Biodiversity and Evolution Chapter 4 Trophic Cascades Wolves

Biodiversity and Evolution Chapter 4

Trophic Cascades – Wolves & Whales § https: //www. youtube. com/watch? v=ysa 5 OBh. Xz. Q § https: //www. youtube. com/watch? v=M 18 Hx. Xve 3 CM

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.

Core Case Study: Why Are Amphibians Vanishing? § Frogs are becoming extinct at 10, 000 times their historical rates § Amphibians • Sensitive biological indicators • Play important ecological roles in their communities • Skin secretions source of many valuable pharmaceutical products

Science Focus 4. 1: Causes of Amphibian Declines § Factors causing decline and disappearance of reptiles and amphibians • • Parasites Viral and fungal diseases Habitat loss and fragmentation Higher levels of UV radiation Pollution Climate change Overhunting

Biodiversity § Short for “biological diversity” § Refers to the number and variety of different species in a given area § Areas with high biodiversity include • Tropical rainforests • Coral reefs • Estuaries

A World of Biodiversity § Estimated 7– 10 million species exist • About 2 million species have been identified • About half of those are insects § Scientists believe that many species still remain unknown

Earth’s Organisms Are Many and Varied § Pollination is a vital ecosystem service performed by insects § Some insect species reproduce rapidly and can produce new genetic traits • Example: pesticide resistance

What Is Biodiversity and Why Is It Important? § Forests have core habitat and edge habitat • Edge effect: conditions different from forest interior such as temperature, light, humidity, etc. • As forests are fragmented, there is less core habitat and more edge habitat • Ecotone: transitional area where two different ecosystems merge

Natural Capital: Major Components of the Earth’s Biodiversity

Levels of Biodiversity § Ecosystem diversity – the variety of habitats, communities, and ecological processes within and between ecosystems § Species diversity – all the differences between populations of species, as well as between different species. § Genetic diversity – all the different genes contained within all members of a population

What Is Biodiversity and Why Is It Important? (3 of 5) § Functional diversity • Variety of processes within ecosystems • Examples: energy flow and matter cycling § Advantages of biologically diverse ecosystems • Produce more plant biomass to support a greater number of consumer species • Contain species traits that enable them to adapt to changing environmental conditions

Math Lab – Exploring Biodiversity § In lab notebook: • Title • Background: 1. Identify AND explain the two levels at which biodiversity is evaluated. 2. Identify AND explain the 3 different indices of community diversity (what are they actually assessing? ). Write the formula for each. • Pre-lab questions #1 -5 • • For #4 show ALL work for indices calculations of communities 1 -3 Include completed data table of index values

What Is Biodiversity and Why Is It Important? (5 of 5) Copyright © 2018 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.

Major Biomes Copyright © 2018 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.

4 -2 Where Do Species Come From? § Concept 4 -2 A The scientific theory of evolution explains how life on earth changes over time through changes in the genes of populations. § Concept 4 -2 B 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).

4. 4 How Does the Earth’s Life Change over Time? § Biological evolution • Earth’s life forms change genetically over time • Widely accepted scientific theory § Natural selection • Process by which species have evolved from earlier species • Charles Darwin • Alfred Russel Wallace § Tree of Life

Six Major Kingdoms of Species as a Result of Natural Selection

Phylogenetic Tree of Life

Synapomorphies

The Fossil Record Tells Much of the Story of Evolution § Fossils • Physical evidence of ancient organisms • Reveal what their internal structures looked like § Fossil record • Entire body of fossil evidence • Uneven and incomplete • Estimate: fossils found so far represent only 1% of all species that have ever lived

Evolution Explains How Organisms Change over Time (2 of 2) Copyright © 2018 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.

