Open Access. Powered by Scholars. Published by Universities.®

Evolution Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 467

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.


On The Edge Of Science?, Mark Briffa, Lynne U. Sneddon Jun 2026

On The Edge Of Science?, Mark Briffa, Lynne U. Sneddon

Animal Sentience

In The Edge of Sentience, Jonathan Birch (2024) provides a thought-provoking synthesis of current perspectives on animal (and artificial) sentience. He addresses the question from conceptual, ethical, regulatory and empirical viewpoints. Here we focus on some of the scientific issues raised, including defining and operationalising the concept of sentience and the implications for policy and regulation. Despite unresolved conceptual challenges, the book makes a compelling case for the continued scientific investigation of animal sentience.


From The Edge To The Grounds Of “Sentientism”, David Degrazia Jun 2026

From The Edge To The Grounds Of “Sentientism”, David Degrazia

Animal Sentience

Birch’s book is a remarkable exploration of the nature of sentience, its moral salience, evidence for its presence, and how to arrive at humane policies regarding our treatment of human beings, animals, brain organoids, and AI systems of uncertain sentience. Although Birch endorses the view that sentience is of fundamental moral importance, he endeavors to remain neutral among reasonable moral views and work out how to navigate through uncertainty—both ethical and epistemological—to arrive at defensible policies. While making common cause with Birch’s project, my own recent book advances a developed case in favor of the “sentientism” Birch endorses.


Natural Behavior Vs. Subjective Experience In Fish Welfare Assessments, Ronald G. Oldfield Jun 2026

Natural Behavior Vs. Subjective Experience In Fish Welfare Assessments, Ronald G. Oldfield

Animal Sentience

Several commentaries on the Oldfield & Bonano (2024) target article proposed that natural behavior should play a larger role in assessing the welfare of fishes in zoos and aquariums. However, the natural-behavior concept of animal welfare has been widely criticized because natural behaviors do not necessarily improve welfare, and unnatural behaviors do not necessarily reduce it. I review the three major concepts of animal welfare — physical health, natural behavior, and affect/feelings — and argue that behavior patterns, whether natural or otherwise, should be evaluated according to their effects on health and subjective experience. Using the affect/feelings concept and the …


Aggression And Fish Welfare: Challenges And Opportunities, Christine M. Soper, Peter D. Dijkstra Apr 2026

Aggression And Fish Welfare: Challenges And Opportunities, Christine M. Soper, Peter D. Dijkstra

Animal Sentience

Oldfield & Bonano’s (2024) [O&B] target article discusses the wellbeing and sociality of bony fishes. Many fish species, such as cichlids, are not only social but territorial. Aggression is normal, but territorial aggression in a captive environment can have a negative impact on welfare. Aggression-related injuries and deaths are prevalent in pet stores as well as research settings. We discuss the need to develop effective methods to minimize the negative consequences of aggression.


Both Studying And Protecting Octopuses “On Their Own Terms”, Jennifer Jacquet, Janelle Kaz, Becca Franks, Christine Webb Nov 2025

Both Studying And Protecting Octopuses “On Their Own Terms”, Jennifer Jacquet, Janelle Kaz, Becca Franks, Christine Webb

Animal Sentience

Cephalopods – indeed, all animals – “must be seen on their own terms,” with respect for their autonomy and their ecological imperatives. This will provide greater scientific insight along with a more ethical and accurate understanding of minds beyond our own.


Cephalopod Consciousness On “Their Own Terms”: Who Are “They”?, Willa M. Lane, Victor Ajuwon, Nicola S. Clayton Nov 2025

Cephalopod Consciousness On “Their Own Terms”: Who Are “They”?, Willa M. Lane, Victor Ajuwon, Nicola S. Clayton

Animal Sentience

Mather’s call to consider cephalopods’ consciousness “on their own terms” raises the question of the extent to which cephalopods can be considered a homogenous group. While coloeoid cephalopods share traits that strongly distinguish them from other molluscs and invertebrates, they show vast ecological and morphological diversity, with implications for the design of empirical investigations of consciousness. Extending Mather’s argument, we apply Birch et al.’s (2020) five-dimensional model to compare octopus, cuttlefish, squid, and nautilus. This comparison shows that even within a graded rather than categorical framework, putative consciousness profiles depend on which taxa are included in discussions of “cephalopod consciousness.” …


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.


