CHARLES DARWIN
THE ORIGIN OF SPECIES BY MEANS OF
NATURAL SELECTION
Compiled by Lorraine Kuun
In a corner inside Westminster abbey there is a flagstone
with the following inscription:
CHARLES ROBERT DARWIN.
Born 12 February, 1809.
Died 19 April, 1882.
Thousands of tourists walk over this stone; close by
there are also stones commemorating Faraday, Herschel
and Maxwell, as well as a statue of Sir Isaac Newton.
However, in the small bookshop there is not a single
copy of The Origin of Species …
Where did it all start?
Darwin was born as the
grandson of two famous
people: his grandfather
Erasmus Darwin was a wellknown medical doctor, poet and
scientist
He was also the author of a book,
Zoonomia, that referred to
evolution, amongst other things.
Darwin grew up in a privileged,
intellectual environment
His other grandfather, Josiah Wedgwood,
was the man who created the famous
Wedgwood pottery.
Both his grandfathers were rich, intelligent
and interested in scientific matters.
Darwin’s mother, Susannah, died when he
was just eight years old.
He was the fifth child, and pampered by his older
sisters. He got on well with his older brother, Eras.
Always a loner …
• Darwin had a lonely childhood. His mother’s
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death affected him profoundly; his deeply
depressed father forbid any mention of her
name.
His older sister tutored him at home until he
started school at 8. He did not like the classical
education as he was more interested in being
out in nature.
Went for long solitary walks and started
collecting objects of nature.
The little boy was a keen naturalist
at an early age …
• At the age of 11 he was
painted with a pot plant in his
arms – a sign of his interest in
Nature?
• He and his older brother, Eras,
had their own home laboratory
where they performed
experiments (and caused one
or two explosions!).
• He also was a keen collector of
beetles – the Victorians almost
had an obsession with
“beetling”.
Charles the student …
• His father wanted him to become a doctor; he did study
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in Edinburgh, but did not like the work and never
qualified.
His biggest interests were hunting and shooting. Got on
well with fellow-students.
Joined Plinian Society whose members read papers on
Natural History to each other.
His father, Robert, then decided Charles should study to
enter Church.
Spent more time collecting beetles than studying. Only
said yes to church because it would give him the
opportunity to continue his studies of nature.
The student gets some direction
and the table is set.
• Met John Henslow,
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professor of Botany.
Opened Darwin’s (21)
eyes to wonders of
Botany.
Graduated from
Cambridge in 1831.
Received invitation to
accompany Fitzroy on
Beagle via Henslow.
Role of Wedgwoods in his life
• Had to convince father of wisdom/ benefit of trip
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to South America.
Uncle Josiah helped him to answer all of father’s
objections.
Cousins were friends and one of them, Emma,
would later become his wife.
The letters of cousins sustained him during long
trip, at times a very lonely adventure.
The captain and the ship…
• Captain Robert Fitzroy in
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command of ship HMS
Beagle since 1831.
Order from admiralty to
chart coastline of South
America and islands,
specifically Patagonia and
around Cape
Need naturalist to make
observations and collect
material, as well as to act
as gentleman companion.
Henslow proposed young
Charles Darwin.
The voyage that started everything…
• Darwin and Fitzroy “clicked” immediately; Darwin had to share
captain’s living quarters as “gentleman” – the class-conscious
Victorian society ruled even here.
• Left on 27 December 1831 – Darwin immediately seasick.
• First port of call the Canaries, then Bahia (now Salvador), moved
down coast towards southern point. Darwin collected specimens
and studied natural environment.
Darwin began reading …
• Darwin received Lyell’s
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book on geology as gift
from Fitzroy (Principles of
Geology). (Lyell later
became a lifelong friend.)
Darwin made notes of
everything he saw, made
drawings and collected
specimens.
He and Fitzroy talked and
argued for hours on matters
related to the environment,
geology and
True to tradition the names
of officers, royals etc. given
to mountains, rivers and sea
passages.
DARWIN’S PASSAGE
MNT
FITZROY
Darwin slowly started to think …
• Earthquake on west
coast of South America
made Darwin realise
how natural geological
processes can gradually
change the appearance
of the earth.
• He also collected fossils
from the area.
• At last they were on
their way to the
Galapagos Islands.
GALAPAGOS
A WORLD ON ITS OWN
• The Galapagos Islands
•
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were named after the
giant tortoises found
there by the earliest
seafarers.
It is a group of volcanic
islands on the equator on
the west coast of South
America.
The islands are still
changing and today serve
as a living laboratory to
study evolution and
changes on earth.
GALAPAGOS
where everything began
• However dramatic it may
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sound, Darwin did not
immediately thought of
evolution and natural
selection.
He did realise that the earth
was much older than
previously thought, and that
changes took place slowly
over long periods of time.
Fossils in mountainous areas
therefore not a result of the
Biblical flood, but because of
geological events.
• He also realised that the
environment played a role
in speciation.
