BIOL 2060 Lecture Notes - Lecture 13: Monarch Butterfly, Algonquin Provincial Park, Brown Anole

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Lecture #13 February 27
The diversity of life cycles (RELATED TO MIDTERM)
o Marine life cycle organisms → read about
o Temporal and spatial scales
Ie. monarch butterflies
Ie. wolf life cycle - algonquin park wolves
Around round lake → deer park
o Deers congregate in the winter (high densities)
o Snow depth is shallower
o Spatial overlap of wolves
Wolves vs. monarchs
o Monarchs - higher rates of reproduction/ produce more young
o Monarchs - mortality rate is higher
o Monarchs - have a toxin in the wings
Different age and stage specific traits affecting individuals fitness
The study of life history: examines underlying strategies to have generated
diversity in life histories
Understanding diversity of life-histories is about trade offs
o Limited resources divided into: maintenance, defence, growth, reproduction
o Maximizing one trait may come at a cost to another
o Tradeoffs that might occur
Larger organisms take longer to mature
Longer to sexually mature - thus reproduction is later
Clutch size in birds
o Number eggs laid in one reproductive bout
o Increases with latitudes and day lengths
o David Lack: longer days allows parents more time to find and deliver food
Generally, natural selection acts on clutch size to maximize fitness in local
Reaches maximum possible clutch size
Clutch size in great tits
What is the optimal clutch size for a female (assuming they are inflexible
year to year
o Mean clutch size = 8.5
o Clutch producing most surviving young = 12
o Hypothesis: year to year food availability changes optimal clutch
size for adults (in terms of both young and adult survival)
Low food year - large clutches >higher cost
Takes into account the geometric mean relative
fitness survival of young and adult s
Cost of reproduction is important
Principle of allocation
Any energy used for one function reduces the amount of energy for other
Do not have the capacity to grow as much
Ie. brown anole lizards
o Cost of reproduction
Produce faster
Trade offs and cost of growing sexually selected traits
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