This revised third edition provides an up to date, comprehensive overview of the field of comparative psychology, integrating both evolutionary and developmental studies of brain and behavior. This book provides a unique combination of areas normally covered independently to satisfy the requirements of comparative psychology courses.
Papini ensures thorough coverage of topics like the fundamentals of neural function, the cognitive and associative capacities of animals, the development of the central nervous system and behavior, and the fossil record of animals including human ancestors. This text includes many examples drawn from the study of human behavior, highlighting general and basic principles that apply broadly to the animal kingdom. New topics introduced in this edition include genetics, epigenetics, neurobiological, and cognitive advances made in recent years into this evolutionary-developmental framework.
An essential textbook for upper level undergraduate and graduate courses in comparative psychology, animal behavior, and evolutionary psychology, developmental psychology, neuroscience and behavioral biology.
The concept of evolution is relatively modern. Although ancient philosophers entertained ideas consistent with some key evolutionary concepts, no surviving texts provide a detailed account of evolutionary change (see Box 1.1). In modern terms, evolution is a phenomenon resulting from the interplay of evolutionary processes, such as natural selection and genetic drift, and evolutionary patterns, such as the constraints imposed by phylogenetic history and existing variations. Evolutionary processes can be viewed as innovative forces producing novelty and change, whereas evolutionary patterns can be viewed as conservative forces providing the raw material for change. For example, the evolution of terrestrial vertebrates (amphibians, reptiles, birds, and mammals) includes species adapted to many environmental conditions (illustrating evolutionary processes). But independently of their diversity, these species share a body plan involving four limbs, whether they are used for running, swimming, climbing, jumping, or flying (illustrating evolutionary patterns). For this reason, the taxon is known as tetrapodsâliterally, four-limbed animals.
Species exhibit a mixture of unique and common traits. Unique traits often illustrate the adaptation of the organismâs morphology and function to its environment. For example, human language suggests adaptation to social environments. Common traits characterize a phylogenyâa lineage of ancestors and descendants. The five-digit (pentadactyl) hand is an example of a basal trait common to humans and other tetrapods.
Evolution is not a directly observable fact in real time because of its slow pace. The growth of a plant is similarly difficult to observe, unless you record it in fast-speed video, which compresses in a few seconds the events that unfold over a few days. The fast-video technique is analogous to artificial selectionâthe intentional mating of organisms that exhibit a certain trait (e.g., low vs. high levels of aggressive behavior). By accelerating divergence, artificial selection experiments show that it is possible to evolve lines of reproductively isolated organisms whose ancestors were capable of interbreeding. But there is, in addition, a large body of indirect evidence for evolution. Evolution implies genealogical links and, thus, evidence is sought in terms of shared traits across species.
Molecular Evidence
Genetic information is encoded in the sequence of nucleotides (adenine, thymine, guanine, and cytosine) that constitute the deoxyribonucleic acid (DNA) molecule. DNA is located inside the cell, either in the cytoplasm as in prokaryote bacteria, or surrounded by a nuclear membrane as in eukaryote animals. The DNA molecule contains information to synthesize proteins according to a genetic code shared by nearly all known living organisms (Bacher, Hughes, Wong, & Ellington, 2004). The process follows a set of steps common to all animals (Figure 1.1):
Box 1.1 Evolution and Animal Behavior: Classic Roots
Anaximandros of Miletos (ca. 610â545 BCE)
Anaximandros suggested that all life originated in the seas and, therefore, human beings had evolved from fish.
Empedocles (ca. 493â433 BCE)
Leucipus (ca. 450â370 BCE)
Democritus (ca. 460â370 BCE)
Epicurus (ca. 341â270 BCE)
These natural philosophers developed atomic theory, a view that matter (including life) is the result of primordial elements called âatomoi,â that is, indivisibles. Atomic theory led to an interest in the origin of life.
