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Biogeography and Dispersal of Micro-organisms: A Review Emphasizing Protists
Presented by Kevin Gilgallon II


Key Terms:
Cryptogram spores Cyst viability

Flagship species

Gondwana

Human dispersal

Laurasia

Local vs. global diversity

Protozoa

Undersampling


How our understanding was flawed:
Our general understanding of micro-organisms is based on scattered fragments of data, often based on conflicting methodology. This leads to We once believed that when it came to micro-organisms that "everything was everywhere". This stemmed from Beijerinck's famous metaphor. However it can not be falsifiable and is a metaphor. We do not know global diversity measure so we can not compare. Undersampling


Specific examples:
Dinoflagellates · Strict endemism · ~80% endemicity in polar regions · Structure involves two flagella that propel the organism in a whirling motion Diatoms · Among the most common type of phytoplankton · Actinella genus contains 29 species, 9 of these are endemic to Australasia, some are limited to a few lakes · Silica shell Coccolithophores · Reliable identification requires an electron microscope · Calcified shell · Classified into 5 zones, however there are few "bipolar " species.


Specific examples:
Chrysophytes · Show distinct distribution patterns based on ecological factors · Good example of distribution, genus Mallomonas has 172 described taxa, 31 cosmopolitan, 59 Northern temperate-subartic-artic, 17 are bipolar, 18 restricted to the tropics, and 17 with scattered distributions. Desmids · Have an obvious cosmopolitan distribution, but there are northern and southern species · M. cruxmelitensis occurs mostly in temperate regions while M. radians has a pantropical distribution Naked amoebae, heliozoa, and heterotrophic flagellates · Difficult to identify · One soil flagellate, Hemimastix Amphikineta, has a distant distribution pattern aligning with Gondwanaland and the transitional area.


Specific examples:
Foraminifera · Data came from fossilized specimen · Globorotalia truncatulinoides, consists of 4 rRNA lineages and should be considered different species. 2 can be found subtropical waters, 1 in the subarctic, and 1 in the subantarctic.


Conclusion