Biodiversity Variety of the earth’s species, the genes they contain, the ecosystems in which they live, and the ecosystem processes such as energy flow and nutrient cycling that sustain all life.

Hot Spots A hotspot is an area where there are many threatened and endangered species There are currently 34 hotspots in the world today

Species Diversity Number and abundance of species present in different communities

Ecological Diversity The variety of terrestrial and aquatic ecosystems found in an area or on the earth

Functional Diversity The biological and chemical processes such as energy flow and matter recycling needed for the survival of species, communities and ecosystems Food Chains & webs

Genetic Diversity The variety of genetic material within a species or a population

Theory of Natural Selection Explains how life has evolved from a common ancestor

Survival of the fittest Organisms suited for the environment will survive to reproduce, thus passing down desirable traits. Examples: Giraffes Camels Influenza virus Venus fly trap NOTE – fittest does not equal strongest!!!

Natural Selection and Geological Processes Location on the earth influences biodiversity (rainforest vs. tundra) Continental movement Earthquakes and volcanoes Climate change Cyclic cooling and heating of the earth Catastrophic events Asteroid impacts, major volcanic eruptions

Continental movement Theory of Continental Drift The earth has large plates located between the lithosphere and asthenosphere These plates move very slowly (1-3cm/yr) This creates oceans, mountain ranges, volcanoes, earthquakes, trenches

225 million years ago 225 million years ago 135 million years ago Figure 4.5 Geological processes and biological evolution. Over millions of years the earth’s continents have moved very slowly on several gigantic tectonic plates. This process plays a role in the extinction of species as land areas split apart and promote the rise of new species when once isolated land areas combine. Rock and fossil evidence indicates that 200–250 million years ago all of the earth’s present-day continents were locked together in a supercontinent called Pangaea (top left). About 180 million years ago, Pangaea began splitting apart as the earth’s huge plates separated and eventually resulted in today’s locations of the continents (bottom right). 65 million years ago Present Fig. 4-5, p. 88

Continental Movement

Climate Change

Climate Change and Natural Selection Changes in climate throughout the earth’s history have shifted where plants and animals can live. Figure 4-6

Catastrophic events Asteroid impacts Super Volcanoes These affect biodiversity locally and on a world-wide scale

Speciation - formation of a new species Two Phases 1. Geographic isolation A population is removed from others of it’s species for a long period of time 2. Reproductive isolation The removed population becomes so genetically different over time that it can no longer interbreed with others of it’s species

Measurements of Biodiversity Species diversity – the number of different species in a community Species evenness – the abundance of species in a community

Richness and Sustainability Higher species richness = higher productivity = higher sustainability Reasons: More likely to withstand droughts, disease, climate change, nutrient shortages Higher number of producers lead to a higher biomass which leads to more carbon and nitrogen cycling

Extinction – the loss of a species Background extinction – low rate of extinctions Mass extinction-high rate of extinctions due to specific cause Climate change

Three types of extinctions Local: A species is no longer found in an area it once inhabited but is still found elsewhere in the world. Ecological: Occurs when so few members of a species are left they no longer play its ecological role. Global (biological): Species is no longer found on the earth.

Global Extinction Some animals have become prematurely extinct because of human activities. Figure 11-2

Steps to extinction Background extinctions: Rare Threatened Endangered

Endangered and Threatened Species: Ecological Smoke Alarms Endangered species: so few individual survivors that it could soon become extinct. Threatened species: still abundant in its natural range but is likely to become endangered in the near future. Figure 11-3

Red lists ICUN – International Union for the Conservation of Nature and Natural Resources Published list of threatened species www. iucnredlist.org

Some species are more prone to extinction: K-strategists Specialists Tertiary consumers Fixed migratory patterns Narrow distribution Commercially valuable Large territories

Swallowtail butterfly Humpback chub Golden lion tamarin Siberian tiger Grizzly bear Kirkland’s warbler Knowlton cactus Florida manatee African elephant Figure 11.3 Endangered natural capital: species that are endangered or threatened with premature extinction largely because of human activities. Almost 30,000 of the world’s species and 1,260 of those in the United States are officially listed as being in danger of becoming extinct. Most biologists believe the actual number of species at risk is much larger. Utah prairie dog Swallowtail butterfly Humpback chub Golden lion tamarin Siberian tiger Fig. 11-3, p. 224

