Living Things The Nature of Science

Levels of Organization Element – atom Molecules Cells Tissues Organs Organ systems Organism Species Populations Communities

Assumptions in Science Natural causality All events are due to natural causes and are potentially within our ability to understand. Uniformity in space and time The laws derived from the study of nature are the same everywhere and have been the same for billions of years. Common perception Everyone generally perceives events similarly.

The Scientific Method Way in which scientists study things in the world. Observation/Problem Question Do Background Research Hypothesis Null Hypothesis Prediction Experiment Collect Data Analyze Results Conclusion sciencebuddies.org

The Experiment Variable A factor that affects an observation/changing quantities Independent Variable – something that is changed by the scientist Dependent Variable – factor that is measured and is dependent on the independent variable Standarized /Controlled Variables – aspects of an experiment that remain the same Control Group Used to rule out other possible variables Do not receive experimental treatment

Scientific Method The results of an experiment must be able to be repeated by other researchers. An experiment must be communicated thoroughly and accurately. Why is this important?

Scientific Theory General explanation of important natural phenomena, based on extensive and reproducible observations. principle or a natural law Ex. Atomic theory (all matter is composed of atoms) Ex. Theory of gravitation (objects exert a law of attraction for one another) Ex. Cell theory(all living things are composed of cells) A theory can be modified or falsified.

The Theory of Spontaneous Generation - Abiogensis Francesco Redi’s Experiment – 17 th century facstaff.gpc.edu

Malte Andersson’s Widowbird Experiment Male long-tailed widow bird. sanparks.org Female long-tailed widowbird birds.com

Orphrys apifera. floralimages.co.uk What Do You See?

What Do Glowing Pigs and Jellyfish Have in Common?

Biodiversity Refers to the total number of species within a given region and the resulting interactions among them www2.warwick.ac.uk sciencelearn.org.nz

3 Domains of Life

5 Kingdoms Eukaryotes (have membrane-bound organelles) 1. Plants 2. Fungi 3. Animals 4. Protists Prokaryotes (lack membrane-bound organelles) 5. Monera/Bacteria Includes bacteria and members of archaea

What is a Living Thing?

Theory of Evolution Formulated by Charles Darwin and Alfred Russel Wallace in the mid-1800s States that modern organisms descended, with modification, from preexisting life-forms Evolution - Change in the genetic makeup of a species Charles Darwin Alfred Russel Wallace