CHARLES DARWIN AND THE EVOLUTION OF THE ATLANTIC OCEAN, THE MACARONESIAN ISLANDS, AND THE AÇORES
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AÇOREANA, 2011, 7: 39-71
CHARLES DARWIN AND THE EVOLUTION OF THE
ATLANTIC OCEAN, THE MACARONESIAN ISLANDS,
AND THE AÇORES
Brian Morton
Department of Zoology, The Natural History Museum, Cromwell Road,
London SW7 5BD, U.K. e-mail: prof_bmorton@hotmail.co.uk
Darwin wrote in his notes for the Voyage of the Beagle when he stopped off
at Terceira on 20 September 1836 on his way back to England:
‘I enjoyed my day’s ride, though I did not find much worth seeing’.
ABSTRACT
The first stop on 16 January 1832 on the voyage of H.M.S. Beagle was the
island of Santiago in the Cape Verde Archipelago. While there, Darwin, only
22 years old and with a Cambridge degree in theology, examined an upli ed
layer of fossiliferous sandy breccia sandwiched between lava flows. These first
observations eventually played an historic role in his and our understanding
of ocean genesis and the colonization and subsequent evolution of island
floras and faunas.
The English botanist Joseph Hooker had noted floristic similarities between
the Falkland Islands and Iceland, neither having hardly any indigenous
species, and South America and Europe, respectively. To explain this, the
English malacologist Edward Forbes proposed in 1846 that a great land mass
had existed in the Miocene encompassing northern Europe and Spain, and
extending out from the Mediterranean far westwards into the Atlantic Ocean
virtually to the coast of North America. On his return to England, Darwin
became skeptical of Forbes’s lost land and sent seeds of the Western Atlantic
fabaceans Entada gigas and Mucuna urens from Açorean beaches to the Royal
Botanic Gardens at Kew where they were planted, germinated and produced
healthy, mature, vines. Subsequently, Darwin set up his own experiments in
the glasshouse at Down House where he immersed the seeds of 87 species
of common plants in seawater for a month. He then tried to germinate them
and found that over half (64) had survived. By his own calculations, ocean
currents could thus have taken such seeds well over half way across the
Atlantic Ocean. He undertook similar work on dried muds collected from
the feet of migrating birds and concluded that no Forbesian landmass was
necessary to explain Hooker’s biogeographic similarities.
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40 AÇOREANA 2011, Suplemento 7: 39-71
The observations of Darwin on Santiago eventually led on Cocos-
Keeling in the Pacific to his concept of oceanic islands having either
risen or sunk, or of sea levels falling and rising, respectively, or both.
Darwin thus set in place an alternative, and more plausible, theory to
that of Forbes, which suggested that newly-emergent islands could be
colonized naturally by plants and animals from other locations and
that, through natural selection, such isolated individuals could evolve
into distinct species.
Thus, although Darwin stayed but a few days in the Açores, the
islands subsequently played a critical role in his understanding of the
evolution of islands and life upon them. Terrestrially, the Açorean flora
and fauna have been much modified by the hand of man. This is also
true of the few low-lying wetlands, but the islands remain, because
of their Atlantic isolation, one of the best places to test Darwin’s
hypotheses about island colonization and to effect Macaronesian
marine conservation.
RESUMO
A primeira paragem em 16 de Janeiro de 1832 na viagem do H.M.S
Beagle foi a ilha de Santiago no Arquipélago de Cabo Verde. Enquanto
ali, Darwin, com apenas 22 anos de idade e graduado em teologia
por Cambridge, examinou uma camada erguida de breccia arenosa
fossilífera entalada entre derrames de lava. Estas primeiras observações
eventualmente tiveram um papel histórico no seu e nosso entendimento
da génese do oceano e da colonização e subsequente evolução das floras
e faunas das ilhas.
O botânico Inglês Joseph Hooker notou semelhanças florísticas entre
as Ilhas Falkland e a Islândia, nenhuma possuindo praticamente espécies
indígenas, e a América do Sul e a Europa, respectivamente. Para explicar
isso, o malacólogo Inglês Edward Forbes propôs em 1846 que uma grande
massa de terra existiria no Mioceno abrangendo a Europa do Norte e a
Espanha, e estendendo-se para fora do Mediterrâneo muito para oeste
Oceano Atlântico adentro virtualmente até à América do Norte. No seu
regresso à Inglaterra, Darwin tornou-se céptico quanto à terra perdida
de Forbes e enviou sementes de fabáceas do Atlântico Oeste Entada gigas
e Mucuna urens das praias Açorianas para os Royal Botanical Gardens
em Kew onde foram plantadas, germinaram e produziram trepadeiras
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MORTON: DARWIN, THE ATLANTIC AND THE AÇORES 41
saudáveis, maturas. Subsequentemente, Darwin preparou as suas
próprias experiências na estufa em Down House onde imergiu em água
do mar durante um mês as sementes de 87 espécies de plantas comuns.
Experimentou então germiná-las e descobriu que mais de metade (64)
haviam sobrevivido. Por seus próprios cálculos, as correntes oceânicas
poderiam pois ter trazido tais sementes bem mais do que metade do
caminho através do Oceano Atlântico. Ele fez trabalho semelhante
com lamas secas recolhidas das patas de aves migradoras e concluiu
que não seria necessária a massa de terra Forbesiana para explicar as
similaridades biogeográficas de Hooker.
As observações de Darwin em Santiago levaram eventualmente, em
Cocos-Keeling no Pacífico, ao seu conceito de ilhas oceânicas haverem
subido ou afundado, ou de mares descendo e subindo, respectivamente,
ou a ambas as situações. Darwin então colocou uma teoria alternativa
à de Forbes, e mais plausível, que sugeria que ilhas recém-emersas
poderiam ser colonizadas naturalmente por plantas e animais de outras
localidades e que, através da selecção natural, esses indivíduos isolados
puderam evoluir em espécies distintas.
Assim, embora Darwin tenha permanecido nos Açores apenas alguns
dias, as ilhas subsequentemente desempenharam um papel crítico na sua
compreensão da evolução das ilhas e da vida nelas existente. Em terra, a
flora e a fauna Açorianas têm sido muito alteradas pela mão do homem.
Tal é verdade acerca das poucas zonas húmidas baixas mas, devido ao
seu isolamento no Atlântico, as ilhas permanecem um dos melhores
lugares para testar as hipóteses de Darwin acerca da colonização das
ilhas e para levar a cabo a conservação marinha da Macaronésia.
