Summary of David Quammen's The Tangled Tree

Everest Media

Description

Please note: This is a companion version & not the original book.
Sample Book Insights:
#1 Charles Darwin kept a secret notebook that he used to record his wildest ideas. He believed that the forms of living creatures weren’t eternally stable, but had changed over time.
#2 Darwin had begun thinking about evolution, and had begun writing down his ideas in a notebook. He had read Zoonomia, a medical treatise written by his grandfather, which contained some provocative musings about how all warm-blooded animals had evolved from one living filament.
#3 Darwin was a young man when he began writing about his ideas on evolution. He noticed patterns in the world around him, and he wondered if there was a law of adaptation at work.
#4 The tree of life was a venerable idea in 1837, and Darwin could adapt it to his purposes as an evolutionary theorist. He drew a sketch of a three-branched coral of life, with the inanimate lower sections.

Sujets

• Life Sciences
• Sciences et techniques
• Genomics
• Genetics
• Science

Informations

• Publié par: Everest Media LLC
• Date de parution: 20 août 2022
• Nombre de lectures: 0
• EAN13: 9798350015829
• Langue: English
• Poids de l'ouvrage: 1 Mo

Extrait

Insights on David Quammen's The Tangled Tree
Contents Insights from Chapter 1 Insights from Chapter 2 Insights from Chapter 3 Insights from Chapter 4 Insights from Chapter 5 Insights from Chapter 6 Insights from Chapter 7
Insights from Chapter 1

#1

Charles Darwin kept a secret notebook that he used to record his wildest ideas. He believed that the forms of living creatures weren’t eternally stable, but had changed over time.

#2

Darwin had begun thinking about evolution, and had begun writing down his ideas in a notebook. He had read Zoonomia, a medical treatise written by his grandfather, which contained some provocative musings about how all warm-blooded animals had evolved from one living filament.

#3

Darwin was a young man when he began writing about his ideas on evolution. He noticed patterns in the world around him, and he wondered if there was a law of adaptation at work.

#4

The tree of life was a venerable idea in 1837, and Darwin could adapt it to his purposes as an evolutionary theorist. He drew a sketch of a three-branched coral of life, with the inanimate lower sections.

#5

The tree of life is an ancient poetic image that has been used in Western thought for centuries. It was first used by Aristotle in his History of Animals, and was later modified by the Swiss naturalist Charles Bonnet in 1745.

#6

The linear approach to depicting life’s diversity was being replaced by its more complex and dimensional successor, the tree. By the late eighteenth century, natural philosophers tried to classify and arrange living creatures into distinct groups and subgroups, reflecting their similarities and differences.

#7

The tree of life was an old symbol by the 1800s, and it was also used to organize biology. It was not meant to imply that all plants had descended from common ancestors by some sort of material process of transformation.

#8

Linnaeus’s Systema Naturae, published in 1735, was a unique and peculiar thing: a big folio volume of barely more than a dozen pages, like a coffee-table atlas, in which he outlined a classification system for all the members of what he considered the three kingdoms of nature: plants, animals, and minerals.

#9

Linnaeus’s system of plant classification was more innovative, comprehensive, and orderly than Augier’s. It was based on the number, size, and arrangement of stamens, and he named twenty-three classes, into which he placed all the flowering plants.

#10

The tree of life was changing, and it was reflecting a challenge to faith. It met strong resistance. The idea was coming soon, and it would change the way we view evolution.

#11

Lamarck’s tree of dots, which depicted animal diversity, was a branched diagram that descended down the page. The secret shape was a tree. In his book Philosophie Zoologique, he included a separate ladder for animals, which showed an ascending series of forms.

#12

Edward Hitchcock was a counterpoint to Lamarck, as he offered a last pre-evolutionary tree in the decades before Darwin changed everything. He was a devout, driven New England Yankee, and his Paleontological Chart reflected his view of humans as the apogee of creation.

#13

Hitchcock was a hypochondriac who was constantly feeling death near him, but he lived to be seventy. He was a pastor for the rest of his life, and he taught chemistry and natural history at Amherst College.

