The Nature of Science

The root sci- means “to know”. – Science is 1 way of investigating the world in which we live. Science strives to: – Explore & understand the natural world – Explain events in the natural world – Use those explanations to make useful predictions

Things that are not science: Art Religion Literature Opinion Is science better than these things? NO

Science can only concern itself with testable things and/or observable things.

Is scientific knowledge a set truth? NO In our scientific explanations, we explain natural phenomena & how things work using the knowledge we have. When our knowledge base changes, our explanations may change. Scientific knowledge changes all the time!

Flat Earth Theory During the Middle Ages, it was widely accepted that Earth was flat. Pythagoras, a great mathematician (Pythagorean Theorem), proved that the Earth was spherical mathematically in the 6 th century BC. Flat Earth Theory Video

Flat Earth Theory Even though Pythagoras disproved it, general society still believed the Flat Earth Theory – Ferdinand Magellan, an explorer, was recruited by Spain to sail the distance around Earth. – If Earth was flat, Magellan’s ships would fall off the edge of Earth!

Flat Earth Theory Magellan’s ships set sail in – His ships returned to Spain in The ships had successfully circumnavigated Earth, proving the Earth was spherical.

What is Biology?

Biology bio- means life -ology means the study of

So… what makes something living? Characteristics of Living Things – all living things have all 8 things in common: 1. They are made up of units called cells. Red Blood Cells

Characteristics of Living Things 2. Reproduction Some living organisms reproduce sexually, while some reproduce asexually.

Characteristics of Living Things 3. Have a universal genetic code DNA or RNA

Characteristics of Living Things 4. Grows & develops

Characteristics of Living Things 5. Responds to the environment Dogs pant when they’re hot.

Characteristics of Living Things 6. Obtains & uses materials & energy

Characteristics of Living Things 7. Homeostasis: maintains a stable internal environment

Characteristics of Living Things 8. Evolution: populations change over time

Branches of Biology Biology is studied at many levels of organization from simple to complex. 1. Molecules: groups of atoms

Branches of Biology 2. Cells: the smallest functional unit of life

Branches of Biology 3. Groups of cells: tissues, organs, organ systems

Branches of Biology 4. Organism: individual living system

Branches of Biology 5. Population: group of organisms of 1 type that live in the same area

Branches of Biology 6. Community: populations that live together in a defined area

Branches of Biology 7. Ecosystem: community & its non-living surroundings

Branches of Biology 8. Biosphere: the part of Earth that contains all ecosystems

Can science be biased? “Women’s Brains” by Stephen J. Gould – Don’t focus on the vocabulary that you don’t know; focus on learning the central idea! Discussion for homework – due tomorrow! – Be ready to discuss in class!