August 31, 2021

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The powers, perversions,
and potential of heredity

by Carl Zimmer.
Dutton/Penguin Random House,
2018 (672 pages)

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    Quote = "What matter is ancestry? A small band of hominins in Africa evolved into Homo sapiens around 300,000 years ago, after which they expanded across that continent and then across the world. Those journeys shaped the genomes that people inherited from their ancestors. And today, if we look at our own genomes, we can reconstruct some of that history, even back to ancestors who were not exactly human." (From Chapter 7, Individual Z, page 213)

    Quote = "As tricky as heritability may be to grasp, it has been a powerful tool for making sense of heredity. Our well-being depends on it, in fact. To a large extent, heritability feeds the world. How much food farmers can harvest from a given acre of land depends largely on the traits of the crops they plant." (From Chapter 9, Nine Foot High Complete, page 263)

    Quote = "Zimmer writes, 'Each of us carries an amalgam of fragments of DNA, stitched together from some of our many ancestors. Each piece has its own ancestry, traveling a different path back through human history. A particular fragment may sometimes be cause for worry, but most of our DNA influences who we are --- our appearance, our height, our penchants --- in inconceivably subtle ways'." (From publisher's blurb)
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note = Numbers in parentheses refer to pages





    4) "ATTAGIRL" (107-134)
PART 2 --- WAYWARD DNA (135-219)



7) INDIVIDUAL Z (182-213)
    Quote = "What matter is ancestry?"

    "A small band of hominins in Africa evolved into Homo sapiens around 300,000 years ago, after which they expanded across that continent and then across the world. Those journeys shaped the genomes that people inherited from their ancestors. And today, if we look at our own genomes, we can reconstruct some of that history, even back to ancestors who were not exactly human." (213)
8) MONGRELS (214-249)
    note = What is meiosis? [The simplest online definition of Meiosis is that it is a process where a single cell divides twice to produce four cells containing half the original amount of genetic information. These cells are our sex cells – sperm in males, eggs in females. During meiosis one cell? divides twice to form four daughter cells.] (Paraphrased by the addition of the online definition of meiosis to the question raised by Zimmer in the book, page 246)
    note = Enlightenment - measuring height and health: "In France children between eight years and twelve years were forbidden from working over 8 hours per day or doing any night work. School became mandatory till age twelve." (256-257)

    note = "Genetic variation might be strong for some traits, and environmental variation might be more important for others. The fraction caused by genetic variation — in other words, the variation that could be inherited by genes — came to be known as heritability. If genetic variation has no influence over the variation in a trait, then its heritability is zero. If the environment has no influence, then the heritability is 100 percent." (263)

    note = "Heritability is one of the trickiest concepts in modern biology. It describes variations only across an entire population. If the heritability of a trait in a group of people is 50 percent, that does not mean that in any given person, genes and environment are each responsible for half of it. And if a trait has a heritability of zero, that does not mean that genes have nothing to do with it. For example, the heritability of the number of eyes is zero, because children are virtually all born with a pair of them...We all inherit a genetic program that guides the development of eyes." (263)

    note = "As tricky as heritability may be to grasp, it has been a powerful tool for making sense of heredity. Our well-being depends on it, in fact. To a large extent, heritability feeds the world. How much food farmers can harvest from a given acre of land depends largely on the traits of the crops they plant." (263)
10) ED AND FRED (286-219)
    note = explain difference between "precision education" and "genetic essentialism" (317-318)

    note = Cite chocolate chip cookie experiment with 3 groups of students who read different articles about the causes of obesity: genes cause, social pressure to eat more than necessary, no cause in article (318-319)

11) EX OVO OMNIA (323-347)
    note = use the "language of heredity" to explain what happens in our own bodies (323-324)

    note = use Aristotle and his egg experiment - to William Harvey 2000 years later when the idea of the human body unfolding homogenously was named "epigenesis" in 17th century (324-325)

    note = use discovery of sperm in the 1670s by Dutch naturalist, Nicolaas Hartsocker (326)

    note = use 1800s with new microscopes as time cell theory was discovered (326)

    note = use cell division of Weismann (328-329)

    note = use info on 700 new neurons in hippocampus/day — discovered in 2013 (346-347)
12) WITCHES'-BROOM (348-369)
    note = use Elephant man/Joseph Merrick who was born in 1862 and was not intellectually disabled (351-352)

    note = Chromosomes carry hereditary factors (352-353)

    note = use data on mutations and mosaicism (354-355)

    note = define the knowledge about mosaics: "A single genome can no longer define us, because our inner heredity toys with DNA, altering just about every piece of genetic material we inherit. Even in our skulls, we grow a witches' broom." (368-369)
13) CHIMERAS (370-401)
    note = freemartins = "sexless female twin of a bull twin that are cellular mergers" (370-372)

    note = research on Tasmanian Devils with facial tumors (391-400)

    note = definition of Schwann cells that typically wrap insulating sleeves around other neurons to help them send their signals. (393)
PART 4 --- OTHER CHANNELS (403-480)

    note = H. Pylori inhabits more than half of all humans' stomachs (414-415)

    note = think of our microbiomes as heritable traits and bifidobacteria (415-416)

    note = use several pages to summarize the amazing story of the evolution of mitochondria (417-419)

    note = use "Gaining mitochondria marked one of the great leaps in the evolution of life" (419)

    note = quote parts of last paragraph to explain (421)

