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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 is photosynthesis
Conast Reply
photosynthesis is the process by which green plants manufacture their own food from water and carbon dioxide using sunlight as a source of their energy releasing oxygen as a by-product.
Everine
what are runners
Godfrey Reply
what is an environment
Bwambale Reply
diagrams are not indicated, why?
Simon Reply
diagrams for what?
Everine
A vaccination is a treatment which makes the body stronger against an infection. The body fights infections using the immune system, which is made up of millions upon millions of cells including T cells and B cells.
Nworie
define the term immunity
Everine
can simply defined as an exemption from an attack
Nworie
is the ability of an organism to resist a particular infection or toxin by a specific antibodies or sensitized white blood cells
Adeb
difference between cell and cell membrane
Sunday Reply
cell is a basic unit of living body however cell membrane is a protective layer of cell.
Suhail
very good
Everine
which topic would you like to discuss today?
Everine
vaccine
Nworie
what do you understand by the term vaccine?
Everine
guy I need the answer of this question what occurs during photosynthesis
REAL Reply
Photosynthesis is the process that plants use to convert light into food. During this process, plants create carbohydrates starting with only carbon dioxide and water. Sunlight provides the energy that makes photosynthesis possible.
Stanley
@Stanley,that's how I could as well put it
Evans
what are different between genotype and phenotype
Martha Reply
what is light microscope and electronic microscope
Martha
what occurs during photosynthesis
Martha
what are importance of biology
Martha
what is the meaning of computer science
Martha
what is ecology
Adeyemo Reply
what is zoology
Adeyemo
zoology branch of biology that study animals
Moses
a branch of biology which deals with the study of animals
Anita
A plant is a living thing that grows in the earth and has a stem, leaves, and roots
Bello Reply
what is a plant
dalitso Reply
A plant is a living thing that grows in the earth and has a stem, leaves, and roots
Bello
a plant is an is a living thing that is classified under autothrops because it makes its own food through the process of photosynthesis .
Joanne
a plant is also known as autotropic category and a plant have root & stem
Anita
what is plant
Odion Reply
Plants are autotrophic
Baramox
Then animal are heterotrophic
Iyiola
what are organisms
Godfred Reply
Living structures
Aryavarta
living and non living which charectrised by different properties
Anita
organisms living and nonliving components of the environment with distinct xtics
Tony
the diagram below show how the blood of a human embryo flows close to the mothers blood in the placenta . which substances are represent at x in higher concentrations than at y
Joyce Reply
what is ecology
Odion Reply
what is cell
Odion
what is cell
Odion
Is the basic unit of life
Agatha
what's biology
Okebe
biology is the study of life
Ali
I want to know more about biology
Okebe
What are enzymes?
Zanga
if you want to know more, please start studying biology from the beginning systematically
Best
enzymes are biological catalyst that speed up d rate biochemical reactions
Ning
What is a cell
Awal Reply
What are tissues
Awal
A cell is the smallest unit of living organisms.
hamidat
Tissues are group of similar cells performing a particular function.
hamidat

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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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