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Full-Text Articles in Evolution

What Does Sentience Mean At The Neural Level?, Björn Brembs Jul 2026

What Does Sentience Mean At The Neural Level?, Björn Brembs

Animal Sentience

Jonathan Birch's (2025) LSE criteria for sentience include motivational trade-offs, exemplified by C. elegansweighing hunger against desiccation risk. Yet once the neural circuit is known, this "trade-off" reduces to a single inhibitory synapse—an ‘elemental’ account discrediting the ‘molar’ one. My commentary illustrates the same discrepancy in Drosophila: dopaminergic ramping during courtship as it progressively suppresses threat-detecting neurons; so persistence past danger reflects recalibrated valuation rather than a weighed decision. As neurobiology increasingly discovers such discrepancies, all criteria resting on behavioral classifications risk being defined away without altering the behavior's validity.


Look Out For Our Kind, Christof Koch Jul 2026

Look Out For Our Kind, Christof Koch

Animal Sentience

Strongly supportive overall of Birch’s broad tent Sentience Project, I offer an alternative dyadic, single-class, two-stage process based on estimating the probability for sentience, and the associated confidence, for any individual or taxonomic group. I criticize Birch’s narrow computational framework when addressing the question of algorithmic sentience; there are alternative approaches.


Ai Is Not The Kind Of Thing That Can Ever Be Sentient, Lori Marino Jul 2026

Ai Is Not The Kind Of Thing That Can Ever Be Sentient, Lori Marino

Animal Sentience

Sentience evolved to allow organisms to move through their environment avoiding harms and achieving benefits. Sentience did not evolve from computation. It evolved from valenced feelings. AI (even robots) are not embodied and are not the kind of thing that needs to be sentient. There is no way to get from computations to feelings. They are qualitatively different things. We should avoid being lulled into thinking that an inanimate object designed to engage our propensity for anthropomorphism, like AI, is actually a mind.


The Evolution Of Self-Awareness In Conscious Organisms, Robert A. Dielenberg Mar 2026

The Evolution Of Self-Awareness In Conscious Organisms, Robert A. Dielenberg

Journal of Conscious Evolution

Self-awareness in conscious organisms remains an enduring puzzle for philosophers and neuroscientists. This paper proposes a tripartite evolutionary model tracing its emergence through three sequential types: the sensory self (primitive egocentric, valence-tagged awareness of sensory states), the bodily self (external objectification of the body as a distinct entity, evidenced by mirror self-recognition in select species), and the cognitive self (internal objectification of the mind enabling recursive self-transformation). Adopting a monist framework, the model treats consciousness as the biological substrate of delayed neural apperception (the “Delayed Present”), within which selves emerge as increasingly sophisticated models. It distinguishes non-human metacognition—implicit, online regulation—from …


The Term Consciousness And Impressive Evidence For Cephalopod Awareness, Donald M. Broom Oct 2025

The Term Consciousness And Impressive Evidence For Cephalopod Awareness, Donald M. Broom

Animal Sentience

Mather presents comprehensive evidence of cephalopod cognitive ability and of a high level of awareness. The importance of taking account of the biological functioning and adaptations to the living environment is emphasised. An argument is presented that it is better to limit the use of the word conscious to ‘not unconscious’ and to use awareness in relation to the various levels of cognitive functioning.


The Consciousness Inherent In Chasing Your Tail, Sergio M. Pellis Dr. Oct 2025

The Consciousness Inherent In Chasing Your Tail, Sergio M. Pellis Dr.

Animal Sentience

Who is conscious and how do we know? Complexity in behavior and cognition is certainly a clue that cannot be ignored in identifying this trait, and as Mather’s target article shows, it is hard not to imagine consciousness arising in cephalopods. But how complex is complex? An alternative may be gleaned from the fact that all living things rely on negative feedback to navigate their worlds, and this requires all sentient beings knowing what is to be stabilized in reflection to themselves. If so, consciousness is a universal trait.


