Architecture: It's Elementary!

Biology: TheDiversity and Unity of Life

ENVS 10 Lecture 1 Intro Book Chapter

The Scope of Life •Biologyis thescientific study of life.

– “Bio”- Life

– “ology”- Study •Life defies a simple, one-sentence definition.

•But all life shares a common set of characteristics.

Lecture Outline •Life 1. SharedCharacteristics of Life 2. Diversityof Life •Biosphere to the CellLife Forms: •Classifying Lifes Diversity 3. Unityof Life •Evolution and Natural Selection 4. HumanImpact on Life

Shared Characteristics of Life 1. Order- all living things exhibit complex but ordered organization. •is aEx: Sunflower highly organized structure.

Figure 1.2

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Shared Characteristics of Life 2. Regulation- The environment outside an organism changes but mechanisms regulate the organisms internal environment, keeping it within limits that sustain life. •Ex: Rabbitcan regulate body temperature with blood flow in ears.

Shared Characteristics of Life 4. EnergyUtilization - Organisms take in energy and transform it in performing all of lifes activities. •Ex: Hummingbird obtains energy from nectar and uses it to power flight and other work.

Figure 1.2

Shared Characteristics of Life 3. Growthand Development-Information carried ingenescontrols the pattern of growth and development in all organisms. •Ex: NileCrocodile

Shared Characteristics of Life 5. Responseto the Environment- All organisms respond to environmental stimuli. •Ex: Venusfly trap closes its trap rapidly in response to insect landing on it.

Figure 1.2

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Shared Characteristics of Life 6. Reproduction-Organisms reproduce their own kind. •Ex: Pandasonly produce other pandas.

The Diversity of Life •Biologists explore life at levels ranging from the biosphere to the molecules that make up cells.

Figure 1.2

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Shared Characteristics of Life 7. Evolution-reproduction underlies the capacity ofpopulationsto change (evolve) over time. •ofEx: appearance pygmy seahorse has evolved in a way to camoflauge itself in its environment.

Classifying Diversity •Taxonomyis the branch of biology that names and classifies species.

•It formalizes the hierarchical ordering of organisms.

Figure 1.2

Figure 1.8

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Classifying Diversity

Figure 14.21

•Bacteria and Archaea are both prokaryotic domains, meaning the organisms in these domains haveprokaryotic cells.

•The prokaryotic cell is simple, small, and contains no organelles.

Figure 1.5

The Three Domains of Life •Biologists divide the diversity of life into three main groups calleddomains.

•The three domains of life are:Bacteria, Archaea, Eukarya.

Figure 1.9.1

•Most of the organisms of the Eukarya domain have eukaryotic cellsthat are larger and more complex than prokaryotic cells and contain organelles.

Figure 1.5

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The Eukarya domain includes four kingdoms:

Figure 1.9.2

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Unity of Life - Evolution •Underlying the diversity of life is a strikingunity, especially at the lower levels of structure. – Example:the universal genetic language of DNA •Biological evolutionaccounts for this combination of unity and diversity. – Lifeevolves. – Evolutionis one of biologys best demonstrated, most comprehensive, and longest lasting theories. – Evolutionis the unifying theme of biology.

The Darwinian View of Life •The evolutionary view of life came into focus in 1859 when Charles Darwin publishedThe Origin of Species. •Darwin was struck by the diversity of animals on the Galápagos Islands. •He thought of adaptation to the environment and the origin of new species as closely related processes. – Aspopulations separated by a geographic barrier adapted to local environments, they became separate species. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings

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Natural Selection •Darwins book developed two main points: –Descent with modification: speciesliving today are modified descendants from ancestral species. •Ex: Diversityof bears is based on different modifications of a common ancestor from which all bears descended. –Natural selectionreproductive success.: unequal Individuals with traits best suited to their environment have the greatest reproductive success. •The mechanism for descent with modification. Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings

Human Impacts •Although life evolves and adapts, humans are now responsible for changing our planet at a rate so fast that adaptations may be impossible. •What are some ways that we are negatively changing our planet? – ClimateChange (global warming) – Deforestation – Pollution(atmosphere, water, etc.)

– Overpopulation(resource exploitation)

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