Biology: The study of life Long ago, the scope of this study left the range of ‘plants and animals’ Known: 2X106 of??? 5 to 100 million. 2 million known Maybe billions amazing locations for life!

Today, we can study life on many scales… From earth’s veil of life called the Biosphere…

The Biosphere

To the tiniest units we can perceive Like molecules

The DNA molecule: a frontier in biology DNA demonstrates both the simplicity, and baffling complexity of living things.

Another scale: Cells – the basic units of life Another scale: Cells – the basic units of life.! Who knows what a polymer is?‘ What we gen see w a student scope. What we recognize is there We’re kind of a POLYMER’ ourselves

All “individuals” are really…. parts of a whole… (for these polar bear ‘parts’ to exist, what others are required?)

The range of the study of life: Reductionism vs Systems biology. Reductionism simplifies. Regents . Systems biology studies how pieces fit together. Includes interactions. Helps see the more complex relationship

Emergent properties become apparent (emerge) as the reductionist facts accumulate into a related system, providing greater understanding Molecules, organelles, cells tissues, organs organ systems Life itself is an emergent property; things affect, and are affected by, other things.

consider a wrist watch. We could study each single part, and we would learn things. Systems looks at those parts in the context of the watch. Sees how the parts working together

Feedback: how life is regulated Living systems at most levels monitor the environment, and attempt to adjust to changes. Feedback tells a living system how it is doing. Regulation = adjustments, maintains homeostasis, sustaining life. It may be chemical or be behavioral.

Increases the ability of an ecosystem to sustain life. BIODIVERSITY (?) Increases the ability of an ecosystem to sustain life. Requires producers, consumers and decomposers “variety is the spice of life”

Taxonomy: reductionism Knowing each category (know them?) identifies specific structural characteristics of a particular organism. Est = 86% of life forms are UNidentified.

The 3 domains of life (the largest grouping) 1990 The 3 domain system used since 1977 Archaea (oldest) ‘Extremeophiles’ (Eu)bacteria [sometimes called prokarya]: Cyanobacteria, eubacteria. Both beneficial & harmful to other living things Eukarya name its 4 kingdoms: Characteristics?

archaeans… methanogens halo –, thermo-, psychrophiles All life fits 1 of these 3 forms

All 3 domains 1. have DNA 2. have similar basic structures, & 3 All 3 domains 1.have DNA 2. have similar basic structures, & 3. perform the life processes Where did all this variety come from? The best scientific explanation: EVOLUTION – Darwin’s ‘descent with modification’, forming branches Based on preferential reproductive success, & random changes to the DNA.

Phyla of K. Animalia 1. Porifera 2. Cnidaria 3. Platyhelminthes 4. Nematoda 5. Annelida 6. Mollusca 7. Arthropoda 8. Echinodermata 9. Chordata

How we learn Good science (almost) always produces reliable DATA

Hypothesis based science vs observational based science List the steps of hypothesis based science 1 2 3 4 5 (6) (7) Observational; Listen! 2015 example

Inductive vs. deductive reasoning Inductive reasoning is the broad, general explanation for observations. Look for adjectives. Think Darwin It’s conclusions may be false Ex: Humans are doing something to the environment causing the climate to warm and storms to be more frequent and intense “Bottom up” approach

Deductive r. answers broad questions by acquiring facts through testing & data collection from multiple sources that supports or refutes a hypothesis. Look for numbers Think Julian Huxley and the modern theory of evolution. “top down” approach. Serengeti, proponent of natural selection, evolutionary synthesis (incl genetics)