-Recent years have seen acknowledgment from a number of researchers that similarities appear to exist in complex cognitive skills of distantly related species -most notably in corvids, parrots, delphinids, and great apes. Discoveries on complex cognitive skills in common hold the promise of interesting and fruitful new perspectives on cognition. That said, some theoretical approaches seem largely to be lacking. We draw attention to the importance of pre-existing constraints on and freedoms of the evolving animal, which might prove as important as external selective pressures in understanding the evolution of cognition. To elucidate our point, we briefly describe one contemporary cognitive-science approach to cognition. Accounts on cognitive evolution both in behavioral ecology and animal cognition are often hampered by simplistic input-output-based views on cognition. Cognition -in particular complex cognition -may influence animal behaviors in ways that cannot be captured by a purely selectionist account. We discuss the evolutionary processes underlying independently evolved yet similar characters. We highlight the importance of the difference between parallel and convergent evolution in understanding whether complex cognition arises repeatedly only through similar selective pressures; or whether underlying, previously evolved structures are crucial for the occurrence of cognitive similarities. In conclusion we suggest that the developmental sequences leading to apparently similar cognitive skills require further investigation to reveal the evolutionary processes behind them. Our aim is not one of providing ultimate answers to the questions we raise; instead, we draw attention to their existence, the better that they may be addressed.
Keywords -Convergent evolution, Embodied cognition, Animal cognition, Complex cognition.Through first half of the 20th Century, the same learning processes were believed to apply to all vertebrates; studying a range of species was unnecessary. Humans were thought to be the only creatures possessing complex cognition. With developments in animal cognition, the picture gradually changed. The field has been growing, as has the number of species studied (Shettleworth, 2009). The realization came that, although many species share many basic cognitive skills, several cognitive expressions diverge. The idea that humans have a cognitive complexity well beyond the rest of the animal kingdom has been called into question. This began with great apes, whose cognitive capacities impressed, largely because of the similarity to our own capacities. Soon other taxa -e.g., corvids, parrots, and delphinidswere shown capable of comparable feats.From a phylogenetic perspective, it was not surprising that our closest living relatives should share many cognitive skills with us. Emphasis has instead been placed on detailing the divergences between humans and other great apes, the better to understand what makes us unique. Far less attention has been paid to the theoretical implications of findin...