...Naturwissenschaften (2004) 91:255–276 DOI 10.1007/s00114-004-0515-y REVIEW Ulrich Kutschera · Karl J. Niklas The modern theory of biological evolution: an expanded synthesis Published online: 17 March 2004 Springer-Verlag 2004 Abstract In 1858, two naturalists, Charles Darwin and Alfred Russel Wallace, independently proposed natural selection as the basic mechanism responsible for the origin of new phenotypic variants and, ultimately, new species. A large body of evidence for this hypothesis was published in Darwin’s Origin of Species one year later, the appearance of which provoked other leading scientists like August Weismann to adopt and amplify Darwin’s perspective. Weismann’s neo-Darwinian theory of evolution was further elaborated, most notably in a series of books by Theodosius Dobzhansky, Ernst Mayr, Julian Huxley and others. In this article we first summarize the history of life on Earth and provide recent evidence demonstrating that Darwin’s dilemma (the apparent missing Precambrian record of life) has been resolved. Next, the historical development and structure of the “modern synthesis” is described within the context of the following topics: paleobiology and rates of evolution, mass extinctions and species selection, macroevolution and punctuated equilibrium, sexual reproduction and recombination, sexual selection and altruism, endosymbiosis and eukaryotic cell evolution, evolutionary developmental biology, phenotypic plasticity, epigenetic inheritance and...
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...* Chapter 25 * Evolution has to work with existing forms * Heterochrony Evolutionary change in rate or timing of developmental events * Padomorphosis Mature state of an organism retains juvenile characteristics Spatial Patterns Rearranges structural features through changes in gene expression or gene duplications. Homeotic genes control 3-D patterns of multicellular organisms Hox gene family: HoxC6 expressed (no limbs), HoxC6 not expressed (limbs can form) Jellyfish to humans Exaptation Traits evolved in one context are used for an entirely different function Feathers first thought to be used as insulation. Feathers are an exaptation- evolved in context of insulation, now used for different function (flight) Adaptive Radiation: a single lineage (common ancestor) undergoes rapid speciation and ecological diversification to form multiple new species. Can occur when: Key Adaptation Adaptations that allow a lineage to exploit new habitats( or resources) and diversify rapidly If key adaptations evolve convergently in different groups: compare diversity of group with key adaptation to diversity of sister group lacking key adaptation (paired t-test) After mass extinction event (leaves many vacant niches for organism to diversify and fill Colonization of a new habitat/location Rapid diversification of “picture-winged” Drosophila on Hawaiian Islands Hypothesis of Chemical Evolution Abiotic synthesis of small organic molecules Observed...
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...When gene flow between two populations ceases, the potential for _____ exists. Speciation Bird guides once listed the myrtle warbler and Audubon's warbler as distinct species that lived side by side in parts of their ranges. However, recent books show them as eastern and western forms of a single species, the yellow-rumped warbler. Apparently, the myrtle warbler and Audubon's warbler _____. A) Successfully interbreed and produce fertile offspring successfully interbreed and produce fertile offspring Imagine that part of a population of South American finches is blown by a storm onto an island far offshore and manages to survive and reproduce there for a period of 10,000 years. After that period, a climate change results in lower sea levels and the reconnection of the island with the mainland. Members of the formerly isolated island finch population can now interact freely with members of the original mainland population. Which of the following observations would, by itself, lead you to conclude unequivocally that the island finch population had evolved into a distinct species, according to the biological species concept? A) Individuals from the different populations sometimes mate with each other, but all of the resulting eggs are sterile. Which of the following conditions is necessary for speciation to occur? D) Reproductive isolation At which point in the adaptation of a population is it clear that speciation has occurred? B) Gene pool changes establish reproductive...
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