INTRODUCTION Darwin arrived at the University
of Edinburgh to read medicine.
C harles Darwin was born on
12 February 1809. One of the
greatest influences in his early
This lasted for but two years and
in 1828 (aged 19), Darwin enrolled
at the University of Cambridge to
life was his paternal grandfather read divinity. Unsuccessfully, as
Erasmus Darwin (1731-1802) who it transpired. Here, however he
recognized and described ‘biolo- came under the influence of two
gical evolution’. In 1825 (aged 16), great men – the geologist Adam
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42 AÇOREANA 2011, Suplemento 7: 39-71
Sedgwick (1785-1873), who had not an outstanding student, in-
become Woodwardian Professor deed his father ‘despaired of
of Geology at Cambridge in 1818, him’ but, today, there is a statue
and the botanist John Stevens of Charles Darwin as a young
Henslow (1796-1861), who had man in the gardens of Christ’s
been appointed Professor of College, Cambridge (Figure 1).
Botany at Cambridge contempo- On the steering wheel of H.M.S.
raneously with Darwin in 1825. Beagle, however, were carved
Darwin left Cambridge in 1931, the words of Nelson’s exhor-
not a clergyman, but with a B.A. tation to his men at Trafalgar:
in Theology, Euclid and Classics. ‘England expects every man to do
He is now, however, with train-
ing by Sedgwick and Henslow
an enthusiastic, albeit, amateur
geologist and botanist. On 24
August 1831, Henslow informed
Darwin that there is a space for
him on H.M.S. Beagle as natural-
ist companion to Captain Robert
FitzRoy (1805-1865). Darwin
accepted the invitation and on
27 December 1831 (aged 22), he
and the Beagle departed on her
second voyage, principally to
conduct a hydrographic survey
of the coast of South America.
The expedition was not to return
to England until 2 October 1836,
almost five years after it had
set sail. In Cambridge, Darwin
had become much influenced
by the writings of Charles Lyell
FIGURE 1. The statue of Charles Darwin
(1797-1875), author of Principles
as a young man in the gardens of Christ’s
of Geology and took Volume I College, Cambridge. ‘I believe that I was
with him on the voyage and considered by all… [to be] an ordinary boy
received Volume II on route.It well below the common standard of intellect’.
has to be said that Darwin was Charles Darwin, 1876.
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MORTON: DARWIN, THE ATLANTIC AND THE AÇORES 43
his duty’. Such a daily reminder in 1462, they became impor-
of his duty must have kept him tant as a stopping off point for
working throughout the long the trans-Atlantic slave trade.
periods of boredom, tedium, sea- Subsequently, the importance of
sickness and homesickness that the islands declined. Darwin ar-
he endured for the 58 months of rived at the capital, Porto Praya
the voyage. (Praia), on the island of St Jago
The Beagle’s last stop on its (Santiago) on the 16 January
five year voyage was the Açores. 1832 (the Beagle’s first stop)
Although Charles Darwin was and described his surroundings
singularly unimpressed by the as wearing a ‘desolate aspect’
islands on his visits to Terceira (Darwin, 1845).
and São Miguel in 1836, the At the time of Darwin’s vi-
archipelago, along with other sit to Santiago, the Christian
macaronesian ones would church still believed in the cos-
eventually play an important mogony of James Ussher (1581-
role in his understanding of 1656), Archbishop of Armagh,
biogeography and the evolution Primate of All Ireland, and Vice-
of island isolated floras and Chancellor of Trinity College,
faunas. The first stop of the Dublin, who had identified crea-
Beagle in 1832 was to be the tion as starting on Sunday 23
Canaries. The island’s Spanish October 4004 B.C. Such a view
authorities, however, had heard had the important support of
that cholera was rampant in Sir John Lightfoot (1602-1675),
England and so forbade any Vice Chancellor of Cambridge
landing. Instead, therefore, the University, who even added an
first stop of H.M.S. Beagle was exact time - 9 a.m. - to the pre-
the Portuguese colony of the scribed date. Having established
Cape Verde Islands. the first day of creation, Ussher
calculated the dates of other bi-
THE CAPE VERDE ISLANDS blical events, concluding, for
example, that Adam and Eve
The Cape Verde Islands are were driven from Paradise on
located 450 kilometres off the Monday 10 November 4004 B.C.
coast of West Africa (Senegal) Charles Lyell, however, did
and were discovered in 1456. not believe any of this. Rather, he
Colonized by the Portuguese believed the Earth to be billions
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44 AÇOREANA 2011, Suplemento 7: 39-71
of years old. In addition to the When Darwin arrived on the
debate regarding the Earth’s age, Cape Verde Islands – as deso-
however, the scientific world late today through over-grazing,
was similarly divided as to as they were then, his mind was
whether the geological record debating the conflicting views
was (i), best interpreted as a in relation to creation, and the
series of catastrophic events, the arguments about catastrophe
most recent being equated with versus gradualism. Captain
the deluge of Noah’s flood with FitzRoy, who was a devout crea-
the ark touching down on Mount tionist, not just believing in the
Ararat, according to Ussher, literal truth of Genesis but con-
on Wednesday 5 May 2348 B.C. demning Lyell as a heretic too,
(thereby achieving convergence
between geology and scripture)
or (ii), as Lyell believed, slowly
acting processes of formation,
erosion, deposition and defor-
mation. The Temple of Serapis,
at Pozzuoli, Naples, actually
provided evidence of the latter,
even then. Here, date mussels,
Lithophaga lithophaga (dattero di
mare) have made holes in the 2nd
century columns, at a height of
~5.7 metres showing that they
were originally uncovered, then
covered and now, again, unco-
vered by the sea – attesting, be-
cause the columns were undis-
turbed, slow, gradual, changes
in sea level over historical time.
The temple and its date mussel FIGURE 2. The Temple of Serapis, at
Pozzuoli, Naples, where date mussels,
artifacts were so important to
Lithophaga lithophaga (da ero di mare)
Charles Lyell that an illustration have made holes in the 2nd century
of it (Figure 2) was used as a fron- columns, at a height (today) of ~5.7
tispiece to his book ‘Principles of metres. The frontispiece to Charles Lyell’s
Geology’ (Lyell, 1830-1833). Principles of Geology (1830-1833).