Archeopteryx

Coelacanth – living fossil

Mosasaurus

Fossil Rocks Anthem § https: //www. youtube. com/watch? v=Cl. J 5 lwl_w. M 0

Bioaccumulation/Biomagnification

The Genetic Makeup of a Population Can Change § Populations evolve by becoming genetically different § Genetic variations/variability • First step in biological evolution • Occurs through mutations in reproductive cells

Individuals in Populations with Beneficial Genetic Traits Can Leave More Offspring § Natural selection • Second step in biological evolution • Adaptation may lead to differential reproduction • Genetic resistance § When environmental conditions change, populations • Adapt • Migrate • Become extinct

Evolution by Natural Selection

Natural Selection 1. 2. 3. 4. Overproduction Genetic Variation Struggle to survive Differential reproduction (fitness)

Divergent evolution

Convergent evolution

Species Can Drive Each Other’s Evolution § Complex predator-prey relationships play a role in natural selection at population level: • Predators kill sick, weak, aged, least-fit individuals; prey that are better able to survive live to produce more offspring, pass on traits § Coevolution: • When populations of two different species interact over a long period of time, changes in the gene pool of one species can lead to changes in the gene pool of the other.

§ Hummingbird Hawk Moth

§ § Cheetah vs. gazelle https: //www. youtube. com/watch? v=KTScfs-o 2 v. Q

Artificial Selection, Genetic Engineering, and Synthetic Biology § Artificial selection • • Selective breeding (or crossbreeding) Occurs between genetically similar species Not a form of speciation Slow process § Genetic engineering • Way to speed process of artificial selection • Gene splicing

Evolution by artificial selection § https: //www. youtube. com/watch? v=F-XTUp. Lmh. Pc

Steps in Genetic Engineering (1 of 3) § Identify a gene with a desired trait in DNA from donor organism § Extract a small DNA molecule (plasmid) from a bacterial cell § Insert the desired gene into the plasmid to form a recombinant DNA plasmid § Insert into the cell of another bacterium that divides and reproduces large numbers of cells with desired trait

Steps in Genetic Engineering (2 of 3) § Transfer the genetically modified bacterial cells to a plant or animal that is to be genetically modified § Result is a genetically modified organism (GMO) § Synthetic biology • Segments of DNA are used to design and create artificial cells, tissues, body parts, and organisms not found in nature

Steps in Genetic Engineering (3 of 3) Copyright © 2018 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.

4 -3 How Do Geological Processes and Climate Change Affect Evolution? § Concept 4 -3 Tectonic plate movements, volcanic eruptions, earthquakes, and climate change have shifted wildlife habitats, wiped out large numbers of species, and created opportunities for the evolution of new species.

Evolution Depends on Genetic Variability and Natural Selection (5 of 6) § Patterns of evolution can be traced and compared using an evolutionary or phylogenetic tree

Evolution Depends on Genetic Variability and Natural Selection (6 of 6) Copyright © 2018 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.

Limits to Adaptation through Natural Selection § Adaptive genetic traits must precede change in the environmental conditions § A population’s reproductive capacity • Species that reproduce rapidly and in large numbers are better able to adapt

Myths about Evolution through Natural Selection Common myths • Survival of the fittest means survival of the strongest • Evolution explains the origin of life • Organisms develop traits out of need or want • Humans evolved from apes or monkeys • Evolution is part of nature’s grand plan to produce perfectly adapted species • Evolution by natural selection is not important because it is just a theory

Geologic Processes Affect Natural Selection § Tectonic plates affect evolution and the location of life on earth • Location of continents and oceans • Species physically move, or adapt, or form new species through natural selection § Earthquakes § Volcanic eruptions

Movement of the Earth’s Continents over Millions of Years

Climate Change and Catastrophes Affect Natural Selection § Ice ages followed by warming temperatures § Collisions between the earth and large asteroids • New species • Extinction

§ https: //www. youtube. com/watch? v=wi. VEby 3 m 9 E § https: //www. youtube. com/watch? v=Ei 8 v. Yu. Ax. EY Y § http: //channel. nationalgeographic. com/videos/ice -age-cycles/

Milankovitch Cycles § Obliquity § Eccentricity § Precession

Spinning Top - Precession § https: //www. youtube. com/watch? v=CYy. WTlebu 6 g

Changes in Ice Coverage in the Northern Hemisphere During the last 18, 000 Years

4 -4 How Do Speciation, Extinction, and Human Activities Affect Biodiversity? § Concept 4 -4 A As environmental conditions change, the balance between formation of new species and extinction of existing species determines the earth’s biodiversity. § Concept 4 -4 B Human activities can decrease biodiversity by causing the premature extinction of species and by destroying or degrading habitats needed for the development of new species.