16) THE TEACHABLE APE (445-480)
    note = Use book reference to Dawkin's Selfish Gene, reprint ed. for his comment: "The word meme seems to be turning out to be a good meme." (452-454)

    note = use Dawkin's quote: "When we die, there are two things we can leave behind us: genes and memes." (452)

    note = quote "The theory of natural pedagogy suggests that blind trust is at least as important as smart thinking" by Celia Hayes, British psychologist (463)

    note = use definition of pedagogy = [online = n. 1580s, from Middle French pédagogie (16c.), from Latin paedagogia, from Greek paidagogia "education, attendance on boys," from paidagogos "teacher" (see pedagogue); most commonly understood as the approach to teaching) refers more broadly to the theory and practice of education, and how this influences the growth of learners. Pedagogy, taken as an academic discipline, is the study of how knowledge and skills are exchanged in an educational context, and it considers the interactions that take place during learning].

    note = [online = Pedagogies vary greatly, as they reflect the different social, political, cultural contexts from which they emerge. Theories of pedagogy increasingly identify the student as an agent, and the teacher as a facilitator. Conventional Western pedagogies, however, view the teacher as knowledge holder and student as the recipient of knowledge; (pedagogy adopted by teachers shape their actions, judgments, and other teaching strategies by taking into consideration theories of learning, understandings of students and their needs, and the backgrounds and interests of individual students. Its aims may include furthering liberal education (the general development of human potential) to the narrower specifics of vocational education (the imparting and acquisition of specific skills).

    note = Instructive strategies are governed by the pupil's background knowledge and experience, situation, and environment, as well as learning goals set by the student and teacher. One example would be the Socratic Method.

    note = paragraph on 469 about cultural heredity that led to the agricultural revolution (469)

    note = use "Brains ounce for ounce require the demand for 20 times as much energy as a muscle." (469)

    note = use rest of paragraph (469-470)

    PART 5 --- THE SUN CHARIOT (481-574)

    note = "We are all fellow mutants" quote by Muller who redefined "Eugenics" to be "the social direction of human evolution." (501)

    note = use info on history of sperm donation since 2000 (505-506)

    note = Gene Therapy = somatic genetic engineering (510-511)

    note = ethical issue of changing the "collective human gene pool" (534)

    note = use capitalism's rush to change heritability (535)
19) THE PLANET'S HEIRS (550-574)
    note = What is a "mutagenic chain reaction"? (560)

    note = explain "gene drives" (561-562)

    note = Human "cumulative culture" allowed hunter-gatherers to learn over generations how to harvest plants and control animals. (562)

    note = "Before ten thousand years ago, children were born into a world sculpted by fire, hunting, and foraging. Farmers began reworking the land on a greater scale, and at an accelerating pace." (562)

    note = use last 2 paragraphs to describe why carbon dioxide is different than the way lead "washed out" of our environment shortly after it was banned from gasoline. (564)

    note = "The stubborn inequalities in the U.S. are not the result of some people living in a physical environment. Their environment is built by social forces, and those forces last for centuries because they are regenerated across the generations." (567)

    note = "Cumulative culture allowed our species to make giant leaps in technological progress, but it also made us prone to inequality. (567)

    note = summarize whole paragraph at bottom (567)

    note = use inheritance facts to explain inequality in wealth gaps among races in U.S. --- cultural inheritances vs. economic inequality (569) and more (568-571)

    note = use following paragraphs to explain "cultural feedback loops" ["between culture and environment" (563) such as Agricultural Revolution --- 10,000 years ago and Industrial Revolution --- 300 years ago (562-563)
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GLOSSARY (575-576)

Allele = A variant form of a gene. In some cases, different alleles will produce variations in an inherited trait (575)

Amino acids = The building blocks of proteins (575)

Brain physiology
    and cultural heredity (469-470)

    and inheritance of behavioral traits (429-430)

    and intelligence research (295-296)

    and mitochondrial replacement therapy (520-521)

    and mosaicism (369-370)

    and Neanderthals (236)

    and neurogenesis (345-347)
Chromosome = A threadlike structure of DNA and proteins. Humans have 23 pairs of chromosomes. (575)

DNA = The double-stranded molecule that encodes genes.

Enzyme = A protein that catalyzes a chemical reaction in the cell, such as breaking down nutrients.

Epigenetic = Related to molecules such as transcription factors and methylation that affect the expression of genes by altering their DNA sequence. (575)

Gene = A segment of DNA that encodes a protein or a functional RNA molecule. (575)

Genome = The complete sequence of DNA in an organism. (575)

Heritability = The proportion of variance in a trait in a population due to genetic variance, measured from 0 to 100 percent. (576)

Meiosis = A type of cell division leading to the development of gametes. (576)

Mitochondria = Fuel-generating organelles inside the cell containing a small amount of DNA. Mitochondria are inherited only through the maternal line. (576)

Mutation = A new genetic variation that arises in a cell and can be inherited by its offspring. (576)

Protein = A long chain of amino acids encoded in a gene. (576)

RNA = A single strand of bases. The production of RNA is a step in the production of proteins, but RNA molecules can also act on their own to catalyze chemical reactions in the cell. (576)

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NOTES (577-598)



INDEX (645-656)
    Brain physiology
    Enlightenment - height (256-257)
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AUTHOR NOTES = Carl Zimmer is an award-winning science writer and writes the Matter column for the New York Times. He is a frequent contributor on NPR's Radiolab and and frequently contributes to The Atlantic, National Geographic, Time, and Scientific American, among others. He has won the American Association for the Advancement of Science's Science Journalism Award three times, among a host of other awards and fellowships. He teaches science writing at Yale University. His books include "Parasite Rex," "Evolution: The Triumph of An Idea," "Soul Made Flesh," and "A Planet of Viruses." Zimmer's books help readers travel to the frontiers of biological research, to discover how scientists are expanding our understanding of the natural world and ourselves.