Paginação_21.indd 44 19-01-2012 11:50:56
MORTON: DARWIN, THE ATLANTIC AND THE AÇORES 45
would be of little help to him in chamid (upper) shell valves,
this debate. crab ‘fingers’ and maerl frag-
But the harbour at Praia ments, attesting to its origin.
on Santiago held a secret that That is, an uplifted shallow, tro-
Darwin discovered. Here, on pical, seabed composed of large
Quail Island (now Ilhéu de Santa sand grains, with a surface
Maria) he noted the presence of cover of calcareous maerl nodu-
a horizontal white band run- les (Darwin’s ‘coral’), attesting
ning through the rocks, about 30 to gentle surface wavelets, and a
feet (~10 metres) above sea-level mixture of organic fragments of,
(Figure 3). It was composed of mostly, mollusc shells derived
a sandy breccia, made of com- from rocky and sandy inshore
pressed shells and ‘corals’ (actu- and soft offshore habitats. The
ally maerl) and continued as far fossils obviously suggest that
as the eye could see. Figure 4A the whole area had once been
shows some of the fossils collec- under water but, for Darwin, the
ted by this author from Darwin’s question was: why not now?
stratum on Quail Island in 2009. The geology of the Cape Verde
The breccia matrix contains pa- Archipelago has been described
tellid and fissurellid limpets, by Mitchell-Thomé (1972) and
other gastropod fragments, ve- Figure 5 is the only detailed
nerid, donacid, glycymerid and map of the geology of the
FIGURE 3. On Quail Island (now Ilhéu de Santa Maria) at Santiago in the Cape Verde
Islands, Darwin noted the presence of a horizontal white band (arrow) running through
the rocks about 30 feet (~10 metres) above sea-level. (Photo: B. Morton).
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46 AÇOREANA 2011, Suplemento 7: 39-71
FIGURE 4. A, Some of the fossils collected by this author from the limestone of Quail
Island in 2009. The breccia matrix contains patellid and fissurellid limpets, other
gastropod fragments, venerid, donacid, glycymerid and chamid (upper) shell valves,
crab ‘fingers’ and maerl fragments. B, The coral Siderastrea radians a ached to a piece
of Darwin’s fossiliferous limestone collected from the beach at San Tome on Santiago.
(Photo’s: B. Morton).
twelve islands and shows that it dips locally below sea level
they represent a within-plate in an asymmetrical fashion. In
archipelago located some 500 Figure 6, A represents the sea; B,
kilometres west of Senegal. The ancient volcanic rocks; C, upper
archipelago probably dates back basaltic lava and arrowed is a
some 180 Ma and the islands are thin layer of white limestone
made up mostly of Tertiary and between them.
younger volcanics. The oldest Four years later on into the
rocks on Maio are Mesozoic voyage, H.M.S. Beagle stopped
limestone but most are Cenozoic at the Cocos-Keeling islands
(
MORTON: DARWIN, THE ATLANTIC AND THE AÇORES 47
in the Cape Verde’s. For here,
he believed the maerl was ‘coral’
and, in fact, corals do occur in
the shallow subtidal of the Cape
Verde’s, for example Siderastrea
radians here attached to a piece
of limestone (Figure 4B), so that
this must have been the first
time he contemplated how such
coral islands evolve.
Also on Santiago, however,
Darwin discovered an African
baobab tree (Adansonia). His
plant is no longer alive (Pearson
& Nicholas, 2007), but there is
FIGURE 5. The only geological map of the still a pair of trees to be found
of the Cape Verde Islands showing that on the island in the valley
the 12 islands represent a within-plate extending north from the
archipelago located some 500 kilometres
original capital, Cidade Velha,
west of Senegal. (Courtesy of Dr Lyall
Anderson, University of Cambridge). on the south coast of Santiago.
The male tree illustrated (Figure
7, note the man standing beside
lost to the depths still holds true it), and the female, are bigger
today, attesting not only to his than Darwin’s and must have
remarkable insight, but also to been mature when he visited
the significance of Quail Island the island. Darwin also knew
FIGURE 6. The woodcut Darwin made of the limestone stratum on Quail Island, Cape
Verde, in which he shows how it dips locally below sea level in an asymmetrical fashion.
A represents the sea, B, ancient volcanic rocks; C upper basaltic lava with a thin layer of
white limestone (arrowed), between them. (A er Darwin, 1844, p. 9.)
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48 AÇOREANA 2011, Suplemento 7: 39-71
importantly, because here his
first thoughts on oceanic island
formation were born and he
began to question the accepted,
literal, truth of creation.
FORBES’S LOST LAND
At the time of Darwin’s visit
FIGURE 7. An African baobab tree
(Adansonia) today, on Santiago, Cape
to Cape Verde, the English natu-
Verde Islands. (Note the man standing ralist, malacologist, geologist,
beside it.) (Photo: B. Morton). palaeontologist and Professor of
Natural Philosophy at Edinbugh
University, Edward Forbes
that the largest baobab trees (1815-1854), and therefore an
could attain a great age of 6,000 eminent person, had proposed
years. Could this therefore, be (Forbes, 1846) that a great land
evidence for a lost landmass that had existed in the Miocene (7-
had once connected Africa with 26 Ma) encompassing northern
these Atlantic islands? If so, his Europe and Spain, and extending
baobab must have sprouted in out from the Mediterranean,
the first week of creation, but past the Açores (and thus way
only if one believed in Bishop beyond the Canaries and Cape
Ussher’s account of Biblical Verde), as far out into the
chronology. But how, therefore, Atlantic as the Sargasso Sea.
could this tree be older than the That is, virtually to the coast
Quail Island fossils? The truth of North America (Figure 8).
is, however, much more prosaic: Such a land largely filled the
the trees were probably taken Atlantic Ocean. Hence, as far as
to the Cape Verde Islands, as Forbes’s theory was concerned,
seeds, by either slaves or their Darwin’s baobab would simply
traders just a few hundred years be a remnant of a time when the
previously. But, at the time, Cape Verde’s had been joined
Darwin was not to know that. to Africa by this, now sunken,
Nevertheless, Darwin’s sojourn inter-connecting landmass.The
on Santiago was significant in English botanist Joseph Dalton
a number of ways but, most Hooker (1817-1911), at 22 (the
Paginação_21.indd 48 19-01-2012 11:51:16MORTON: DARWIN, THE ATLANTIC AND THE AÇORES 49
FIGURE 8. Forbes concept of a land that largely filled the Atlantic Ocean, thereby
accounting for Hooker’s similarities in the plant and animal fossils of Europe and North
America. (From Forbes, 1846).