The voyage is almost over
• The voyage of The Beagle
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would last 5 years in the
end, and included
Australia, New Zealand
and Cape Town, South
Africa.
Darwin’s observations
and preserved specimens
were sent to Cambridge
from time to time.
Darwin wrote long letters
to Henslow with detailed
descriptions and
observations.
DARWIN’s reputation made well in
advance
• Henslow read Darwin’s
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•
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notes and letters to
interested friends at the
Royal Society .
He also organized
exhibitions of Darwin’s
preserved specimens, and
made sure that they were
classified and restored
where necessary.
Darwin’s name as scientists
was made by Henslow by
the time he returned to
England.
He was received as a hero
by the intellectuals and
gentlefolk of the Victorian
society.
• Landed at Falmouth on 2
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October 1836, almost 5
years after their
departure.
Met Richard Owen,
prominent biologist, who
would prepare and
classify his enormous
collection.
LIFE AFTER THE BEAGLE
• Darwin’s health problems
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started almost immediately
after his return.
They would plague him for
the rest of his life,
sometimes even stopping
him from work.
It was originally thought
that he picked up some
“bug” on his travels, but he
himself and later medical
experts think it might have
been a problem with his
immune system.
• Darwin always blamed
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himself for marrying a close
cousin (although he loved
her very much) – some of
his children also suffered
from immune diseases.
Darwin was an extremely
dedicated scientist, and with
his reputation as well as his
father’s financial support, he
could pursue a career as a
naturalist.
He moved to London
although he missed the
countryside.
His wife Emma was his lifelong
support and devoted partner.
• He thought of marriage
and made a list of the
pros and cons. The list
still exists.
• The marriage was very
•
• He married his cousin
and childhood friend,
Emma Wedgwood.
happy; they were blessed
with 6 sons and 4
daughters.
They also moved to the
village of Downe, living in
Down House.
DARWIN’S WORK:
• Darwin worked extremely
hard at organizing his notes
on the Beagle voyage.
• He and Fitzroy initially
planned to co-write a book,
but the break between the
two men occurred soon after
the end of the voyage. It was
mostly caused by different
thoughts on what they saw
on their trip, as well as
Fitzroy’s sometimes irrational
behaviour.
• Eventually the book was
published in two parts;
Darwin’s being the best-seller
and Fitzroy being jealous.
• Darwin started to make
sense from all that he has
seen and learnt, and started
on his great work, The
Origin. He kept it secret,
though …
The Origin …
• Darwin was “brought up
•
as a Christian, studied to
be a cleric, and died an
atheist”.
Contrary to popular belief,
his theory of evolution did
not make him doubt God;
he went on the voyage as
not totally a believer.
• His concern for his wife,
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Emma and her strong
faith, kept him from
making his ideas on
evolution known
immediately.
He also worried about
public opinion.
It eventually took him 20
years before he published
his ideas.
In the meanwhile he was not idle
• Darwin published a
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book on the geology
of South America.
After a chance remark
about scientific
credibility he studied
and reclassified the
Barnacles – a study
that took 8 years and
established him as a
renowned scientist.
• He also intermittently
•
suffered from a variety of
symptoms, all pointing to
a weak immune system,
disabling him from time
to time.
One of his favorite
children, 10-year Annie,
died of organ failure, a
tragedy from which he
never quite recovered.
This, more than most
things, removed him from
God.
THE “ORIGIN” IS STILL WAITING
TO HAPPEN
• Darwin continued his
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work on evolution and
natural selection,
constantly thinking and
rethinking his ideas.
He also made contact
with Lyell (Principles of
Geology), met Hooker,
and attended meetings of
the Geological Society
and the Royal Society .
At this stage he was still
careful not to say too much
about his work; his notes
and drawings show his
progress.
At one stage he wrote to Hooker …
I am convinced (quite contrary to the
opinion I started with) that species are
not (it is like confessing to a murder)
immutable.
The time is ripe …
• Darwin’s words to Hooker illustrates his own
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initial doubts.
Lyell and Hooker not totally convinced either.
After two years of his own studies, thoughts and
observations Hooker becomes one of Darwin’s
staunchest supporters.
The first edition is started in 1844 as a brief
review of 231 pages.
Time is running out …
• Darwin met Huxley, also
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am ardent supporter.
He corresponds with
Wallace and to his utter
shock and amazement,
found that Wallace had
the same ideas on
evolution!
ALFRED
WALLACE
• Lyell and Hooker forced
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Darwin to publish his
work.
The submitted Darwin’s
review, with Wallace’s
letter, to the Linnaean
Society on 1 July 1858.
Wallace received
recognition for his work
and Darwin is recognized
as the first author of the
“evolution theory”.
A NEW BEST-SELLING AUTHOR
• The Origin of Species
by Means of Natural
Selection was published
in the winter of 1859.
• The first run of 1 250
copies was immediately
sold out.
• It met with an uproar,
from both sides –
Darwin took to his
beloved sand walk to
think … and worry.
Exactly what did “Origin” say?
• Remember, Darwin was
• It was widely discussed in
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NOT the first to talk about
evolution!