Zimmer began his career at Discover magazine, where he ended up as a senior editor. After publishing his first book, "At the Water's Edge," Zimmer became a full-time writer, contributing to many magazines including National Geographic, The Atlantic, and Wired. Zimmer began contributing to the New York Times in 2004, and in 2013 he launched "Matter," a weekly column on everything from Neanderthal DNA to the future of life on Earth. Among his awards, Zimmer has earned the National Academies Communication Award and the Stephen Jay Gould Prize. He is a three-time winner of the American Association for the Advancement of Science Journalism Award. Zimmer is --- to his knowledge --- the only writer after whom a species of tapeworm has been named!

SUMMARY = Award-winning, celebrated New York Times columnist and science writer Carl Zimmer presents a profoundly original perspective on what we pass along from generation to generation. The book weaves historical and current scientific research, his own experience with his two daughters, and the kind of original reporting expected of one of the world's best science journalists. Heredity is redefined in this sweeping, resonating overview of a force that shaped human society — a force set to shape our future even more radically: "Extraordinary" -- New York Times Book Review; "Magisterial" -- The Atlantic; "Engrossing" -- Wired; and "Leading contender as the most outstanding nonfiction work of the year" -- Minneapolis Star-Tribune.

BOOK DESCRIPTION = Carl Zimmer's lucid exposition and storytelling provides a new definition of what heredity is. The book is a resounding tour de force that ultimately unpacks urgent bioethical quandaries arising from new biomedical technologies. Also, he analyzes long-standing presumptions about who we really are and what we can pass on to future generations. Even though Charles Darwin played a crucial part in turning heredity into a scientific question, he failed spectacularly to answer it. The birth of genetics in the early 1900s seemed to answer the question precisely.

Gradually, people translated their old notions about heredity into a language of genes. As the technology for studying genes became cheaper, millions of people ordered genetic tests to link themselves to missing parents, to distant ancestors, to ethnic identities... Heredity is not just about genes that pass from parent to child. It continues within our own bodies, as a single cell gives rise to trillions of cells that make up our bodies. We say we "inherit genes" from our ancestors --- using a word that once referred to kingdoms and estates. But actually we inherit other things that matter as much or more to our own lives, from microbes to the technologies that we use to make life more comfortable.

Zimmer writes, "Each of us carries an amalgam of fragments of DNA, stitched together from some of our many ancestors. Each piece has its own ancestry, traveling a different path back through human history. A particular fragment may sometimes be cause for worry, but most of our DNA influences who we are --- our appearance, our height, our penchants --- in inconceivably subtle ways."

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LIBRARY JOURNAL REVIEW = Zimmer (creative writing, Yale Univ.; Soul Made Flesh) has years of experience as a science journalist, and with this book strives to combine his varied research about heredity into one place. Heredity is really the only term to describe the material because Zimmer discusses much more than genes, including the "father of modern genetics" Gregor Mendel and the latest research on microbiomes, along with more controversial topics such as eugenics and genetic engineering. Particularly interesting is the discussion of epigenetics, a system reminiscent of Lamarkism that affects gene expression without altering the DNA itself. Jean-Baptiste Lamarck was a contemporary of Charles Darwin who believed individuals could pass down adaptations acquired during their lifetimes to their descendants. Zimmer makes the science personal by exploring his own family genealogy, DNA, and microbiome. The only drawback of this book, besides its length, is the vagueness of the chapter headings, which reveal little about what each section will hold. VERDICT Overall, Zimmer's latest offers a comprehensive look at all aspects of heredity in readable and accessible text for anyone interested in the topic.-Cate Schneiderman, Emerson Coll., Boston

PUBLISHERS WEEKLY REVIEW = In a magnificent work exploring virtually all aspects of heredity, journalist Zimmer (Parasite Rex), masterfully blends exciting storytelling with first-rate science reporting. Although he lucidly explains the basics of Mendelian genetics-which address inheritance and biological diversity-he goes far beyond that topic to explore the complexities of genetic inheritance. For example he notes that there are at least 800 genes influencing height in humans, but collectively they explain only about one-quarter of the heritability of that trait. Zimmer is not shy about taking on controversial topics like the genetics of race, arguing that there are not genetic fingerprints for race ("Ancient DNA does not simply debunk the notion of white purity. It debunks the very name white"), and making the case that it is currently all but impossible to draw significant conclusions about the roles genes play in overall intelligence. He also probes developing field of epigenetics (changes in gene expression rather than alteration of genetic code) as well as the role of genetics in developmental and cancer biologies. Zimmer's writing is rich, whether he is describing the history of the field or examining the latest research and ethical issues certain to arise. His book is as engrossing as it is enlightening. Agent: Eric Simonoff, WME.