Giant panda Black-footed ferret Whooping crane Northern spotted owl Blue whale Figure 11.3 Endangered natural capital: species that are endangered or threatened with premature extinction largely because of human activities. Almost 30,000 of the world’s species and 1,260 of those in the United States are officially listed as being in danger of becoming extinct. Most biologists believe the actual number of species at risk is much larger. Mountain gorilla Florida panther California condor Hawksbill sea turtle Black rhinoceros Fig. 11-3, p. 224

Indian Tiger Range 100 years ago Range today (about 2,300 left) Figure 11.8 Natural capital degradation: reductions in the ranges of four wildlife species, mostly as the result of habitat loss and hunting. What will happen to these and millions of other species when the world’s human population doubles and per capita resource consumption rises sharply in the next few decades? (Data from International Union for the Conservation of Nature and World Wildlife Fund) Range 100 years ago Range today (about 2,300 left) Fig. 11-8a, p. 230

Black Rhino Range in 1700 Range today (about 3,600 left) Figure 11.8 Natural capital degradation: reductions in the ranges of four wildlife species, mostly as the result of habitat loss and hunting. What will happen to these and millions of other species when the world’s human population doubles and per capita resource consumption rises sharply in the next few decades? (Data from International Union for the Conservation of Nature and World Wildlife Fund) Range in 1700 Range today (about 3,600 left) Fig. 11-8b, p. 230

African Elephant Probable range 1600 Range today Fig. 11-8c, p. 230 Figure 11.8 Natural capital degradation: reductions in the ranges of four wildlife species, mostly as the result of habitat loss and hunting. What will happen to these and millions of other species when the world’s human population doubles and per capita resource consumption rises sharply in the next few decades? (Data from International Union for the Conservation of Nature and World Wildlife Fund) Probable range 1600 Range today Fig. 11-8c, p. 230

Asian or Indian Elephant Figure 11.8 Natural capital degradation: reductions in the ranges of four wildlife species, mostly as the result of habitat loss and hunting. What will happen to these and millions of other species when the world’s human population doubles and per capita resource consumption rises sharply in the next few decades? (Data from International Union for the Conservation of Nature and World Wildlife Fund) Former range Range today (34,000–54,000 left) Fig. 11-8d, p. 230

Extinction Rate The percentage of species that go extinct within a certain time period The current extinction rate is increasing at an alarming rate due to human activities

History of Extinctions Endangered Species History of Extinctions Extinctions have existed long before humans had an influence The current extinction crisis is the first to be caused by a single species- US! . This is happening faster than ever; a few decades versus thousands to millions of years. Humans are eliminating not only the species but, the environment. Ex. Tropical rainforest

Effects of Humans on Biodiversity The scientific consensus is that human activities are decreasing the earth’s biodiversity. Figure 4-13

Human Caused Extinction Causes include: HIPPO C Habitat Destruction Invasive species Population Growth Pollution Over-harvesting Climate Change

Species and families experiencing mass extinction Bar width represents relative number of living species Millions of years ago Era Period Extinction Current extinction crisis caused by human activities. Many species are expected to become extinct within the next 50–100 years. Quaternary Today Cenozoic Tertiary Extinction 65 Cretaceous: up to 80% of ruling reptiles (dinosaurs); many marine species including many foraminiferans and mollusks. Cretaceous Mesozoic Jurassic Extinction Triassic: 35% of animal families, including many reptiles and marine mollusks. 180 Triassic Extinction Permian: 90% of animal families, including over 95% of marine species; many trees, amphibians, most bryozoans and brachiopods, all trilobites. 250 Permian Carboniferous Extinction 345 Figure 4.12 Fossils and radioactive dating indicate that five major mass extinctions (indicated by arrows) have taken place over the past 500 million years. Mass extinctions leave many organism roles (niches) unoccupied and create new niches. Each mass extinction has been followed by periods of recovery (represented by the wedge shapes) called adaptive radiations. During these periods, which last 10 million years or longer, new species evolve to fill new or vacated niches. Many scientists say that we are now in the midst of a sixth mass extinction, caused primarily by human activities. Devonian: 30% of animal families, including agnathan and placoderm fishes and many trilobites. Devonian Paleozoic Silurian Ordovician Extinction 500 Ordovician: 50% of animal families, including many trilobites. Cambrian Fig. 4-12, p. 93

Natural Extinctions Causes include Climate change Change in ecosystem Lack of adaptations to change

How do extinctions affect us? Use value lost – medicinal use, recreation, crops, lumber Economic value – ecotourism (African safari) Genetic information – genetic diversity lost Non-use values – appreciation

Case Study: The U.S. Endangered Species Act Biodiversity hotspots in relation to the largest concentrations of rare and potentially endangered species in the U.S. Figure 11-18