It was an acceptable
concept in Aristotelian times
and after.
St Augustine and Thomas of
Aquinas also accepted the
concept.
The 15th century church in
Spain started a campaign
against it.
Lamarck and Lyell both
published ideas and
“evidence” in the 19th
century…
•
the mid-nineteenth
century.
Darwin (and Wallace)
provided an explanation
of how evolution occurs.
The novelty of Darwin’s
work is that it was in
language that people
without scientific
background could easily
understand.
EVOLUTION IN A NUTSHELL
• According to Darwin
1.
evolution worked like
this:
It keeps an existing
species tailored to its
existing ecological
niche, as long as
that niche still exists.
2. New species can be
created from the
varieties among
existing species.
This may happen
when groups or
individuals become
separated from one
another and take up
slightly different life
styles – through
change or necessity.
“Adaptive radiation”
• Darwin’s Galapagos
finches are an excellent
example of speciation:
Adaptiewe radiasie by vinke
• The finches of Galapagos
lived in different habitats
on the islands. Slowly
new adaptations enabled
them to exploit different
food sources. Slowly they
developed into new
species; one with a beak
to crack seeds, another to
get worms from wood
etc.
The “Origin” causes an uproar …
• The problem was not
evolution as such, but the
fact that Darwin included
man by implication (even
though “The descent of
man ..” would only be
published later.
• “The Origin” , according to
critics, said that man and
the apes developed from a
common ancestor, by
implication man came from
an ape (although Darwin
never said exactly that).
• Debate followed debate,
cartoons were published
– for and against Darwin,
his book and his theory.
• “Origin” remains a
bestseller.
What was/is the problem people
have with evolution?
• It does not allow for so-called Intelligent Design
– Darwin (and those after him) relied on
“coincidences”.
• Man is treated as any other animal – he is not
more special than any other organism.
• The Creationists believe that Earth was created
in seven 24-hour days: the Bible’s story of
Creation should be taken literally.
Why do we not agree with the
previous viewpoints?
• The randomness of change does not mean that
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there is no God. God did create heaven and
earth, but used (and still uses) natural processes
such as natural selection.
Man, although in the (spiritual) image of God, is
another biological organism who shares 98% of
his DNA with chimpanzees!
There is overwhelming evidence that life on
earth is very old, actually 3,5 billion years!
More about evolution …
• Adaptations between
organisms of the same
species, and between
different species are
driven by “the struggle
for life”.
• This struggle for
existence does not only
influence the everyday
life of an organism, but
also its ability to
reproduce.
• The secret to
adaptations lies in
natural selection.
• “Natural selection is daily
and hourly scrutinizing,
throughout the world,
every variation, even the
slightest; rejecting that
which is bad, preserving
and adding up all that is
good …”
Darwin says …
• The earth is much older • Adaptations of
than originally thought.
• Natural processes e.g.
earthquakes contribute
to changes of the earth
over long periods of
time.
• Organisms adapt to
changing conditions.
organisms occur “by
chance” through
natural selection.
• “Survival of the fittest”
means survival of those
most suited to survive
in a changing
environment.
Darwin vs Lamarck
• Lamarck said that
conditions forced
organisms to adapt, and
that new adaptations can
be transferred to the next
generation. These
changes can transfer
from one generation
to the next.
• Darwin said that
changes were
coincidental (by chance)
and that these changes
occur over a long period
of time. Some can be to
the benefit of the
organism and will ensure
survival.
Patterns of van evolution
• Evolution is not a
direct sequence of
organisms with
changes.
• Evolution causes
groups to be less and
less related to each
other, the longer the
time span, and vice
versa.
What Darwin did not know …
• Today we know that many catastrophic
events caused mass extinctions.
• These extinctions gave rise to “explosions”
of new species.
• Some areas are richer in species than
others – centres of biodiversity.
Another problem that Darwin had ...
• Darwin knew that natural selection “chooses
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suitable characteristics”, but how this happened
and how even regular features were transferred,
he did not know.
The irony was that a contemporary of Darwin,
the Austrian monk Gregor Mendel, developed
the science of Genetics.
Mendel studied the inheritance of traits, but
because of geographical isolation, language and
long distances, the two never new one another.
Darwin did work on much more
than just evolution
• Darwin was a dedicated
•
scientist and published
books, most of them
best-sellers on topics
such as orchids, insects,
farming, vegetable
growing etc.
He was also a landowner
with tenant farmers,
invested money and took
part in local politics.
• One of his children,
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Francis, worked with him
in his later years and was
responsible for the
preservation of Darwin’s
diaries and notes.
Down house can be
visited today; Darwin’s
study is a special place of
interest.
The famous sand walk
still exists and can be
followed.
THE END
• Charles Robert Darwin
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died on 19 April 1882.
He never received the
honour he deserved from
his country of birth, but
was buried in
Westminster as were
many other important
men of science.
His funeral service was
attended by every
prominent scientist of the
time as well as hundreds
of other people.