CHAPTER 4 Biodiversity and Evolution

Core Case Study: Why Should We Protect Sharks? 400 known species Only _____ deaths per year from shark attacks but 79-97 _________________ sharks killed every year Caught for their _____________ (finning) Organs, meat, hides Fear 32% of shark species threatened with extinction Act as _______________ species that keep their ecosystem functioning Cancer resistant…we could use this information to fight cancer in own species 6 million fins keystone

Threatened Sharks Hammerhead Shark Eats stingrays Whale Shark Figure 4.1: The threatened whale shark (left), which feeds on plankton, is the largest fish in the ocean. The endangered scalloped hammerhead shark (right) is swimming in waters near the Galapagos Islands, Ecuador. They are known for eating stingrays, which are related to sharks. Hammerhead Shark Eats stingrays Whale Shark Eats phytoplankton Fig. 4-1, p. 80

4-1 What Is Biodiversity and Why Is It Important? Concept 4-1 The biodiversity found in genes, species, ecosystems, and ecosystem processes is vital to sustaining life on earth.

Biodiversity Is a Crucial Part of the Earth’s Natural Capital (1) Biological diversity, ___________________, is the… ________________ of earth’s species, the genes that they contain, and the ecosystems in which they live Species: set of individuals who can mate and produce ___________________ offspring So far biologists have identified ________________ species…we think that there are many more unidentified species in the ___________________ and ____________ biodiversity variety fertile 1.9 million rainforests oceans

Biodiversity Is a Crucial Part of the Earth’s Natural Capital (2) There are four major components of biodiversity… Species diversity – variety of species Genetic diversity – enables life on earth to adapt and survive dramatic _____________________ changes Ecosystem diversity – variety of _______________ or regions with distinct climates/species Functional diversity – variety of process such as _________________ and _________________...that affect food webs environmental biomes energy flow matter cycling

Genetic Diversity The variety of genetic material within a Functional Diversity The biological and chemical processes such as energy flow and matter recycling needed for the survival of species, communities, and ecosystems. Ecological Diversity The variety of terrestrial and aquatic ecosystems found in an area or on the earth. Solar energy Chemical nutrients (carbon dioxide, oxygen, nitrogen, minerals) Heat Heat Heat Decomposers (bacteria, fungi) Producers (plants) Consumers (plant eaters, meat eaters) Heat Heat Figure 4.2: Natural capital. This diagram illustrates the major components of the earth’s biodiversity—one of the earth’s most important renewable resources and a key component of the planet’s natural capital (see Figure 1-4, p. 9). See an animation based on this figure at CengageNOW. Question: What role do you play in such degradation? Genetic Diversity The variety of genetic material within a species or a population. Species Diversity The number and abundance of species present in different communities. Fig. 4-2, p. 82

Coastal mountain ranges Mississippi River Valley Variety of Terrestrial Biomes Denver Baltimore San Francisco Las Vegas St. Louis Coastal mountain ranges Sierra Nevada Great American Desert Rocky Mountains Great Plains Mississippi River Valley Appalachian Mountains Figure 4.5: The major biomes found along the 39th parallel across the United States are shown in this diagram. The differences in tree and other plant species reflect changes in climate, mainly differences in average annual precipitation and temperature. Coastal chaparral and scrub Coniferous forest Desert Coniferous forest Prairie grassland Deciduous forest Fig. 4-5, p. 84

Classifying Homo Sapiens Classification system to help scientists study biodiversity Figure 2 This diagram illustrates the taxonomic classification of the latest human species, Homo sapiens sapiens. Supplement 5, Fig. 2, p. S19

Edward O. Wilson First scientist to use the term biodiversity in a research paper Long career studying ___________ diversity Worked to develop the theory of ___________ biogeography…which deals with how island biodiversity is affected by the ________ and _____________ of the island insect island Figure 4.B: Edward O. Wilson. size location Fig. 4-B, p. 85

Science Focus: Have You Thanked the Insects Today? Bad rep: sting us, bite us, spread disease, eat our food, invade plants _________________________: lets flowering plants reproduce sexually Free pest control: insects eat ____________ insects We need insects more than they need us Pollination other

