BIO PHIL 36 Krashniak; Desmond

 Krashniak, A. The struggle for life and adaptation by natural selection. Biol Philos 36, 28 (2021). https://doi.org/10.1007/s10539-021-09803-4

p. 2

• the role of struggle has been minimized in contemporary analyses of the process of natural selection, and natural selection is commonly described today as a process which does not necessarily involve struggle. In spite of that, there have been some attempts to show that struggle is in fact an essential part of the process of natural selection. 
• Analisará as opiniões de Godfrey-Smith e Lewens
• O artigo foca no papel limitador do ambiente para o crescimento populacional das espécies. Luta como uma relação causal entre organismos na forma de competição pela sobrevivência e reprodução
• O papel da luta foi minimizado com o tempo, principalmente entre a década de 70 e 80

3

• Lewontin: 1. variação; 2: herança; 3. diferença de aptidão. Esse resumo não enfatiza o papel da luta. Mas outros, como Godfrey-Smith dizem que ela é fundamental para produzir adaptações.

4

• Godfrey-Smith
• Minimal Darwinian population: pop que exibe variação, hereditariedade e diferença de aptidão. Só podem passar por mudanças triviais que não produzem novidade.
• 5
• "Paradigm" Dar. Pop.: selection can only be said to create new variants when selection for a variant increases the absolute numbers of this variant [porque pode ocorrer que ocorra a diminuição do tamanho populacional (o que reduziria a chance de aparecimento de novas variantes), mas a variante mais adaptada ainda cresça em termos relativos] Isso ocorre quando há uma luta na qual o aumento da prole de um resulta necessáriamente na diminuição da prole de outro. Não é claro como isso conecta o sucesso em termos absolutos e relativos. 
• p. 10: outras condições para uma PDP, sistema de herança de alta fidelidade, modularidade no desenvolvimento de traços e um "smooth fitness landscape".

6

• Lewens
• On Lewens’s interpretation, Godfrey-Smith is arguing that when there is struggle, selection for a variant, which refers to the fact that this variant increases in frequency at the expense of other variants, necessarily increases the absolute numbers of this variant and hence the chances of the appearance of new variants [BUT] the fact that there is struggle, in the sense of the causal relation defned by Godfrey-Smith, does not always imply that the selected variants which increase in frequency also increase in absolute numbers [...] concludes that Godfrey-Smith’s argument fails to show that struggle leads natural selection to produce adaptations

8

• Sem luta não há proporcionalidade direta entre sucesso absoluto e relativo, pois em um ambiente sem luta a aptidão maior de uma determinada variante não afeta a outra, assim ela pode aumentar relativamente mas não absolutamente.

9

• When there is struggle between variants, the absolute reproductive rate of each variant is not only afected by its own phenotype, but also by the phenotypes of the other variants that exist in the population. In such cases, selection for a variant [say B], the fact that [B] is better adapted to the environment than [A], increases the absolute reproductive rate of [B]. If [B] were not better adapted than [A], its absolute reproductive rate would be lower. In contrast, when there is no struggle between variants, even if there is selection for a variant, the absolute reproductive rate of this variant is only afected by its own phenotype, and not by the adaptive advantage of this phenotype over the phenotypes of other variants.
• GODFREY diz que a luta leva ao aumento dos números absolutos da variante. Para Lewens, a seleção pode aumentar o valor relativo de um ao mesmo tempo que diminui o número absoluto de ambos. Assim "a luta não previne a seleção por uma variante de dimunuir seus números absolutos".
• Mas Godfrey pode querer dizer: "Even when there is selection for variant B over A, and B increases in absolute numbers, selection for B is not necessarily what leads B to increase in absolute numbers. Only when there is struggle between A and B, selection for B over A leads B to have a greater absolute reproductive rate than it would have had if there had not been selection for it. Thus, Godfrey-Smith is right in arguing that struggle leads selection for a variant to increase the absolute numbers of this variant."

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• if there is no struggle between A and B, the absolute reproductive rate of B and the chances of C to appear are not afected by selection for B, the fact that the phenotype of B is better adapted than that of A, but only by the phenotype of B. In such cases, even if C appears in the population, selection for B did not afect the chances of the appearance of C, which means that C is not a product of selection for B. In contrast, if there is struggle between A and B, selection for B over A is relevant for the absolute reproductive rate of B and the chances of the appearance of C. In such cases, if there were not selection for B, the absolute reproductive rate of B and the chances of the appearance of C would be lower. Thus, when there is struggle between A and B, and C appears, C is a product of selection for B over A.
• Thus, the analysis [...] does not show that struggle increases the chances of highly adapted variants to evolve, like modularity and high-fdelity inheritance do, but rather that struggle makes those highly adapted variants that evolve the products of natural selection. On the other hand, conditions like modularity and high-fdelity inheritance do not make adaptations the product of selection, like struggle does. [...] 
• [...] Conditions of the frst kind are necessary for selection to produce highly adapted traits in the sense that they are required for a process of natural selection to result in such traits. These conditions enable or increase the chances that a cumulative selection process will result in highly adapted traits. Modularity and high-fdelity inheritance are instances of such conditions. Conditions of the second kind are necessary for selection to produce highly adapted traits in the sense that they are required in order for the highly adapted traits that evolve to be products of natural selection. These conditions do not increase the chances of an evolutionary outcome, adaptation, but rather afect the role of the process of selection in producing this outcome. When these conditions take place and a population evolves highly adapted traits, these traits evolve due to natural selection. Struggle is one such condition.