same age as Darwin when he -known example at the time
joined H.M.S. Beagle), enlisted was the beach pea (Lathyrus ja-
on Captain James Clark Ross’s ponicus), illustrated in Figure
Expedition to Antarctica (1839- 9, which was then thought to
1843). Subsequently, Hooker have a North American and rare
noted the floristic similarities British occurrence and thus pro-
between the Falkland Islands vide evidence of a formerly con-
and Iceland, neither of which tiguous Atlantic distribution.
had hardly anything indige- Edward Forbes’s lost landmass
nous, and South America and also explained this, thereby fur-
Europe, respectively. One well- ther accounting for similarities
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on H.M.S. Challenger that, on
its famous, pioneering, voyage
between 1872-1876, found life at
9,000 metres. Challenger, like the
Beagle, put into Porto Praia on
St Iago (Santiago), Cape Verde
Islands, and Henry Nottidge
Moseley (1844-1891), one of the
naturalists on board, was keen
to see the rocks described by
FIGURE 9. The beach pea, Lathyrus Darwin - so significant had they
japonicus. (B. Morton). become.
Forbes died at an early age of
in the plant and animal fossils of 39, his theories, though interes-
Europe and North America. It is ting, all subsequently shown to
now known that the beach pea, be wrong. But the Challenger
whose seeds can survive many Expedition did more – its 50
months in seawater, has a cir- volumes of research findings,
cum-polar distribution. Later, largely edited by John Murray
Darwin, after looking at seed (1841-1914), who had been
dispersal more scientifically, Wyville-Thompson’s assistant
would offer an alternative hypo- on the voyage and who took
thesis to that of Forbes. over the editing and publishing
Forbes had also dredged of the expedition’s results (com-
in the Aegean from 1841-42 pleted in 1896), effectively, laid
aboard H.M.S. Beacon giving the foundations for the mo-
rise to his second, Azoic (or dern science of o ce a n o g ra p h y.
Lifeless), theory, that no life Mu rra y, for example, was the
existed below a depth of ~500 first person to note the existen-
metres. This view, too, would ce of the Mid-Atlantic Ridge and
later be challenged by Charles ocean trenches and, indeed, coi-
Wyvi l l e Th omp s on (1830- ned the word ‘oceanography’.
1882) who succeeded Forbes as And, for continuing and refining
Professor of Natural Philosophy this newest of sciences, we have
at Edi nb urg h Un ivers ity. to thank the researches of three
Thompson aimed to disprove other 20th century physical ocea-
the Azoic Theory and did so nographers.
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ALFRED WEGENER, EDWARD
BULLARD AND FREDERICK
VINE
Forbes’ view of a sunken
land bridge across the Atlantic
persisted into the 20th century
and it was not until 1911 that the
German meteorologist Alfred
Wegener (1880-1930), noticing
that the fossils of identical plants
and animals could be found on
opposite sides of the Atlantic,
suggested that the continents
were ‘drifting’ apart.
Orthodox science, that is, those
believing Forbes, at the time
explained this by postulating
that land bridges, now sunk, had
once connected far-flung conti- FIGURE 10. The maps in the 1966
nents. Wegener also, however, edition of A. Wegener’s book illustrating
continental dri for three epochs.
noted the close fit between the
coastlines of South America and
Africa and wondered whether
the continents might not have (1907-1980), who became profes-
been joined at one time. He ar- sor of Geodesy and Geophysics
gued the continents could drift at Cambridge University, later
about, laying down the ground- produced a computer fit of the
work for the 1950’s palaeomag- continents that Wegener had
netism research that reconstruc- called ‘Pangaea’, showing just
ted the world’s historical geolo- how the continents do actually
gy in terms of a unified theory fit very closely into a jigsaw-like
of continental drift. Figure 10 picture.
shows the maps in the 1966 edi- In 1963, the Cambridge geo-
tion of Wegener’s book illustra- physicist Frederick Vine (born
ting continental drift for three 1939) proved the concept of sea-
epochs. Edward Crisp Bullard -floor spreading by studying
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the reversals in the polarity of they were planted, germinated
the Earth’s magnetic field. Vine and produced healthy mature
showed that the parallel bands vines. Clearly, these and, indeed
of palaeomagnetic anomalies other seeds of several species of
on either side of oceanic moun- sea beans are capable of survi-
tain ridges resulted from the ving Gulf Stream transport from
combined effects of reversals in the tropical Western Atlantic to
the polarity of Earth’s magnetic the Açores, including Mucuna
fields and the generation of new urens as well as M. sloanei and
floor along the axes of the rid- M. fawcetti. The seeds of these
ges. Today, through the science three species of coastal legumi-
of geomagnetism, we can inter- nous vines share the characteris-
pret the evolution of the earth’s tic of a darkly pigmented hilum
continents and oceans over time, encircling five-sixths of the mar-
explaining why similar fossils gin of each. The embryo within
occur on different continents. the seed is protected by a thick,
Through the pioneering work of resistant, exocarp capable of
Wegener, Bullard and Vine, we prolonged exposure to seawater
now know an enormous amount (Gunn et al., 1976).
about the Earth’s seabed, inclu- In fact, the Açores receives a
ding its age(s) and about the pla- variety of seeds and vegetative
tes that form the continents and dissemules, many of which ori-
are separated from each other ginate from the tropical Western
by the mid-oceanic ridges. The Atlantic (Table 1). The sea heart,
Açores Archipelago sits on the Entada gigas, is the most com-
Mid-Atlantic Ridge. mon disseminule on Açorean be-
aches, delivered by Gulf Stream
DARWIN’S EXPERIMENTS currents from Caribbean shores.
Entada gigas is a large, climbing,
Upon his return to England, tropical, coastal, vine producing
Darwin became skeptical of large chocolate-brown seeds up
Forbes’s lost land and after re- to six centimetres in diameter
ceiving several seeds of the and some two centimetres thick.
Western Atlantic Entada gigas The seeds are buoyant and can
and Mucuna urens from Açorean remain afloat at sea for at least
beaches, sent them to the Royal two years (Gunn et al., 1976).
Botanic Gardens at Kew where Veríssimo (1989) suggested that
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TABLE 1. Plant disseminules recorded from Açorean beaches (a er Gunn et al., 1976).
