Carl Sagan, Ann Druyan
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Subjects -> Nonfiction -> Social Sciences -> Sociology -> General
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Customer Reviews:
Total reviews: 53
Average rating: 4.5 of 5
Easy read on a hard subject 5 out of 5 stars.
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It seems unlikely that any reader of these words can be unfamiliar with Carl Sagan's extensive body of work. He was virtually without peer as a popularizer of scientific thought in our era. His public television presence as a highbrow Mr. Wizard, will be in re-runs long into the future. CONTACT, the movie version of his novel concerning a future link to other intelligences has given his thinking a pop-cultural spin. Less visible to the lay public is his brilliant scientific career, with expertise in biology and astronomy that made him a key player in NASA's Mariner, Viking and Voyager space missions -- searching for evidence of life out there. This volume is just one more piece of his puzzle, and a wonderful one. Writing with Ann Druyan, who also co-wrote the Cosmos television series, Sagan here explores the story of our beginnings. From life's emergence the authors trace the threads of chemistry and biology that have come together as the human species. The emphasis is everywhere on transition -- the constancy of change. Numerous chapters conclude with boxed quotes labelled "On Impermanence," eloquent reminders of that theme. We are too short-lived and too little informed of our parentage beyond a few or several generations back to be much more than orphans in a basket on the planet's doorstep, the authors posit. This is their exploration for roots. Intriguing hints fly in from the past. Testosterone, androgen and estrogen have the same effects on birds, ants, lizards, mice and men and women. Old, old hormones, cooked up by DNA way back where all our family trees unite. Dominance and submission are the tools of social organization in chickens, komodo dragons and elk. A little xenophobia is good for genetic diversity, but too much brings failure due to incest, so the mating of occasional Romeos and Juliets is excellent for both family's gene pools. Over-specialization is every bit as hazardous as over-generalization in the game of survival. If you are too perfectly suited to your niche your kind can be wiped out by small changes -- if you are too widely adaptable you may never find a niche in which to prosper. Yin and Yang. SHADOWS contains the clearest explanation I have encountered of why and how evolution works its relentless magic. (This book should be required reading for members of the Kansas School Board. Assumption of literacy on their part is just a wild guess -- maybe a hireling could read it aloud at their meetings?) A short summation will suffer from brevity, but here goes: The genetic codes which control development are incredibly long sequences composed of just four different molecular building blocks which are read-off in groups of three. It is the order of the molecules that creates the message (just as in our language where the orderly arrangement of any of 26 letters creates meaningful words.) Only a small portion of the genetic information in a cell is actually used; a lot of it is ignored (again due to parts of the message which say "read this" or "ignore this.") Mutations involve accidental re-ordering of the letters, and again, as in language, most produce nonsense words. Mutations in "read this" sections usually result in failure of an organism but very occasionally make it more fit for survival and the improvement is passed on. Mutations in the "ignore this" sections can persist for generations without harm until a mutation in the instruction to "read this" occurs. Suddenly new possibilities are made available (rediscovery of an ancient text), again with some successful and many failing. This results in what is now called "punctuated equilibrium" which suggests that evolution occurs in fits and starts, triggered most often by large scale environmental change and modification of the "read this" instruction set. Okay, I tried. Read the book. Excellent. Far deeper and lots wider than I can adequately describe in a brief review.
Editorial Review:
"Dazzling...A feast. Absorbing and elegantly written, it tells of theorigins of life on earth, describes its variety and charaacter, and culminates in a discussion of human nature and teh complex traces ofhumankind's evolutionary past...It is an amazing story masterfully told."
FINANCIAL TIMES (LONDON)
World renowned scientist Carl Sagan and acclaimed author Ann Druyan have written a ROOTS for the human species, a lucid and riveting account of how humans got to be the way we are. It shows with humor and drama that many of our key traits--self-awareness, technology, family ties, submission to authority, hatred for those a little different from ourselves, reason, and ethics--are rooted in the deep past, and illuminated by our kinship with other animals. Astonishing in its scope, brilliant in its insights, and an absolutely compelling read, SHADOWS OF FORGOTTEN ANCESTORS is a triumph of popular science.