BOOK LIST REVIEW = *Starred Review* When Gregor Mendel died, in 1884, his funeral drew thousands of grieving peasants but not a single scientist. Zimmer here illuminates the Augustinian friar's once-unrecognized scientific breakthrough as a pivotal turning point in a human investigation of heredity, which has replaced Aristotle's speculative conjectures on the topic with the empirical knowledge compiled in the 21st century chromosomal map of the human genome. That map and potent new micro-technologies for manipulating the biochemistry of the mapped genes have opened astonishing possibilities both for probing the distant past of human origins and for creating a brave new future of human development, free from genetic disease and weakness. But alongside this trajectory of stunning progress, readers trace a history of misconceptions about heredity. Some of those misconceptions such as Darwin's mistaken pangenesis theory of all body cells influencing heredity have arguably benefited science by stimulating debate and better research. Others, such as those motivating Nazi eugenicists, have augured only brutal racism. As revolutionary science now opens the prospect of designer "superbabies" tantalizing some, horrifying others Zimmer challenges the widespread misconception that DNA alone determines human identity, adducing compelling evidence that the way genes express themselves depends on environment, nutrition, and even culture. A wide-ranging and eye-opening inquiry into the way heredity shapes our species.--Christensen, Bryce

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[1] An Amazon Best Book of June 2018: Heredity is a lot more complex than most people think. In the book, New York Times columnist Carl Zimmer dives deep into the ways that we pass along our genetic inheritance. Through history, science, and a boatload of personal curiosity (the book originated from questions he had regarding his own child, and he had his entire genome mapped in the process of writing it), Zimmer seeks to retell the story of heredity in broader and more inclusive terms than the ones we are used to hearing. For example, who we become is determined by our ancestors' genes, yes; but it is also a product of our own cells --- because one cell can contribute to millions of future cells. How we treat ourselves, what we learn, and even how we feel, eventually contributes to our hereditary future. The forces at work are myriad, mostly unseen, and subject to variables that we barely understand. Zimmer is trying to help us here, to teach us, and in doing so he succeeds in entertaining us as well. -- Chris Schluep, Amazon Book Review.

[2] "Extraordinary...This book is Zimmer at his best: obliterating misconceptions about science with gentle prose. He brings the reader on his journey of discovery as he visits laboratory after laboratory, peering at mutant mosquitoes and talking to scientists about traces of Neanderthal ancestry within his own genome. Any fan of his previous books or his journalism will appreciate this work. But so, too, will parents wishing to understand the magnitude of the legacy they're bequeathing to their children, people who want to grasp their history through genetic ancestry testing and those seeking a fuller context for the discussions about race and genetics so prevalent today." -- The New York Times Book Review.

[3] "Magisterial...In Zimmer's pages, we discover a world minutely threaded with myriad streams of heredity flowing in all directions, in variegated patterns and different registers." -- The Atlantic.

[4] "The strength of the book is its combination of accuracy, journalistic clarity and scientific authority...If the science doesn't matter to you now, it will soon." -- The Washington Post.

[5] "Zimmer is careful and well-informed... Acquired traits can be inherited. Biological time can turn backward. And monsters are real." -- Wall Street Journal.

[6] "Carl Zimmer's magnum opus, probing myriad strands of science through the prism of decades long, stellar reporting, and a leading contender as the most outstanding nonfiction work of the year…a lush, enthralling book that transforms the reader with its insights." -- Minneapolis Star-Tribune.

[7] "Expansive, engrossing, and often enlightening... Zimmer takes readers on a tale through time and technology, from the inbred Holy Roman Empire to the birthplace of American eugenics to the Japanese lab where scientists are reprogramming skin cells into eggs and sperm." -- Wired.

[8] "A chronicle of timeless values, and the permanent importance of bonds of kinship and the passing of generations in human culture. It is also a stark caution against human hubris, as the early decades of hereditary science show just how much damage science can cause when it's poorly done and unethically applied. Finally, it is a wondrous exposé of the rapid-fire results and advances being made in 21st-century genetics, and the social and cultural consequences that they might unleash." -- National Review.

[9] "Nuanced, entertaining and balances eloquent story-telling with well-researched science... Anyone interested in their path through history, and what they may hand on, will find much to excite them... She Has Her Mother's Laugh is, as promised, a showcase of the powers, perversions and potential of what we truly gain from our past and pass on to our future." -- New Scientist.

[10] "A beguiling narrative… Whatever your views on the power of genes versus other forms of heredity, you will be in for a few surprises." -- Nature.

[11] "Into this zeitgeist enters Carl Zimmer's most enjoyable new book, She Has Her Mother's Laugh, with a sweeping overview of the history of our understanding of heredity… [He is] one of the best science journalists of our time." -- Science

[12] "A magnificent work...Journalist Zimmer masterfully blends exciting storytelling with first-rate science reporting. His book is as engrossing as it is enlightening." -- Publishers Weekly (starred review).

[13] "A thoroughly enchanting tour of big questions, oddball ideas, and dazzling accomplishments of researchers searching to explain, manipulate, and alter inheritance." -- Kirkus Reviews (starred review).

[14] "A wide-ranging and eye-opening inquiry into the way heredity shapes our species." -- Booklist (starred review).

[15] "Zimmer's latest offers a comprehensive look at all aspects of heredity in readable and accessible text for anyone interested in the topic." -- Library Journal.

[16] "This massive, multifaceted account of heredity's history and possible future illuminates the subject as something much more complex than genes passed from generation to generation." -- Shelf Awareness.

[17] "A story filled with palace intrigue and breathtaking innovation." -- O, The Oprah Magazine.

[18] "This is clearly Zimmer's best book. It's an opus in which he goes through the entire history of genetics and epigenetics, and writes about getting his own genome sequenced too. The book is one of the best books ever written about genetics, along with Siddhartha Mukherjee's The Gene. They're the two bookends." -- Science Friday, Best Science Books of 2018.

