1432 27 MARCH 2020 • VOL 367 ISSUE 6485 SCIENCEPHOTO: CAVAN-IMAGES/SHUTTERSTOCK.COME
ach December for decades now, I’ve
spent a few days in Pacific Grove, Cali-
fornia, attending the Asilomar Chro-
matin, Chromosomes, and Epigenetics
Conference. Before reading Neil Shu-
bin’s Some Assembly Required, how-
ever, I never knew that the city’s first female
mayor, Julia Platt, was also an accomplished
embryologist. Having been shut out of aca-
demic positions, which were, at the turn of
the 20th century, seldom given to women,
she pivoted instead to politics, where her
legacy includes the establishment of a ma-
rine protected area in California’s Monterey
Bay. This anecdote is one of many intimate
and thoughtful stories t ucked into the pages
of this brief overview of Earth’s 4 billion
years of evolution.
Shubin, an accomplished paleontologist
and evolutionary biologist, begins his his-
tory in Victorian England, which, he writes,
“was a crucible for enduring ideas and dis-
coveries.” “There is something poetic to theEVOLUTIONARY BIOLOGYBy Michael A. Goldman notion that knowing how DNA works in the
history of life relies on ideas developed dur-
ing an age when people didn’t know that
genes even existed,” he continues.
Here, he relates the story of St. George
Jackson Mivart, apprentice to Thomas Henry
Huxley. Mivart, we learn, although
initially a supporter of Darwin’s
theory of evolution, became a vo-
cal critic, focusing on “the incom-
petency of natural selection to
account for the incipient stages of
useful structures.” Darwin would
respond to this criticism in the
1872 edition of On the Origin of
Species, arguing that “This subject
is intimately connected with that
of the gradation of the characters,
often accompanied by a change of
function.” These words, Shubin writes, “con-
tain the seeds for a new way of seeing major
transitions in the history of life.”
Among the exciting topics covered in
Shubin’s sweeping evolutionary history are
the transition to land-living animals, the
origins of flight, the race for the double he-
lix, and anecdotes from pioneering work in
molecular evolution and gene regulation.
He recounts the discovery of repetitive DNAsequences and Barbara McClintock’s trans-
posable elements, and he explores Rich-
ard Goldschmidt’s controversial “hopeful
monsters” hypothesis of macroevolution.
We learn that Lynn Margulis submitted
her dogma-defying endosymbiosis work to
15 journals before her insights were recog-
nized—some assembly required, indeed.
Shubin also recounts the charming story
of Susumu Ohno, the Japanese American
geneticist whose research confirmed that
gene duplication played a critical role in
molecular evolution. Ohno, we learn, pains-
takingly weighed paper cutouts of chromo-
somes from different mammalian species
and found that, although the chromosome
numbers differed widely, the estimated
total amount of DNA was similar in each
case. When he moved on to salamanders,
however, he was in for a surprise. Some had
genomes far larger than those of humans.
“With his cardboard cutouts, Ohno discov-
ered something that billions of dollars of
genome projects were to confirm decades
later,” writes Shubin.
Shubin argues that if we were to rerun
the course of evolution multiple times, the
results would most likely be the same. He re-
fers to this as the inevitability of evolution,
which stands in opposition to the theory that
evolution is based on chance events, the out-
come of which is contingent on specific con-
ditions. But the experimental observations
on which Shubin bases his argument—some
of which originated in his own research—
were made at the microscale. As Blount et al.
have pointed out, “... repeatability is common
when the founding populations are closely
related, perhaps resulting from
shared genetics and developmen-
tal pathways, whereas different
outcomes become more likely as
historical divergences become
greater” ( 1 ). Furthermore, no
experiments have yet accounted
for cataclysmic events such as
the Cretaceous-Paleogene ex-
tinction event.
One of the book’s best features
is a 30-page notes section at the
end, in which each note could be
fodder for an entire volume. These notes
are separated by chapter, and many tell a
short, engaging story, often accompanied by
annotated suggestions for further reading.
Readers will want to peruse this section and
follow up on some of those readings. jREFERENCES AND NOTES- Z. D. Blount, R. E. Lenski, J. B. Losos, Science 362 ,
eaam5979 (2018).
10.1126/science.aba6134
Hemingway’s six-toed “mitten” cats offer clues
about how the genome assembles a body.Engaging anecdotes add intimacy to tales of Earth’s
4 billion years of evolution
BOOKS et al.
The reviewer is at the Department of Biology, San Francisco
State University, San Francisco, CA 94132, USA.
Email: [email protected]Some Assembly
Required
Neil Shubin
Pantheon, 2020. 288 pp.Evolution gets personal
INSIGHTS