Disseminule Common name Family Source, habit and habitat
Astrocaryum sp. Starnut palm Palmaceae Caribbean; wet lowland forest tree
Calocarpum mammosum Egg fruit Sapotaceae Tropical America; tree
Crescentia cujete Calabash tree Bignoniaceae New World tropics; tree
Dioclea reflexa Sea purse Leguminoseae Asia; vine
Entada gigas Sea heart Leguminoseae Caribbean; climbing vine
Manicaria saccifera Sea coconut Palmaceae American tropics; coastal tree
Merremia discoidosperma Many’s bean Convolvulaceae Central America; woody, wet forest
Mucuna sloanei True sea bean Leguminoseae Caribbean vine
Sacoglo is amazonica Cojon de burro Humiriaceae South America; lowland forest tree
Sapindus sapinaria Black pearl/Soapberry Sapindaceae American tropics; tree
Christopher Columbus (1451- germinated after an immersion
1506), upon finding E. gigas period of 28 days and a few
seeds along the shores of either survived immersions of 137
Porto Santo or Madeira during days. Nine legumes were tried
his residence on the islands be- and, with one exception, all
tween ~1479-1482, used the ob- died, including the common
servation to support his argu- pea (Pisum sativum) although, as
ment for, an as yet undiscove- noted above, it is known that the
red (then in ignorance of Viking sea pea occurs in North America
achievements and the evidence and along the southeast coast
thereof on Newfoundland), west- of England, for example on the
ward land – the Americas – or, Dungeness shingle banks, on the
rather, as he thought, Asia. southeast coast of England, and
As a consequence of the has a circum-polar distribution.
results of the Kew experiments, Darwin also noted that
Darwin set up his own in the many of the seeds, without
Old Laboratory and Greenhouse either the capsule or fruit, sank
in the grounds of Down House within a few days and could
where he immersed the seeds of not, therefore, have survived a
87 species of common plants in long sea voyage. Later, he tried
seawater for a month. He then larger fruits and capsules and
tried to germinate them and, to eventually to dry and then try the
his surprise, 64 subsequently stems and branches of 94 plants
Paginação_21.indd 53 19-01-2012 11:51:1954 AÇOREANA 2011, Suplemento 7: 39-71
with ripe fruits. The majority to evolve into distinct species.
sank quickly, including fresh Thus, Darwin’s interpretation
cuttings whereas dried ones of the stratum on Quail Island
floated for longer. For example, initially stimulated him to think
ripe hazelnuts sank immediately about how oceanic islands are
whereas dried ones floated formed, but his experiments on
for 90 days and subsequently seed dispersal also demonstrated
germinated, as did the ripe to him how such new entities
seeds of Helosciadium (water might be colonized. This latter
parsnip) and an asparagus-plant observation ultimately led to his
(Asparagus officinalis) with ripe great theory about the evolution
berries (85 days). Of the 94 dried of life itself.
plants, 18 floated for >18 days.
Darwin consulted ‘Johnston’s THE AÇORES
Physical Atlas’ wherein it was
stated that the average rate of The Açores archipelago is
several Atlantic currents is 33 located on the Mid-Atlantic
miles·day-1, with some running Ridge on its only triple junction.
at 60 miles·day-1, and concluded The discovery of the Açores,
that 14 out of 100 (14%) plants ac co rd in g to 1 4 t h ce n tu ry
might be floated across 924 miles Genoese maps, the Portulanos,
of sea and if blown to a favourable seems to have taken place
spot, would germinate. By his between 1317 and 1339 (Bento,
own calculations, therefore, 199 4 ) bu t th e Po rtu g u e s e
ocean currents could thus have navigator Diogo de Silves is
taken such seeds well over half credited with the discovery of
way across the Atlantic, that is, the islands in 1427. Portuguese
easily, to the Açores. settlers first colonized the islands
Darwin’s experiments thus permanently beginning with
set in place an alternative, more Santa Maria in 1432, São Miguel
plausible, theory to that of in 1439 and the other seven
Forbes and which suggested that subsequently. Darwin and the
newly emergent islands could be Beagle stopped off in the Açores
colonized by plants and animals (the last stop) for six days on the
from other locations and that way back to England and visited
through natural selection such Terceira on 20 September 1836
isolated individuals could come and São Miguel subsequently,
Paginação_21.indd 54 19-01-2012 11:51:20MORTON: DARWIN, THE ATLANTIC AND THE AÇORES 55
although he probably did not the nine Açorean islands to have
disembark the ship at the latter. a sedimentary cover and has a
His comment about Terceira rich fossil record dating from
(Darwin, 1845) was: the Late Miocene-Early Pliocene
to the Pleistocene (Madeira et
‘I enjoyed my day’sride, though I al., 2007). As on Santiago in the
did not find much worth seeing’. Cape Verde Islands, there is on
Santa Maria an uplifted Early
We h ave to remembe r, Pliocene fossiliferous stratum
however, that Darwin was and Janssen et al. (2008, figure
terribly homesick, indeed had 3) illustrate an accumulation
been for many months. He of Cavolinia marginata in a
even dismissed Australia as crustacean burrow from the
uninteresting! There, he did not Lower Pliocene of Cré, on this
even see a kangaroo! As we now island. Ages of fossil molluscs
know, however, the Açorean recovered from Santa Maria
islands are extremely interesting, range from 10.03 to 2.24 Ma
especially geologically. Santa (Kirby et al., 2007).
Maria is the oldest island of the Similarly, to the rear of the
Açores and arose from the sea long expanse of sandy beach
in the Late Miocene ~7 million on the southern shore of Porto
years ago. It is the only one of Santo, one of the Madeiran
islands, there is a raised beach
of offshore sand (Figure 11) not
unlike that seen on the coast at
Tarrafal on Santiago (Cape Verde
I s la n d s ). H e n ce , th ro u g h o u t
Macaronesia, there is ample
evidence of uplifted marine
sediments attesting not only to
active vulcanism over relatively
recent time but to the insight of
Darwin in recognizing this very
FIGURE 11. A raised beach towards the early on during his voyage with
rear of the long sandy beach on the south the Beagle.
coast of Porto Santo, Madeira. (Photo: B. We also know that sometime
Morton). between 3.1-3.6 million years
Paginação_21.indd 55 19-01-2012 11:51:2056 AÇOREANA 2011, Suplemento 7: 39-71
FIGURE 12. The map of the Gulf Stream created by Benjamin Franklin on 2 May 1775.