[19] "A rich and wide-ranging exploration of the mysterious science that makes us, somehow, who we are." -- Jamie Green, Thrillist's Best Books of 2018.

[20] "No one unravels the mysteries of science as brilliantly and compellingly as Carl Zimmer, and he has proven it again with the book — a sweeping, magisterial book that illuminates the very nature of who we are." -- David Grann, author of Killers of the Flower Moon and The Lost City of Z

[21] "The book is at once far-ranging, imaginative, and totally relevant. Carl Zimmer makes the complex science of heredity read like a novel, and explains why the subject has been — and always will be — so vexed." -- Elizabeth Kolbert, author of Pulitzer Prize-winning The Sixth Extinction.

[22] "Humans have long noticed something remarkable, namely that organisms are similar but not identical to their parents—in other words, that some traits can be inherited. From this observation has grown the elegant science of genetics, with its dazzling medical breakthroughs. And from this has also grown the toxic pseudosciences of eugenics, Lysenkoism and Nazi racial ideology. Carl Zimmer traces the intertwined histories of the science and pseudoscience of heredity. Zimmer writes like a dream, teaches a ton of accessible science, and provides the often intensely moving stories of the people whose lives have been saved or destroyed by this topic. I loved this book." -- Robert Sapolsky, Stanford University, author of Behave.

[23] "The book is a masterpiece --- a career-best work from one of the world's premier science writers, on a topic that literally touches every person on the planet." -- Ed Yong, author of I Contain Multitudes.

[24] "Nobody writes about science better than Carl Zimmer. As entertaining as he is informative, he has a way of turning the discoveries of science into deeply moving human stories. This book is a timely account of the uses and misuses of some of the science that directly impact our lives today. It is also a career moment by one of our most important and graceful writers. Here is a book to be savored." -- Neil Shubin, University of Chicago, author of Your Inner Fish.

[25] "Zimmer is a born story-teller. Or is he an inherited story-teller? The inspiring and heartbreaking stories in the book build a fundamentally new perspective on what previous generations have delivered to us, and what we can pass along. An outstanding book and great accomplishment." -- Daniel Levitin, author of This is Your Brain on Music and The Organized Mind.

[26] "One of the most gifted science journalists of his generation, Carl Zimmer tells a gripping human story about heredity from misguided notions that have caused terrible harm to recent ongoing research that promises to unleash more powerful technologies than the world has ever known. The breadth of his perspective is extraordinarily compelling, compassionate, and valuable. Please read this book now." -- Jennifer Doudna, UC Berkeley, coauthor of A Crack in Creation.

[27] "Carl Zimmer lifts off the lid, dumps out the contents, and sorts through the pieces of one of history's most problematic ideas: heredity. Deftly touching on psychology, genetics, race, and politics, She Has Her Mother's Laugh is a superb guide to a subject that is only becoming more important. Along the way, it explains some remarkably complicated science with equally remarkable clarity—a totally impressive job all around." -- Charles C. Mann, author of 1491: New Revelations of the Americas Before Columbus.

[28] "Carl Zimmer is not only among my favorite science writers — he is also now responsible for making me wonder why there is more Neanderthal DNA on earth right now than when Neanderthals were here, and why humanity is getting taller and smarter in the last few generations. The book explains how our emerging understanding of genetics is touching almost every part of society, and will increasingly touch our lives." -- Charles Duhigg, author of Smarter Faster Better and The Power of Habit.

[29] "With this book, Carl Zimmer rises from being our best biological science writer to being one of our very best non-fiction writers in any field, period." -- Kevin Padian, professor of integrative biology, UC Berkeley.

[30] "How every characteristic — from genes to personality — is passed down from one generation to the next is one the most fundamental, complex, misunderstood and misused enigmas of biology. In this beautifully written, heartfelt and enjoyable masterpiece, Zimmer weaves together history, autobiography and science to elucidate the mysteries of heredity and why we should care. I couldn't put this book down, and can't recommend it too highly." -- Daniel E. Lieberman, Harvard University, author of The Story of the Human Body.

[31] "The book is at once enlightening and utterly compelling. Carl Zimmer weaves spellbinding narrative with luminous science writing to give us the story of heredity, the story of us all. Anyone interested in where we came from and where we are going — which is to say everyone — will want to read it." -- Jennifer Ackerman, author of The Genius of Birds and Chance in the House of Fate.

[32] "Traversing time and societies, the personal and the political, the moral and the scientific, the book takes readers on an endlessly mesmerizing journey of what it means to be human. Carl Zimmer has created a brilliant canvas of life that is at times hopeful, at times horrifying, and always beautifully rendered. I could hope for no better guide into the complexities, perils, and, ultimately, potential of what the science of heredity has in store for the world." -- Maria Konnikova, author of The Confidence Game

[ 33] "With his latest work, Zimmer has assured his place as one of the greatest science writers of our time. The book is an extraordinary exploration of a topic that is at once familiar and foreign, and touches every one of us. With the eloquence of a poet and the expertise of a scientist Zimmer has created a nonfiction thriller that will change the way you think about your family, those you love, and the past and future." -- Brian Hare, Duke University, coauthor of The Genius of Dogs

[34] "Zimmer offers a compelling look at genetics...You will leave this book realizing how little we know about how we come to be." -- Bitch Media

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[1] ScienceReadingGal - A solid step toward reforming outdated and narrow notions of heredity = Public understanding of heredity has profound consequences for many dimensions, including research funding, toxicology, medicine, regulation, and even warfare. For example, warped views of heredity fueled ideologies that killed tens of millions in WWII and more recently has funneled the bulk of precious research dollars into the ridiculously shallow box of genetic causation for today's public health crises. Because our limited views of heredity need a sweeping update, I give this book 5 stars for its scope, ambition, and exquisite quality of execution. It takes us a solid step in the right direction, and will greatly enrich public dialogue.

