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Plants with low fecundity produce few energy-rich seeds (such as coconuts and chestnuts) with each having a good chance to germinate into a new organism; plants with high fecundity usually have many small, energy-poor seeds (like orchids) that have a relatively poor chance of surviving. Although it may seem that coconuts and chestnuts have a better chance of surviving, the energy tradeoff of the orchid is also very effective. It is a matter of where the energy is used, for large numbers of seeds or for fewer seeds with more energy.

Early versus late reproduction

The timing of reproduction in a life history also affects species survival. Organisms that reproduce at an early age have a greater chance of producing offspring, but this is usually at the expense of their growth and the maintenance of their health. Conversely, organisms that start reproducing later in life often have greater fecundity or are better able to provide parental care, but they risk that they will not survive to reproductive age. Examples of this can be seen in fishes. Small fish like guppies use their energy to reproduce rapidly, but never attain the size that would give them defense against some predators. Larger fish, like the bluegill or shark, use their energy to attain a large size, but do so with the risk that they will die before they can reproduce or at least reproduce to their maximum. These different energy strategies and tradeoffs are key to understanding the evolution of each species as it maximizes its fitness and fills its niche. In terms of energy budgeting, some species “blow it all” and use up most of their energy reserves to reproduce early before they die. Other species delay having reproduction to become stronger, more experienced individuals and to make sure that they are strong enough to provide parental care if necessary.

Single versus multiple reproductive events

Some life history traits, such as fecundity, timing of reproduction, and parental care, can be grouped together into general strategies that are used by multiple species. Semelparity occurs when a species reproduces only once during its lifetime and then dies. Such species use most of their resource budget during a single reproductive event, sacrificing their health to the point that they do not survive. Examples of semelparity are bamboo, which flowers once and then dies, and the Chinook salmon ( [link] a ), which uses most of its energy reserves to migrate from the ocean to its freshwater nesting area, where it reproduces and then dies. Scientists have posited alternate explanations for the evolutionary advantage of the Chinook’s post-reproduction death: a programmed suicide caused by a massive release of corticosteroid hormones, presumably so the parents can become food for the offspring, or simple exhaustion caused by the energy demands of reproduction; these are still being debated.

Iteroparity describes species that reproduce repeatedly during their lives. Some animals are able to mate only once per year, but survive multiple mating seasons. The pronghorn antelope is an example of an animal that goes into a seasonal estrus cycle (“heat”): a hormonally induced physiological condition preparing the body for successful mating ( [link] b ). Females of these species mate only during the estrus phase of the cycle. A different pattern is observed in primates, including humans and chimpanzees, which may attempt reproduction at any time during their reproductive years, even though their menstrual cycles make pregnancy likely only a few days per month during ovulation ( [link] c ).

Questions & Answers

double stranded DNA is found in which viruses?
Deborah Reply
what would happen if humans were not multicellular
Grace Reply
ettr
Grace
sorry but no
Grace
i haven't any things
mascuud
Is there any other type of a eukaryotic cell.
Grace Reply
what is bionomial nomenclature
Rachaelda Reply
state the role of mitochondria
Rachaelda
mitochondria ia power House of the cell. it provides energy and as ATP. Cells energy currency.
Haider
The scientific method of giving short names on the basis of genius and species.
Haider
it is introduce by carlous Lennieus
Haider
it is naming of living organism where by they are given two names one generic and the other specific name
Kenneth
what is element
Kofi Reply
Structure of water molecule and it's biological significance. .....help guys
Ashly
what is the formula for chemical equetion
Justo Reply
Why mitochondria is called the power house of the congo the bahamas cell
Farrukh Reply
how can I learn this subject?
mascuud Reply
what's microscope?
Mathias Reply
A device used to study a very small specimen thst cannt br seen with the naked eyes for example cells, or microorganisms.
Danisha
a medical device used to study cells bacteria viruses and parasites e.g electron microscope for studying cells.
Grace
exactly microscope
Randa
is an instrument use to view microorganisms such as viruses and bacteria
Ohene
it is an instrument used to magnify micro-scopic organism
Kenneth
microscopic
Coster
microscope
Adam
what does multi seminar mean
Grace Reply
many seminars
Grace
how many cells on the human
Amar Reply
how is genetic testing?
Nyabuoy
test
Nyuongatdet
which party of an internal leaf which represent organ and tissue
fernando
3 trilleons cells on the human
Jyoti
name the groups of bacteria, what they cause and explain the components of bacterial cell
Emmanuel
what are the three level of relationship that exist between organism?
Chinedu
trillions of cells
Grace
unicellular
Kenneth
who many cell are in the human body
Ayasso Reply
trillions of cells
Grace
what causes coloring of skin variation
Prince Reply
what is your answer
Jonathan Reply
which qn
Randa
what is chemosynthesis
Irene
who many cell are in the human body
Ayasso
there are billion cells in human body
fazeela
what are three stages of mitosis
jerry
they're alot cells in our body
jerry
what are the stages of mitosis
jerry
they are prophez methaphez anaphez. thelophez
fazeela
anyone to explain each of the following,, prophase, metaphase, anaphase and telophase
jerry
what is a filial
Mbah Reply
denoting the offspring of a cross
Grace

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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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