He thought of it as a river.
ago, after the Middle Pliocene by Benjamin F ra n k lin (1 7 0 6 -
upli of the Central American 17 9 0 ), w h o was postmaster
Seaway, the connection between general of the American colony
the Pacific and Atlantic Oceans at the time, during a voyage from
was closed at the approximate England to the soon to become
position of modern Panama United States in 1775 (Figure 12).
(Vermeij & Rosenberg, 1993), iso- He recorded that the current was
lating coral reefs in the Caribbean some 3.5 °C warmer than the
and creating the modern pa ern surrounding sea and by taking
of circulation of both oceans, but regular temperature readings
importantly for the Atlantic – the could trace its course. It is this
Gulf Stream –, first mapped current which allows the Azores
Paginação_21.indd 56 19-01-2012 11:51:20MORTON: DARWIN, THE ATLANTIC AND THE AÇORES 57
to be colonized sporadically by colonization times and routes
species with long-lived larvae but also marine biogeography.
from the Caribbean, such as Today, the Açorean islands
the taenioglossan tonnoidean are influenced by the North
gastropod Charonia variegata Atlantic Current at the surface
(Lamarck, 1816) recorded only and by water arriving from
once from Faial at 15 metres the Mediterranean at mid-
depth (Gofas & Beu (2002). Also water depths. The variety of
in the early Pliocene, the Bering currents influencing the islands
Strait between Alaska and Siberia at different depths thus has the
opened and cool-temperate and potential therefore to create
polar marine species were able in the Açores a meeting place
to move between the North of marine plants and animals
Pacific and the Arctic-Atlantic from different locations (Morton
basins (Vermeij, 1991). et al., 1997). It should therefore
Such relatively recent histori- be possible to monitor past
cal events have been responsible and present colonization (and
for not just the Atlantic circula- spreading) events to not just test
tion pattern we see today, but Darwin’s theory of island and
also for the species of marine biological evolution but to expand
plants and animals found on it into a programme that tests
the shores and shallow subtidal current ideas about the human-
waters of the Macaronesian, in- assisted introduction of exotic
cluding Açorean, islands as they species (Morton & Bri on, 2000b).
arose successively either prior or
subsequent to these major events The above-described variety
(Morton & Britton, 2000a). We, of ocean currents is predomi-
therefore, know much about the nantly responsible for the histo-
circulation of the Atlantic Ocean rical import onto the Açorean is-
and how it has evolved and in lands’ shores of its characteristic
broad terms how and when the marine flora and fauna (Morton
marine biota of the Açorean is- & Britton, 2000a). Just as Darwin
lands arrived. That the islands showed with plant seeds,
emerged either before or after Dinesen (pers. comm.) has sug-
these events, however, make gested that the planktonic lar-
them a chronometer for the tes- vae of many marine invertebra-
ting of theories related to island tes may spend up to four weeks
Paginação_21.indd 57 19-01-2012 11:51:2058 AÇOREANA 2011, Suplemento 7: 39-71
in the upper water mass where been colonized since the early
current speeds of ~1.8 km h-1 are part of the 15th century, the ori-
common. Such larvae, again as gins and routes of such intro-
with Darwin’s seeds, could thus ductions have been lost in time.
be transported ~1,200 kilome- Morton & Britton (2000b) have
tres from their spawning site and reviewed this subject.
hence easily reach Açorean waters.
Subsequently, such larvae may AÇOREAN BIOTIC
travel for up to three weeks in ENDEMICITY
near-bottom waters before set-
tling is required for post-meta- The terrestrial environment
morphic survival. During this of the Açores has been much
time, at a common speed for near modified by man since the initial
bottom advection of 0.18 kilome- colonization of the islands in the
tres hour-1 (50 mm second-1), early part of the 15th century.
the larvae could be transported Thus, of the ~3,000 species of
horizontally for a further 90 ki- vascular plants found on the
lometres, during which time Açores, only 72 [68 according
settlement-inducing cues could to Borges & Gabriel, 2009] are
be encountered. Hence, it is endemic (the Açorean enigma;
not surprising and despite their Carine & Schaefer, 2009) and,
isolation, that the marine envi- even so, some 52 of these
ronment of the Açorean islands are considered threatened.
comprises communities, which Borges & Gabriel (2009) have
contain species that are largely catalogued the terrestrial taxa
encountered elsewhere, notably of the Açores and identified
in the Mediterranean (Morton a total of 4,515 species. Of
& Britton, 2000a) and that are these, 420 are considered to be
transported to them in surface endemic: that is, 267 arthropods,
ocean currents. 68 spermatophytes, 12 lichens,
Thus, both algae and animals 9 bryophytes, 49 gastropods, 3
may have arrived at the Açores nematodes and 13 chordates.
with ocean currents, or through Some endemic terrestrial bio-
rafting on mats of floating vege- diversity may have been lost
tation or wood and via human because it is estimated that,
interventions although, in the overall, but 2% of natural forest
latter case, as the islands have remains on the islands.
Paginação_21.indd 58 19-01-2012 11:51:20MORTON: DARWIN, THE ATLANTIC AND THE AÇORES 59
This has had readily identi- the degree of isolation, that is,
fiable consequences for some the distance from a mainland
species and in the past, the sta- and its biota. In the case of the
tus of the endemic Açorean bull- Açores, some 1,200 kilometres
finch – the priolo – (Pyrrhula mu- from mainland Europe, combi-
rina) was considered threatened ned with the relative youth of
although it is possibly making the islands, the low level of en-
a recovery in some locations. demicity is hardly surprising.
