Lecture 3 Implications & extensions

Mass & energy balance The standard DEB model specifies fluxes of 4 organic compounds food, faeces, structure (growth), reserve (including reproduction) The fluxes of 4 mineral compounds (CO 2, H 2 O, O 2, NH 3 ) follow from conservation of chemical elements C, H, O, N and strong homeostasis The standard DEB model assumes that only food is limiting Dissipating heat follows from conservation of energy and strong homeostasis (constant chemical potentials)

Method of indirect calorimetry Empirical origin (multiple regression): Lavoisier 1780 Heat production = w C CO 2 -production + w O O 2 -consumption + w N N-waste production DEB-explanation: Mass and heat fluxes = w A assimilation + w D dissipation + w G growth Applies to CO 2, O 2, N-waste, heat, food, faeces, … For V1-morphs: dissipation  maintenance

Mass fluxes  flux notice small dent due to transition maturation  reproduction At abundant food: growth ceases at l = 1 allocation to reproduction use of reserve not balanced by feeding in embryo

Diapauze 2.6.2c seeds of heather Calluna vulgaris can germinate after 100 year

Foetal development weight, g time, d Mus musculus Foetus develops like egg but rate not restricted by reserve (because supply during development) Initiation of development can be delayed by implantation egg cell Nutritional condition of mother only affects foetus in extreme situations Data: MacDowell et al 1927

Egg-foetus transitions in Poeciliopsis P. elongata P. fasciata P. turrubarensis 1.1.4J, cont 2

Dynamic mixtures of V0- & V1-morphs V1-morph V0-morph Respiration: assim + maint + growth Assim, maint  mass Growth in diam  time at constant food

White et al 2011 Am. Nat., 178: Dynamic mixtures of V0- & V1-morphs 0.5 cm/yr cm/yr cm/yr cm/yr cm/yr cm/yr Celleporella

Dynamic mixtures of V0- & V1-morphs Celleporella 0.5 cm/yr , 24 cm/yr White et al 2011 Am. Nat., 178:

Acceleration of development Embryo: isomorphic v constant Early juvenile: V1-morphic v, {p Am } increase with length Late juvenile/adult: isomorphic v, {p Am } constant Found in: bivalves, gastropods, copepods, amphipods, decapods, collembolas, echinoderms, lancelets, tunas, flatfish, anchovy, Danio, caecilians, marsupials

Anchovy Engraulis encrasicolus time, d length, cm 0.16 cm 0.22 cm 0.4 cm 0.9 cm 1.2 cm >4 cm embryo Pecquerie 2008 PhD thesis VU A’dam

Stage transitions at maturity thresholds Danio rerio 28.5°C Augustine et al 2011 Comp. Biochem. Physiol. A 159 :275– a

Stage transitions at maturity thresholds Augustine et al 2011 Comp. Biochem. Physiol. A 159 :275–283 Danio rerio 28.5°C Data: Lauwrence et al 2008 caloric restiction Data: Augustine < birth : isomorph birth-metamorphosis: V1-morph > metamorphosis : isomorph 7.8.2b

Acceleration of development 7.8.2c indirect direct acceleration development no yes Pseudophryne bibronii Geocrinia vitellina Crinia georgiana Crinia nimbus

Acceleration of development 7.8.2d O 2 nmol/h Dry mass, mg Crinia georgiana Pseudophryne bibronii age, d hatch birth Mueller et al 2011, subm max dry weight 500 mg max dry weight 200 mg 12 °C 1 0 ½ ¾ ¼  1 0 ½ ¾ ¼ metam

Aging 6.1g

Aging: relation to O 2 -use 6.1h, time, d survival prob Reodruction rate, #/d Data: Ernsting & Isaaks high food 10/20°C high food 10/10°C low food 10/20°C Differences in life span are caused by differences in respiration Survival in adult Notiophilus biguttatus modified by food and temperature

Aging: sex differentiation 6.1i time, d survival prob body length, mm Data on Daphnia magna: MacArthur & Baillie 1929 Differences in aging between sexes are caused by differences in g

Aging: endotherms & feeding 6.1l time, d survival probability embryo weight, g body weight, g Mus musculus data: Weindruch et al 1986, MacDowell et al 1927 feeding level Life span hardly depends on food in ecotherms decreases for increasing food in endotherms Van Leeuwen et al 2002 Biogerontology 3:

Aging & Energetics 6.1m Olm Proteus anguinus: a † > 100 a a b = 140 d, a p = 14 a, R = 35/12.5 a -1 Can live 10 months without food, so can switch to torpor state Voituron et al 2010 Biol. Lett.

Aging 6.1.1

Aging module of DEB theory 6.1.1a

Aging: non-growing ectotherms 6.1.1b time, d survival probability Data: Rose 1984 Weibull with shape parameter 3

Aging in adult insects age after eclosion, d surviving number # of eggs/beetle, d -1 Drosophila melanogaster Notiophilus biguttatus Data: Rose 1984 Data: Ernsting & Isaaks, 1991 High food, 20/10 °C 0.63 a -2 High food, 10 °C a -2 Low food, 20/10 °C a -2 survival based on observed reproduction No growth initial random mort Weibull Model  =3

General Weibull fits DEB 6.1.1c Data from Elandt-Johnson & Johnson 1980 for white USA males in the period Both models are fitted to the same data They fit equally well and have both 4 parameters Contrary to the Weibull model the DEB model - is based on tested assumptions - has links with energetics via h W and h G.

Aging: growing ectotherms 6.1.1d time, d survival prob body weight, g Data: Slob & Janse 1988 Weibull with shape 3 fits ectothermic survival well, even if growth period not small relative to life span

Aging: Function Observation: Aging related hazard rate remains low during embryonic and juvenile stages becomes high at start of reproduction Suggestion: Organisms decrease protection level in adult stage use ROS to create genetic diversity among gametes use genetic diversity for adaptation to changing environment efficient defence (peroxidase dismutase) or repair systems or reduced ROS production can increase life span, but reduce genome diversity