The Origin of Species

Again, how awesome was Charles Darwin?

Extremely awesome. Like extremely awesome. On a whim he decided to go on a lengthy sea voyage instead of become a minister. This voyage took him to the Galapagos islands, and it was there Darwin discovered his passion and goal of proving evolution. Instead of just accepting that the Earth was 6,000 years old and that species were static in their evolution, he studied fossil and geological records to discover they were not

What is the significance of Daphne Major?


It's an isolated, uninhabited island in the Galápagos in which 60 different types of ground finches were living. This inspired much work with small populations in evolutionary study.

What is the significance of Cichlids? 


Over 1000 species of Cichlids live in Lake Victoria. They are a study in sexual reproduction and inbreeding because there are many cichlids that differ in only color, not anything biological, but they don't seem to interbreed. In a few studies, it is shown that the fish have certain color receptors that signal them to mate with only the colors they are sensitive to.

The Facts:

-Biological species concept: It defines a species as a group of populations whose members have the potential to interbreed in nature and produce fertile offspring

-Reproductive isolation: prevents genetic exchange and maintains the gap between species by isolating those that are genetically similar from those who are different

-Morphological species concept: classification is based mainly on observable and measurable physical traits such as shape, size and other features of form

-Ecological species concept: Identifies species in terms of their ecological niches

-Phylogenetic species concept: defines a species as the smallest group of individuals that shares a common ancestor that forms one branch on the tree of life

-Reproductive barrier: a biological feature of the of the organism itself that prevents fertilization between species

-Prezygotic barriers: Prevent mating or fertilization between species

-Postzygotic barriers: After hybrid zygotes are formed, most offspring will not survive. 

-Reduced hybrid fertility: A type of postzygotic barrier that produces infertile offspring.

-Punctuated equilibria: Used to describe long periods of little change evolutionarily

Some Key Terms:

-Speciation: the emergence of new species

-Taxonomy: the branch of biology that names and classifies species and groups into broader categories

-Sympatric speciation: a new species arises within the same geographic area as a parent species
-Allopatric speciation: Formation of many species living today by changing of allele frequencies
-Adaptive Radiation: The evolution of many species from a common ancestor
-Temporal isolation: Mating or flowering occurs at different times of day or seasons
-Habitat isolation: Populations live in different habitats and do not meet

-Behavioral isolation: There is little or no sexual attraction between different species

-Mechanical isolation: Structural differences in genitalia or flowers to prevent copulation or pollen transfer

-Gametic isolation: Male and/or female gametes dies before uniting or fail to unite

Diagram:

This is a diagram of the 3 Domains: Archaea, Bacteria and Eukarya. Domain is the highest taxonomic classification, and within the Domain Archaea you have the kingdom archaeobacteria (which are prokaryotes), and in Bacteria you have Eubacteria. The Domain Eukarya is the broadest, having 4 kingdoms: Protista, Fungi, Plantae, and Animalia

Summary:

A Cool Video:

http://www.youtube.com/watch?v=CKDSiNf_rLo