Sadly, the book does falter in one key area: Zimmer's weak treatment of epigenetic inheritance. First, he mistakenly calls it a "new flavor of Lamarckism," which is incorrect. The research in this area largely involves direct exposures to early germ cells, and the heritable consequences thereof, and not with some fluffy idea about "acquired characteristics" wending their way into the germline. Moreover, while Zimmer briefly mentions nutrition, plasticizers, and pesticides as exposures that may influence nongenetic germline-borne heredity, he altogether ignores the compelling and deeply troubling evidence of generational pathology caused by the toxic pregnancy drug diethylstilbestrol (DES). How he could have overlooked heritable consequences of the greatest medical catastrophe of our age, yet decide to devote 2/3 of a page to an uber-skeptic like Kevin Mitchell is beyond me. But fear not, good readers, the other 99.99% of the book is outstanding and deserves your attention.

[2] bpathakjee - The book reads like a well crafted Novel = Herr Zimmer does it again ! I have been his fan since his earlier book on E coli. Average readers without biology backgrounds need not get intimidated by length of the book. The book reads like a well-crafted novel. He explains complex concepts in very simple words interspersed with human interest stories. This book covers new material and has a different approach compared to Dr. Siddhartha Mukherjee's popular book, Gene.The extensive Bibliography is helpful for further reading. This work represents science writing at its best.

[3] R. Kuehni - Make sure you read Part V in detail = It is not quite clear for what group of people it was written: a little too complex and lacking illustrations for generalists and a little too generalized for experts. I agree with the reviewer who suggests that a potential purchaser/reader might want to look at some parts of an electronic version to be able to form an opinion if the book is for him/her. What I found most surprising in the existing reviews is that nobody seems to address the content of Part 5, the development and usage of CRISPR and related technology. It has the potential of changing humanity for better or for worse and it is up to humans to decide which direction to take, in a general way as the decision or lack of it to control earth's surface temperature. It is a subject that should be studied and discussed much more by the general public. People can learn about the problems and opportunities in this book.

[4] Amazon Customer - Vital reading for young couples = I am not a professional academic. I purchased it based on an amazing consensus of notable biologists recomendations. I was not disappointed other than the fact that it finally ended in Chapter 19. I kept wanting more. To me it is the history and future of life on our planet. I am in my late 60's. The ground Zimmer covers in his historical narratives struck me personally as amazing. Such a diverse accounting of past personnages. I figured that Pearl S. Buck could never play a part in such a book: surprise! But the up-to-date timeliness is really what makes it so important. Hope one gets to read it and give to younger folk as it's lessons are vital for a proper perspective on future progeny. Wife and I already purchased and gave away to 4 couples in the 30's age group.

[5] Orange Monkey - What an insanely great book! = Some books just grip you by the throat and won't let go. This one does that. But in a nice way. I was just going to look something up that I had read about in a book review in New Scientist, and then I just could not stop. Incredibly interesting material, and told in a way that on top of the enjoyment and delight I feel, I also feel a sting of jealousy. Oh man how I wish I could write like that. Superior storytelling, it's at the level of, and at times surpasses that of Malcolm Gladwell due to the mastery of such an interesting area. Enjoy!

[6] Doctor who is an avid reader - Although Zimmer's detailed telling of the story of hereditary was a wonderful read for me, 3 areas were outstanding and explained clearly: 1. the obsession of European royalty with blood lines and the problems it led to as typified by the Habsburgs, 2. Epigenetics and how genes can be turned on and off, including how diet and pollutants can affect the epigenome and CRISPR mechanism that enables CRISPR produced enzymes to bind to a specific DNA segment, cut it and thus shutting off the gene. Many years have passed since my first lesson in genetics was a black and white movie of Theodosius Dobzhansky explaining the basics of genetics. A lot has changed since then! Carl Zimmer's recent book can bring everyone up to date even if they started learning about genetics long after Dr. Dobzhansky died in 1975. Dr. Dobzhansky would find this book an enlightening read of everything that has happened since his death, I did and you will too.

[7] B Brown = The book could have been better and easier to understand if it had been accompanied by drawings and diagrams. There are none in this book. But the book is well-written with fascinating stories.

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The worst scares of my life have usually come in unfamiliar places. I still panic a bit when I remember traveling into a Sumatran jungle only to discover my brother, Ben, had dengue fever. I lose a bit of breath any time I think about a night in Bujumbura when a friend and I got mugged. My fingers still curl when I recall a fossil-mad paleontologist leading me to the slick mossy edge of a Newfoundland cliff in search of Precambrian life. But the greatest scare of all, the one that made the world suddenly unfamiliar, swept over me while I was sitting with my wife, Grace, in the comfort of an obstetrician's office.

