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By the end of this section, you will be able to:
  • Describe how life history patterns are influenced by natural selection
  • Explain different life history patterns and how different reproductive strategies affect species’ survival

A species’ life history    describes the series of events over its lifetime, such as how resources are allocated for growth, maintenance, and reproduction. Life history traits affect the life table of an organism. A species’ life history is genetically determined and shaped by the environment and natural selection.

Life history patterns and energy budgets

Energy is required by all living organisms for their growth, maintenance, and reproduction; at the same time, energy is often a major limiting factor in determining an organism’s survival. Plants, for example, acquire energy from the sun via photosynthesis, but must expend this energy to grow, maintain health, and produce energy-rich seeds to produce the next generation. Animals have the additional burden of using some of their energy reserves to acquire food. Furthermore, some animals must expend energy caring for their offspring. Thus, all species have an energy budget    : they must balance energy intake with their use of energy for metabolism, reproduction, parental care, and energy storage (such as bears building up body fat for winter hibernation).

Parental care and fecundity

Fecundity is the potential reproductive capacity of an individual within a population. In other words, fecundity describes how many offspring could ideally be produced if an individual has as many offspring as possible, repeating the reproductive cycle as soon as possible after the birth of the offspring. In animals, fecundity is inversely related to the amount of parental care given to an individual offspring. Species, such as many marine invertebrates, that produce many offspring usually provide little if any care for the offspring (they would not have the energy or the ability to do so anyway). Most of their energy budget is used to produce many tiny offspring. Animals with this strategy are often self-sufficient at a very early age. This is because of the energy tradeoff these organisms have made to maximize their evolutionary fitness. Because their energy is used for producing offspring instead of parental care, it makes sense that these offspring have some ability to be able to move within their environment and find food and perhaps shelter. Even with these abilities, their small size makes them extremely vulnerable to predation, so the production of many offspring allows enough of them to survive to maintain the species.

Animal species that have few offspring during a reproductive event usually give extensive parental care, devoting much of their energy budget to these activities, sometimes at the expense of their own health. This is the case with many mammals, such as humans, kangaroos, and pandas. The offspring of these species are relatively helpless at birth and need to develop before they achieve self-sufficiency.

Questions & Answers

What contribute to evolution of eukaryotes
Chiquita Reply
how transpiration occur in aquatic plants
Sajid Reply
what is the study of allelemorph
Faith Reply
what is protein
Majid Reply
any of a class of nitrogenous organic compounds which have large molecules composed of one or more long chains of amino acids and are an essential part of all living organisms, especially as structural components of body tissues such as muscle, hair, etc., and as enzymes and antibodies.
what is DNA replication?
Anirban Reply
separation of the DNA to produce new daughter cell. mostly in the form of meiosis
what is xenia
Mani Reply
can i get a broader difference between inductive reasoning and deductive reasoning
Daniel Reply
what are the types of tissues and there functions
what is signal cascade?
nur Reply
it is the process by which plants produce their fo
Getabalew Reply
what are the substrates of this process
definition of photosynthesis
Fiko Reply
it is simply the process by which plants get there food from the sun through the use of chlorophyll
what are the advantages and disadvantages of external and internal fertilization
Mohd Reply
which type of blood group can be tranfer easily after Accidents
Durgesh Reply
O positive cause it is a general donor
It can give to other blood group except O negative that can only get from O negative
which is the polygonum type of embryo sac in angiosperms
Madhura Reply
Describe how hormones regulate blood pressure, blood volume, and kidney function
junius Reply
2 Positive water potential is placed on the left side of the tube by increasing Ψp such that the water level rises on the right side. Could you equalize the water level on each side of the tube by adding solute, and if so, how?
Sarah Reply
where are the enzymes required for electron transport system located
how transpiration occur in aquatic plant

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Source:  OpenStax, Biology. OpenStax CNX. Feb 29, 2016 Download for free at http://cnx.org/content/col11448/1.10
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