I. What is Biology? Begs two questions – “what is science?” and “What distinguishes living systems?” II. What is Science? III. Ways of Knowing IV. What.

I. What is Biology?

Begs two questions – “what is science?” and “What distinguishes living systems?”

II. What is Science?

III. Ways of Knowing

IV. What Distinguishes Living Systems?

IV. What Distinguishes Living Systems?

A.Characteristics

1. O__

2. R__

3. R__

4. G__

5. E__

6. E__

IV. What Distinguishes Living Systems?

A.Characteristics

1. Ordered Organization – highly complex and non-random systems requiring energy input for their maintenance. They are open systems that can achieve greater order by an input of more energy or greater efficiency.

IV. What Distinguishes Living Systems?

A.Characteristics

1. Ordered Organization – highly complex and non-random systems requiring energy input for their maintenance. They are open systems that can achieve greater order by an input of more energy or greater efficiency.

- highly organized at different spatial and temporal scales

Spatial Scales:

1. Biosphere: Earth is ~4 x 107 m in circumference 2. Ecosystem: drop of pondwater (1 x 10-3 m) to Amazon Rain Forest (5 x 106 m).3. Community: equally variable 4. Population: equally variable 5. Individual: Smallest Mammal - Pygmy Shrew: 2 inches (5 x 10-2 m)

Largest Animal Ever - Blue Whale: 100 feet (3 x 101 m) Human - 6 ft... 2 x 100 mLargest Organism: Fungus covering 37 acres (7 x 102 m)

6. Organs: variable 7. Cells: Liver Cell: 2 x 10-5 m (2/100ths of a mm)

E. coli Bacterium: 2 x 10-6 (1/10th of a liver cell) Virus: 2.5 x 10-8 (1/100th of a bacterium)

8. Organelles: Ribosome: 1.8 x 10-8 m Mitochondrion: 2.5 x 10-6 m (about bacteria sized)

9. Molecules: Hemoglobin (average protein): 6.8 x 10-9 m (1/1000th of a bact.) Phospholipid: 3.5 x 10-9 m

Amino Acid: 5.0 x 10-10 m 10. Atoms: Carbon: 1 x 10-10 m (1/10,000,000,000 m - a ten billionth of a meter)

(a ten millionth of a millimeter) (a ten thousandth the length of a liver cell)

11. Nucleus: 2 x 10-15 m. 5 orders of magnitude smaller than the width of the atom!!!

So, the nucleus is only 1/50,000th the width of the atom.

Atoms are mostly space… matter is mostly space…

In fact, a cubic centimeter of nuclear matter (no space) would weigh 230 million tons (Physics by J. Orear, 1979)

Analogy: If a basketball 1 ft. in diameter represents the nucleus of an atom, the edge of the electron cloud would be about 5 miles away in either direction; the atom would be 10 miles wide (~ 50,000 ft.)… that’s a lot of empty space.

Analogy: You and the Earth are separated by 7 orders of linear magnitude. A millimeter (about the size of a bold-faced period) and a carbon atom are separated by 7 orders of linear magnitude. So, to a carbon atom, the period is it's Earth.... mind blowing... Cells make up living systems that can be 12 orders of magnitude larger (cell to biosphere).

B. Temporal Scales:1. Age of Earth: 4.5 x 109 yrs (4.5 billion)2. History of Life on Earth: 3.5 x 109 years 3. Oldest Eukaryotic Cells: 1.8 x 109 years 4. Oldest Multicellular Animals: 6.1 x 108 years5. Oldest Vertebrates: 5.0 x 108 (500 million)6. Oldest Land Vertebrates: 3.6 x 108 7. Age of Dinosaurs - Mesozoic: 240-65 million8. Oldest Primates: 2.5 x 107 (25 million)9. Oldest Hominids: 4.0 x 106 (4 million – 1/1000th of earth history)10. Oldest Homo sapiens: 2.0 x 105 (200,000)11. Oldest Art: 3.0 x 104 (30,000; 1/100,000th of Life's History)12. Oldest Agriculture: 1.0 x 104 (10,000)13. Oldest Organism: Bristlecone pines: 5 x 103

14. Human cell: brain/muscle 70 yrs Red Blood Cell - weeks Skin cell – days

15. Supply of ATP in cell - 2 seconds

16. Rates of chemical reactions - milliseconds (3.1 x 10-10 ms/year).

The history of life, spanning billions of years, is dependent on reactions that occur at a temporal scale separated by 19 orders of temporal magnitude.

