The anthropic principle and its implications for biological evolution

“9 See Carter ( 1983 ) and Snyder-Beattie et al. ( 2021 ).”

“In its weakest form, it simply asserts that humanity’s existence is probabilistically likely in a large enough universe (Carter, 1983).”

“In 1998, J. Leslie, using the Copernican principle and based on previous works by Carter (1983) and Gott (1994), calculated the total number of people to be born before total extinction of the human race.”

“what then can science say about the likely future of the human lineage? One extensively discussed argument, known as the Doomsday Argument, concludes that we are likely headed for self-destruction [2, 3].”

“Selection occurs because “what we observe must be compatible with our existence as observers” (Carter, 1983).”

“In addition Brandon Carter (1974:347–363), a British mathematician reflecting on the Anthropic Principle, observed that the universe took billions of years to prepare for a species with the potential to survive no longer than a few million years. In his view, ‘God certainly has a plan for humanity, and he put great ca…”

“1) is intimately connected to the famous Doomsday Argument [41] – [44].”

“…argument, which predicts a 95% probability of human extinction within the next 10 millennia, is consistent with the view that species evolvability decreases over time due to growing reproductive inefficiency or genomic brittleness (Carter 1983; Gill 2002; Gott 1993; Leslie 1992; Lu and Li 2001).”

“Carter (1983) has pointed out that the timescale for the evolution of intelligence on the Earth (∼ 4 Gyr) is comparable to the main sequence lifetime of the Sun (∼ 10 Gyr).”

“See Carr and Rees (1979), Davies (1982), and Carter (1983) for good general discussions of the many ways in which the universe appears to be "fine-tuned" for human life. be here!”

“Yet, can they be considered scientific explanations? The SAP, as in Carter's argument, lends itself most directly to be coupled with the hypothesis of many worlds. In its strongest form, this hypothesis is expressed by the MAP. As was mentioned, though, a hypothesis of many worlds tends to blur the distinction between…”

“In cosmology, singularities include the formation and behavior of black holes [2], [30], the origin of the universe [31], [32], and the particular values assumed by the constants of nature and the boundary conditions of the standard models [33]–[36].”

“In the light of our reconstruction of that argument, readers familiar with the Doomsday argument (Carter, 1983; Leslie, 1989) will recognize that both these arguments have the same form.”

“Or, at least, I should consider such continued existence less likely, after considering this argument, than I did previously (Carter 1983; Leslie 1996).”

“Using (1) Vilenkin and Garriga have proposed an elegant solution to the problem of small observable cosmological constant which not only fits the observations (see [8]–[10]) but also naturally solves an adjacent problem of cosmic coincidences.”

“In 1983, Brandon Carter argued that intelligent life is exceptionally unlikely because there are “hard” evolutive steps for life to evolve intelligence [23].”

“The quintessential example is the ‘Doomsday argument’ [4], about which there is much debate [5–11].”

“1 Introduction How long into our future will mankind last? The “Doomsday Argument” (Carter 1983, Gott 1993, Leslie 1996, Leslie 2010) is an effort to answer this question quantitatively. The argument is based on the fact that samples from a known distribution are rarely found at its extreme ends. In only 1% of random…”

“One of them (red) might be the Doomsday Argument.”

“A famous argument related to the choose of a probability measure is the doomsday argument [217, 218].”

“Anthropic reasoning is best known in the form of the Cosmological Anthropic Principle[1] and the infamous Doomsday Argument[3].”

“Carter’s hard-step reasoning suggests that if several difficult evolutionary transitions were required, intelligent life might often arise only near the end of a planet’s habitable lifetime [24].”

“Interestingly, unlike Carter’s original conjecture [14], neither Hanson’s nine-step list [46] nor the five hard steps proposed by Lingam and Loeb [69, 70] and later evaluated by Mills et al. [79] explicitly account for the two unique METs involving “coding thresholds”.”

“The Carter abiogenesis argument (Carter [1983]) is based on the selection effect implied by our existence: humanity finds itself on a planet where abiogenesis must have taken place, and therefore, it is argued, this observation alone provides no information about the actual probability of…”

“An infrequently discussed, but important challenge for any experimental program on the origin of life is the role of post-selection 31,32 and human intervention 33 .”

“The “Carter model” (Carter 1983; Hanson 1998; Carter 2008) posits that intelligent life emerged as the result of a series of one or more extremely unlikely evolutionary transitions or “hard steps” across Earth history.”

“In 1983, physicist Brandon Carter proposed the hard-steps model for physical intelligent life (Carter 1983).”

“Gott’s most famous contribution was probably his estimation of the expected lifetime of the human race (1993), which was substantially in line with Carter’s ([15]).”

“Anthropic reasoning using the SSA is not without concern—perhaps most vividly illustrated with the notorious doomsday argument ( B. Carter 1983; H. B. Nielsen 1989; J. R. Gott 1993 ) .”

“This is 17 Linear or quadratic evolution is predicted in the B. Carter (1983) model, if there are only one or two “hard steps” in the evolution of technological societies (see also R. Hanson et al. 2021). because the effect is negligible for small redshifts.”

“If instead Carter’s hard step model [Carter, 1983] is adopted, where the probability of emergence of complex, intelligent life is proportional to the stellar lifetime raised to some integer power, our occurrence around a yellow star is indeed highly atypical [Waltham, 2017].”

“En el origen de esta idea popular tan extendida está Freud, quien en Una dificultad del psicoanálisis (1974[1917]), con sugerentes argumentos detalla cómo el ser humano habría sufrido en sus carnes desde Copérnico una ofensa cosmológica que lo habría desplazado del centro de la Creación, seguida de una ofensa biológic…”

“Strong anthropic principle (SAP) (Carter (3): "[T]he universe (and hence the fundamental parameters on which it depends) must be such as to admit the creation of observers within it at some stage.”

“The anthropic principle states that our scientific observations and theories of the universe must be compatible with the development of sentient life and in particular with our existence as conscious observers [1, 2].”

“En palabras de Carter [17, p. 348”

“This version of the anthropic principle is based on anthropic 435 arguments – a number of fundamental physical constants, the numerical parameters of which are ideally coordinated with the conditions appropriate for a reasonable life (Carter, 1983; El-Kader, 2018).”

“Examples of “theories” from Carter (1983) include the hypotheses: life is very rare, even in favorable conditions; gravitational coupling strength is fixed across time; and, the expected average time t intrisically most likely for the evolution of a system of observers intelligent enough to…”

“It is to be noted that since I first made such a prediction, about a quarter of a century ago [17], there has already been an inflection, whereby, according to official United Nations statistics, see Figure 2, the second time derivative of the global human population has changed sign and become negative.”

“In terms of a traditional scientific approach that is more appropriate for the present work, theoretical hypotheses have only gone as far as arguing in favor of terrestrial life being a rare case in a galactic scale (Carter, 1983).”