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These conditions have created divergent optimum reproductive strategies between the sexes. Males are driven to mate as many times, and with as many females, as possible in order to maximize the number of eggs he fertilizes. Simultaneously, however, females seek to offset the disproportionate costs of reproduction by obtaining a paternal investment from the male, which can come in the form of food, protection, defense of resources, or other energetic expenditures. The female may select mates based on secondary sexual trait indicators of “good providers.” Inducing the male to bear a greater share of the reproductive burden allows the female to store resources for future offspring (reduces her parental investment) (Schneider and Lubin 1998).

Female selection for paternal investment may impose a suite of costs not directly associated with resource provision, such as elaborate male courtship costs (Schneider and Lubin 1998). In species of arachnids and insects, females often guard the ootheca before it hatches, but males do not directly provide parental care. Thus, parental investment and sexual conflict chiefly occur within the context of mating (Schneider and Fromhage 2005).

Life-history parameters such as the timing of sexual maturation and oviposition, expected number of matings, body size, maturity, and generation length are likely to influence the degree and outcome of intersexual conflict (Buskirk et al. 1984). Dynamics of functional morphology and ecology may also limit or enhance mating costs/benefits, impacting intersexual conflict (Andrade 2003).

Several hypotheses explain ways in which sexual cannibalism can occur by natural selection. This chapter first discusses the interpretation of sexual cannibalism as a case of paternal investment : females require substantial nutrients to produce their eggs, and extract food from the male’s own biomass. This “foraging strategy” hypothesis is based on experiments with mantises since male self-sacrifice drastically increases the reproductive yield of the female (Barry et al. 2008). Enhancing female fecundity improves the male’s direct fitness because he can pass on more of his genes through healthy offspring. This chapter also reviews corroborating evidence from redback spider males, who initiate their own cannibalism to maximize reproductive benefit in a hostile environment that opposes repeated mating (Andrade 1996). An outwardly brutal mating interaction may ultimately be adaptive for members of both sexes.

This chapter proceeds to examine the limitations of, and alternatives to, the above hypothesis. Many male spiders and mantises are not complicit in self-sacrifice, indicating that cannibalism is not adaptively favorable to males (Liske and Davis 1987; Wilder and Rypstra 2008). Additionally, sexual cannibalism is prominent in size dimorphic spider species, in which males are too small to substantively feed females. These observations give rise to claims that cannibalism in the context of mating is actually a non-sexual, predator-prey interaction (Wilder and Rypstra 2008b). Alternatively, a sexual selection hypothesis suggests that females discriminately eliminate undesirable mates by devouring them (Elgar and Nash 1988). Overall, the examination of sexual cannibalism reveals the variable influences of species morphology and environmental conditions on a behavior’s evolutionary significance. Also, since both reproductive and mortality considerations are inherent in sexual cannibalism, examining its adaptive value offers intriguing insight into the fitness dynamics of sexual interactions

Questions & Answers

what is a gross domestic product
Amogelang Reply
Explain what is a production possibility curve
Sharon Reply
A curve that indicates the various production possibilities of two commodities when resources are fixed...
Geoffrey
what is market?
Jasmin Reply
ware the Byers and seller's that please is called market
suresh
a place where buyers and sellers meet
Tariro
I don't like this market definition.
Jasmin
market is any arrangement whereby buyers and sellers are brought together for the purpose of transacting business. It could be a geographical location or any other means such as internet, mobile phone etc. as long as buyers and sellers are brought together for the purpose of exchange.
Agusimba
A market is a place where buyers and sellers buy and sell goods through bargaining.
Jasmin
yes ,you are correct Agusimba sir.
Jasmin
exception of the low of demond
Rohit Reply
short run AC curves?
Jasmin Reply
you mean shirt run cost curves?
REBECCA
A short-run cost curve shows the minimum cost impact of output changes for a specific plant size and in a given operating environment. Such curves reflect the optimal or least-cost input combination for producing output under fixed circumstances.
REBECCA
nooo am not from India why!?
Godwin Reply
Godwin which level of education are you please
Millionaires
millionaires am in SHS 2
Godwin
who was the father of economic ?why?
Mahesh Reply
Rationing and hoarding
Semiat Reply
how do the size of a country's population affect labour force
Evans Reply
a mixed economic system
Ngong Reply
What are the types of price elasticity of demand
Juliana Reply
what are massures to promote geographical mobility of labor?
Ngong
Is to make sure that a labourer to know more about his salary to earn before going to the direction
shehu
types of Price elasticity of demand are fairly elastic demand, fairly inelastic demand, unity demand, perfectly elastic demand and perfectly inelastic demand.
Semiat
what is trade
PHILIPPE Reply
Trade is a basic economic concept involving the buying and selling of goods and services, with compensation paid by a buyer to a seller, or the exchange of goods or services between parties. Trade can take place within an economy between producers and consumers.
Miss
what is fisical policy?
ha Reply
fisical policy or fiscal policy?
Miss
what are.the characteristics of economic goods
Hamis
what are the importance of labour market?
Rachael
how discrib the rural development and their four stages
Sheikh Reply
ye economics se related ha
Sheikh
1..traditional stage..no science and technology is applied hence poor productionuu.2..the take off stage..some development strategies are initiated eg transport system is improved but the traditional cultural belief still remain .3..the prematurely stage..technological methods of production are appl
President
applied leading to higher GDP..4..stage of mass consumption..
President
What is Easiest Formula For National Income?
Tenzin Reply
national income/ agrrigate net value
Sheikh
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Source:  OpenStax, Mockingbird tales: readings in animal behavior. OpenStax CNX. Jan 12, 2011 Download for free at http://cnx.org/content/col11211/1.5
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