Integration Integration

Next week (5/19): Next week (5/19):

Chapter 10.6 – 11Chapter 10.6 – 11

Grade for graduation class Grade for graduation class

Factors determine the future population size: Factors determine the future population size:

natality (+), mortality (-), immigration (+), emigrationatality (+), mortality (-), immigration (+), emigration (-)n (-)

Systems of sexuality in animalsSystems of sexuality in animalsTerm FormTerm Form

‧‧Gonochorism Gonochorism 雌雄異體 雌雄異體 Dioecious male or femaleDioecious male or female

‧‧Hermaphroditism Hermaphroditism 雌雄同體雌雄同體 Simultaneous male/ femaleSimultaneous male/ female

Sequential Sequential

。。 Protandric Protandric 先雄後雌 先雄後雌 male → femalemale → female

。。 Protogynous Protogynous 先雌後雄 先雌後雄 fefemale → malemale → male

。。 Sequential alternating with sex reverSequential alternating with sex reversalsal

Sex determination of Sex determination of CrepidulaCrepidula s sp. p. (Barnes et al., 1993)(Barnes et al., 1993)

幼體期高死亡率的原因幼體期高死亡率的原因 生物因子生物因子 捕食捕食 空間競爭空間競爭 耐飢力耐飢力

非生物因子非生物因子 ------潮間帶潮間帶 乾燥乾燥 溫度溫度

海洋無脊椎動物幼體期有高死亡率海洋無脊椎動物幼體期有高死亡率

策略一策略一 : : Longer life spanLonger life span策略二策略二 : : 提早性成熟提早性成熟

Marine invertebrate larval development

A. Indirect development (metamorphosis is involved) a. Planktotrophic development: e.g. mussel, oyster b. Lecithotrophic development: e.g. Babylonia snail c. Direct release from egg cases: e.g. some snails d. Within-parent direct development: some sea snails

B. Direct development: e.g. amphipod, octopus

Settlement and metamorphosis Gregarious settlement Other positive cues (e.g. food) Negative cues (e.g. predator) Passive entrainment Identified chemical cues: proteins, neurotransmitters, polypeptides, polysacchrides, oligopeptides, free fatty acids etc.Application: aquaculture and prevention biofouling.

Advantages of complex life cycle Advantages of complex life cycle (Barnes et al., 1993)(Barnes et al., 1993)

1.1. Exploitation of the temporary food resource Exploitation of the temporary food resource provided by phytoplanktonic bloomsprovided by phytoplanktonic blooms

2.2. Colonization of new habitatsColonization of new habitats

3.3. Expansion of geographical rangeExpansion of geographical range

4.4. Avoidance of catastrophe associated with locAvoidance of catastrophe associated with local habitat failureal habitat failure

5.5. Avoidance of local and sib-competitionAvoidance of local and sib-competition

6.6. Exposure of diverse offspring to the maximuExposure of diverse offspring to the maximum degree of habitat diversity m degree of habitat diversity

7.7. Avoid inbreedingAvoid inbreeding

Evolution pattern of species with planktotrophic larvae:

Geologically long-lived and low extinction rates

Low speciation rate

Wide distributional range

生命起源自海洋生命起源自海洋

以脊椎動物的演化為例以脊椎動物的演化為例

鳥類鳥類

魚類 兩生類 爬蟲類 魚類 兩生類 爬蟲類

哺乳類 哺乳類

鯨類的反向操作鯨類的反向操作

鯨類的祖先是由陸地回到海洋鯨類的祖先是由陸地回到海洋

是由像牛的中爪獸演化成古鯨是由像牛的中爪獸演化成古鯨類，再變成現在的鯨類類，再變成現在的鯨類

避免強大的競爭壓力避免強大的競爭壓力

躲避天敵躲避天敵

目的目的