Biodiversity

What is biodiversity?

The variety of life existing on multiple levels.

What does ecosystem diversity refer to?

The range of different habitats or number of ecological niches per unit area in an ecosystem.

—> due to the varied environments on Earth

What is genetic diversity?

The variety in the gene pool of each species.

What causes variations in genetic diversity between populations?

Geographically separated populations.

What defines species diversity?

The variety of species per unit area.

What two factors are included in species diversity?

The number of species present and their relative abundance.

What does richness refer to in ecological terms?

The number of species in an area.

What does evenness refer to?

The relative abundance of each species.

What is Simpson's Reciprocal Index used for?

To describe and compare communities and their diversity.

What is the formula for Simpson's Reciprocal Index?

D = N(N-1) / Σ n(n-1)

N is total individuals of all species

n is the number of individuals of each species

What can be sampled by random quadrat?

Species numbers and abundances.

What could low biodiversity indicate?

Pollution, eutrophication, recent colonization, or agricultural management.

How can biodiversity be inferred from fossil evidence?

By studying historical changes in biodiversity.

How many mass extinctions have occurred?

Five mass extinctions (last one was 66 million years ago)

What pattern is observed in biodiversity between mass extinction events?

It tends to rise gradually.

What reliable methods can measure changes in biodiversity?

Carrying out reliable surveys.

What aspects of a species can indicate changes in biodiversity?

Population numbers, genetic diversity, and range of the species.

What aspects of an ecosystem can indicate changes in biodiversity?

Species diversity, richness, evenness, area occupied, and extent of ecosystem degradation.

What can indicate the biodiversity status of a taxonomic group?

The number of threatened species within the group.

What current crisis is affecting biodiversity?

The sixth mass extinction is happening rapidly due to human influence.

What human activities contribute to the current biodiversity crisis?

Spread of invasive species, hunting, pollution, deforestation, urbanization.

What has caused the rise in activities harming biodiversity?

Overpopulation (increasing from 2 to 8 million people since 1920)