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Flashcards in Ecology Deck (485)
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121

symmetric male hypothesis

bilateral species
an excellent genotype can correct asymmetries during development

122

developmental instability

asymmetries in structure
minor errors in embryological development and growth

123

can lead to asymmetry

stress, pollutants, parasitism, homozygosity, poor genotype

124

symmetric male hypothesis bird study

symmetry was altered in male birds tail feathers
female switches her favourite to most symmetric male

125

symmetric male hypothesis is commonly observed in

insects, fish, birds, mammals

126

symmetry can be evaluated by

sight and sound

127

example of symmetry evaluation by sound

crickets having symmetric (monotone) frequency wing harps- indictor of body symmetry

128

fluctuating asymmetry

random deviation from perfect bilateral symmetry in otherwise symmetrical morphological traits, originates from developmental errors during ontogeny

129

fluctuating asymmetry reflects

inability of a genotype to buffer itself effectively against environmental perturbations

130

symmetric male hypothesis fish study

females have significant preferences for fish with symmetric vertical bars

131

facial asymmetry in rhesus macaques

honest indicator of health
used in mate choice situations

132

display evaluation

females evaluate quality, complexity, coordination of display (dances, songs)

133

inbreeding avoidance

all animal/plant species in the wild have mechanisms to avoid inbreeding

134

animal species can detect genetic kinship based on

pheromones

135

MHC

major histocompatibility complex

136

what is MHC

~30 genes coding for proteins in cell membranes essential for immune system, 2 different proteins at each gene, each gene multiple alleles, each individual unique, MHC molecules bind to specific receptors and have distinct odours

137

females prefer what in regards to MHC

males with the most dissimilar odour (genotype) to themselves

138

how birth control affects females and MHC

females are attracted to male similar to self-- birth control mimics pregnancy-- want family close

139

MHC based mating preference may be affected by

genetic background, sex, early life experience

140

inbreeding is potentially problematic in all animal species. the major ecological cost of inbreeding is

reduced capacity to cope with environmental changes

141

increased homozygosity is not an ecological cost

it is a genetic cost

142

advantages of group living

increased food search efficiency
increased capture efficiency of large prey
increased detection of predators
increased defense against predators
selfish herd theory

143

examples of increased food search efficiency in group living

seed detection by songbirds
fish detection in gulls- repeatedly catching fish signals a good feeding area

144

examples of increased capture efficiency in group living

wolves, lions
african hunting dogs- pack 20 catch ~80,000 kJ/dog/day, threshold number before a large difference is seen

145

increased detection of predators in group living

'many eyes' theory- Hawks have significantly lower attack successes with large number of pigeons present.
1-10 pigeons = 60-80% success
>50 pigeons = ~10% success

146

increased defense against predators

mobbing- ex. small birds can mob owls

147

selfish herd theory

dilution effect- schooling/herding/flocking- if there is an attack on a group it is less likely the attacker will get you

148

examples of species that exploit selfish herd theory

wildebeest, pronghorn, herring, flamingos

149

evolution of selfish herd theory

belted kingfisher in a tree above a lake.. if fish are individual and he has one is his sights the probability that he is looking at that one is 1, if that fish joins a group the probability that he the one being spotted is decreased..

150

Disadvantages of group living

increased transmission of parasites
shared resources and resource depletion
conflicts/stress