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Home , Holarctic realm, Nearctic realm, Palearctic realm

since the Age of Exploration began, the geographical pattern of life's kinds it has become progressively clearer that is not haphazard or random... different parts of the world support in general, continental biotas are uniform, greatly different assemblages of organisms yet distinct from others, sometimes greatly so two aspects to this matter: elements of a given biota tend to be more closely-related among themselves Description - what is the pattern? than with those of other continents

Analysis - how did the pattern arise? Wallace described this in his global system of http://publish.uwo.ca/~handford/zoog1.html Zoogeographical Realms 15 1 15 Zoogeographical Realms 2

Wallace's Realms almost..... Gaviidae -

this realm has no endemic families. But are endemic Antilocapridae to = Nearctic + Palearctic 15 ...... correspond to continents 3 15 4

Palearctic Realm

this realm is truly the "bird-realm"

a great number of among the many families are endemic endemic families including tinamous are anteaters and and toucans cavies panda 15 5 15 6

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Ethiopian Realm Oriental Realm gibbon

leafbird

aardvark

15 lemur ostrich 7 15 8

Australasian Realm so continental biotas are distinct; Monotremes - but they are not equally distinct egg-laying mammals 79 families of terrestrial mammals RE GIONS! near.! neotr. palæar. ethio. orien. austr. nearctic! ! ! 4! ! ! ! 51/79! = 73% endemic neotropical! ! 6! 15!! ! ! to realms platypus palæarctic! ! 5! 2! 1! ! ! ethiopean! ! 0! 0! 11 16!! oriental! ! ! 1! 1! 10 12! 5! cockatoos australian! ! 0! 0! 0 0! 0! 10 echidna wallabies & kangaroos - marsupials TOTALS! ! 14! 22! 19 31! 20! 10 15 9 15 68% 52% 10

how do we explain these patterns of today's organisms are all descendants of and sharing of regional biotas? lineages which have UNIQUE ORIGINS UNIQUE IN TIME & SPACE life and the planet both have A VERY LONG HISTORY time/space coincidences of group origins during which they have both changed influence today's distribution of groups but after group's origination, as life has changed and diversified GEOGRAPHY CHANGES so the earth's surface has provided changing opportunities for colonization - isolation disappearance sometimes restricted, sometimes broad connection break-up 15 11 15 12

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CONTINENTAL DRIFT 370 - land plants 270 - Pangea as land-masses skate about, separating & colliding, biotic lineages are evolving

where you originate and what happens to where you originate profoundly affects your future prospects distribution is a dynamic phenomenon, shifting with time & circumstance 15 13 30015 - 200 - mammals start14

150 - dino-time 60 - mammals & Glacial Maximum - 18K y.a. another kind of impact on distributions

gondwanalan d

11005 - dino-peak 10 - cooling & drying15 15 16

several reptile & lineages fundamentals of distribution are ∴ provided by evolved before the split-up of Pangea; deep history of continents & biota they ∴ show little regional endemism as they change but most bird & mammal divergence took place during Cenozoic but also relevant are organisms' capacities for (well after the break-up) dispersal, migration and nature of barriers "perceived" barriers: therefore these groups show clearest patterns mountain ranges oceans most distinctive = most isolated migrations can blur "homeland" patterns

15 (during key periods) 17 15 18

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a biogeographic puzzle - solved NEXT CLASS

Global Climate, Productivity & Soils

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