Web Resources:

• Google Maps

• Millennium Ecosystem Assessment

• An Overview of Biodiversity, from the World Conservation Monitoring Center. This is an excellent resource for biodiversity. 

• The Diversity of Life from the World Resources Institute. Includes an explanation of cultural diversity.

• National Biological Information Infrastructure. This is a huge database containing information on biodiversity.

• Biodiversity and Conservation, a hypertext book.

• Biodiversity and Conservation: The Web of Life, a featured program at the Field Museum of Natural History in Chicago!

• Illinois Natural History Survey. A state agency, on the UIUC campus that is charged with studying the state's flora and fauna.

What is Biodiversity?

• Defining the "B" word from biodiversity.ca.gov

Biodiversity (=biological diversity) is defined at three levels:

• genetic diversity

• species diversity

• ecosystem diversity.

Biodiversity increases when new genetic variation is produced, a new species arises, or a novel ecosystem (or habitat) is formed.

Biodiversity decreases when the genetic variation within a species decreases, a species becomes extinct, or an ecosystem (or habitat) is lost.

Biodiversity is a dynamic process, and what we see now is the product of hundreds of millions of years of evolutionary history.

Genetic Diversity

The variety of genetic information contained in all of the individual plants, animals, and microorganisms in the world.

It occurs between species, as well as within and between populations of the same species. Individuals belonging to the same species are usually not identical genetically.

• Intraspecific genetic diversity from the American Geophysical Union (AGU)

Genetic variation within a single species can be attributed to the enormous variety and complexity of habitats, and the different ways organisms have adapted to these habitats.

Genetic diversity can be measured using a variety of DNA and protein-based techniques to determine genotypic differences.

It can also (in part) be catalogued based on differences in expressed, phenotypic traits.

• people diversity.

(For example, of all the genes in humans, 10,000 are outwardly (visibly) expressed and vary from person to person.

Lecture Activity

As a review for the upcoming exam, consider the following questions:

1. What are the sources of genetic variation in a population?

2. How does new genetic variation arise?

3. How does genetic variation spread through a population?

Species Diversity

The variety of living species.

The question "What is a species?" turns out to be tricky... from The American Museum of Natural History.

Systems for the classification of species go back at least 2,500 years to the Greeks (Aristotle and Plato) and were formalized by Linneaus in the 18th century.

Lewis textbook definition is called the biological species concept

"a group of similar species that interbreed in nature and are reproductively isolated from all other such groups"

A less restrictive (more pragmatic) definition is the phylogenetic species concept

"The irreducible group of common ancestry which are diagnosably distinct from all other such groups"

An estimated 1.7 million species have been described to date.

Classification of Life: All life is grouped into three domains from the University of California Museum of Paleontology:

Bacteria (the "prokaryotes"), 4000 species.

Archaea, 500 species. The Archaea were discovered by Dr. Carl Woese of UIUC!

Eukarya (the eukaryotes), 1,700,000 species. The Eukarya includes the protists, plants, fungi, and animals (traditionally considered kingdoms).

Species diversity is not evenly distributed across the globe. In general, species richness is concentrated in equatorial regions (tropical rainforests) and decreases as one moves to the poles (or increases in altitude). 40-50% of all species are found in wet tropical rainforests, a region that comprises only 2% of the Earth's land surface.

Of 250,000 flowering plant species described, 125,000 are found in three tropical countries: Brazil, Zaire, and Indonesia. For comparisons, 18,000 are found in the U.S. (incl. Hawaii and Puerto Rico) and about 2,000 in Illinois.

How many species are there? How many have yet to be described?
(Some examples from: Systematics Agenda 2000: Charting the Biosphere.)

Numbers are approximate. Almost 60% of all species described have been insects.

Species are still being discovered aeroung the Earth.

• Oceanic Expedition Uncovers Vast Genetic Diversity Conversation with Craig Venter on the PBS on-line NewsHour

• Census of Marine Life. First report: Oct, 2003.

