Unit 1-2a Organization of Life

Life On Earth Biosphere – The region on Earth where all living things are found; From the highest mountain to the ocean floor The biosphere is divided into many biomes which are made up of many individual… Ecosystems – All of the living and non-living elements in an area

Exploring The Ecosystem Living things within an ecosystem can be grouped into a… Community – A group of various species that interact Ex: Grass, elephants & wildebeests Within that community are many… Populations – A group of the same species living in a specific area Ex: A population of wildebeests And a population is made of many… Organisms – An individual living thing Ex: Bob the Wildebeest Habitat – An area where an organism lives

What Is A Species? Species – A group of organisms that can mate to produce fertile offspring, such as the Canis lupus familiaris, aka… Dogs! How can these very different animals still belong to the same species? Because they make puppies that continue to reproduce.

Unit 1-2b Theory Of Evolution

How Can Life On Earth Change? Once upon a time, most people believed that living things on Earth had not changed since the beginning of time. But evidence, including the fossil record, proves otherwise! Variations or mutations (changes in DNA) can become an… Adaptation – An inherited trait that increases the chance for an organism to survive and reproduce Over long periods of time, if the adaptation becomes common, the species may evolve into something new.

Natural Selection Natural selection is the process by which individuals that had favorable traits and adaptations were able to survive in their environment and reproduce. Over long periods of time, if the adaptation becomes common, the species may evolve into something new. This change in genetic characteristics in a population from generation to the next is evolution.

How Can Species Evolve? The Story of Darwin’s Finches Charles Darwin – Studied many finches from the Galapagos Islands and found that they all had one common ancestor, the Warbler Finch. The Warbler Finch had flown from S. America to the Galapagos Islands and bore many different offspring that spread out to the different islands. The finches that survived had adapted beaks that allowed them to get the food that was available at each island.

Which Traits Are The Best? The story of the Peppered Moth Which peppered moth variation is better, black or white? Originally, the white moth was better suited to the light trees found in England and had a larger population. But during the Industrial Revolution, soot and ash darkened the trees giving black moths an advantage. Today, the environment is cleaner and the white moth population is increasing again. Because the environment is constantly changing, there isn’t one specific trait that guarantees success.

The Stages Of Evolution 1. Offspring all act and look differently 2. Many of these differences are inherited 3. Many offspring won’t survive long enough to reproduce 4. Individuals with the best traits for survival will be able to reproduce more often, passing on those traits 5. Over long periods of time, the better suited individuals will increase with each generation, changing the species

What Causes Evolution? There are four triggers that can initiate evolution… Migration/Isolation – Darwin’s finches Environmental Changes – The peppered moth Artificial Selection – Breeding of organisms by humans Coevolution – When two species evolve in response to each other Ex: Hummingbird & flowering plant

Unit 1-2c Diversity of Life

Even with all its diversity, life on Earth has commonality. Defining Life Even with all its diversity, life on Earth has commonality. All living things… Made up of one or more highly organized cells Grow and develop Reproduce offspring Use energy for metabolism (the chemical processes of life) Outward response to the environment Maintain homeostasis (a stable internal condition regardless of the changing external environment)

There are six kingdoms to organize all of life on Earth. Kingdoms of Life There are six kingdoms to organize all of life on Earth. Archaebacteria – Single-cell organisms living in the most extreme places on Earth Hot springs over 100oC Bottom of the ocean Bacteria- Single-cell organisms that are commonly found everywhere Soil, your stomach & bathrooms These bacteria groups do not have a nucleus and divide to reproduce.

Fungi – Organisms with a nucleus and cell wall that gets energy from decomposing matter Single cell yeast Multi-cellular mushrooms Protists – An organism with a nucleus that is not a fungus, plant or animal Single cell, animal-like, amoebas Multicellular, plant-like, seaweed Fungi & Protists can be single or multicellular but both have cells with a nucleus.

Plants – Multicellular organisms that have a nucleus and cell wall; Produce their own food; Most plants have… Vascular tissue – Transports water and nutrients Lower plants, like mosses, don’t have this tissue Also, plants can be… Angiosperms – Produce flowers and fruit with seeds inside or Gymnosperms – Produce seeds that are protected inside cones

Animals – Multicellular organisms that use other organisms as a source of food 99% of animals are invertebrates – without backbones (often have shells or exoskeletons) The other 1% are vertebrates – with backbones