Evolution and evolvability · Article

Natural selection and the struggle for existence

Natural selection is the argument, set out by Darwin in 1859, that more individuals are born than can survive, so a struggle for existence follows. Any variation that profits its bearer improves the chance of survival and is passed on¹². The idea matters here because later authors dispute how far it accounts for adaptation, for form and for the behaviour of organisms⁴⁹.

Earliest held: 1859, Darwin
Most discussed in: On the origin of species by means of natural…, 1859
In the library: 569 passages in 42 works
Rewritten: 2026-10-05

Malthus and Darwin

Darwin (1859) described the principle as the doctrine of Malthus applied to the whole animal and vegetable kingdoms². He argued that more individuals are born than can possibly survive, so a struggle for existence recurs. A being that varies in a manner profitable to itself has a better chance of surviving and is naturally selected¹. Darwin added that among plants and animals there can be no artificial increase of food and no prudential restraint from marriage². Rádl (1930) wrote that Wallace, having adopted the method of Malthus, reached the same two ideas, because they are logical consequences of the premises⁶.

Disputed readings

Authors accepted the struggle but disagreed on its scope and use. Kropotkin (1902) complained that Darwin never examined the relative importance of the two aspects under which the struggle for existence appears in the animal world⁴. Timiriazeff (1912) pointed to observation instead. When mixed sweet pea seeds were gathered and resown on the same bed each year, some colours ousted the others within a few years⁵. James (1890) reported Mosso's objection to a selection account of the angry frown. Mosso held that the pupil dilation coupled with it is unfavourable for vision and should have been weeded out³.

Selection and adaptation today

Recent authors ask what selection alone can explain. Soen and colleagues (2015) propose that natural selection and adaptive improvisation within the individual are interdependent, and that one is insufficient without the other⁷. Kouvaris and colleagues (2017) note that suitable variation in new environments suggests foresight, which they call incompatible with the short-sighted concept of natural selection⁸. If form is inherent and readily achieved, selection for incrementally improved fitness is less decisive in diversification than generally believed⁹.

SourcesEach quotation was checked word for word against the passage it opens.

any being, if it vary however slightly in any manner profitable to itself, under the complex and sometimes varying conditions of life, will have a better chance of surviving, and thus be naturally selectedDarwin, 1859 · On the origin of species by means of natural selection, or the preservation of… · open at passage 22
It is the doctrine of Malthus applied with manifold force to the whole animal and vegetable kingdoms; for in this case there can be no artificial increase of food, and no prudential restraint from marriage.Darwin, 1859 · On the origin of species by means of natural selection, or the preservation of… · open at passage 122
Professor Mosso objects to any explanation of the frown by its utility for vision, that it is coupled, during emotional excitement, with a dilatation of the pupil which is very unfavorable for distinct visionJames, W., 1890 · The Principles of Psychology, Vols. 1-2 · open at passage 2798
Darwin never attempted to submit to a closer investigation the relative importance of the two aspects under which the struggle for existence appears in the animal worldKropotkin, P., 1902 · Mutual Aid: A Factor of Evolution · open at passage 29
gather all the seeds each year and sow them again on the same bed, to find in a few years' time that some colours will oust the others from the bedTimiriazeff, C. A., 1912 · The Life of the Plant · open at passage 557
Having adopted the method of Malthus, Wallace could not avoid reaching the ideas of a struggle for existence and of a natural selection, as these are merely the logical consequences of the premises.Rádl, E., 1930 · The History of Biological Theories · open at passage 98
natural selection and adaptive improvisation are inter-dependent. Simply put, one is insufficient without the other.Soen Y, Knafo M, Elgart M, 2015 · A principle of organization which facilitates broad Lamarckian-like adaptations… · open at passage 69
Such a capacity suggests foresight that is incompatible with the short-sighted concept of natural selection.Kouvaris K, Clune J, Kounios L, Brede M, Watson RA, 2017 · How evolution learns to generalise: Using the principles of learning theory to… · open at passage 0
the role of natural selection for incrementally improved fitness becomes less decisive as the driving force of organismal diversification and complexification than generally believedNewman SA, 2019 · Inherency of Form and Function in Animal Development and Evolution · open at passage 11

Linked ideas

Evolvabilityrelated to

Kouvaris and colleagues treat the capacity to vary usefully in new environments as a problem that selection alone seems unable to explain.

Inherency of form, mesoscopic materials and the physical origin of body plansin tension with

Newman argues that inherent physical form makes incremental selection less decisive than the Darwinian account assumes.

Exploratory adaptation and random-network searchrelated to

Adaptation by improvisation within the individual is proposed as working alongside selection, not replacing it.

Collective intelligence of cellsin tension with

Kropotkin's criticism of a narrow Malthusian struggle bears on how cooperation is weighed against competition.

Trial and errorrelated to

Selection among varied candidates and trial-and-error within an organism are both processes of keeping what works.

Habit and plasticityin tension with

Darwin (via James) denies instincts arise from inherited habit, favoring selection of chance tendencies; Bateson rejects shaping of plastic organisms by selection alone; Friston treats both as timescales of adaptation.

Germ-plasm theory and chromosome individualityrelated to

Loeb objected that Weismann used natural selection to explain forms such as roots and polyps, and argued this would not help physiological morphology.

Niche constructionrelated to

Passages call niche construction arguably a force on par with natural selection (debated), one that modifies selection pressures on organisms and other species, so it feeds back into selection.

Fitness of the environmentin tension with

Henderson separated environmental fitness from the organism's adaptation, which selection accounts for.

Teleology and purposiveness in biologyprecursor of / follows

Selection is the standard account of how adaptive design arises without a plan.

Active gas secretion and acclimatisation to altitudeprecursor of / follows

Darwin used the swimbladder to argue that natural selection can convert an organ of flotation into a lung.

Where it is discussedPassages matching natural selection, struggle for existence, Malthus, survival of the fittest

1859	On the origin of species by means of natural selection, or the preservation of… · Darwin	197
1930	The History of Biological Theories · Rádl, E.	114
1925	Elements of Physical Biology · Lotka, A. J.	26
1894	Materials for the Study of Variation Treated with Especial Regard to… · Bateson, W.	23
1992	On Growth and Form · Thompson, D. A. W.	20
1901	Regeneration · Morgan, T. H.	20
1906	Behavior of the Lower Organisms · Jennings, H. S.	18
1902	Mutual Aid: A Factor of Evolution · Kropotkin, P.	17
2017	How evolution learns to generalise: Using the principles of learning theory to… · Kouvaris K, Clune J, Kounios L, Brede…	14
1899	General Physiology: An Outline of the Science of Life · Verworn, M.	12