Bis2b Biodiversity Week 1 Lecture 2

What is biodiversity?

The variety of life in all its forms and combinations and at all levels of organization (genetic diversity, species diversity, and ecosystem diversity).

What is the difference between species richness and species evenness?

Species Richness: The total number of different species present in a given area.

Species Evenness: A measure of the relative abundance of each species (how equally individuals are distributed among the species).

Species Richness

The total number of different species present in a given area.

Species Evenness

A measure of the relative abundance of each species (how equally individuals are distributed among the species).

What is the Biological Species Concept (BSC)?

Defines a species as a group of individuals that can successfully interbreed in nature and produce fertile offspring, and are reproductively isolated from other groups.

What is the Morphological Species Concept?

Defines a species based on shared structural or anatomical features. It is often used for fossils or asexual organisms where reproductive behavior cannot be observed.

What is the Phylogenetic Species Concept?

Defines a species as the smallest diagnosable cluster of individual organisms within which there is a parental pattern of ancestry and descent (the smallest monophyletic group on a phylogenetic tree).

What is Biogeography?

The study of the geographical distribution of plants, animals, and other organisms across the globe and through geological time.

What is Vicariance?

The geographical separation and isolation of a biological population by a physical barrier (such as a mountain range, river, or continental drift), leading to the evolution of new species.

What is the Rain Shadow Effect?

A dry area on the leeward (downwind) side of a mountainous area. Moist air rises on the windward side, cools, and drops rain; by the time the air crosses the mountain, it has lost its moisture, creating an arid or desert region on the other side.

What is the difference between Climate and Weather?

Weather: The short-term conditions of the atmosphere (such as temperature, humidity, and precipitation) at a specific time and place.

Climate: The long-term average weather patterns of a specific region over an extended period (typically 30 years or more).

weather

The short-term conditions of the atmosphere (such as temperature, humidity, and precipitation) at a specific time and place.

climate

The long-term average weather patterns of a specific region over an extended period (typically 30 years or more).

What determines the boundaries of different Terrestrial Biomes?

Primarily determined by large-scale climate patterns, specifically the average annual temperature and the average annual amount of precipitation.

What is the Greenhouse Effect?

A natural process where atmospheric gases (like CO_2, CH_4, and water vapor) trap heat radiated from Earth's surface, keeping the planet warm enough to sustain life.

How do human activities accelerate Climate Change?

By burning fossil fuels and clearing forests, humans rapidly increase the concentration of greenhouse gases in the atmosphere, trapping excess heat and disrupting global climate systems.

What are the three primary species concepts used to define a species?

Biological, morphological, phylogenetic

Biological Species Concept:

Groups of actually or potentially interbreeding natural populations that are reproductively isolated from other groups.

Morphological Species Concept:

Groups organisms based on shared physical/structural characteristics.

Phylogenetic Species Concept:

Defines a species as the smallest monophyletic group on a phylogenetic tree.

What is the Latitudinal Diversity Gradient?

A global pattern where species richness is highest in equatorial/tropical regions and steadily decreases as you move toward the poles.

What is a biome?

A large, naturally occurring community of flora and fauna occupying a major habitat, characterized by distinctive vegetation and adapted organisms.

how do we define terrestial biomes?

Through mean annual temp and mean annual precipitation

What is the primary mechanism driving rapid global climate change?

The accelerated greenhouse effect, caused by human activities (burning fossil fuels, deforestation) releasing excess gases like CO_2 and CH_4, which trap heat in Earth's atmosphere.