Unit 4: Speciation and Extinction 5 days

November 17 th : Trophic Levels

Food Chains

Food Webs

Herbivore Capybara Cattle Deer Antelope Elephant Panda Goat Gorilla Zebra Rhino Manatee Hippo Llama Rabbit Macaws Geese Toucan Hoatzin Iguana Caterpillar Grasshopper

Herbivore Toolkit Eyes on side of head Speed Height Groups Group birth Polymorphism Camouflage Stotting (gazelles) Highly developed senses Alarm signals Autotomy (limb dropping) Toxins

Plant Defenses

Types of Herbivory Frugivore = fruit Folivore = leaves Nectarivore = nectar Granivore = seeds Palynivore = pollen Mucivore = sap Xylophages = wood

Carnivore All cats Most dogs All weasels All cetaceans Most bats All bird of prey All vultures Many waterfowl All crocodilians All snakes Some lizards Some turtles Most frogs All sharks Most fish All spiders All jellyfish All centipedes Some mollusks Some crustaceans

Carnivore Toolkit Forward facing eyes Short digestive tract Claws Teeth

Omnivore Pig Human Bear Hedgehog Skunk Raccoon Squirrel Mice Chimps Chicken Raven Magpie Many lizards Many turtles Piranha Some ants

Why is Omnivory Beneficial?

Apex Predators

November 19 th : Evolutionary Arms Race Cheetah and Thompson’s Gazelle

Old World Swallowtail vs. Fringed Rue

Rough-Skinned Newt vs. Garter Snake

Great White Shark vs. Sea Turtle

Human vs. Tiger

The Red Queen Hypothesis

December 1 st : Speciation, Biodiversity, Hybridization, Convergence and Divergence

Anagenesis Whole population evolving

Cladogenesis One population branching

Artificial vs. Natural Selection

Genetic Variation Driven by mutations

Hybridization

Adaptive Radiation One species undergoes minor mutations and diverges into multiple species each slightly more suited to different habitats and lifestyles.

Darwinian Mantra Random mutation causes differentiated reproductive success, which leads to the spread of traits through populations, which leads to the overall evolution of a species.

Darwinian Mantra Not SURVIVAL of the fittest… Rather, REPRODUCTION of the fittest.

Darwinian Mantra Populations evolve. Species evolve. Individuals do NOT evolve.

Divergent Evolution When a species undergoes cladogenesis and breaks into different species, that each occupy a different ecological niche.

Convergent Evolution When two or more species that are distantly related genetically, but occupy similar ecologic niches, are shaped by nature to resemble each other.

Convergent Evolution

December 2 nd : Endangered Species

Least Concern

Near Threatened

Conservation Dependent

Vulnerable

Endangered

Critically Endangered

Extinct in the Wild Algoas Curassow – 1987 Pere David’s Deer – 2008 Scimitar Oryx – 2000 Wyoming Toad – 1991

Extinct Yangtze River Dolphin – 2006 Bubal Hartebeest – 1923 Dodo – 1700 Giant Sloth – 1500

December 3 rd : Mass Extinctions

The Big 5 Ordovician – Silurian 440 to 450 mya: 57% of genera died Late Devonian event 360 to 375 mya: 70% of all species Permian – Triassic event 251 mya: 83% of genera – “The Great Dying” – Largest – 96% of marine species went extinct – Made room for dinosaur dominance Triassic – Jurassic event 205 mya: 48% of genera – All large amphibians – Left no competition for dinosaurs Cretaceous – Tertiary 65 mya: 75% of all species – K-T boundary – Made room for mammal and bird dominance

What Causes Mass Extinction?

The Holocene Extinction

Extras Despotic Hierarchy One individual is dominant, all others are equally submissive. Humans Many primates Bees Fish Lions Seals Walrus Hyenas

Extras Linear Hierarchy Line of dominance in which each individual has its rank. Wolves Dogs Elephants Chickens Other birds Chimpanzee

Extras Patriarchy Deer Moose Antelope Gorillas Seals Walrus Humans (often)

Extras Matriarchy Bees Wasps Elephants Killer whales Hyenas Humans (rarely)

Extras Co-Dominance Wolves Other dogs Chickens Chimpanzees Many other primates Humans (often) Penguins Naked mole rat