Précis Of The Edge Of Sentience: Risk And Precaution In Humans, Other Animals, And Ai, Jonathan Birch Jan 2025

Précis Of The Edge Of Sentience: Risk And Precaution In Humans, Other Animals, And Ai, Jonathan Birch

Animal Sentience

We often face grave practical decisions that seem to hinge on whether a system is sentient. This family of cases includes invertebrate animals, people who are unresponsive after brain injury, fetuses, neural organoids, and now AI technologies. We must decide what to do despite ongoing disagreement about the nature of sentience. In our state of uncertainty, we should pragmatically transform the question from “Is it sentient?” to “Is it a sentience candidate, an investigation priority, or neither?”. When a system is a sentience candidate, it is negligent to fail to consider precautions. We should instead evaluate precautions for their proportionality …


To Be Conscious Or Not To Be, Bjørn Grinde Nov 2024

To Be Conscious Or Not To Be, Bjørn Grinde

Animal Sentience

Carolyn Ristau has done a fine job summarizing the work and life of the zoologist Donald Griffin. Most scientists now accept the existence of animal sentience, but identifying which species possess consciousness remains controversial. Griffin defined consciousness as "the subjective state of feeling or thinking about objects and events.” Nonconscious processes are faster and more energy-efficient, however, and often drive behavior. Consciousness probably evolved for complex decision-making, shaped by evolutionary continuity, with feelings as a common currency for evaluating outcomes. Its survival advantage may be limited, and its presence across species varies depending on evolutionary trajectories.


Disentangling Sentience From Developmental Plasticity, Jonathan Birch May 2023

Disentangling Sentience From Developmental Plasticity, Jonathan Birch

Animal Sentience

Plants, like animals, display remarkable developmental plasticity, inviting the metaphorical use of terms like “decision” and “choice”. In the animal case, this is not taken to be evidence of sentience, because sentience is a complex product of development, not something that guides it. We should apply the same standards when evaluating the evidence in plants. It is hard to overstate the contrast with the case of invertebrates such as octopuses, where pain markers that were originally developed for use in mammals have been clearly demonstrated and plausible neural substrates for sentience have been identified.


Sensing Is A Far Cry From Sentience, Antonio Damasio, Hanna Damasio Apr 2023

Sensing Is A Far Cry From Sentience, Antonio Damasio, Hanna Damasio

Animal Sentience

The hypothesis that plants might be sentient confuses the notion of sentience (or consciousness) with that of sensing. Sentience/consciousness implies feeling, experience, and subjectivity. Sensing does not. Plants can sense/detect and even respond appropriately in the absence of any sentience/consciousness.


Plant Sentience: The Burden Of Proof, Jon Mallatt, David G. Robinson, Michael R. Blatt, Andreas Draguhn, Lincoln Taiz Apr 2023

Plant Sentience: The Burden Of Proof, Jon Mallatt, David G. Robinson, Michael R. Blatt, Andreas Draguhn, Lincoln Taiz

Animal Sentience

Segundo-Ortin & Calvo’s (2023) target article takes a less speculative and more evidence-based approach to plant sentience than did previous works promoting that idea. However, it retains many of the idea’s longstanding difficulties such as starting from a false dichotomy (plants must be either hardwired or sentient), not accepting the full burden of proof for an extraordinary claim, confusingly redefining accepted cognitive terms, implying cell consciousness, not adopting the most parsimonious explanations for plant behaviors, and downplaying all the counterevidence. We advise rectifying these problems before plant sentience can become a full-fledged scientific domain.


Questions About Sentience Are Not Scientific But Cultural, Yoram Gutfreund Apr 2023

Questions About Sentience Are Not Scientific But Cultural, Yoram Gutfreund

Animal Sentience

Abstract: The findings of complex cognitive-like behaviours in plants are surprising and exciting. However, they do not provide a scientific reason for ascribing sentience to plants. The target article, in trying to provide evidence for sentience in plants, exposes the weakness of the science of animal consciousness in general. In this commentary, I try to explain why the scientific method is incapable of resolving the question of which organisms or systems are sentient.