Grace was pregnant with our first child, and our obstetrician had insisted we meet with a genetics counselor. We did not see the point. We felt untroubled in being carried along into the future, wherever we might end up. We knew Grace had a second heartbeat inside her, a healthy one, and that seemed enough to know. We did not even want to find out if the baby was a girl or a boy. We would just debate names in two columns: Liam or Henry, Charlotte or Catherine.

Still, our doctor insisted. And so one afternoon we went to an office in lower Manhattan, where we sat down with a middle-aged woman, perhaps a decade older than us. She was cheerful and clear, talking about our child's health beyond what the thrum of a heartbeat could tell us. We were politely cool, wanting to end this appointment as soon as possible.

We had already talked about the risks we faced starting a family in our thirties, the climbing odds that our children might have Down syndrome.

We agreed that we would deal with whatever challenges our child faced. I felt proud of my commitment. But now, when I look back at my younger self, I am not so impressed. I didn't know anything at the time about what it is who were doing just that. Through them, I would get a glimpse of that life: of round after round of heart surgeries, of the struggle to teach children how to behave with outsiders, of the worries about a child's future after one's own death.

But as we sat that day with our genetics counselor, I was still blithe, still confident. The counselor could tell we did not want to be there, but she managed to keep the conversation alive. Down syndrome was not the only thing expectant parents should think about, she said. It was possible that the two of us carried genetic variations that we could pass down to our child, causing other disorders. The counselor took out a piece of paper and drew a family tree, to show us how genes were inherited.

"You do not have to explain all that to us," I assured her. After all, I wrote about things like genes for a living. I didn't need a high school lecture.

"Well, let me ask you a little about your family," she replied.

It was 2001. A few months beforehand, two geneticists had come to the White House to stand next to President Bill Clinton for an announcement. "We are here to celebrate the completion of the first survey of the entire human genome," Clinton said. "Without a doubt, this is the most important, most wondrous map ever produced by humankind."

The "entire human genome" that Clinton was hailing did not come from any single person on Earth. It was an error-ridden draft, a collage of genetic material pieced together from a mix of people. And it had cost $3 billion. Rough as it was, however, its completion was a milestone in the history of science. A rough map is far better than no map at all. Scientists began to compare the human genome to the genomes of other species, in order to learn on a molecular level how we evolved from common ancestors. They could examine the 20 thousand--odd genes that encode human proteins, one at a time, to learn about how they helped make a human and how they helped make us sick.

In 2001, Grace and I couldn't expect to see the genome of our child, to examine in fine detail how our DNA combined into a new person. We might as well have imagined buying a nuclear submarine. Instead, our genetics counselor performed a kind of verbal genome sequencing. She asked us about our families. The stories we told her gave her hints about whether mutations lurked in our chromosomes that might mix into dangerous possibilities in our child.

Grace's story was quick: Irish, through and through. Her ancestors had arrived in the United States in the early twentieth century, from Galway on one side, Kerry and Derry on the other. My story, as far as I understood it, was a muddle. My father was Jewish, and his family had come from eastern Europe in the late 1800s. Since Zimmer was German, I assumed he must have some German ancestry, too. My mother's family was mostly English with some German mixed in, and possibly some Irish — although a bizarre family story clattered down through the generations that our ancestor who claimed to be Irish was actually Welsh, because no one would want to admit to being Welsh. Oh, I added, someone on my mother's side of the family had definitely come over on the Mayflower. I was under the impression that he fell off the ship and had to get fished out of the Atlantic.

As I spoke, I could sense my smugness dissolving at its margins. What did I really know about the people who had come before me? I could barely remember their names. How could I know anything about what I had inherited from them?

Our counselor explained that my Jewish ancestry might raise the possibility of Tay-Sachs disease, a nerve-destroying disorder caused by inheriting two mutant copies of a gene called HEXA. The fact that my mother wasn't Jewish lowered the odds that I had the mutation. And even if I did, Grace's Irish ancestry probably meant we had nothing to worry about.

The more we talked about our genes, the more alien they felt to me. My mutations seemed to flicker in my DNA like red warning lights. Maybe one of the lights was on a copy of my HEXA gene. Maybe I had others in genes that scientists had yet to name, but could still wreak havoc on our child. I had willingly become a conduit for heredity, allowing the biological past to make its way into the future. And yet I had no idea of what I was passing on.

Our counselor kept trying to flush out clues. Did any relatives die of cancer? What kind? How old were they? Anyone have a stroke? I tried to build a medical pedigree for her, but all I could recall were secondhand stories. I recalled William Zimmer, my father's father, who died in his forties from a heart attack — I think a heart attack? But didn't an old cousin once tell me about rumors of overwork and despair? His wife, my grandmother, died of some kind of cancer, I knew. Was it her ovaries, or her lymph nodes? She had died years before I was born, and no one had wanted to burden me as a child with the oncological particulars.

How, I wondered, could someone like me, with so little grasp of his own heredity, be permitted to have a child? It was then, in a panic, that I recalled an uncle I had never met. I didn't even know he existed until I was a teenager. One day my mother told me about her brother, Harry, how she would visit Harry's crib every morning to say hello. One morning, the crib was empty.

The story left me flummoxed, outraged. It wouldn't be until I was much older that I'd appreciate how doctors in the 1950s ordered parents to put children like Harry in a home and move on with their lives. I had no grasp of the awkward shame that would make those children all the more invisible.

I tried to describe Uncle Harry to our genetics counselor, but I might as well have tried sketching a ghost. As I blathered on, I convinced myself that our child was in danger. Whatever Harry had inherited from our ancestors had traveled silently into me. And from me it had traveled to my child, in whom it would cause some sort of disaster.

