Evolution
unifying concept in biology that involves a change in the inherited characteristics of biological populations over successive generations
Taxonomy
science of grouping, naming and classifying living organisms based on their shared characteristics
Origin of Life Theories
A. Chemosynthesis Theory (gases & biomololecules)
B. Panspermia (space)
Chemosynthesis Theory
- states that life eveolved 3-4 billion years ago when gases such as methane, ammonia, hydrogen and water vapor react to produce the first organic compounds
- RNA is the first nucleic acid formed
- DNA evolved later as a stable genetic material
Panspermia
-states that life on earth was bought by meteorites, asteroids and planetoids from space
Theory of Natural Selection
-states that organisms undergo changes in their traits to better adapt to their environment
Proponent :
Charles Darwin-observed animals and plants in the Galapagos Island and discussed natural selection as a means of survival in his book “On the Origin of Species”
Species
members of a population that can successfully and naturally interbreed and produce viable offspring
Phylogeny
-evolutionary history of a species
Speciation
-evolutionary process in which new species arise
Homology/ Homologous
-refers to similar characteristics orginating from common ancestry (Diversion)
-same history, different function
Example: arms of human, cat, whale and bat
Analogy/ Analogous
-structures that perform similar function but do not
share common ancestry (Conversion)
-same function, different history
Examples: Wings of moth, bat and bird
Modes of Evolution
A. Phyletic Evolution (no original species)
B. Branching Evolution (with original species)
Phyletic Evolution
-transformation of entire species into different species all together
Branching Evolution
- formation of new species but retaining the original species
- Adaptive Radiation- form of branching evolution wherein a single species transforms into many different species over time
Carolus Linnaeus
-founded taxonomy and the binomial system “for the greater glory of God”
Binomial System
- First name: Genus
- Second name: Species
Taxonomy Rank
Domain Kingdom Phylum / Division for plants Class Order Family Genus Species
*two different organisms are more closely related to each other if they share a common lower taxonomic rank
Three Domain System ( A, B, E)
A. Domain Archaea
B. Domain Bacteria
C. Domain Eukarya
Domain Archaea
- prokaryotic
- no nuclear membrane
- unicellular
- no peptidoglycan layer in cell wall
- found in inhospitable extreme environemnt
-Kingdom: Kingdom Archaebacteria
Examples:
a. Methanogens- metabolize H2 and CO2 into methane
b. Halophiles- tolerate high salt concentrations
c. Thermoacidophiles- tolerates high pH and high temperatures
Domain Bacteria
- prokaryotic
- no nuclear membrane
- unicellular
- has peptidoglycan layer in cell wall
- contains bacteria rRNA
-Kingdom: Kingdom Eubacteria
Examples:
a. Cyanobacteria-photosynthesizing bacteria
b. Staphylococcus aureus- bacteria present on skin
Domain Eukarya
- eukaryotic
- has nuclear membrane
- unicellular/multicellular
-Kingdoms: Protista, Fungi, Animalia, Plantae
Kingdom Protista
-single celled eukaryotes
Examples:
a. Algae-photosynthetic protist
b. Amoebae- irregularly shaed, causes amoebiasis
Kingdom Fungi
- unicellular/ multicellular
- no chlorophyll
- saprophytic nutrition
- acquire nutrients through adsorption
- have cell wall (chitin)
- capabe of mitosis and meiosis and sexual reproduction
- don’t have lysosomes like plants
Examples:
a. Molds- found on bread
b. Yeast- used for baking
Kingdom Animalia
- multicellular
- eukaryotic
- store carbohydrate in the form of “glycogen”
- reproduce sexually
- transmits impluse
Endoderms- warm-blooded
Ecthoderms- cold-blooded
Phylums: Porifera, Cnidaria, Platyhelminthes
Nematoda, Annelida, Mollusca, Arthropoda, Echinodermata, Chordata