Desmond, H. The selectionist rationale for evolutionary progress. Biol Philos 36, 32 (2021). https://doi.org/10.1007/s10539-021-09806-1

2

• Discute a noção de progresso evolutivo e seus problemas: the concept of evolutionary progress seems to justify practises or policies that are at odds with ethical judgment. Just as the concept of human nature has been used to justify dehumanization (Kronfeldner 2017), concepts of evolutionary progress were used to justify eugenics (see Desmond forthcoming), and the associated distinction between “higher” and “lower” organisms has been used to justify exploiting sentient, nonhuman species
• Contudo, alguns autores propõem um entedimento neutro de progresso devido a seleção natural, um jeito de dizer que algo é melhor ou pior sem ser subjetivo. Mas segundo Gould, não é possível derivar progresso da teoria, pois ela se detém a adaptação a circunstância dinâmicas locais.
• Desmond chama isso de: the groundedness problem: there is no selectionist rationale for progress that is grounded in the nature of natural selection. 3 [...]  if suddenly static environments were to become more frequent, either in the future or in some alternative scenario, then information processing would be selected against.

3

• Outro problema: Redundância. SN parece superflua para explicar o aumento em complexidade. Se a vida começa em complexidade mínima então ela só pode aumentar a partir daí.

4

• Argumentos de progresso: tentam generalizar vastas escalas de tempo e número de linhagens, mas com um escopo bem estreito; Há uma reduação a apena algum parâmetro mensurável de modo que a história evolutiva possa ser representada graficamente com distribuições de frequencias variáveis ao longo do tempo; foco em algum tratamento estatístico específico; buscam tendências; exibem robustez contrafactual 6 (All generalisations about the living world: (a) are just mathematical, physical, or chemical generalisations (…) or (b) are distinctively biological, in which case they describe contingent outcomes of evolution (Beatty 1995, pp. 46–47).).

6

• Raciocínios selecionistas denotam um padrão de seleção que deve ser baseado (grounded) em um princípio bassilar. Isto é, assume-se que algo é selecionado pelo ambiente e que o padrão gerado pelo tempo pode ser dfefindo como progresso.

7

• Given efectively random environments and without long-term constraints on natural selection, all evolutionary histories instantiate a trend in a measure M that is caused by selection for increased M.

8

• propõe que o progresso não é dissociável da SN. when selection is an adaptation-producing and/or competitive process, the outcomes of a selection-caused trend can be thought of as the ‘victors’ and/or the ‘superiorly adapted’ relative to a given environment. Evolution by natural selection produces ‘better’ outcomes in the following value-neutral sense: they are defned relative to the ‘preferences’ of natural selection, not relative to human moral or societal preferences. The relevant parameters could be better competition, or better adaptation.

9

• É possível portanto um uso neutro do progresso.

14

• Sobre a visão neutra: the neutral view assumes that all possible measures M are efectively selectively neutral over geological timescales. In this way, the neutral view depends on two types of modality: the possible measures M, and the range of possible selective environments. The inconsistency here, to put it roughly, is that the modal range of possible M is “much larger” than that of possible selective environments. The neutral view needs to hold for any M—even biologically implausible or uninteresting M—because of the distinctively mathematical character of the neutral view. (Recall that this mathematical character is crucial to justify the neutral view’s status as null, and hence to present selectionist rationales with the redundancy problem.) However, as will now be argued, there is no reason to expect a measure M picked randomly to be selectively neutral. In fact, the default expectation could be for a random M to be selectively disfavoured. Thus the mathematical character that guarantees the neutral view its status as null simultaneously erodes its explanatory power of evolutionary trends. [...]  In other words, the neutral view’s assumption that all measures are (efectively) selectively neutral cannot be interpreted as an unproblematic, fall-back assumption. It has the same speculative status as when some proponents of progress assumed that some measures are (efectively) selectively favoured across geological time.

15

• In conclusion, the neutral view on passive evolutionary trends seems to render selectionist rationales redundant. However, the neutral view is guilty of the same speculation about what environments occur in possible replays of life’s tape that some selectionist rationales are guilty of. Or in other words, the neutral view ultimately faces the same groundedness problem as the selectionist rationales it aims to undercut.

