lecture 7 (evolutionary ecology) - bio.classes.ucsc.edubio.classes.ucsc.edu/bioe107/lecture 7...

Evolutionary ecology

Interaction webInteractions include:•Consumer-prey•Competition•Mutualisms•Physical environment

Kinds of interactions

A. With physical environmentB. Species interactions

1) Directi. One-way interactionsii. Reciprocal interactions—can lead to coevolution

2) Indirect

Reciprocal interaction

A

B

Reciprocal interaction

A

B

Coevolution

Direct vs. indirect interactions

A B

C D

E F

Evolutionary Ecology—mostly considers:

1. how interactions (among species and between species and their physical environment) shape species through selection and adaptation;

2. consequences of the resulting evolutionary processes on populations, communities and ecosystems.

Example 1Endothermy in fishes

Influence of environment on speciescharacteristics

(Water Temperature)

Frequency (Hz)Frequency (Hz)00 22 44 66 88 1010 1212 1414

pow

er

W

pow

er

W

kgkg

11

00

22

44

66

88

1010

1212

1414

1515ooCC

2020ooCC2525ooCC

3030ooCC

T. T. albacaresalbacares

Hot Tuna are Faster & More PowerfulHot Tuna are Faster & More Powerful

Tunas Have High Oxidative Cell Tunas Have High Oxidative Cell MetabolismMetabolism

1

2

Scombroid fishes—tunas and billfishes

Tropical predatory fishes

• Billfish, tunas, sharks• Clear, warm water• Premium on performance of brain, vision• Evolution of endothermy• Rapid growth; short life spans

Example 2

Color and speciation in African cichlids

Species interactions

Loss of species

• Agriculture—nutrients and run-off• Reduced water clarity• Reduced color discrimination in cichlids• Loss of bright colors, increased

interbreeding, reduction in species

Coevolution

+/- antagonistic

-/- competive

+/+ mutualistic

+/o commensalistic

Consumer(Parasite)

Prey(Host)

DefenseResistance

+

-

Examples 3 and 4—coevolution in antagonists

Example 3—nest parasites, coevolution in hosts and parasites

Robin

Pied wagtail

Dunnock

Reed warbler

Meadow pipit

Great reed warbler

Example 4—food chain length and plant/herbivore coevolution

Plants

Herbivores

Even-number Odd-numbered

Stronginteraction

Weakinteraction

The players

Sea otters Sea urchins Macroalgae

In situ grazing

-20

0

20

40

60

80

100

Otters Abundant Otters Absent

Perc

ent L

oss

per 2

4 hr

Experimental

Control

Approach: North Pacific/Australasian comparison

Kelp Forest of the World

Mann 1972

Plant/herbivore coevolution

Plants

Herbivores

Carnivores

Australasia Northeast Pacific

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

0

0.05

0.10.15

0.2

0.25

0.3

0.350.4

0.45

0.5

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Northeast Pacific OceanN = 27 Species

AustralasiaN = 39 Species

% Total Phlorotannins

Prop

ortio

n of

Spe

cies

% Dry Wt.

513.4

513.4

513.4

513.4

Phlorotannins from

New Zealand Algae

Ecklonia radiata

Carpophyllum maschalocarpum

North American Algae

Agarum cribrosum

Dictyoneurum californicum

Tegulafunebralis

Tegulabrunnea

* NS

* ***

S.purpuratus

California Herbivores

* * *

* NS NS

NS

0.073 ** *

** ** *

NS ** *

** *

Evechinus chloroticus

NS

NSNS*

0.057

TurboCentrostephanusrodgersii sulcata

New Zealand Herbivores

NS NS* NS

******

smaragdusCook ia

NSNS NS

NS NSNSNSNS

NSNSNSNS

NSNS

NS*

NS*

ndndNS

*

Steinberg, Estes & Winter, PNAS, 1995

Plants

Herbivores

Carnivores

Defense

Resistance

Example 5

Indirect effects:

Sea otters on kelp (previous)

Led to• Steller’s sea cow• Body size in abalones

Steller sea cow

•A dugongid sirenian—radiated into North Pacific with onsetof recent Glacial Age and polar cooling in the North Pacific.

•An obligate kelp feeder—dentition used for feeding on marine angiosperms lost entirely.

•Patterns driven by the radiation and proliferation of the kelps.

Steller’s sea cow

Sea otter Limit grazing urchinsPoorly defended (high quality) kelp

Radiation of hydrodamalineSirenians (Steller sea cows)In the North Pacific

Abalones--why interesting?

Good fossil record

Variation in maximum size among species

H. varia

H. rufescens

22

1

5

2

4

4

3

1

7

22

110 8

7

7

101

79

8

= Cretaceous = Paleogene= Neogene= Pleistocene

Numerals represent extant species

Fossil and extant abalones

Maximum size vs. habitat

Japan

NE Pacific

Australia

New Zealand

East Africa

Indo-Pacific

W Atlantic-Caribbean

Tropical E Pacific

South African

Mediterranean

W Africa

Sea otter Limit grazing urchinsPoorly defended (high quality) kelp

Evolution of large body size in abalones

Spatio-temporal patterns in co-evolution

A Greya Moth about to Lay Eggs In, and Pollinate, a Woodland Star (Lithophragma) Flower

Pollen at end ofmoth’s abdomen

Source: John N Thompson

Flower-moth interactionsMoth:• Deposits eggs in floral ovary• Pollinate flower but moth larvae feed on developing

seeds

Plant:• Benefits from pollination (mutualism) but incurs cost from

seed loss (antagonism)

By comparing plant reproductive success between floral capsules with and without moth eggs, it is possible to determine if the interaction is commensal, antagonistic, or mutualistic

WithGreya eggs

Assessing Whether Woodland Star Plants Depend on Greya moths

Without Greya eggs

Source: John N Thompson

California

Oregon

Washington

Idaho

IDAHO0 100Km.

Salmon R.

Selway R.

Snake R.

= Mutualistic= Antagonistic= Commensalistic

Thompson and Cunningham 2002 NatureThompson and Fernandez 2006 Ecology

Geographic Mosaic of Ecological Outcomes

• Geographic selection mosaics (GxGxE)• Coevolutionary hotspots and coldspots• Trait remixing

Source: John N Thompson

Geographic Mosaic of Coevolution:Coevolution as an Ongoing Ecological Process

Trophy Hunting

Fisheries

Often target the larger fish in a population

Silversides

David Conover, SUNY Stony Brook

Smaller individuals selectively removed

Larger individuals selectively removed

Monhegan 1880s

Cod in the Gulf of Maine

0500100015002000250030003500400045000

20

40

60

80

100

120

Years Before Present

Atla

ntic

cod

bod

y le

ngth

(cm

)Cod Size Over Past 4500 years

5000

New synthesis of evolutionary ecology

ECO

EVO

ECO EVO

Fig. 1 (A) Dynamics for evolutionary and ecological traits in G. fortis.

T W Schoener Science 2011;331:426-429

Published by AAAS

Fig. 2 (A) Population numbers for the five ungulate species in Ezard et al.’s (18) study.

T W Schoener Science 2011;331:426-429

Published by AAAS

Fig. 4 Experimental approach used in ongoing study of eco-evolutionary dynamics in Caribbean lizards.

T W Schoener Science 2011;331:426-429

Published by AAAS