Bio%20201%20S12%20Lect%2015%20%28True%29%20v3

Succulent a facultave cam plant sedum

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Unformatted text preview: heries) •  black rockfish (Sebastes melanops) on N. Amer. Pacific coast •  females get larger with increasing age •  females reproduce much more, the larger they get –  female size propor:onal to # eggs –  size of oil droplet in an egg greatly influences larval survival and growth rate (energy supply) •  larger females produce larger oil droplets •  Oregon: 1996- 1999 avg. age of females harvested decreased from 9.5 to 6.5 years –  likely to have strong consequences for future harvests –  new regula:ons may be needed popula:on growth •  reproduc:ve poten:al of organisms is huge, but never comes close to being realized –  single bacterial cell reproducing by binary fission •  within one month popula:on would weigh more than the visible universe and be expanding at the speed of light –  single pair of cod •  in 6 years descendants would fill the Atlan:c Ocean hLp://www.cartoonistgroup.com/store/add.php?iid=27208 exponen:al growth assumes: births and deaths are at constant rates and are constantly taking place for example year 1 popula:on size = 50 individuals year 5 popula:on size = 250 individuals r = dN/dT = 200/4 = 50 highest possible growth rate: intrinsic rate of increase •  rmax –  per capita intrinsic rate of increase •  has a characteris:c value for each species •  rare: only when condi:ons are op:mal and usually cannot be sustained for long dn/dt = rmax * N => rmax = dn/dt / N per capita intrinsic rate of increase in our example if we assume these were op:mal condi:ons, then at year 1 rmax = 50/50 = 1 per capita intrinsic rate of increase hLps://www.msu.edu/course/isb/202/ebertmay/2004/predic:ng_change/rmax.jpg hLps://www.msu.edu/course/isb/202/ebertmay/2004/predic:ng_change/rmax.jpg If our example was in days, not years then this would be like the rmax of Paramecium Tradeoff: Body size and reproduc:ve capacity •  On average, small organisms have higher rates of per capita increase and more variable popula:ons than large organisms. Another tradeoff: Reproduc:on vs. survival Source: Gunderson 1997 Adult fish mortality (survival) and reproduc8ve effort more complete model: logis:c popula:on growth •  r = growth rate •  K = carrying capacity an example of a “sigmoidal” shaped curve in nature related to popula8...
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This note was uploaded on 10/02/2013 for the course BIO 201 taught by Professor True during the Spring '08 term at SUNY Stony Brook.

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