17-8

• Heterogeneidade ambiental: In general, this refers to a distinction to be made between two types of adaptive process: adaptation within a common selective environment, and adaptation by avoiding selective competition and exploiting novel ecological opportunities (i.e., adaptive radiation). In the frst type, the EH-exploiting type gains a selective advantage over the EH-ignoring type; in the second type, the EH-exploiting type radiates away and does not selectively compete with the EH-ignoring type within a common selective environment. The latter type of adaptive process is incredibly fundamental, even if underappreciated by philosophers of biology: e motility, cooperation, and metabolic adaptations like endothermy are also assigned this adaptive role in the scientifc literature (for an overview, see Desmond 2021). A novel, unexploited pattern of EH can refer to novel resources, or to unpopulated habitats (e.g., islands), but also to spatiotemporal patterns of EH that competitors cannot yet detect. 
• While this process of adapting to novel ecological opportunities is not directly selective (rather, it is one of ecological radiation), it does involve the avoidance of selective competition. Patterns of EH outside the selective environment only become (relative) ecological opportunities when selective competition within the selective environment creates a dearth of opportunity. The latter follows from the basic fact that all resources are limited: this is not just the Malthusian rationale for natural selection within a common environment (Darwin 2008), but also the precondition for adaptive radiation as a way of escaping selective competition (Grant 2013; Tan et al. 2016). 
• The reason why this type of adaptive dynamic is relevant for the purposes of this paper is that novel, unexploited patterns of EH are ubiquitous. To take an example from the origins of life: one of the most viable hypotheses about the last universal common ancestor is that it inhabited hydrothermal environments (Weiss et al. 2016). For these early life forms, concentrations of solar radiation represented a type of EH that was still entirely untapped.
• Há uma tendência de exploração da heterogeneidade ambiental. Explicado a seguir

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• 1. he absolute size requirement for a trend is met because novel and exploitable patterns of EH, albeit at varying spatiotemporal scales and in diferent variables, are present in every natural environment.
• 2. Second, the relative size requirement does not matter for a trend in EH-exploitation: there is no need to speculate about how probable the environment of a given lineage will favour EH-exploitation. The rationale for increased EH exploitation employs a diferent kind of thinking, one where the adaptive process alters the selective environment instead of selective environments exogenously driving the adaptive process. As detailed in Sect. 6.2, increases in EH-exploitation involve exploring novel niches, thereby escaping from selective competition with EH-ignorers. Thus, a trend in EH-exploitation is a ratchet-like increase, involving radiation into new niches, rather than a trend caused by selective environments varying like coin fips
• 3.This means that it no longer makes sense to evaluate the relative frequency of selectively favourable environments. Evolving lineages simply change their own selective environments as well as those of other lineages (since lineages constitute each other’s environment). Specifcally, even if whole clades were to face conditions that favour a decrease in EH-exploitation, this in itself creates novel opportunities for EH-exploitation in other lineages. Environmental heterogeneity is a multidimensional, consumable resource that cannot ever be entirely consumed: this is sufcient for a trend in EH-exploitation.

20

• Na exploração de EH a tendência não é aumento escalar, mas desdobramento evolutivo.

21-2

• Reconsiderar a exploração de EH como um tipo de progresso gera dois progress-claims que não são afetados pelo problema da redundância nem pelo da groundness.
• 1. progresso por desdobramento: In unfolding progress, “better” is defned as a life form that can increasingly interact with and exploit [22] ubiquitous resource (i.e., EH), even though the latter is at all times only partially accessible to extant organisms.
• 2.Progresso competitivo: Here “better” is defned as “more ecologically successful”, attributable to lineages that capture a larger share of energy in ecological networks than their ecological competitors.
• Nenhum desses dois leva a uma ordering, ou seja, não permitem comparações fora de contexto.

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Conclusão

Any selectionist rationale for progress must (1) be grounded in the nature of natural selection (and, in particular, should not rely on speculation about what types of selective environments are more probable than others), and (2) show how passive trends cannot always be more parsimoniously explained as resulting from random walks. The most common view on this matter is that both hurdles cannot be cleared. By contrast, this paper argued that random walks do not necessarily lead to passive trends, unless one makes speculative assumptions about the probabilities of selective environments. Moreover, environmental heterogeneity need not only be a source of contingency. Heterogeneity itself is ubiquitous, and an exploitable resource. Hence the selection for capacities that exploit novel patterns of environmental change is a sound basis for a selectionist rationale. 

The trend implied by this selectionist rationale involves changes in ecology frst and foremost, rather than in morphology. Lineages radiate into novel ecological niches, and thus this trend, where the totality of environmental heterogeneity (EH) unfolds, looks nothing like the classic linear representations of progress. Life as a whole expands into niches where EH is exploited to greater degrees, without necessarily eliminating lifeforms that exploit EH to lesser degrees.

 In showing that the hurdles facing selectionist rationales can be cleared, I do not pretend to have presented a full rehabilitation of the concept of evolutionary progress. However, what I do hope to have shown is that the search for a selectionist rationale for progress, grounded in natural selection, is eminently reasonable, and worthy of serious discussion—and not only in the context of science education, or the anthropology of folk biology.