• Two new primate species discovered in the Amazon in 2002 from National Geographic

 Ecosystem Diversity

The variety of habitats, biological communities, and ecological processes occurring within and between each type of ecosystem.

Ecological processes, such as water and nutrient cycling, energy flow, succession, predation, competition, parasitism, primary production, decomposition of organic matter, soil rehabilitation, pest and disease regulation, water quality, and pollination, are maintained by a wide range of biologically diverse populations in natural ecosystems.

Ecosystem diversity is a precondition for species and genetic diversity.

• Natural community classification for Illinois

• Ecosystem diversity along Lake Michigan

• From Rainforest to Grassland: Plants and Their Communities Across Washington state

Reduction of Biological Diversity

Mass extinctions have re-set the level of biodiversity on earth through deep time.

• The "big five" mass extinctions

  Figure 14.12 in Hoefnagels pg. 298

  We are in a biodiversity crisis--the SIXTH and FASTEST mass extinction in Earth's history! (Read about it in Hoefnagels, pg. 298-299)

• Climate Change by humans started 8,000 years ago? from Science Daily

• The Current Mass Extinction About 27,000 species go extinct annually. This translates to three to three species per hour!

• Losses of biodiversity are irreversible. Replacement of the number of species (though not the same ones) takes approximately 10 million years.

1. Species Loss (Extinction)

• Extinction is accelerating. The rate of species extinction is 1,000-10,000 times higher now than at any time before humans evolved.

• 20% of all bird species have gone extinct during the last 2000 years and 11% more are endangered now. In the US, over the last 100 years, 2% of the amphibians, 1.2% of the fish, 1% of the plants, and 9% of the freshwater mussels have vanished. Note that these are all species easily observed and recorded. Other losses are unknown.

• Conservation measures, sustainable development, and stabilization of human population numbers and consumption patterns seem to offer some hope that the next mass extinction will not result like previous ones, when 90% of the world's species were lost.

• In Illinois, 329 species of flowering plants are threatened or endangered.

• For additional information:

• Endangered or threatened species in the U.S.

• Endangered or threatened species in Illinois

• The Sixth Extinction, by Niles Eldridge. An excellent read!

• Recorded Extinctions, by Peter Bryant

• Extinction of the dinosaurs

2. Population Loss (Loss of Genetic Variation)

• The decline in numbers and sizes of populations.

• Potential for inbreeding and lack of variety in mate selection.

• Invasive Species, from USDA and More on invasive species, from the US Geological Survey.

• Loss of genetic diversity in Illinois populations of the Greater Prairie Chicken.

• UIUC's Head of Animal Biology, Ken Paige, has been studying the genetics of the Greater Prairie Chicken.

3. Habitat Loss

See Figure 42.3, pg. 845 in Hoefnagels

• Google Maps - look for deforestation in the Amazon Rainforest of Brazil
  

• About 60% of all the tropical forests which existed 100 years ago are now gone. Now, 1-2% of the remaining tropical forests are removed each year. This is equivalent to losing an area the size of Florida every year!

• This translates to about 2.4 acres (1 hectare) per second, equivalent to two football fields (or 149 acres per minute or an area larger than NYC every day)

• If deforestation continues at current rates, it is estimated that all tropical rainforests will be destroyed by the year 2030.

• Habitat loss directly impacts species diversity and genetic diversity

• For additional information:

• For a discussion on rates of extinctions, especially in the tropics, check out the Rainforest Action Network for rates of rainforest destruction.

• Prior to settlement, more than 60% of Illinois, approximately 22 million acres, were covered with prairie. Today, just over 2,000 acres of high quality prairie remain, less than one-hundredth of one percent. Tall grass prairies are endangered ecosystems in Illinois. The Tallgrass Prairie in Illinois, by Ken Robertson, INHS.

Model of Biological Diversity

A Model of Biodiversity to pull it all together.

Illinois Biodiversity

INHS has several resources to explore biodiversity in Illinois