A method of generating a clonal population of template nucleic acids, comprising: (a) providing a support comprising multiple immobilized primers and a first duplex template nucleic acid attached to the support, wherein the first duplex comprises a first partner strand comprising an extended first immobilized primer generated by template-dependent extension of the first immobilized primer, and a second partner strand hybridized thereto and wherein: the second partner strand comprises an immobilized primer-binding sequence complementary to the immobilized primer, and the first partner strand comprises a sequence of nucleotides complementary to a non-immobilized primer; (b) partially dissociating the duplex nucleic acid at the end containing a sequence complementary to the non-immobilized primer and hybridizing a non-immobilized primer to the first partner strand; (c) extending the hybridized non-immobilized primer to generate an extended non-immobilized primer strand while displacing the second partner strand; (d) hybridizing the displaced second partner strand to a second immobilized primer on the support; (e) extending the second immobilized primer on the support to generate a second duplex nucleic acid comprising the second partner strand and an extended second immobilized strand; and (f) repeating steps (b) - (e) for each duplex nucleic acid attached to the support to generate a clonal population of template nucleic acids attached to the support, wherein the method is performed under isothermal conditions., and wherein partially dissociating the duplex nucleic acid is conducted in the presence of a recombinase. (a) providing a support comprising multiple immobilized primers and a first duplex template nucleic acid attached to the support, wherein the first duplex comprises a first partner strand comprising an extended first immobilized primer generated by template-dependent extension of the first immobilized primer, and a second partner strand hybridized thereto and wherein: the second partner strand comprises an immobilized primer-binding sequence complementary to the immobilized primer, and the first partner strand comprises a sequence of nucleotides complementary to a non-immobilized primer; the second partner strand comprises an immobilized primer-binding sequence complementary to the immobilized primer, and the first partner strand comprises a sequence of nucleotides complementary to a non-immobilized primer; (b) partially dissociating the duplex nucleic acid at the end containing a sequence complementary to the non-immobilized primer and hybridizing a non-immobilized primer to the first partner strand; (c) extending the hybridized non-immobilized primer to generate an extended non-immobilized primer strand while displacing the second partner strand; (d) hybridizing the displaced second partner strand to a second immobilized primer on the support; (e) extending the second immobilized primer on the support to generate a second duplex nucleic acid comprising the second partner strand and an extended second immobilized strand; and (f) repeating steps (b) - (e) for each duplex nucleic acid attached to the support to generate a clonal population of template nucleic acids attached to the support, wherein the method is performed under isothermal conditions., and wherein partially dissociating the duplex nucleic acid is conducted in the presence of a recombinase.