Abstract: The phylogenetic relationship between Equus przewalskii and E. caballus is often a matter of debate. Although these taxa have different chromosome numbers, they do not form monophyletic clades in a phylogenetic tree based on mtDNA sequences. Here we report sequence variation from five newly identified Y chromosome regions of the horse. Two fixed nucleotide differences on the Y chromosome clearly display Przewalski's horse and domestic horse as sister taxa. At both positions the Przewalski's horse haplotype shows the ancestral state, in common with the members of the zebra/ass lineage. We discuss the factors that may have led to the differences in mtDNA and Y-chromosomal observations.

Abstract: Primer sequences flanking 13 microsatellite loci isolated from the domestic horse (E. caballus) were successfully used to amplify homologous loci in the Przewalski's horse (E. przewalskii). The results demonstrate that the level of polymorphism at all 13 loci in the Przewalski's horse was comparable to that in the domestic horse and the overall exclusion probability in the Przewalski's horse was calculated to be 0.9994. The results suggest that it should be possible to use E. caballus-derived microsatellite markers to provide parentage verification and additional valuable information to the captive management of E. przewalskii. The ability to amplify corresponding loci in the remaining five species of the genus was also confirmed, illustrating the general application of markers isolated from the domestic horse to the evaluation of polymorphism in the other six species of the genus.

Abstract: It is often assumed that there is more than one kind of learning--or more than one memory system--each of which is specialized for a different function. Yet, the criteria by which the varieties of learning and memory should be distinguished are seldom clear. Learning and memory phenomena can differ from one another across species or situations (and thus be specialized) in a number of different ways. What is needed is a consistent theoretical approach to the whole range of learning phenomena, and one is explored here. Parallels and contrasts in the study of sensory systems illustrate one way to integrate the study of general mechanisms with an appreciation of species-specific adaptations.

Abstract: Dogs have an unusual ability for reading human communicative gestures (e.g., pointing) in comparison to either nonhuman primates (including chimpanzees) or wolves . Although this unusual communicative ability seems to have evolved during domestication , it is unclear whether this evolution occurred as a result of direct selection for this ability, as previously hypothesized , or as a correlated by-product of selection against fear and aggression toward humans--as is the case with a number of morphological and physiological changes associated with domestication . We show here that fox kits from an experimental population selectively bred over 45 years to approach humans fearlessly and nonaggressively (i.e., experimentally domesticated) are not only as skillful as dog puppies in using human gestures but are also more skilled than fox kits from a second, control population not bred for tame behavior (critically, neither population of foxes was ever bred or tested for their ability to use human gestures) . These results suggest that sociocognitive evolution has occurred in the experimental foxes, and possibly domestic dogs, as a correlated by-product of selection on systems mediating fear and aggression, and it is likely the observed social cognitive evolution did not require direct selection for improved social cognitive ability.

Abstract: The position advanced in this paper is that the bedrock of emotional feelings is contained within the evolved emotional action apparatus of mammalian brains. This dual-aspect monism approach to brain-mind functions, which asserts that emotional feelings may reflect the neurodynamics of brain systems that generate instinctual emotional behaviors, saves us from various conceptual conundrums. In coarse form, primary process affective consciousness seems to be fundamentally an unconditional “gift of nature” rather than an acquired skill, even though those systems facilitate skill acquisition via various felt reinforcements. Affective consciousness, being a comparatively intrinsic function of the brain, shared homologously by all mammalian species, should be the easiest variant of consciousness to study in animals. This is not to deny that some secondary processes (e.g., awareness of feelings in the generation of behavioral choices) cannot be evaluated in animals with sufficiently clever behavioral learning procedures, as with place-preference procedures and the analysis of changes in learned behaviors after one has induced re-valuation of incentives. Rather, the claim is that a direct neuroscientific study of primary process emotional/affective states is best achieved through the study of the intrinsic (“instinctual”), albeit experientially refined, emotional action tendencies of other animals. In this view, core emotional feelings may reflect the neurodynamic attractor landscapes of a variety of extended trans-diencephalic, limbic emotional action systems-including SEEKING, FEAR, RAGE, LUST, CARE, PANIC, and PLAY. Through a study of these brain systems, the neural infrastructure of human and animal affective consciousness may be revealed. Emotional feelings are instantiated in large-scale neurodynamics that can be most effectively monitored via the ethological analysis of emotional action tendencies and the accompanying brain neurochemical/electrical changes. The intrinsic coherence of such emotional responses is demonstrated by the fact that they can be provoked by electrical and chemical stimulation of specific brain zones-effects that are affectively laden. For substantive progress in this emerging research arena, animal brain researchers need to discuss affective brain functions more openly. Secondary awareness processes, because of their more conditional, contextually situated nature, are more difficult to understand in any neuroscientific detail. In other words, the information-processing brain functions, critical for cognitive consciousness, are harder to study in other animals than the more homologous emotional/motivational affective state functions of the brain.