Island evolution

1
Island evolution
Evolutionary forces on islands Evolutionary
trends on islands
Morphology
Gigantism and nanism Loss of dispersal abilities
2
Pringleophaga marioni, Marion Island
Lepidoptera Tineidae
Paractora dreuxi, Marion Island
Diptera Helcomyzidae
3
Galapaganus, Galapagos Islands
Sequiera et al. 2000
4
winged/apterous
mainland/island
Naupactus xanthographus
Naupactus verecundus
Naupactus dissimulator
Galapaganus howdenae
Galapaganus galapagoensis
Galapaganus caroli
Galapaganus vandykei
Galapaganus collaris
Galapaganus conwayensis
Galapaganus ashlocki
Sequiera et al. 2000
5
Coleoptera
80
Orthoptera
60
ArcSine-transformed flightless (mainland areas)
Diptera
40
Hemiptera
20
0
Thysanoptera
0
20
40
60
80
ArcSine-transformed flightless (oceanic islands)
Psocoptera
Roff 1990
Neuroptera
6
nr of species flightless/total
nr of transitions
7
Porzana monasa (1828), Kosrae Island
Porzana sandwichiensis (?1884), Hawaii Islands
Porzana palmeri (1920, 1948), Laysan Island
Porzana atra, Henderson Island
8
Amauornis akoof
Amauornis favirostris
Porzana monasa
Porzana tabuensis
Porzana atra
Porzana sandwichensis
Amauornis bicolor
Amauornis olivieri
Porzana palmeri
Porzana pusilla
Porzana parva
Porzana fusca
Porzana paykullii
Porzana carolina
Porzana fluminea
Porzana porzana
Anurolimnas fasciatus
Poliolimnas flaviventer
Slikas et al. 2002
9
Kagu, Rhynochetos jubatus, New Caledonia
10
Rodriguez solitaire, Pezophaps solitaria,
Rodriguez
Dodo, Raphus cucullatus, Mauritius
11
Kakapo, Strigops habroptilus, New Zealand
12
Anas chlorotis, New Zealand
Anas nesiotis, Campbell Islands
Anas aucklandia, Auckland Islands
13
Flightless cormorant, Phalacrocorax harrisi,
Galapagos
Cormorant, Phalacrocorax carbo
14
1cm
mandibles
Apteribis, Hawaii Islands ()
15
Kauai
Molokai
Oahu
Maui
Lanai
Hawaii
Sorensen et al. 1999
moa-nalo (), Hawaiian Islands
16
number of evolutionary transitions
number of flightless species
total number of species
Ostriches Struthionidae 1 1 1 Africa Rheas Rheid
ae 2 2 South America Cassowaries Casuariidae 4
4 Australia, New Guinea Kiwis Apterygidae 3 3 N
ew Zealand Emus Dromaiidae 1 1 Australia Moas
Dinornithidae 13 13 New Zealand Dromornithidae
8 8 Australia Elephant birds Aepyornithidae 9 9
Madagascar Dodos Raphidae 2 2 2 Mascarene
Islands Rails Rallidae 17 17 122 Various
islands Kagus Rhynochetidae 1 1 1 New
Caledonia Parrots Psittacidae 1 1 358 New
Zealand Ibises Plataleidae 3? ? ? Hawaii Pengu
ins Spheniscidae 18 1 18 Southern
hemisphere Cormorants Phalacrocoracidae 1 1 37 G
alapagos Islands Grebes Podicipedidae 3 3 21 Sou
th America Murres Alcidae 1 1 23 Atlantic
Ocean Ducks Anatidae 4 2 148 Various
coastlines
17
Loss of dispersal abilities
ecological release (lack of predators)
18
2.0
Log winglength (cm)
1.0
Bird families
No flightless species
Contains flightless species
0
0
1
2
3
4
Log body mass (g)
McCall et al. 1998
19
Broom stick, Bidens pilosa, Tropics
Bog Beggarticks, Bidens conjuncta, Hawaii Islands
20
pappus
achene
Lactuca muralis, Vancouver Island
Cody Overton 1996
21
2.0
2000
1500
Volume pappus / Volume achenes
1000
500
0
1-4
5-7
10
8-9
mainland
Age (years)
Lactuca muralis, Vancouver Island
Cody Overton 1996
22
Island evolution
Evolutionary forces on islands Evolutionary
trends on islands
Morphology
Gigantism and nanism Loss of dispersal
abilities Development of woodiness
23
Cabbage tree, Dendroseris litoralis, Juan
Fernandez Islands
24
Sow Thistle, Sonchus fruticosus, Madeira
25
Narrowleaf plantain, Plantago lanceolata, Eurasia
Plantago princeps, Hawaii
26
Competition hypothesis growing taller is
advantageous
Longevity hypothesis woodiness allows extended
lifespans, increases chance of sexual reproduction
Climate hypothesis islands have milder
and moister climates
Development of woodiness
27
Island evolution
Evolutionary forces on islands Evolutionary
trends on islands
Morphology
Gigantism and nanism Loss of dispersal
abilities Development of woodiness Tendency
towards melanism
28
lower predation pressure
tendency towards melanism
thermal advantage
29
Viper, Vipera berus, Swedish islands in the
Baltic Sea
30
70
60
50
40
Melanism frequency ()
30
20
10
0
inland
coastal
insular
Viper, Vipera berus, Swedish islands in the
Baltic Sea
Forsman 1995
31
0.9
Annual survival rate
0.7
zigzag males
0.5
melanistic males
1986-87
87-88
88-89
89-90
90-91
Year
Viper, Vipera berus, Swedish islands in the
Baltic Sea
Forsman 1995
32
Japanese four-lined ratsnake, Elaphe
quadrivirgata, Yakushima Island
Tanaka 2007
33
16
12
melanistic
striped
deviation from preferred range (C)
8
4
0
Jul
Sep
Oct
Nov
Month
Japanese four-lined ratsnake, Elaphe
quadrivirgata, Yakushima Island
Tanaka 2007