Cephalopod Consciousness: Asking The Right Questions, Gordon Burghardt Oct 2025

Cephalopod Consciousness: Asking The Right Questions, Gordon Burghardt

Animal Sentience

Jennifer Mather has provided a comprehensive and fascinating overview of the various cognitive accomplishments of cephalopods and their sensory, behavioral, and neurophysiological attributes. The advances in our understanding of a clade that has been separated from vertebrate evolution by well over half a billion years is a testament to advances in both methodology and the questions we now feel free to address. Mather embeds her review in the issue of consciousness, which is certainly a perennial issue in mental evolution, going back to Romanes and earlier. I argue that the term “consciousness” has such a checkered history and is used …


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 …


What Is It Like To Be A Diplomat? Reflections On Donald Griffin And Emotion, Oliver H. Turnbull Dec 2024

What Is It Like To Be A Diplomat? Reflections On Donald Griffin And Emotion, Oliver H. Turnbull

Animal Sentience

This commentary addresses three aspects of Donald Griffin’s work: (1) his thoughts beyond cognition, on emotion; (2) his views on the earliest origins of mind, including primitive forms of consciousness; and (3) his diplomatic use of memorable phrases to facilitate change.


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.


Communication In Noise Is The Window On Cognition, R. Haven Wiley Nov 2024

Communication In Noise Is The Window On Cognition, R. Haven Wiley

Animal Sentience

As Griffin surmised, communication is the window on cognition, but as shown here, only if it is noisy. This commentary is an invitation to consider the full implications of the evolution of noisy communication. A combination of Information Theory, Signal Detection Theory, and Natural Selection, in a unified theory of the evolution of communication, reveals that noise is inevitable. All organisms are thus decision makers. Perception, thought, freedom of decision, self-awareness, metabolism, and natural selection all share the consequences of signals in noise. A full understanding of each requires attention to the errors of receivers. Griffin’s hunch is correct with …


Understanding The Welfare Of Aquarium Fish, Paul Rose Nov 2024

Understanding The Welfare Of Aquarium Fish, Paul Rose

Animal Sentience

Bony fishes (Osteichthyes) are prevalent in public and domestic aquaria, yet evidence-based welfare practices exist for only a limited number of species. Oldfield & Bonano’s (O&B’s) target article highlights critical questions about the wellbeing and sociality of Osteichthyes. Advancing research on their biology, physiology, psychology, and behavior is essential to develop and validate welfare measures, ensuring guidelines for welfare-focused housing and husbandry.


Précis Of: "Birds, Bats And Minds: Tales Of A Revolutionary Scientist, Donald R. Griffin", Carolyn A. Ristau Oct 2024

Précis Of: "Birds, Bats And Minds: Tales Of A Revolutionary Scientist, Donald R. Griffin", Carolyn A. Ristau

Animal Sentience

Donald Griffin co-discovered bat sonar and founded the field of echolocation. He studied bird migration and founded Cognitive Ethology, the study of animal awareness and mental experiences. In all these endeavors, he faced hostile opposition. The biography (Ristau 2024) examines Griffin's life and the scientific explorations by him and others in these fields. This Précis emphasizes his arguments and supporting evidence for animal consciousness as well as his later research. Griffin considered the inhibiting assumptions made by scientists, including Cartesian views, the misunderstanding of innate behaviors, prejudice against lower animals, concern with violations of parsimony, and the assertions of the …


Wildlife Conservation: The Importance Of Individual Personality Traits And Sentience, Karen A. Owens, Gosia Bryja, Marc Bekoff Jul 2024

Wildlife Conservation: The Importance Of Individual Personality Traits And Sentience, Karen A. Owens, Gosia Bryja, Marc Bekoff

Animal Sentience

Individual differences in personality types within the same species have been studied much less than differences between species and populations. Personality differences are related to risk-taking and exploration, which in turn correlate with individuals' daily responses, decisions, and fitness. Bold and shy personality types can have different advantages and disadvantages under different social or environmental pressures. Analyzing personality differences has helped clarify how elk habituate to a well-populated area and how management strategies can be adapted to them. For wolves newly repatriated to Colorado, individual personality factors are likely to prove important for adapting to their new homes as well …


Individuality Matters But Its Cause Has Consequences, Daniel T. Blumstein Jan 2024

Individuality Matters But Its Cause Has Consequences, Daniel T. Blumstein

Animal Sentience

I discuss the relationship between individuality and heritability and note that the mechanism driving individual differences matters for conservation and management outcomes.


Donald Griffin: A Visionary In Science And Consciousness, Charles Foster Jan 2024

Donald Griffin: A Visionary In Science And Consciousness, Charles Foster

Animal Sentience

Carolyn Ristau’s (2024) timely biography reviews Donald Griffin’s pioneering ideas with depth and historical perspective, describing Griffin’s approach to science, his openness to interdisciplinary insights, and his bold stance on consciousness. Ristau’s work highlights Griffin’s relevance to contemporary debates on consciousness and natural selection.