How Do New Species Evolve? § New species arise in two phases • Geographic isolation • Occurs first • Populations migrate or are separated by some other cause • Reproductive isolation • Mutation and change by natural selection occurs in the geographically isolated groups • Eventually prevents breeding between the groups • Have become genetically different

Geographic Isolation Can Lead to Reproductive Isolation

Khan academy – Island Biogeography § https: //www. khanacademy. org/science/biology/e cology/biogeography/v/new-localities-lead-tonew-biodiversity

Bear Island – Jelly Bear Evolution game § Genotypic vs Phenotypic § Gene vs. allele § Polymorphism: • Occurring in several different forms • Variation in phenotypic feature (bear color) § Speciation through geographic isolation = allopatric speciation § In lab notebook: • Title, # 1(biotic/abiotic chart) • Research and Discussion Questions #1 -5 • You can use cell phones for research purposes

How Evolution Works § https: //www. youtube. com/watch? v=h. Of. RN 0 Kih. O U

Evolution in Action § http: //www. amnh. org/explore/sciencebulletins/(watch)/bio/documentaries/evolution-inaction-isolation-and-speciation-in-the-lowercongo-river

Extinction is Forever § Extinction § Background extinction • Typical low rate of extinction • 0. 0001% of all species per year § Endemic species • Particularly vulnerable

Extinction Eliminates Species § Mass extinction • Significant rise above background level • 20– 95% of species are eliminated • Causes unknown but could include: • Giant volcanic eruptions • Collisions with meteors or asteroids • Provides opportunity for evolution of new species

Extinction Eliminates Species (3 of 3) Copyright © 2018 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.

Recently Extinct Species § Thylacine: § https: //www. youtube. com/watch? v=4 Lk 3 r. QQxud M § https: //www. youtube. com/watch? v=jbmvwieu. Kr. U

§ Ordovician-Silurian – Most life was in the sea. Trilobites and brachiopods (450 -440 MYA) § Devonian (375 -360 MYA) – extreme climate change – marine organism (3/4 species) § Permian- 96% of all species – shallow seas worst affected (250 MYA) § Triassic - Jurassic (200 MYA) – extreme volcanic activity (Basalt traps) and asteroid § Cretaceous- Tertiary (K/T) – Death of dinosaurs (asteroid) 66 MYA – 75% all species

§ https: //www. youtube. com/watch? v=YLnl. Mm. TW 7 S 8 § http: //phys. org/news/2015 -11 -ancient-massextinction-dominance-tiny. html § https: //www. youtube. com/watch? v=I 5 Aa. Cy. I_m. Io

6 th Mass Extinction § https: //www. youtube. com/watch? v=z 9 g. Hu. Awxw As

Species Prone to Extinction § Some species are more prone to extinction than others • • Those that migrate Those that need large or special habitat Those that are exploited by humans Those with special requirements

Species Prone to Extinction § Endangered species – a species that is likely to become extinct if protective measures are not taken immediately § Threatened species – a species that has a declining population and that is likely to become endangered if it is not protected § Other categories as well

How Do Humans Cause Extinctions? § Destruction of habitats: deforestation, agriculture, construction/urbanization • Human population growth • Increased consumption § The introduction of nonnative species § Pollution • acid rain, loss of ozone layer, chemical toxins § The overharvesting of species • Poaching and hunting of threatened species

Qualities of Species that make recovery difficult?