Plant Sentience Revisited: Sifting Through The Thicket Of Perspectives, Paco Calvo, Miguel Segundo-Ortin Jan 2023

Plant Sentience Revisited: Sifting Through The Thicket Of Perspectives, Paco Calvo, Miguel Segundo-Ortin

Animal Sentience

In our target article (Segundo-Ortin & Calvo 2023), we proposed the intriguing possibility of plant sentience, drawing parallels with non-human animal studies. This response aims to sift through the rich thicket of perspectives offered by our commentators. To do so, we assess the risks of employing double standards, as well as the tendencies of anthropomorphizing and zoomorphizing in plant studies. We also emphasize the need for clarity in linguistic and conceptual terms, examine the neurophysiological evidence for plant sentience, and discuss the ethical implications of such recognition.


Plant Sentience? Between Romanticism And Denial: Science, Miguel Segundo-Ortin, Paco Calvo Jan 2023

Plant Sentience? Between Romanticism And Denial: Science, Miguel Segundo-Ortin, Paco Calvo

Animal Sentience

A growing number of non-human animal species are being seriously considered as candidates for sentience, but plants are either forgotten or explicitly excluded from these debates. In our view, this is based on the belief that plant behavior is hardwired and inflexible and on an underestimation of the role of plant electrophysiology. We weigh such assumptions against the evidence to suggest that it is time to take seriously the hypothesis that plants, too, might be sentient. We hope this target article will serve as an invitation to investigate sentience in plants with the same rigor as in non-human animals.


The Biological Influence Of Stories & The Importance Of Reading Fiction, Elise N. Good, Katharine Schaab Jul 2022

The Biological Influence Of Stories & The Importance Of Reading Fiction, Elise N. Good, Katharine Schaab

The Kennesaw Journal of Undergraduate Research

Fictional narratives and stories have persisted throughout human history. However, perhaps due to a bias that stories offered nothing more than entertainment for the reader or perhaps that they are not useful outside of the realm of academia, the research within science academia has been lacking in literature on why these narratives have endured. Unfortunately, due to the lack of conversation across disciplines, particularly those of science and literature, this subject has not been thoroughly investigated through an interdisciplinary lens. Within this paper, the goal is to analyze the benefits of fictional narratives through biological, evolutionary, and neuropsychological perspectives. Research …


Pain Sentience Criteria And Their Grading, Eva Jablonka, Simona Ginsburg Jan 2022

Pain Sentience Criteria And Their Grading, Eva Jablonka, Simona Ginsburg

Animal Sentience

On the basis of the target article by Crump and colleagues, we suggest a more parsimonious scheme for evaluating the evidence for sentience. Since some of the criteria used by Crump et al. are not independent and some are uninformative we exclude some criteria and amalgamate others. We propose that evidence of flexible learning and prioritization, in conjunction with relevant data on brain organization, is sufficient for assigning pain-sentience to an animal and we suggest a scoring scheme based on four criteria.


Truly Minimal Criteria For Animal Sentience, Mark Solms Jan 2022

Truly Minimal Criteria For Animal Sentience, Mark Solms

Animal Sentience

The criteria for determining animal sentience proposed in the target article are sensible but they lack an explicit functional justification for the focus on pain. This commentary provides an abbreviated account of the most basic functional principles that underpin animal sentience and articulates some minimal criteria for determining its presence.