The counselor didn't look worried as I spoke. That irritated me. She asked me if I knew anything about Harry's condition. Was it fragile X? What did his hands and feet look like?

I had no answers. I had never met him. I had never even tried to track him down. I suppose I had been frightened of him gazing at me as he would at any stranger. We might share some DNA, but did we share anything that really mattered?

"Well," the counselor said calmly, "fragile X is carried on the X chro- mosome. So we don't have to worry about that."

Her calmness now looked to me like sheer incompetence. "How can you be so sure?" I asked.

"We would know," she assured me. "How would we know?" I demanded.

The counselor smiled with the steadiness of a diplomat meeting a dictator. "You would be severely retarded," she said.

She started to draw again, just to make sure I understood what she was saying. Women have two X chromosomes, she explained, and men have one X and one Y. A woman with a fragile X mutation on one copy of her X chromosome will be healthy, because her other X chromosome can compensate. Men have no backup. If I carried the mutation, it would have been obvious from when I was a baby.

I listened to the rest of her lesson without interrupting.

A few months later, Grace gave birth to our child, a girl as it turned out. We named her Charlotte. When I carried her out of the hospital in a baby seat, I couldn't believe that we were being entrusted with this life. She did not display any sign of a hereditary disease. She grew and thrived. I looked for heredity's prints on Charlotte's clay. I inspected her face, aligning photos of her with snapshots of Grace as a baby. Sometimes I thought I could hear heredity. To my ear, at least, she has her mother's laugh.

As I write this, Charlotte is now fifteen. She has a thirteen-year-old sister named Veronica. Watching them grow up, I have pondered heredity even more. I wondered about the source of their different shades of skin color, the tint of their irises, Charlotte's obsession with the dark matter of the universe, or Veronica's gift for singing. ("She did not get that from me." "Well, she certainly did not get it from me.")

Those thoughts led me to wonder about heredity itself. It is a word that we all know. Nobody needs an introduction to it, the way we might to mei- osis or allele. We all feel like we're on a first name basis with heredity. We use it to make sense of some of the most important parts of our lives. Yet it means many different things to us, which often don't line up with each other. Heredity is why we are like our ancestors. Heredity is the inheritance of a gift, or of a curse. Heredity defines us through our biological past. It also gives us a chance at immortality by extending heredity into the future.

I began to dig into heredity's history, and ended up in an underground palace. For millennia, humans have told stories about how the past gave rise to the present, how people resemble their parents--or, for some reason, do not. And yet no one used the word heredity as we do today before the 1700s. The modern concept of heredity, as a matter worthy of scientific investigation, didn't gel for another century after that. Charles Darwin helped turn it into a scientific question, a question he did his best to answer. He failed spectacularly. In the early 1900s, the birth of genetics seemed to offer an answer at last. Gradually, people translated their old notions and values about heredity into a language of genes. As the technology for studying genes grew cheaper and faster, people became comfortable with examining their own DNA. They began to order genetic tests to link themselves to missing parents, to distant ancestors, to racial identities. Genes became the blessing and the curse that our ancestors bestowed on us.

But very often genes cannot give us what we really want from heredity. Each of us carries an amalgam of fragments of DNA, stitched together from some of our many ancestors. Each piece has its own ancestry, traveling a different path back through human history. A particular fragment may sometimes be cause for worry, but most of our DNA influences who were are--our appearance, our height, our penchants--in inconceivably subtle ways.

While we may expect too much from our inherited genes, we also don't give heredity the full credit it's due. We've come to define heredity purely as the genes that parents pass down to their children. But heredity continues within us, as a single cell gives rise to a pedigree of trillions of cells that make up our entire bodies. And if we want to say we inherit genes from our ancestors--using a word that once referred to kingdoms and estates--then we should consider the possibility that we inherit other things that matter greatly to our existence, from the microbes that swarm our bodies to the technology we use to make life more comfortable for ourselves. We should try to redefine the word heredity, to create a more generous definition that's closer to nature than to our demands and fears.

I woke up one bright September morning and hoisted Charlotte, now two months old, from her crib. As Grace caught up on her sleep, I carried Charlotte to the living room, trying to keep her quiet. She was irascible, and the only way I could calm her was to bounce her in my arms. To fill the morning hours, I kept the television on: the chatter of local news and celebrity trivia, the pleasant weather forecast, a passing report of a small fire in an office at the World Trade Center.

Having been a father for all of two months had made me keenly aware of the ocean of words that surrounded my family. They flowed from our television and from the mouths of friends; they looked up from newspapers and leaped down from billboards. For now, Charlotte could not make sense of these words, but they were washing over her anyway, molding her developing brain to take on the capacity for language. She would inherit English from us, along with the genes in her cells.

She would inherit a world as well, a human-shaped environment that would help determine the opportunities and limits of her life. Before that morning, I felt familiar with that world. It would boast brain surgery and probes headed for Saturn. It would also be a world of spreading asphalt and shrinking forests. But the fire grew that morning, and the television hosts mentioned reports that a plane had crashed into it. I rocked Charlotte as the television wove between ads and cooking tips and a second plane crashing into the second tower. The day mushroomed into catastrophe.

Charlotte's fussing faded into sleepy comfort. She looked up at me and I down at her. I realized how consumed I had become with wondering what versions of DNA she might have inherited from me. I kept my arms folded tightly around her, wondering now what sort of world she was inheriting.

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