Evolution and Biodiversity

Concepts  Origins  Evolutionary Processes  Ecological Niches  Species Formation  Species Extinction

Origins and Early Evolution of Life  Chemical evolution  Biological evolution

Click to view animation. Animation Stanley Miller's experiment animation.

Plants begin invading land Evolution and expansion of life First fossil record of animals Age of reptiles Age of mammals Insects and amphibians invade the land Modern humans (Homo sapiens) appear about 2 seconds before midnight Recorded human history begins 1/4 second before midnight Origin of life (3.6–3.8 billion years ago) noon midnight

Evolution Concepts  Microevolution  Macroevolution  Gene pool  Mutation  Natural selection

Natural Selection  Differential reproduction  Adaptive trait  Coevolution

Natural Selection  Directional Selection  Stabilizing Selection  Disruptive Selection

Click to view animation. Example of directional selection animation.

Click to view animation. Stabilizing selection animation.

Click to view animation. Disruptive selection animation.

Ecological Niches  Ecological niche  Fundamental niche  Realized niche

Broad and Narrow Niches  Generalist species  r - selected  Generalist species  r - selected  Specialist species  k - selected  Specialist species  k - selected

Black skimmer seizes small fish at water surface Flamingo feeds on minute organisms in mud Scaup and other diving ducks feed on mollusks, crustaceans, and aquatic vegetation Brown pelican dives for fish, which it locates from the air Avocet sweeps bill through mud and surface water in search of small crustaceans, insects, and seeds Louisiana heron wades into water to seize small fish Oystercatcher feeds on clams, mussels, and other shellfish into which it pries its narrow beak Dowitcher probes deeply into mud in search of snails, marine worms, and small crustaceans Knot (a sandpiper) picks up worms and small crustaceans left by receding tide Herring gull is a tireless scavenger Ruddy turnstone searches under shells and pebbles for small invertebrates Piping plover feeds on insects and tiny crustaceans on sandy beaches Niches

Unknown finch ancestor Insect and nectar eatersFruit and seed eaters Greater Koa-finch Kona Grosbeak Akiapolaau Maui Parrotbill Kuai Akialoa Amakihi Crested Honeycreeper Apapane Adaptive Radiation

Speciation  Speciation  Geographic isolation  Reproductive isolation

Extinction  Background extinction  Mass extinction  Adaptive radiation  Mass depletion  Human Impacts

EURASIA AFRICA SOUTH AMERICA INDIA 135 million years ago Present 65 million years ago 225 million years ago 120°80°0° 120° 80° 40° 120° GONDWANALAND 120° LAURASIA PANGAEA ANTARCTICA AUSTRALIA MADA- GASCAR MADA- GASCAR

Terrestrial organisms Marine organisms Quaternary Tertiary Cretaceous Jurassic Triassic Permian Carboniferous Devonian Silurian Ordovician Cambrian Pre-cambrain Number of families Millions of years ago

Human Impacts on Evolution  Artificial Selection  Genetic Engineering  Concerns about Genetic Engineering  Artificial Selection  Genetic Engineering  Concerns about Genetic Engineering

Crop Crossbreeding Desired trait (color) ApplePear Offspring Crossbreeding Best results New offspring Desired result

Phase 1 Make Modified Gene Identify and extract gene with desired trait Identify and remove portion of DNA with desired trait Remove plasmid from DNA of E. coli Insert extracted DNA (step 2) into plasmid (step3) Insert modified plasmid into E. coli Grow in tissue culture to make copies cell gene DNA plasmid E. coli DNA Genetically modified plasmid

Phase 2 Make Transgenic Cell Transfer plasmid copies to a carrier agrobacterium Agrobacterium inserts foreign DNA into plant cell to yield transgenic cell Transfer plasmid to surface microscopic metal particle Use gene gun to inject DNA into plant cell A. tumefaciens (agrobacterium) Plant cell Nucleus Host DNA Foreign DNA

Phase 3 Grow Genetically Engineered Plant Transgenic cell from Phase 2 Cell division of transgenic cells Culture cells to form plantlets Transgenic plants with new traits Transfer to soil

Click to view animation. Evolutionary tree of life animation.

Click to view animation. Evolutionary tree diagrams interaction.