Generalizing Frameworks For Sentience Beyond Natural Species, Michael Levin Jan 2022

Generalizing Frameworks For Sentience Beyond Natural Species, Michael Levin

Animal Sentience

Crump et al. (2022) offer a well-argued example of an essential development: a rigorous framework for assessing sentience from the perspective of moral concern over an agent’s welfare. Current and forthcoming developments in bioengineering, synthetic morphology, artificial intelligence, biorobotics, and exobiology necessitate an expansion and generalization of this effort. Verbal reports (the Turing Test) and homology to human brains are utterly inadequate criteria for assessing the status of novel, unconventional agents that offer no familiar touchstone of phylogeny or anatomy. We must develop principled approaches to evaluating the sentience of (and thus, our responsibility to) beings of unfamiliar provenance and …


Sentience In Decapods: An Open Question, Mark Briffa Jan 2022

Sentience In Decapods: An Open Question, Mark Briffa

Animal Sentience

Crump et al.’s framework is a powerful tool designed to assist decisions on the ethical treatment of decapod crustaceans. However, the question of whether decapods are sentient (i.e., whether they feel), remains open, perhaps indefinitely. More optimistically, we might design experiments that distinguish among different levels of awareness, sometimes viewed as components of sentience. We should strike a balance between assuming that all organisms are sentient and making unnecessary anatomical assumptions about sentience. Refining current experiments may provide concrete insights about awareness in Decapoda and other taxa.


Does The Sentience Framework Imply All Animals Are Sentient?, Kristin Andrews Jan 2022

Does The Sentience Framework Imply All Animals Are Sentient?, Kristin Andrews

Animal Sentience

The eight criteria proposed in Crump et al.’s framework for evaluating pain sentience in decapod crustaceans are just the tip of the iceberg when it comes to markers that could increase confidence in an animal’s sentience more generally. Some of the commentaries have already pointed out that pain is only one kind of sentience (Souza Valente). It has also already been pointed out that there are other criteria for pain that could be usefully added to the framework’s eight (Burrell). This expansive thinking about criteria that can be used to increase confidence in sentience raisess the question: in an expansive …


Distinguishing Epistemic And Moral Grounds For Legal Protection, Carlos Montemayor Jan 2022

Distinguishing Epistemic And Moral Grounds For Legal Protection, Carlos Montemayor

Animal Sentience

The criteria proposed by Crump et al. are based on various cognitive roles associated with sentience. A subset of them may be sufficient for certain kinds of welfare, but the presence of all of them should be considered as clearly sufficient for substantial kinds of legal protection based on their relation to capacities that we consider essential for moral standing in human beings.


Decapod Sentience: Promising Framework And Evidence, Jon Mallatt, Todd E. Feinberg Md Jan 2022

Decapod Sentience: Promising Framework And Evidence, Jon Mallatt, Todd E. Feinberg Md

Animal Sentience

Strong points of the target article by Crump et al. are that it offers clear criteria for judging whether decapods are sentient, an effective semi-quantitative grading system for this purpose, and an astute, critical review of the literature. It concludes plausibly that major subgroups of decapods are sentient. A minor problem is that it includes classical, Pavlovian learning as a marker of sentience along with the more valid marker of complex (e.g., operant) learning. Another minor problem is that it does not distinguish results that are negative because of likely absence of sentience from results that are negative because they …


Animal Sentience Research: Synthesis And Proposals, Andrew Crump, Heather Browning, Alex Schnell, Charlotte Burn, Jonathan Birch Jan 2022

Animal Sentience Research: Synthesis And Proposals, Andrew Crump, Heather Browning, Alex Schnell, Charlotte Burn, Jonathan Birch

Animal Sentience

Most commentaries on our target article broadly support our approach to evaluating evidence of animal sentience. In this Response, we clarify the framework’s purpose and address criticisms of our criteria. A recurring theme is that a framework to synthesise current evidence of sentience is not the same as an agenda for future directions in animal sentience research. Although future directions are valuable, our framework aims to evaluate existing evidence and inform animal welfare legislation.


Legal Recognition Of Animal Sentience: The Case For Cautious Optimism, Jane Kotzmann Jan 2022

Legal Recognition Of Animal Sentience: The Case For Cautious Optimism, Jane Kotzmann

Animal Sentience

Rowan et al.’s target article provides a valuable indication of the work that was required to reach the point where animals are recognised as sentient in various laws. To ensure this work was not in vain, the language of sentience needs to be used as a moral currency to demand further cultural change involving greater human respect for animals.


