birds advanced egg-laying timing as springs warmed, demonstrating real-time adjustment to climate change.

IUCN

International Union for Conservation of Nature; authority on species status; observed that Parus major's population trend appears to be increasing and not at Vulnerable thresholds.

Refuges (glacial refugia)

Populations of trees persisted in small pockets during the last glacial maximum, enabling rapid postglacial expansion.

Rapid biological evolution

Fast genetic adaptation observed in some wild organisms and invasive species in response to climate change.

Migration via seeds and pollen

Trees don’t move themselves; their seeds and pollen disperse by wind/animals, leading to gradual geographic migration with varying rates among species.

Tree migration differences (Ice Ages)

Different tree species moved northward at different rates; e.g., Hemlock and Beech show asynchronous yet ongoing range shifts.

Biological invasions

The introduction and establishment of species into new habitats; can be natural or human-facilitated, often reshaping ecosystems.

Surtsey

New island off Iceland formed by volcanic eruption (1963–1967); rapid natural colonization by plants and animals illustrates swift invasions.

Cattle egret (Bubulcus ibis) invasion

African white bird that followed cattle into South America and later spread to North America and Australia, aided by winds; a notable natural invasion.

Ecological succession

Development of an entire ecosystem after a disturbance, from pioneer species to late-successional species as communities recover.

Pioneer species

Early-colonizing species after disturbance (e.g., fireweed) that quickly occupy bare ground and stabilize soil.

Fireweed

A pioneer plant that rapidly invades disturbed areas, can fix atmospheric nitrogen, and aids subsequent species’ invasion.

Mount St. Helens example

1980 eruption showed rapid ecological succession: pioneer species invaded, followed by later-successional plants and animal life returning.

Late-successional species

Species that establish as ecosystems mature and competition increases; adapted to stable, developed environments.

Extinctions in the past 2.5 million years

Few species went extinct despite major climate changes; geographic barriers affected extinctions (e.g., Europe vs North America differences).

Ice-age extinction patterns in Europe vs North America

European tree extinctions largely due to barriers to southward migration; North American patterns differed due to continental geography.

IUCN 2014 threatened totals

7,678 vertebrates; 10,584 plants; total 22,413 species listed as threatened.

US endangered/threatened counts

Under the Endangered Species Act: 1,209 endangered and 359 threatened (total 1,568).

Cost of saving endangered species

Estimates suggest extremely high costs (potential trillions) depending on assumptions; highlights financial and political challenges in conservation.

Fragility myth consequences

Belief in widespread fragility can mislead policy, overestimate costs, and divert resources from where they would be most effective.

Pollen data and refugia evidence

Pollen deposits and macrofossils provide fossil records showing past species distributions and refugia during climate changes.

Last glacial maximum

The peak of the last Ice Age; important context for studying how species persisted and migrated under climate stress.