power sex suicide mitochondria and the meaning of life dec 2005

[...]... they would hardly exercise even the most pointy-headed boffins Yet when posed together as a group, the answers impart a seamless account of the whole trajectory of evolution, from the origin of life itself, through the genesis of complex cells and multicellular organisms, to the attainment of larger size, sexes, warm-bloodedness, and into the decline of old age and death The sweeping picture that emerges... by the detailed sequence of the mitochondrial genome: the mitochondrial genes only encode a handful of proteins (13 to be exact), along with all the genetic machinery needed to make them The great majority of mitochondrial proteins (some 800) are encoded by the genes in the nucleus, of which there are 30 000 to 40 000 in total The apparent independence of mitochondria is therefore truly apparent, and. .. porphyrin synthesis and even the Krebs cycle, which could in principle take place anywhere else in the cell, and merely found a convenient location in the mitochondria Instead, we’ll see why mitochondria made such a difference to life, and to our own lives We’ll see why mitochondria are the clandestine rulers of our world, masters of power, sex, and suicide PART 1 Hopeful Monster The Origin of the Eukaryotic... cytoplasm There it docks onto one of the many thousands of protein-building factories in the cytoplasm, the ribosomes As molecular structures these are enormous; as visible entities they are miniscule They can be seen studding some of the cell’s internal membranes, giving them a rough impression on the electron microscope, and dotting through the cytoplasm They are composed of a mixture of other types of. .. endosymbionts In the first decades of the twentieth century, virtually all parts of the cell were considered as possible endosymbionts, perhaps modified 14 Clandestine Rulers of the World by their mutual coexistence, including the nucleus, the mitochondria, the chloroplasts (responsible for photosynthesis in plants), and the centrioles (the cell bodies that organize the cytoskeleton) All these theories were... ‘captured’ and put to use But now, after a decade of careful genetic analysis, it looks as if all known eukaryotic cells either have or once had (and then lost) mitochondria The implication is that the origin of complex cells is inseparable from the origin of the mitochondria: the two events were one and the same If this is true, then not only did the evolution of multicellular organisms require mitochondria, ... Molecular Biology at the University of the West of England John has a wonderfully wide-ranging, eclectic knowledge of biology, and his comments often took me by surprise They made me rethink the workability of some of the ideas I put forward, and having done so to his satisfaction (I think) I am now more confident that mitochondria really do hold within them the meaning of life Other specialists have... among themselves for nearly four billion years, and yet only came up with the eukaryotic cell once The acquisition of mitochondria was the pivotal moment in the history of life We are discovering new habitats and relationships all the time They are a fabulously rich testing ground of ideas To give just a single example, one of the more surprising discoveries at the turn of the millennium was the abundance... British newspaper ran the story under the colourful heading ‘Babies born with two mothers and one father’ This characteristically vivid product of the press is not totally wrong—while all the genes in the nucleus came from the ‘real’ mother, some of the mitochondrial genes came from the ‘donor’ mother, so the babies did indeed receive some genes from two different mothers Despite the birth of more than 30... possessed by an organism, and may run to billions of letters A gene is essentially the code for a single protein, which usually takes thousands of letters Each protein is a string of subunits called amino acids, and the precise order of these dictates the functional properties of the protein The sequence of letters in a gene specifies the sequence of amino acids in a protein If the sequence of letters is changed . class="bi x0 y0 w0 h1" alt="" Power, Sex, Suicide Mitochondria and the Meaning of Life This page intentionally left blank Power, Sex, Suicide Mitochondria and the Meaning of Life NICK LANE 1 3 Great. The Vital Force: Proton Power and the Origin of Life 65 4. The Meaning of Respiration 71 5. Proton Power 85 6. The Origin of Life 94 Part 3 Insider Deal: The Foundations of Complexity 105 7. Why. Murder or Suicide: The Troubled Birth of the Individual 189 11. Conflict in the Body 200 12. Foundations of the Individual 215 Part 6 Battle of the Sexes: Human Pre-History and the Nature of Gender