Interestingly, this species is to- Further, even though they are
day restricted to the eastern end, volcanic, oceanic islands are ty-
Nordeste, of the island of São pically unproductive. This is be-
Miguel. In Darwin’s time, howe- cause such young, steep, islands
ver, it would have had a much cannot hold water nor retain nu-
wider distribution on this island trients and this helps us under-
and thus if he had landed on São stand why the carrying capacity
Miguel, he may well have seen it, of islands is low. That is, they
easily recognized it as subtly cannot sustain the energy-ex-
different from the European pensive lives of large animals,
bullfinch (Pyrrhula pyrrhula) and, either herbivorous or carnivo-
thereby, not only considered the rous. Similarly, there are few en-
Açores to be more interesting demic species of marine plants
than he did, but obtaining a clear and animals on such young is-
example of island endemicity. We lands (Morton & Britton, 2000a,
have to remember, moreover, that b). Some algae, a couple of
Darwin did not discover the signi- fishes, a chiton, an ophiuroid,
ficance of the Galapagos finches’ a few sponges, barnacles and,
endemicity until a er his return possibly, some of the 20 rissoid
to England – the priolo, however, gastropods recorded from the
had he seen it, might well have Açores, including Alvania medio-
revealed it to him whilst on the littoralis (Ávila et al., 2008), are
voyage. considered to be endemic. As
Of the 107 species of Açorean more research is undertaken,
terrestrial snails, some 50% (49) however, so either conspecifics
are endemic (Borges & Gabriel, or very closely related species
2009). Island endemicity is re- are found nearby, such as in the
lated to age, size, elevation, Mediterranean, the Canaries or,
climate, niche availability and even, on seamounts elsewhere.
Paginação_21.indd 59 19-01-2012 11:51:2160 AÇOREANA 2011, Suplemento 7: 39-71
Frias Martins (1995) recognized northern shore of the island of
the Açorean rocky shore elobiid São Jorge. The sea grass Ruppia
snail Ovatella vulcani as endemic, maritima is known only from Fajã
but as this is a pulmonate, like dos Cubres (Morton et al., 1995)
its endemic terrestrial leptaxine whilst within the sediments of
relatives, this may well be true. Fajã de Santo Cristo, also on São
The intertidal limpet Patella can- Jorge, occurs the only known,
dei gomesii is considered to be probably introduced, popula-
an Açorean endemic subspecies tion of Venerupis decussata in the
(Cúrdia et al., 2005). Macaronesian islands (Morton &
With such a wide variety of Tristão da Cunha, 1993). Both of
degrees of exposure to wave ac- these lagoons have been descri-
tion in the Açorean littoral, there bed in general terms by Morton
is a propensity for great mor- & Tristão da Cunha (1993) and
phological variation as has been Morton et al. (1995, 1998), and
demonstrated for the only com- there is a marsh at Lajes on the
mon intertidal littorine, Littorina island of Pico and which has
striata (Backeljau et al., 1995). been described, also in general
Without care, such ecopheno- terms, by Morton et al. (1996).
typic variation may lead to the All these isolated miniature la-
unwarranted description of en- goonal wetlands are threatened
demicity. an d a re in u rg e n t n e e d o f
greater study. For example, it
MARINE CONSERVATION IN has been shown by Jordaens et
THE AÇORES al. (2000) that there has been a
loss of genetic variation in the
The only places where ter- strongly isolated population of
restrially derived nutrients are Tapes (=Venerupis) decussata in
retained on steep, typically re- the Fajã de Santo Cristo such that
cently formed, volcanic, off- it is highly vulnerable to extirpa-
shore islands are lagoons and tion.
this makes such habitats extre- In some locations on the
mely important. By their very Açores we can demonstrate that
nature, the young Açorean is- marine colonization has been not
lands arise near vertically from just fast, but dramatic, occurring
the seabed and two lagoons oc- within just a few years. On the
cur on the steep (precipitous) island of Terceira, there was a
Paginação_21.indd 60 19-01-2012 11:51:21MORTON: DARWIN, THE ATLANTIC AND THE AÇORES 61
FIGURE 13. A, The quarry at Cabo da Praia on Terceira in 1995 and B, in 2006. (Photo’s
courtesy of J.A. Paulus Bruno).
marsh at Paul, Praia da Vitória now, 26 species identified. It is
(Morton et al., 1997). This, today considered to be the most
however, has now been drained. significant coastal wader site in
There was, however, a coastal the archipelago. The question is,
quarry at Cabo da Praia, also however, since, the quarry was
on Terceira, and which when only constructed in ~1983, how
studied for the book ‘Coastal did such a collection of species
Ecology of the Açores’ (Morton et come to colonize it?
al., 1998) was found to contain
tidally inundated pools (Figure
13A). It was also shown to be
home to numerous species of
coastal plants, two species of
Assiminea (Gastropoda), the
amphipod Orchestia mediterranea
and, a near-unique (for the
Açores) collection of migrating
coastal birds including some
American vagrants, for instance, FIGURE 14. The floor of the quarry at Cabo
the Hudsonian godwit (Limosa da Praia on Terceira in March 2010 a er a
haemastica). Since first described cleanup by the Environmental Division of
by Morton et al. (1997), growing Bensaúde, one of the companies that has
a concession for the fuel storage facilities
numbers of bird species have
at Pedreira do Cabo da Praia, adjacent
been recorded from the quarry to the wetland. (Photo: Marco Lopes,
at Cabo da Praia (Table 2) with, Bensaúde).
Paginação_21.indd 61 19-01-2012 11:51:2162 AÇOREANA 2011, Suplemento 7: 39-71
TABLE 2. Birds recorded from the quarry at Cabo da Praia, Terceira.
