Origins of Sex: Three Billion Years of Genetic RecombinationYale University Press, 1 gen 1990 - 258 pagine A fascinating and detailed examination of the evolution--and occasional devolution--of sexuality in microorganisms and more complex forms of life. Margulis and Sagan trace sex from its inauspicious beginnings in bacteria threatened by ultraviolet radiation to its intimate relation with the origin of mitotic division of nucleated cells. The origin of meiotic sex through cannibalism followed by centriole reproductive tardiness and the connection of cell symbiosis to sex and differentiation are explored. "The authors have not only given us a new and exiting scenario for the evolution of sex, but have also provided us with critical ways in which we can test their hypotheses. . . . This is a stimulating book that is sure to invoke criticism and discussion; I strongly recommend it."--Symbiosis "The book is well organized and well written, leading the reader from one thought to another almost effortlessly. Background information is presented to aid those of us who are not experts in this field, and a glossary is appended. The book could be used at all levels of study, from interested undergraduates in general biology though postdoctoral students of genetics and evolution. I recommend this thought-provoking book to you for both your enjoyment and your enlightenment."--Richard W. Cheney, Jr., Journal of College Science Teaching "This book, undoubtedly controversial, is a thoughtful and original contribution to an important aspect of cellular biology."--John Langridge |
Sommario
INTRODUCTION | 1 |
WHAT IS LIFE? | 9 |
WHAT IS EVOLUTION? | 16 |
WHAT IS SEX? | 25 |
THREATS TO DNA AND THE EMERGENCE OF SEXUALITY | 38 |
RECOMBINATION AND BACTERIAL MATING | 54 |
THE EMERGENCE OF PROTISTS | 62 |
THE ORIGIN OF CHROMOSOMES | 114 |
CANNIBALISM AND OTHER MERGERS | 146 |
PAIRING AND HALVING | 153 |
MEIOSIS AND CELL DIFFERENTIATION | 170 |
BIG EGGS AND SMALL SPERM | 183 |
THREE BILLION YEARS OF | 204 |
Glossary | 227 |
References | 237 |
249 | |
Parole e frasi comuni
algae amino acid amoebae ancestors animals and plants asexual autopoiesis axonemes bacteria biological Blastocladiella cell division cellular centrioles chromatin chromosomes ciliates composed conjugation cycle cytoplasm differentiation dinomastigotes diploid diploid cell electron enzymes eukaryotic eukaryotic cells evolution evolutionary evolved example fertilization fungi fuse fusion gametes gamonts gender genes genetic genome genophore haploid heterotrophic histone host individual involved karyotic kinetids kinetochores kinetosomes lineages male Margulis mastigotes mating types meiosis meiotic sex meiotic sexuality microbes microbial community micrograph micrometers microtubule organizing centers mitochondria mitosis mitotic spindle mixis molecular molecules motility MTOCs multicellular mutations nuclear membrane nuclei nucleic acid nucleosomes nucleotide offspring cells organelles origin of sex oxygen parent photosynthetic plastids population produce prokaryotic protein protists protoctists recombination repair replication replicon reproduction ribosomes sequence single species sperm spirochetal remnants spirochetes spores Stentor structures symbionts synaptonemal complex synthesis thymine tion tissue tubulin ultraviolet light undulipodia viruses zoospore zygote