منابع مشابه
Frail Hypotheses in Evolutionary Biology
In the last decades, under the headings of ‘‘mutation strategies,’’ ‘‘evolvability,’’ or ‘‘soft inheritance,’’ many ideas have been advanced on mechanisms assumed to promote innovative evolution beyond what one may anticipate from the classical model of random mutation and selection. Many population geneticists find these ideas superficially seducing but mathematically unfounded. While agreeing...
متن کاملEvolutionary Hypotheses for Human Childhood
The origins of human childhood have fascinated scholars from many disciplines. Some researchers argue that childhood, and many other human characteristics, evolved by heterochrony, an evolutionary process that alters the timing of growth stages from ancestors to their descendants. Other scholars argue against heterochrony, but so far have not offered a well-developed alternative hypothesis. Thi...
متن کاملBig-time insights from a tiny bird fossil.
Birds are among the most diverse and widely distributed groups of vertebrate animals. There are well over 10,000 recognized species alive today, occupying virtually every subaerial ecosystem (1). The amazing breadth of extant bird diversity is manifested in dizzying varieties of forms, colors, and lifestyles, ranging from iridescent, hovering, nectar-feeding hummingbirds to nocturnal, flightles...
متن کاملThe wings before the bird: an evaluation of flapping-based locomotory hypotheses in bird antecedents
BACKGROUND Powered flight is implicated as a major driver for the success of birds. Here we examine the effectiveness of three hypothesized pathways for the evolution of the flight stroke, the forelimb motion that powers aerial locomotion, in a terrestrial setting across a range of stem and basal avians: flap running, Wing Assisted Incline Running (WAIR), and wing-assisted leaping. METHODS Us...
متن کاملEvolutionary ecology of spoken language: co-evolutionary hypotheses are testable.
Evolutionary ecological frameworks can give us new insights into the emergence of human adaptations such as language and cultural learning. There now exist several well-specied models of the social and ecological conditions in which the human capacity for language came under strong positive selection pressure. We critically review them, and ask how we can test them using archaeological evidenc...
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ژورنال
عنوان ژورنال: Nature
سال: 1986
ISSN: 0028-0836,1476-4687
DOI: 10.1038/322677b0