1

What is botany?2 Kingdom System of Classification: Plants & Animals

(Linnaeus, ~1750)

5 Kingdom System:Monera, Protista, Plantae, Fungi, Animalia

(Robert Whittaker, 1969)

3 Domain System: Bacteria, Archaea, Eukarya(our current best hypothesis)

What does this timeline illustrate about the process of science?

Five Kingdoms

Three Domains The land plant Divisions

Protists

Red Green Brown

Bryophytes

Ferns

Gymnosperms

Angiosperms

750 mya

400 mya

280 mya

150 mya

What is botany?Short answer: the study of plants (Kingdom

Plantae, in Domain Eukarya)

For Bio 1C: the study of Kingdoms Plantae, Fungi,“Protista,” and some photosynthetic members of

Domain Bacteria

What is Ecology?

• The scientific study of the interactions betweenorganisms and their environments is calledecology

• provides a basic understanding of how naturalprocesses and organisms interact,

• gives us the tools we need to manage the planet’slimited resources over the long term

2

Major Components of theEnvironment

• Abiotic components, which consist ofnonliving chemical and physical factors,such as temperature, light, water, minerals,and air

• Biotic components, which include the livingfactors—all the other organisms that arepart of an individual’s environment.

Hierarchy of Interactions

• We can divide ecology into fourincreasingly comprehensive levels:organismal ecology, population ecology,community ecology, and ecosystemecology

Life on Earth - Timescale

3.4 BYA - heterotrophs

2.7-2.2 BYA O2 begins to Accumulate

2.2 BYA first Eukaryotes

700 MYA sharp increase inAtmospheric O2. Reached modern levels in Cambrian570-510 MYA

450 MYA life on oceans surface and on to land

The land plant Divisions

Protists

Red Green Brown

Bryophytes

Ferns

Gymnosperms

Angiosperms

750 mya

400 mya

280 mya

150 mya

The changing earth:The Origin of Life

• Early Earth was a very different place thanit is now.– Chemically reactive atmosphere– Very little Oxygen– Very High UV and other energy sources (UV

damages DNA/RNA)

Fig. 14.2

3

Pasteur 1850s•SpontaneousGeneration vs.Biogenesis

Pasteur and biogenesis of microorganisms (Layer 3)

So How did Life Originate?• Four Stage Hypothesis

1. Abiotic synthesis of Organic Monomers (thebuilding blocks)

2. Abiotic Synthesis of Polymers, including aminoacids and nucleic acids.

3. Formation of “Pre-cells” or protobionts:droplets with membranes that maintained aninternal chemistry distinct from theirsurroundings.

4. Self replecating molecules arose, makinginheritance possible

The Miller-Urey experiment: 1953

•Origin of Lifeexperiments•Miller-Urey Testedfor Synthesis ofOrganic Monomers

•Got all 20 aminoacids, sugars, lipids,nucleotides, evenATP!

Deep sea hydrothermal vents could also haveplayed a role…

•Producing organic polymers:drippingmonomers onto hot sand, clay or rock.

•Conditions existed near active volcanoesand…deep sea vents

Stage 4- Laboratory versions of“Protobionts” or Pre-cells

4

Lynn Margulis:serial endosymbiosis Origin of Eukaryotic Cells

Single Celled to MulticelledWhat is an “adaptation”?

• From an evolutionary perspective: Anadaptation is any trait or feature of an organismthat increases its chances of reproducing.

• From an interpretive perspective: Anadaptation is any structure or mechanismexhibited by an individual species that allows it tomeet its physiological requirements under theconditions posed by a particular habitat.

Some adaptations…

• Adaptations to live near shore (algae) totake advantage of nutrients

• Transitioning to land means need water!Animals move, Fungi live underground(essentially)

• Plants developed specialized tissue systems• The vascular system in plants• Protected gametophytes

Linnaeus:1750’s

Binomial nomenclature

5

Three members of the violet genus Viola.They differ in features due to localadaptations, but there is an overallsimilarity. This genus has about 500species

Taxonomy

Five Kingdoms

R.H Whittaker1969

Three Domains

Cladistics:Cladograms andmolecular data

Evolutionary Trees What are the tools used by scientiststo observe and understandevolutionary relationships?

• 1. Artificial selection• 2. Fossil record• 3. Comparative anatomy• 4. Comparative embryology• 5. Comparative biochemistry• 6. Biogeography

6

What about analogousstructures?

• Convergent evolution• Co-evolution

Some major episodes in the history of life

Systematics: connecting phylogenyand taxonomy

• Taxonomy = the science of classifyingorganisms

• Phylogenetics = the study of phylogeny, or thehistory of evolutionary relationships amongspecies

Figure 25.8 Taxonomy starts with the latin binomial, and exhibits a hierarchicalstructure reflecting phylogenetic relationships among taxa or groups of organisms

Latin “binomial” ortwo-part name(genus and species)

Figure 25.9 The connection between classification and phylogeny: this phylogenetic treeorganizes taxa into a hypothesized tree of evolutionary relatedness, with species at the

tips of the branches.

How are thesephylogenetictreesconstructed?

Traditional Approach:Phenetics

Classifications basedon perceived overallsimilarity