Evolution and Diversity

Essential question How does natural selection determine the evolution and survival of a species?

Evolution A change in genetic characteristics from one generation to the next Why are plants and animals suited to their environment? Slow process caused by mutations and natural selection

Human Mutation Rate 100-200 per generation 1 mutation per 30,000,000 base pairs Source: Nature August 27, 2009

Natural Selection Unequal survival and reproduction rates due to the presence or absence of traits Gradual Many generations

Charles Darwin British naturalist HMS Beagle – 1831-1836 Origin of Species – 1859 Alfred Russel Wallace – Borneo

Main Points of Darwin’s Theory of Evolution: 1.) Environments are hostile. 2.) All organisms have the ability to produce more offspring than can survive. 3.) Individuals vary in their traits. 4.) Some traits give certain individuals an advantage. 5.) Positive traits are passed on to offspring.

Mutation A change of the DNA sequence of an organism resulting in the creation of a new character or trait not found in the parent.

Adaptation A change in anatomy, physiology or behavior that increases an organism’s chances for survival and reproduction.

Coevolution The process of two species evolving in response to long term interactions with one another.

Artificial Selection The selective breeding of organisms by humans for specific characteristics.

Resistance The ability of an organism to tolerate a chemical or disease causing agent.

The Diversity of Life Six Kingdoms: Archaebacteria Eubacteria Fungi Protists Plants Animals

Archaebacteria Single celled No nuclei Live in extreme environments Methanogens Thermophiles

Eubacteria Single celled No nuclei Common (bacteria in soil and intestines, blue-green algae[cyanobacteria]) Bacteria Important decomposers Break down organisms and recycle nutrients - nitrogen fixers - E. coli –good and bad

Fungi Have nuclei and cell walls Absorb food through breaking down organic matter (decomposer) Mushroom- the reproductive structure of a fungus Underground network of fibers

Protists Usually single celled Live in water Amoebas, diatoms Algae- phytoplankton to giant kelp

Plants Multicelluar Cell walls Make their own food. - Photosynthesis Vascular tissue to transport nutrients xylem (up) and phloem (down) Lower Plants – Mosses (no vascular system) and ferns (seedless)

Plants Gymnosperms Woody plants that produce “naked” seeds - conifers - pollen, seeds - live in dryer conditions - economically important – lumber and paper

Plants Angiosperms Flowering plants (seeds in fruit) Most of our food

Animals Cannot make their own food Cells lack cell walls Mobility

Animals Invertebrates No backbone Insects Gastropods Giant squid

Animals Vertebrates Have a backbone - mammals - birds - fish - amphibians

Animals Warm blooded - Endotherm - Mammals, birds

Animals Cold blooded Ectotherm Reptiles, amphibians, fish