Importance of Insects Figure 4.A: Importance of insects: The monarch butterfly, like bees and numerous other insects, feeds on pollen in a flower (left), and pollinates flowering plants that serve as food for many plant eaters, including humans. The praying mantis, which is eating a house cricket (right), and many other insect species help to control the populations of most of the insect species we classify as pests. Monarch butterfly pollinating a flower as it feeds Praying mantis feeding on a cricket Fig. 4-A, p. 83

4-2 How Does the Earth’s Life Change Over Time? Concept 4-2A The scientific theory of evolution explains how life on earth changes over time through changes in the genes of populations. Concept 4-2B Populations evolve when genes mutate and give some individuals genetic traits that enhance their abilities to survive and to produce offspring with these traits (natural selection).

Biological Evolution by Natural Selection Explains How Life Changes over Time (1) Fossils…_______________ or ________________ replicas of skeletons, bones, teeth, shells, leaves, seeds or _______________ of such items Physical evidence of ____________ organisms Reveal what their external structures looked like Fossil record: entire _________of fossil evidence Uneven and incomplete… we probably only have fossils of 1% of all species that lived on earth mineralized petrified impressions ancient body

Fossilized Skeleton of an Herbivore that Lived during the Cenozoic Era Figure 4.6: This fossilized skeleton is the mineralized remains of an herbivore that lived during the Cenozoic era from 26 to 66 million years ago. Fig. 4-6, p. 86

Biological Evolution by Natural Selection Explains How Life Changes over Time (2) Biological evolution: how earth’s life changes over time through changes in the __________________ characteristics of populations First person who attempted to explain the process behind evolution was ______________ ______________...published his explanation in 1859: On Origin of Species by Means of Natural Selection Alfred _______________ also studied natural selection at the time and derived similar conclusions Natural selection: individuals with certain __________ are more likely to survive and _______________ under a certain set of _____________________ conditions genetic Charles Darwin Wallace traits reproduce environmental

Evolution of Life on Earth Theory of evolution states that all species descend from earlier _______________ species Basically, life comes from life ancestral Figure 1 This diagram provides an overview of the evolution of life on the earth into six major kingdoms of species as a result of natural selection. Supplement 5, Fig. 2, p. S18

Evolution by Natural Selection Works through Mutations and Adaptations (1) ________________ evolve by becoming genetically different Can an individual evolve during its lifetime? Ex: If a human runs every day will he/she be able to run as fast as a cheetah? Genetic variations First step in biological evolution Occurs through _______________ in reproductive cells…that get passed along ________________ Mutations: random changes in ________ molecules Populations No mutations to offspring DNA

Evolution by Natural Selection Works through Mutations and Adaptations (2) Natural selection: favors some individuals over others Second step in biological evolution Adaptation – any heritable trait that gives you a survival/reproductive _________________ Adaptations may lead to differential reproduction….enables individuals with the trait to produce more ___________________ offspring advantage surviving

Evolution by Natural Selection Genetic resistance: ability of one or more members of a population to resist a _________________ designed to kill it chemical Figure 4.7: Evolution by natural selection. (a) A population of bacteria is exposed to an antibiotic, which (b) kills all individuals except those possessing a trait that makes them resistant to the drug. (c) The resistant bacteria multiply and eventually (d) replace all or most of the nonresistant bacteria. Fig. 4-7, p. 87

Case Study: How Did Humans Become Such a Powerful Species? Human adaptations… Strong opposable thumbs Walk upright Complex brain

Adaptation through Natural Selection Has Limits Adaptive genetic traits must _____________change in the environmental conditions Reproductive capacity Species that reproduce rapidly and in large numbers are _______________ able to adapt precede better

Three Common Myths about Evolution through Natural Selection “Survival of the fittest” is not “survival of the strongest” Organisms do not develop traits out of need or want No grand plan of nature for perfect adaptation

Review Questions What are the four major components of biodiversity demonstrated in this figure? Ecosystem diversity functional diversity Species diversity genetic diversity

Review Questions Place the following concepts in the correct order… populations evolve genes mutate individuals are selected 3 1 2