All Living Organisms Are Sentient, Arthur S. Reber, Frantisek Baluska, William B. Miller Jr. Jan 2022

All Living Organisms Are Sentient, Arthur S. Reber, Frantisek Baluska, William B. Miller Jr.

Animal Sentience

We argue that all living organisms, from the simplest unicellular prokaryotes to Homo sapiens, have valenced experiences—feelings as states of preference—and are capable of cognitive representations. Bacteria can learn, form stable memories, and communicate, hence solve problems. Rowan et al.'s statement that "Subjective feelings are just that — subjective — and are available only to the animal (or human) experiencing them" is true but irrelevant. When we see a fish flopping about in the bottom of a boat we immediately recognize suffering without having a glimpse of the nature of piscine distress. Some controlled anthropomorphism can go a …


The Science Of Animal Sentience And The Politics Of Animal Welfare Should Be Kept Separate, Marian Stamp Dawkins Jan 2022

The Science Of Animal Sentience And The Politics Of Animal Welfare Should Be Kept Separate, Marian Stamp Dawkins

Animal Sentience

Although linked historically by Rowan et al., the scientific study of animal sentience and political campaigns to improve animal welfare should be kept separate, for at least two reasons. First, the separation makes it clear that standards of evidence acceptable for ethical or political decisions on animal welfare can be lower than those required for a rigorously scientific approach to animal sentience. Second, it helps to avoid confirmatory bias in the form of giving undue weight to results that are in line with pre-conceived ideas and political views.


Strong Inferences About Pain In Invertebrates Require Stronger Evidence, Edgar T. Walters Jan 2022

Strong Inferences About Pain In Invertebrates Require Stronger Evidence, Edgar T. Walters

Animal Sentience

Evidence for sentience in animals distantly related to humans is often sought in observations of behavioral and neural responses to noxious stimuli that would be painful in humans. Most proposed criteria for painful sentience in “lower” animals such as decapod crustaceans have no necessary links to the affective (“suffering”) component of pain. The best evidence for painful affect in animals is learned aversion to stimuli associated with noxious experience, and conditioned preference for contexts associated with relief from aversive consequences of noxious experience, as expressed in voluntary behavior. Such evidence is currently lacking for any invertebrate except octopus.


The Reality And Prevalence Of Animal Sentience, Antonio Damasio Jan 2022

The Reality And Prevalence Of Animal Sentience, Antonio Damasio

Animal Sentience

Rowan et al use findings from neurobiology, clinical neurology, and general biology to argue for the extensive presence of sentience in animals, but they are wisely cautious concerning when in the phylogenetic scale that emergence occurred.


Consider The Agent In The Arthropod, Nicolas Delon, Peter Cook, Gordon Bauer, Heidi Harley Jul 2020

Consider The Agent In The Arthropod, Nicolas Delon, Peter Cook, Gordon Bauer, Heidi Harley

Animal Sentience

Whether or not arthropods are sentient, they can have moral standing. Appeals to sentience are not necessary and retard progress in human treatment of other species, including invertebrates. Other increasingly well-documented aspects of invertebrate minds are pertinent to their welfare. Even if arthropods are not sentient, they can be agents whose goals—and therefore interests—can be frustrated. This kind of agency is sufficient for moral status and requires that we consider their welfare.


Brain Complexity, Sentience And Welfare, Donald M. Broom Jul 2020

Brain Complexity, Sentience And Welfare, Donald M. Broom

Animal Sentience

Neither sentience nor moral standing is confined to animals with large or human-like brains. Invertebrates deserve moral consideration. Definition of terms clarifies the relationship between sentience and welfare. All animals have welfare but humans give more protection to sentient animals. Humans should be less human-centred.