IV. What Distinguishes Living Systems?

A.Characteristics

1. Order

2. Reproduction:

asexual/clonal/fragmentation

sexual: production of new genome

Inexact reproduction (through mutation and sex) creates hierarchical patterns of relatedness among organisms over time:

genealogies and phylogenies

me

brother

cousin

you

Genealogy of Human Populations

Genealogy of Primates

IV. What Distinguishes Living Systems?

A.Characteristics

1. Order

2. Reproduction

3. Response to the Environment (internal and external):

- physiologically (cells/tissues)

- behaviorally (organisms)

- genetically (populations adapt/evolve)

IV. What Distinguishes Living Systems?

A.Characteristics

1. Order

2. Reproduction

3. Response to the Environment

4. Growth:

- single cells get larger (but less efficient)

- increase size by increasing cell number

IV. What Distinguishes Living Systems?

A.Characteristics

1. Order

2. Reproduction

3. Response to the Environment

4. Growth

5. Energy Transformations – Metabolism:

- take in energy (radiant and/or chemical)

- use some, waste some (can’t violate second law) to link atoms together into biomolecules.

5. Energy Transformations - Metabolism

First Law: Energy is neither created nor destroyed, but can be transformed

Second Law: No energy transformation is 100% efficient; some is lost as ‘entropy’ (often heat).

Metabolic process are usually coupled reactions, pairing a constructive (anabolic) reaction that builds molecules with destructive (catabolic) reactions that provide the building blocks and energy.

IV. What Distinguishes Living Systems?

A.Characteristics

1. Order

2. Reproduction

3. Response to the Environment

4. Growth

5. Energy Transformations – Metabolism

6. Evolve:

Populations change over time. One way they change is to adapt to their environment. Organisms with useful traits reproduce more successfully than others (Natural Selection); the frequency of these traits change over time and populations diverge.

I. What is Biology?II. What is Science?III. Context: Ways of KnowingIV. What Distinguishes Living Systems?

V. The Evolution of Biology

Although humans have always been interested in nature and life, the application of logic, reasoning, and finally experimentation to these questions is a fairly recent cultural invention. In other words, science in general, and biology in particular, are recent inventions.

V. The Evolution of Biology

A. The Greeks

V. The Evolution of Biology

A. The Greeks (400-300 bce)

- Hippocrates

V. The Evolution of Biology

A. The Greeks (400-300 bce)

- Plato

UNIVERSAL PHILOSOPHY (four dogmas)

• Essentialism (cave allegory)

• Universal Harmony

• Demi-Urge

• Soul

The cave

V. The Evolution of Biology

A. The Greeks (400-300 bce)

- Aristotle

Logic - induction could lead to new ideas - to be evaluated by deduction

Scala Naturae

V. The Evolution of Biology

A. The GreeksB. The Persians (900-1000 ce) - Ibn a-lHaytham (Alhazen) - al-Biruni - Ibn Sena (Avicenna)

V. The Evolution of Biology

A. The GreeksB. The PersiansC. Middle Ages (450-1400 ce) - Constantine the Great - Thomas Aquinas

- “translators”

Christianity absorbed Platonic Essentialism- Single complete, harmonious creation by Christian God - Static, unchanging - Plenitude: created in totality and perfection - no breaks in Aristotle's scale of nature

V. The Evolution of Biology

A. The GreeksB. The PersiansC. Middle AgesD. The Renaissance (1400-1700)

- Copernicus - Vesalius

V. The Evolution of Biology

A. The GreeksB. The PersiansC. Middle AgesD. The Renaissance (1400-1700)

- Copernicus - Vesalius - Galileo - Kepler - Newton

V. The Evolution of Biology

A. The GreeksB. The PersiansC. Middle AgesD. The RenaissanceE. The Enlightenment (1700’s)

- Linnaeus

V. The Evolution of Biology

A. The GreeksB. The PersiansC. Middle AgesD. The RenaissanceE. The Enlightenment (1700’s)

- Linnaeus - Buffon

"Not only the ass and the horse, but also man, the apes, the quadrupeds, and all the animals might be regarded as constituting but a single family... If it were admitted that the ass is of the family of the horse, and different from the horse only because it has varied from the original form, one could equally well say that the ape is of the family of man, that he is a degenerate man, that man and ape have a common origin; that, in fact, all the families, among plants as well as animals, have come from a single stock, and that all the animals are descended from a single animal, from which have sprung in the course of time, as a result of progress or of degeneration, all the other races of animals. For if it were once shown that we are justified in establishing these families; if it were granted that among animals and plants there has been (I do say several species) but even a single one, which has been produced in the course of direct decent from another species; if, for example, it were true that the ass is but a degeneration from the horse - then there would no longer be any limit to the power of nature, and we should not be wrong in supposing that, with sufficient time, she has been able from a single being to derive all the other organized beings. But this is by no means a proper representation of nature. We are assured by the authority of revelation that all animals have participated equally in the grace of direct Creation and that the first pair of every species issued forth fully formed from the hands of the Creator." George Louis Leclerc, Compte de Buffon, Histoire Naturelle (1753)

V. The Evolution of Biology

A. The GreeksB. The PersiansC. Middle AgesD. The RenaissanceE. The Enlightenment (1700’s)

- Linnaeus - Buffon - Lamarck - Cuvier