island evolution
DESCRIPTION
Island evolution. Evolutionary forces on islands Evolutionary trends on islands. Morphology Behaviour. Development of tameness. Falkland Islands fox, Dusycion australis , Falkland Islands. Blue-footed booby, Sula nebouxii, Galapagos. Tamar wallaby, Macropus eugenii , Kangaroo Island. - PowerPoint PPT PresentationTRANSCRIPT
Island evolutionEvolutionary forces on islandsEvolutionary forces on islandsEvolutionary trends on islands
Development of tameness
MorphologyMorphologyBehaviour
Falkland Islands fox, Dusycion australis, Falkland Islands
Blue-footed booby, Sula nebouxii, Galapagos
Tamar wallaby, Macropus eugenii, Kangaroo Island
Avera
ge fl
igh
t in
itia
tion
dis
tan
ce
20
0
10
30
Tutanning GardenIsland
KangarooIsland
New Zealand
House mice, Mus musculus, feeding on Tristan albatross, Diomedea dabbenena, Gough Island
Island evolutionEvolutionary forces on islandsEvolutionary forces on islandsEvolutionary trends on islands
Development of tamenessDevelopment of tamenessRelaxation in territoriality
MorphologyMorphologyBehaviour
House mouse, Mus domesticus, Isle of May and UK mainland
05
10152025
investigate
00.5
11.5
22.5
3
defend
0
1
2
3
4
attack
00.5
11.5
22.5
chase
0
0.2
0.4
0.6
0.8
shove
0
0.5
1
1.5
sit by
Gray & Hurst 1998House mouse, Mus domesticus, Isle of May and UK mainland
Relaxation in territoriality• smaller territories• increased overlap• tolerance towards subordinates• reduced aggressiveness• abandonment of territorial defence
Resource hypothesis
Competition release
Abundant resources
Defence hypothesis
Predation release Mild climate
Increased survival of "have-nots"
Increased territorial defence costs
Island evolutionEvolutionary forces on islandsEvolutionary forces on islandsEvolutionary trends on islands
Reduced fecundity
MorphologyMorphologyBehaviourBehaviourLife history
reduced clutch sizehigher quality young
Energy reallocation hypothesispredation relaxation, density compensation select for investment in fewer,higher qualityyoung
Resource predictability hypothesismilder climate, reduced seasonality favours a reduction in clutch size
clutch size ~ instant food availability
population density
winter
breeding season
Island evolutionEvolutionary forces on islandsEvolutionary forces on islandsEvolutionary trends on islands
Reduced fecundityReduced fecundityChanges in reproductive strategy
MorphologyMorphologyBehaviourBehaviourLife history
Dioecy
Tag alder, Alnus serrulata
Monoecious
male
female
malefemale
Holly, Ilex aquifolium
Dioecious Hermaphrodite
male
female
Lily, Lilium
hermaphrodite85%
dioecious6-7%
monoecious5-6%
worldwide
hermaphrodite62.4%
dioecious14.7%
monoecious7.6%
Hawaii
dioecy
avoidinginbreeding depression
sex allocation theory
proportion of investment in male flowers
0.0 0.2 0.4 0.6 0.8 1.0
Fert
ility
0.0
0.2
0.4
0.6
0.8
1.0
1.2
proportion of investment in male flowers
0.0 0.2 0.4 0.6 0.8 1.0
Fert
ility
0.0
0.5
1.0
1.5
2.0
proportion of investment in male flowers
0.0 0.2 0.4 0.6 0.8 1.0
Fert
ility
0.0
0.2
0.4
0.6
0.8
1.0
1.2
proportion of investment in male flowers
0.0 0.2 0.4 0.6 0.8 1.0
Fert
ility
0.0
0.5
1.0
1.5
2.0
Island evolutionEvolutionary forces on islandsEvolutionary forces on islandsEvolutionary trends on islands
Reduced fecundityReduced fecundityChanges in reproductive strategy
MorphologyMorphologyBehaviourBehaviourLife history
DioecyDioecyLoss of flower attractiveness
Sun orchid, Thelymitra longifolia, New Zealand Psychopsis papilio, South America
Bellflower, Campanula punctata, Izu Islands
Bombus diversus
Bombus ardens
Lasioglossum
0 100 km
Oshima
Toshima
Niijima
KozuMiyake
Mikura
Hachijo
Honshu
Coro
lla w
idth
(m
m)
20
0
10
30
1 2 3 4 5 6Pollinator width (mm)
Kozu
MiyakeHachijo
ToshimaNiijimaOshima
Honshu
Island evolutionEvolutionary forces on islandsEvolutionary forces on islandsEvolutionary trends on islands
Reduced fecundityReduced fecundityChanges in reproductive strategy
MorphologyMorphologyBehaviourBehaviourLife history
DioecyDioecyLoss of flower attractivenessLoss of flower attractivenessAnemophily
Rhetinodendron berteroi, Juan Fernandez Islands
Plocama pendula, Canary Islands
Anemophily
Windy conditionsallow wind pollination
Lack or paucityof animal pollinators
Inbreedingavoidance
Island evolutionEvolutionary forces on islandsEvolutionary forces on islandsEvolutionary trends on islands
Reduced fecundityReduced fecundityChanges in reproductive strategy
MorphologyMorphologyBehaviourBehaviourLife history
DioecyDioecyLoss of flower attractivenessLoss of flower attractivenessAnemophilyAnemophilyUnusual pollinators
Bumble bee, Bombus canariensis, Canary Islands
88%
Mauritius ornate day gecko, Phelsuma ornata, Ile aux Aigrettes, Mauritius
71%
Aeonium holochrysum, Canary Islands
80%
Madeira wall lizard, Teira dugesii, Madeira
Lilford's wall lizard, Podarcis lilfordi, Balearic Islands
Island evolutionEvolutionary forces on islandsEvolutionary forces on islandsEvolutionary trends on islands
Reduced fecundityReduced fecundityChanges in reproductive strategyChanges in reproductive strategyUnusual dispersal agents
MorphologyMorphologyBehaviourBehaviourLife history
Podarcis lilfordi, Balearic Islands
Podarcis pityusensis, Balearic IslandsGallotia atlantica, Fuerteventura
Robust skink, Cyclodina alani, New Zealand
Aldabra giant tortoise, Dipsochelys dussumierri, Ile aux Aigrettes (Mauritius)
Ile-aux Aigrettes ebony, Diospyros egrettarum, Ile aux Egrettes, Mauritius