Plant Sentience: Not Now, Maybe Later?, Helen Tiffin Jul 2023

Plant Sentience: Not Now, Maybe Later?, Helen Tiffin

Animal Sentience

Segundo-Ortin’s target article provides compelling evidence for physiological and behavioral complexity in plants, bringing us closer to a recognition of some kind of plant cognition – but it does not as yet offer firm grounds for inferring sentience (feeling) in plants, The recent history of the scientific demonstration and recognition of animalsentience in invertebrates, for example, does not entirely rule out the possibility that further research might provide support for plant sentience. Should this ever turn out to be the case, the ethical problems raised are not insurmountable, and would not threaten the now proven case for animal sentience


Animal Communication And Sentience, Catia Correia-Caeiro, Katja Liebal Jun 2023

Animal Communication And Sentience, Catia Correia-Caeiro, Katja Liebal

Animal Sentience

Segundo-Ortin & Calvo (S&C) argue for sentience in plants on the basis of several studies of what they describe as "cognitive abilities" in plants. As other commentaries (e.g., Brooks Pribac, 2023; Damasio & Damasio, 2023; ten Cate, 2023) have pointed out, however, there is some misuse of several concepts, and a lack of evidence for sentience. We try to clarify three questions in S&C’s discussion: (1) How is communication defined and conceptualised in animal research? (2) Is plant communication comparable to animal communication? (3) Is communication (or the process we see in plants) a good basis for inferring sentience in …


Associative Learning: Unmet Criterion For Plant Sentience, Luigi Baciadonna, Catherine Macri, Martin Giurfa May 2023

Associative Learning: Unmet Criterion For Plant Sentience, Luigi Baciadonna, Catherine Macri, Martin Giurfa

Animal Sentience

In a thought-provoking target article, Segundo-Ortin & Calvo (S&C) discuss the possibility that plants are sentient, focusing on a series of capacities normally attributed only to human and nonhuman animals. S&C propose learning as a marker for sentience. We review studies reporting associative learning in plants and find that they either lack essential controls or fail to produce replicable results. The capacity to learn has not yet been demonstrated in plants, so it cannot be used to support the hypothesis that plants are sentient. Further studies are needed. But agnosticism about sentience should not deter us from investigating unexpected new …


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.


Complex Floral Behavior Of An Angiosperm Family, Tilo Henning, Moritz Mittelbach May 2023

Complex Floral Behavior Of An Angiosperm Family, Tilo Henning, Moritz Mittelbach

Animal Sentience

Segundo-Ortin & Calvo provide a comprehensive overview of the many aspects of plant behavior examined to date. In our view, multiple lines of evidence make it difficult to deny plant sentience. We add further evidence to support the conclusion that plants are sentient organisms. As in animals, the behavior of plants can be seen and studied as an evolutionary trait, subject to and a consequence of increasing complexity in the interactions of plants with their environment. Our example is the evolution of floral behavior in Loasaceae, where complex patterns of stamen movement have co-evolved in interaction with specialized pollinators.


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.


Plant Sentience: "Feeling" Or Biological Automatism?, Andrea Mastinu Apr 2023

Plant Sentience: "Feeling" Or Biological Automatism?, Andrea Mastinu

Animal Sentience

Sentience refers to the ability of an organism to have subjective experiences such as sensations, emotions and awareness. Whereas some animals, including humans, are widely recognized as sentient, the question of whether plants are sentient is still debated among scientists, philosophers, and ethicists. Over the past 20 years, many scientists such as Trewavas, Baluška, Mancuso, Gagliano, and Calvo have reported interesting discussions about memory, behavior, communication, and intelligence in plants. However, the reported conclusions have not convinced the entire scientific community. In this commentary, I would like to focus on two critical aspects related to sentience: cognition and emotion


Plant Sentience: A Hypothesis Based On Shaky Premises, Carel Ten Cate Apr 2023

Plant Sentience: A Hypothesis Based On Shaky Premises, Carel Ten Cate

Animal Sentience

Plants may produce fascinating behavioural phenomena for which the label ‘cognitive process’ may be applicable, at least by some definitions. Segundo-Ortin & Calvo (2023) base their hypothesis that plants might be sentient on the premise of demonstrated presence of cognitive complexity. However, the way phenomena are ascribed, and how the term ‘cognitive’ is used by Segundo-Ortin & Calvo, deviates from the common practice in studies of animal cognition, implying greater complexity than seems justified. It thus provides a questionable basis for attributing sentience to plants.