4 -5 What Is Species Diversity and Why Is It Important? § Concept 4 -5 Species diversity is a major component of biodiversity and tends to increase the sustainability of ecosystems.

Areas of Critical Biodiversity § Some regions have higher biodiversity than others § Endemic species – meaning species that are native to and found only within a limited area

Areas of Critical Biodiversity § Tropical Rain Forests • Cover less than 7 percent of the Earth’s land surface • Over half of the world’s species live in these forests • Many new species still left to discover

Biodiversity Hot Spots § Biodiversity hot spot – the label given to the most threatened areas of high species diversity on Earth

Discussion § Benefits of Biodiversity? What are they?

§ At least 40 per cent of the world’s economy and 80 per cent of the needs of the poor are derived from biological resources. In addition, the richer the diversity of life, the greater the opportunity for medical discoveries, economic development, and adaptive responses to such new challenges as climate change.

Species Diversity: Variety, Abundance of Species in a Particular Place § Species diversity • Species richness • Species evenness § Diversity varies with geographical location • Most species-rich communities • • Tropical rain forests Coral reefs Ocean bottom zone Large tropical lakes

Species Richness vs. Species Evenness

Species Richness vs. Species Evenness

Variations in Species Richness and Species Evenness

Species-Rich Ecosystems Tend to Be Productive and Sustainable § Species richness seems to increase productivity and stability or sustainability § How much species richness is needed is debatable

4 -6 What Roles Do Species Play in Ecosystems? § Concept 4 -6 A Each species plays a specific ecological role called its niche. § Concept 4 -6 B Any given species may play one or more of five important roles—native, nonnative, indicator, keystone, or foundation roles—in a particular ecosystem.

Each Species Plays a Unique Role in Its Ecosystem § Ecological niche, niche • Pattern of living § Generalist species • Broad niche § Specialist species • Narrow niche

Specialist Species and Generalist Species Niches

Case Study: Cockroaches: Nature’s Ultimate Survivors § Cockroaches and raccoons • Generalists • Can eat wide variety of food items • Survive in wide variety of environmental conditions wide range of tolerance

Case Study: Cockroaches: Nature’s Ultimate Survivors § Giant panda and tiger salamanders • Specialists • Can eat one or few food items • Survive in very specific environmental conditions narrow range of tolerance

Specialized Feeding Niches of Various Bird Species in a Coastal Wetland

Niches Can Be Occupied by Native and Nonnative Species § Native species § Nonnative species; invasive, alien, or exotic species • May spread rapidly • Not all are villains

Case Study: A Keystone Species that almost Went Extinct § The American alligator • Keystone species in its subtropical wetland ecosystem • Digs gator holes that hold freshwater and serve as a refuge for aquatic life • 1930 s: hunted for sport, meat, and skin • 1967: added to endangered species list • 1977: impressive comeback • More than a million alligators today in Florida

The American Alligator Copyright © 2018 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part, except for use as permitted in a license distributed with a certain product or service or otherwise on a password-protected website for classroom use.

Indicator Species Serve as Biological Smoke Alarms § Indicator species • Can monitor environmental quality • • Trout Birds Butterflies Frogs

Warm-up § What is a keystone species and what is a foundation species? § Refer to page 77 in your textbook. In what ways is the American Alligator a keystone species?

Keystone, Foundation Species Determine Structure, Function of Their Ecosystems § Keystone species • Keystone species have a large effect on the types and abundance of other species • Pollinators • Top predator § Foundation species • Create or enhance their habitats, which benefit others • Elephants • Beavers

Keystone Species

Steller’s Sea Cow

Sea Otters, Kelp and Sea Urchins § https: //www. youtube. com/watch? v=h. RGg 5 it 5 FMI

Some Species are More Equal Than Others § https: //www. youtube. com/watch? v=h. RGg 5 it 5 FMI

Classwork First § Answer chapter 4 MC questions page 76 A-77 A Second § Work with a partner. § Read and discuss the case studies in Chapter 4 of the book.