Endemism, provincialism, and disjunction

Question 1

Endemism

Answer 1

The occurence of taxa with native distributions restricted to a particular geographic location. Endemism can be variable in scale from a small area to whole continents

Question 2

Provincialism

Answer 2

geographic overlap of endemism across multiple taxa. Alternatively, the delineation of geographic areas with particular biotic characteristics based on the distinctiveness of species assemblages.

Question 3

Disjunction

Answer 3

two or more closely related (usually monophyletic) taxa or populations occurring in geographically separated areas.

Question 4

Endemism examples

Answer 4

Olympic mudminnow is in a small region in washington

Pygmy rabbit is in an area in western US

Question 5

Endemism is typically nested

Answer 5

Kangaroo family heteromyidae - endemic to Southwest NA, Central America and SA

• Kangaroo mice (micodipodops) endemic to great basin region in western NA
• Within microdipodops, the pale kangaroo mouse is endemic to sandy habitats of Lahontan Trough in south-central nevada
• Within that group there are two separate mitochondrial DNA lineages endemic to eastern and western portions of the range

Question 6

Autoendemics

Answer 6

Evolved in an area within their current distribution (ex knagaroo mouse)

Question 7

Alloendemics

Answer 7

originated somewhere else, dispersed to their current locality and subsequently have gone extinct elsewhere- known as relicts , ex olympic mudminnow

Question 8

Taxonomic relicts

Answer 8

Remnants of, at one time, a much more diverse taxon

ex. coelacanth

Question 9

Biogeographic relicts

Answer 9

Taxa that at one time had much wider geographic distributions

Question 10

Neo endemics

Answer 10

endemics of recent origin (ex stickleback benthic and limnetic species pairs)

Question 11

Paleoendemics

Answer 11

endemics that originated long ago (ex olympic mudminnow)

Question 12

Provinces fit into a hierarchy of areas of endemism

Answer 12

Realms (terrestrial or marine)

• > regions (schlaters zoogeographic regions)
• > subregions
• > provinces
• > districts

Question 13

Concordance

Answer 13

suggests common historical events have shaped biotas within a given area (ex. geological, climatological or oceanographic events)
Ex: 91% of Australian mammal species are endemic to australia (compared to the 19% of the holarctic) - Longterm isolation of Australia from other landmasses has probably driven high degree of endemism
Ex: high degree of endemism in the NA Great Basin

Question 14

Provincialism separation

Answer 14

Provinces like regions may be separated by biogeographic lines
Ex: the freshwater fish of middle america are separated

Question 15

Marine Provincialism

Answer 15

Less well developed than terrestrial provincialism due to connectivity and dispersal

Question 16

Defining provinces

Answer 16

Defined by geographic features and patterns of diversity, irrespective of endemism
Ex. Fish faunal regions of Canada based on similarity of species between secondary watersheds
Ex. Amazonian ecoregions, which are divided by large river systems and also delineate range limits across species groups

Question 17

Disjunctions can occur at any spatial scale

Answer 17

e.g. Lungfishes in SA and Africa and Australia

Cutthroat trout in Western NA separated by a tiny strip

Question 18

Causes of Disjunction

Answer 18

1) Vicariance (ex. Flightless birds tinamous, rheas, ostrich, emu, Kiwi, cassowary)
2) Extinctions (ex. tailed frog in northern rocky mountains and cascade mountains habitat in the middle disappeared following glaical retreat therefore extinction in the middle- middle area is xeric (dry))
(ex. same with cutthroat trout)
3) long distance dispersal ex. Galaxis aka inanga found in New zealand, australia likely to have come from New zealand