A 4.2 conservation of biodiversity

What is biodiversity?

The variety of life in all forms, levels, and combinations.

What are the three levels of biodiversity?

Ecosystem, species, and genetic biodiversity.

What is genetic biodiversity?

Genetic variation within a species.

How many major mass extinctions have occurred?

5

What caused past mass extinctions?

Volcanic activity, asteroid impacts, climate changes.

When was the last mass extinction?

66 million years ago

What is happening now regarding extinction?

A human‑driven sixth mass extinction.

What does fossil evidence suggest about current biodiversity?

It is likely at its highest point ever.

What does anthropogenic mean?

Human‑derived activities causing extinction.

What are the five main human causes of extinction?

Overharvesting, habitat destruction, invasive species, pollution, climate change.

What mnemonic helps remember extinction causes?

POIC.

What caused giant moas to go extinct?

overhunting

Why did Caribbean monk seals go extinct?

Overhunted for oil and meat.

What caused the Mount Glorious Torrent Frog’s extinction?

Deforestation and invasive species.

What are major causes of ecosystem loss?

Land‑use change, water diversion, overexploitation, pollution, climate change.

What happened to Southeast Asia’s mixed dipterocarp forest?

Logged heavily and replaced by oil palm plantations.

Why does dipterocarp forest loss increase CO₂ emissions?

Peat soil disturbance releases CO₂.

What happened to the Aral Sea?

Rivers were diverted, turning it into a desert.

How did Aral Sea salinity change?

Increased from 1% to 22%, causing fish extinction.

What organization provides biodiversity crisis evidence?

IPBES.

What data is used to monitor biodiversity?

Population sizes, species diversity, ecosystem extent, species ranges, manual surveys.

How does population growth affect biodiversity?

Creates unsustainable pressure on natural resources.

What is in situ conservation?

Protecting species in their natural habitats.

What is ex situ conservation?

Protecting species outside natural habitats (zoos, seed banks, germ plasm storage).

What is rewilding?

Restoring damaged ecosystems to their natural state.

What does EDGE stand for?

Evolutionarily Distinct and Globally Endangered.

What two criteria define EDGE species?

Evolutionary uniqueness + high global extinction risk.

Why prioritize EDGE species?

They preserve ancient, irreplaceable branches of the tree of life.