Ecological selection

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Ecological selection (or environmental selection or survival selection or individual selection or asexual selection) refers to natural selection without sexual selection, i.e. strictly ecological processes that operate on a species' inherited traits without reference to mating or secondary sex characteristics.[citation needed] The variant names describe varying circumstances where sexual selection is wholly suppressed as a mating factor.[citation needed]

Ecologists often study ecological selection when examining the abundance of individuals per population across regions, and what governs such abundances.[1]

Circumstances in which it occurs

Ecological selection can be said to be taking place in any circumstance where inheritance of specific traits is determined by ecology alone without direct sexual competition, when e.g. sexual competition is strictly ecological or economic, there is little or no

A. m. scutellata, and the European honey bee.[2]

In

artificial selection
from operating, e.g. arranged marriages, where parents rather than the young select the mate based on economic or even astrological factors, and where the sexual desires of the mated pair are often subordinated to these factors, are artificial unless wholly based on an ecological factor such as control of land which is held by their own force.

In forests, ecological selection can be witnessed involving many factors such as available sunlight,

Seedlings that were once removed by ecological selection now become favored, because the shaded forest floor
has become ideal for such shade tolerant species. This is a great example of how ecological selection can create niches for different species by performing the same function with different outcomes.

Vs. sexual selection

In cases where ecological and sexual selection factors are strongly at odds, simultaneously encouraging and discouraging the same traits, it may also be important to distinguish them as sub-processes within natural selection.

For instance, Ceratogaulus, the

runaway evolution. The species seems to have suddenly died out when horns reached approximately the body length of the animal itself, possibly because it could no longer run or evade predators—thus ecological selection seems to have ultimately trumped sexual. [citation needed
]

It is also important to distinguish ecological selection in cases of extreme ecological abundance, e.g. the human

mail order bride
" who primarily mates for economic advantage.

Differentiating ecological selection from sexual is useful especially in such extreme cases; Above examples demonstrate exceptions rather than a typical selection in the wild. In general, ecological selection is assumed to be the dominant process in natural selection, except in highly cognitive species that do not, or do not always, pair bond, e.g. walrus, gorilla, human. But even in these species, one would distinguish cases where isolated populations had no real choice of mates, or where the vast majority of individuals died before sexual maturity, leaving only the ecologically selected survivor to mate—regardless of its sexual fitness under normal sexual selection processes for that species.

For example, if only a few closely related males survive a natural disaster, and all are able to mate very widely due to lack of males, sexual selection has been suppressed by an ecological selection (the disaster). Such situations are usually temporary, characteristic of populations under extreme stress, for relatively short terms. However, they can drastically affect populations in that short time, sometimes eliminating all individuals susceptible to a pathogen, and thereby rendering all survivors immune. A few such catastrophic events where ecological selection predominates can lead to a population with specific advantages, e.g. in colonization when invading populations from more crowded disease-prone conditions arrive with antibodies to diseases, and the diseases themselves, which proceed to wipe out natives, clearing the way for the colonists.

In humans, the intervention of artificial devices such as ships or blankets may be enough to make some consider this an example of

artificial selection
. However it is clearly observed in other species, it seems unreasonable to differentiate colonization by ship from colonization by walking, and even the word "colony" is not specific to humans but refers generically to an intrusion of one species on an ecology to which it has not wholly adapted. So, despite the potential controversy, it may be better to consider all examples of colonist-borne diseases to be ecological selection.

For another example, in a region devastated by

environmental
", and the term environmental selection may be preferable in these cases.

See also

References

  1. PMID 19732211.[permanent dead link
    ]
  2. S2CID 22128779
    .
  3. ^
    S2CID 23528064
    .
  4. ^ Barnes, B.V.; Spurr, S.H. (1980). Forest Ecology. New York: Wiley.
  5. S2CID 86520815
    .
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