#14

Charles Lyell’s books took readers onto a slippery slope, towards a theory of evolution. In 1840, seven years after Lyell’s third volume appeared, Hitchcock published his own Elementary Geology, and with it that Paleontological Chart of Lombardy poplars.

#15

Darwin realized that offspring tend to resemble their parents and grandparents, and that variation exists. He then realized that population growth always outstrips the available means of subsistence, and that this leads to competition and deprivation.

#16

Darwin’s theory of natural selection was based on three principles: grandchildren like grandfathers, the tendency to small change, and great fertility in proportion to support of parents. He saw how they fit together, and how they accounted for differential survival.

#17

The delay between the writing of those four lines in his secret E notebook and the first public announcement of Darwin’s theory was because he was a poor man’s son working his way through the tropics by selling decorative specimens. He didn’t have the connections or education that Darwin had.

#18

The theory was presented as a pastiche of Wallace’s paper plus excerpts from Darwin’s unpublished writings before a British scientific club in the summer of 1858. It made no impression on anyone.

#19

The tree simile in The Origin of Species was a paragraph long and ended with how evolution is similar to a tree, with branches that diverge and grow horizontally.

#20

The tree figure, which was the best graphic representation of life’s history, evolution through time, the origins of diversity and adaptation, was suddenly wrong.
Insights from Chapter 2

#1

The genetic code is written in an alphabet of four letters, each letter representing a component of the DNA double helix. The four letters are: A, C, G, and T. DNA’s full name is deoxyribonucleic acid.

#2

There are four kinds of molecule essential to living processes: carbohydrates, lipids, nucleic acids, and proteins. Proteins are linear chains of amino acids, folded upon themselves into elaborate secondary structures. They serve a wide range of structural, catalyzing, and transporting functions.

#3

By the mid-1950s, Crick was back in England, and he had a contract with the Medical Research Council, a government agency with some mandate for fundamental as well as medical research. He was not an experimentalist, but a theoretician. He was sharing his office, pub lunches, and conversations with another scientist, Sydney Brenner.

#4

The idea of using molecular phylogenetics to draw evolutionary histories was first suggested by Crick in a paper he wrote with Watson in 1953. He didn’t use the words molecular phylogenetics, but that’s what he was getting at.

#5

Several other scientists began working on the same idea at around the same time. They called it chemical paleogenetics and they all converged on it by different routes.

#6

The molecular clock is the idea that the minor changes in molecular variants are proportional to elapsed time over the eons, and it has been called one of the simplest and most powerful concepts in the field of evolution. It has been controversial, however.

#7

Zuckerkandl and Pauling helped launch a new scientific enterprise, and when a Journal of Molecular Evolution came into being, in 1971, they were its first editors in chief. Their name isn’t familiar to the wider world, but if you say Zuckerkandl and Pauling to a molecular biologist today, he or she will think molecular clock.

#8

The molecular clock was not yet something that interested Woese, but he was interested in the genetic code and how it had evolved. He knew that a team led by Marshall Nirenberg had made better progress with an experimental approach than the RNA Tie Club had with collegial theorizing.

#9

The genetic code is the central biological concern of Woese. He understood that life could not have progressed beyond its simplest primordial forms without a translation system for applying the information in DNA. He wanted to understand not just how that decoding mechanism worked, but also how it had come into being roughly four billion years ago.

#10

On June 24, 1969, Woese wrote a letter to Francis Crick in Cambridge, asking for his moral support, as he was about to make what for him was an important and nearly irreversible decision: to unravel the course of events leading to the origin of the simplest cells.

#11

The components of the translation apparatus are the ribosomes, which are found in all cells and translate genetic information into proteins. Woese wanted to understand how the genetic code itself might have evolved.

#12

The translation apparatus is made up of ribosomes, which are the smallest identifiable structures within a cell. They function as assembly mechanisms taking in genetic information and producing proteins.

#13

Woese saw the secret truth that RNA, not just a molecule, is really more interesting and dynamic than its famed counterpart, DNA. He wanted to use ribosomal RNA as the ultimate molecular fossil record. He needed a lab set up for reading at least portions of the ribosomal RNA.

#14