Lucretius (95â55 BCE)
An Epicurean philosopher, Lucretius wrote On the Nature of the Universe (De Rerum Natura; Lucretius, 1943). He suggested that living organisms originated in the âmother earth.â Since âall things move, all are changed by nature and compelled to alterâ (V, 830â831). Many of these organisms were aberrant, simply resulting from the random combination of atoms. It followed that many of these âmonstersâ (Lucretiusâs term), were not fit to survive and reproduce and thus became extinctâan idea conceptually close to the contemporary notion of natural selection.
Aristotle (384â322 BCE)
Aristotle collected and classified fauna and flora specimens that officials in Alexander the Greatâs army collected for him. Taxonomic principles originated in his efforts to organize this vast information. He recognized and classified 540 animal species, segregating them into the enaima (or vertebrates) and the anaima (or invertebrates) depending on the presence or absence of blood, respectively. In his Historia Animalium, Aristotle (1965) proposed the concept of scala naturae, a gradualist view of nature. He wrote, âNature proceeds from the inanimate to the animals by such small steps that, because of the continuity, we fail to see to which side the boundary and the middle between them belongsâ (VII, 588b). From plants to animals, the ladder (an appropriate metaphor for scala naturae) suggested, âone after another shows more possession of life and movementâ (VII, 588b). Aristotle suggested (I, 488b) that, âMany animals have the power of memory and can be trained; but the only one which can recall past events at will is man.â Such statements were derived from extensive behavioral observations. Aristotleâs descriptions of the foraging and social behavior of bees, migratory behavior of cranes and pelicans, electric discharge of the torpedo fish, brood parasitism by European cuckoos, and parental care behavior of the catfish, among others, attest to his systematic and objective approach. Of course, not all his observations were correct. Errors can often be justified by Aristotleâs lack of instruments and reference sources (Sarton, 1952).
Plutarch (ca. 50â120 CE)
Plutarch wrote two essays of importance to comparative psychology: Whether land or sea animals are cleverer and Beasts are rational (Plutarch, 1957). In opposition to the Stoics, who had maintained that only humans exhibit rationality, Plutarch took a gradualist view, arguing that species differences were of degree, not kind. In the first book cited, Plutarch wrote (963): âWhereas it is the presence of understanding, of one kind in one animal, of another kind in another, and in varying degrees that has produced the observable differences.â In his work on rationality, Plutarch developed the notion that animal instincts are not examples of untrained faculties, but the product of self-training. His facts may be questionable (e.g., âWho taught tortoises to devour marjoram after eating the snake?â 991F), but the idea has contemporary appeal. Plutarch also emphasized that animals are not only good learners but also good teachers. One example involves song learning in birds (992C): âNightingales set the example for their young to sing; while nestlings that are caught young and brought up by human care are poorer singers, as though they had left the care of their teacher too early.â
Conclusions
Although there were rudimentary notions of evolution in the atomist philosophers, evolutionary principles were either not fully developed or the critical writings have been lost. Moreover, despite some notable exceptions (e.g., Plutarch), classic thinkers tended to emphasize a deep gap between humans, who stand alone in their possession of reason, and all other animals. The absence of a theory linking human and animal psychology probably discouraged the scientific study of animal behavior.
DNA replication. Duplicates of the DNA molecule are formed during cell division.
Transcription. Conversion of DNA into RNA (ribonucleic acid).
Splicing. Removal of noncoding sections of RNA (called introns) and fusion of coding sections of RNA (called exons) to form messenger RNA (mRNA).
Translation. mRNA is used as a template to synthesize proteins.
During transcription, mRNA mirrors the sequence of bases in the DNA molecule except that thymine is replaced by uracil. Triplets of nucleotides, arranged in a specific order and called codons, are translated into the 20 known amino acids, the building blocks of all proteins. Translation occurs according to the code described in Table 1.1. Some amino acids are coded by more than one codon. Synonymous codons tend to differ in the third base. There are also triplets coding for a STOP command. This genetic code is common to all animals and, with few exceptions, is common to all living organisms. The universality of such a specific genetic code suggests that all life forms evolved from a common ancestor.