July 1997 October 1997 July/August
February 2006 March 2006
Species (Morton et al., (Morton et al., 2007
(S. Rodebrand) (B. Carlsson)
1998) 1998) (B. Carlsson)
Charadrius hiaticula (Ringed plover) 3 1
Charadrius dubius (Li le-ringed plover) Pairs 20-30
(96-126, x =
Charadrius alexandrinus (Kentish plover) 30 (Resident) 30 39 30 >112 in May
and June)
Charadrius semipalmatus (Semipalmated
1 -
plover)
1 (First 6 (Winter
Pluvialis squatarola (Grey plover)
summer) plumage)
Calidris canutus (Red knot) 7 3 3
Calidris alba (Sanderling) 1 >100 41 60
Calidris minuta (Li le stint) 3 3
Calidris minutilla (Least sandpiper) 1 -
Calidris fuscicollis (White-rumped
1 -
sandpiper)
Calidris ferruginea (Curlew sandpiper) 2 2
5 (Winter
Calidris alpina (Dunlin) 4
plumage)
Tringa ochropus (Green sandpiper) 1
3 (breeding
Limosa limosa (Black-tailed godwit) 1 1
plumage)
Limosa lapponica (Bar-tailed godwit) 8 1
Limosa haemastica (Hudsonian godwit) 1
Numenius phaeopus (Whimbrel) 2 1 6 4
12 (Adults +
Arenaria interpres (Turnstone) 20 29 50 (29-68, x = 54)
first summer)
Philomachus pugnax (Ruff ) 1
Sterna hirundo (Common tern) Present 40
Sterna dougallii (Roseate tern Present 2
Larus cachinnans (Yellow-legged gull) Present
3 (Winter
Larus ridibundus (Black-headed gull)
plumage)
Ardea cinerea (Grey heron) 3 4
Egre a garze a (Li le egret) 1 2
Anas platyrhynchos (Mallard) 2 females
Charles Darwin also pondered earth adhering to it. … the earth
such a question and in the The had been kept for three years, but
Origins of Species by means of when broken, watered and placed
Natural Selection, he considered under a bell glass, no less than
that birds might be responsible 82 plants sprung from it…’ and
for such rapid colonizations. He ‘can we doubt that the many birds
reported that: which are annually blown by gales
‘..the leg of a red-legged partridge across great spaces of ocean and
(Caccabis rufa) had a ball of hard which annually migrate….must
Paginação_21.indd 62 19-01-2012 11:51:22MORTON: DARWIN, THE ATLANTIC AND THE AÇORES 63
occasionally transport a few seeds upon whose shoulders Darwin
embedded in dirt adhering to their stood. John Stevens Henslow
feet or beaks’ (Darwin, 1878). was Darwin’s early botanical
Regrettably, along with the mentor. The botanist Joseph
destruction of the marsh at Dalton Hooker inspired Darwin
Paul, the entrance to the unique, to study biogeography and how
man-created, quarry habitat at plants are transported across
Cabo da Praia, has been largely the oceans. Darwin’s greatest
developed (Figure 13B). But mentor, the geologist Charles
what a wonderful project it Lyell, inspired him to think first
would have constituted to test about geology (on Cape Verde)
Darwin’s theories of how coastal and then to marry his thoughts
plants and maybe animals could on this subject with his others
have colonized Açorean shores on biology to come up with the
– both by transport across the great unifying theory of the evo-
sea with ocean currents and by lution of life on Earth, but also
birds. the evolution of the Earth itself.
A postscript to this develop- And, eventually, to discover how
ment, however, is that one of the island floras and faunas are ob-
companies which has a conces- tained and, themselves, evolve
sion for the fuel storage facilities in wonderful isolation. Robert
at Pedreira do Cabo da Praia on FitzRoy, Captain of H.M.S.
Terceira, adjacent to the quarry,
has, in March 2010, undertaken
a cleanup of the floor of Cabo
da Praia (Figure 14), perhaps
signaling a change in environ-
mental awareness in relation to
this highly important Açorean
wetland.
Many great men both taught
and influenced Charles Darwin,
as a young, 22 year-old, adven- FIGURE 15. The eruption of Sabrina
turer on H.M.S. Beagle. These Island on 19 June 1811, as drawn by
included a number of distin- Lieutenant John William Miles of H.M.S.
guished 19th century scholars Sabrina. (A er Tillard, 1812).
Paginação_21.indd 63 19-01-2012 11:51:2264 AÇOREANA 2011, Suplemento 7: 39-71
Beagle, became the foil against third son so that, in many ways,
whom, as his companion natu- the cultural and, especially, the
ralist, Darwin debated the ideas maritime histories of Portugal
that were slowly fomenting in and England are inextricably
his mind. FitzRoy eventually linked, even today. I had the
became a Vice-Admiral, famous privilege of meeting Colonel
in his own right for creating the Agostinho in 1965 in Angra do
modern science of weather fore- Heroísmo.
casting. As a devoted Christian, Although the Açorean islands
however, he would eventually were of little interest to Darwin
divorce himself from Darwin’s when he visited them in 1836,
heresy and, as he saw it, unjus- his views changed subsequently.
tly awarded fame, and commit- Firstly, his attention was drawn
ted suicide by cutting his own to the islet of Sabrina that arose
throat on 30 April 1865. from the sea during June and
Interestingly, an eminent July 1811 (Tillard, 1812) just
Açorean, Colonel José Agostinho opposite Ponta da Ferraria
( 1888- 1978), bec ame c h ief on São Miguel (Figure 15).
scientist with the Portuguese Coincidentally, H.M.S. Sabrina
National Weather Service and, was in the vicinity and onto the
for providing the British with shores of the newly formed islet
meteorological and sea-state stepped Captain James Tillard to
data during the Second World claim it for Great Britain. This
War, was made an Honorary caused a diplomatic rift until the
Commander in the Order of the islet disappeared back into the
British Empire by King George sea from which it had arisen in
VI. This act and its recognition August 1811. Nevertheless, for
is in remarkable recognition of Darwin, this was incontrovertible
the Anglo-Portuguese Alliance proof that volcanic islands
of 1373. This came about when do arise and may sink over
John I (1358-1433), the tenth King the course of their lifetimes,
of Portugal and the Algarve, albeit with great differences in
now famously, married, in 1387, rates. A similar event occurred
Philippa of Lancaster, daughter in the 20th century when the
of John of Gaunt (1340-1399) Capelinhos volcano erupted
of England. Prince Henry the on the west coast of Faial in
Navigator (1394-1460) was their 1957. This eruption was studied
Paginação_21.indd 64 19-01-2012 11:51:23MORTON: DARWIN, THE ATLANTIC AND THE AÇORES 65
by the Açorean vulcanologist However, more interestingly,
Frederico de Menezes Avelino in response to a request from
Machado (1918-2000) and which Furtado for research advice, in
when I visited it in 1965 was still a reply letter dated 3 July 1881,
volcanically active. Machado Darwin suggested to him that:
was assisted in this research by (1), If possible, the most distant
Victor Hugo Lecoq de Lacerda outlying islands and their plants
Forjaz (born 1940), who became and animals should be com-
Professor of Vulcanology at pared with those of the other is-
the University of the Açores lands; (2), all the plants and ani-
and is today Director of the mals from the highest mountain
Observatório Vulcanológico e summits on all the islands ought to
Geotérmico dos Açores. be collected; (3), searches made
Secondly, and more impor- for glacial deposits and for the
tantly, however, Darwin en- presence of fossil remains, in
tered into correspondence with such stones and (4), any light-
Francisco d’Arruda Furtado -houses should be inspected for
(1854-1887), a native Açorean, any land-birds that might have
much interested in natural his- flown into the glass and killed.
tory, a devotee of Darwin, and In such cases, their feet and beaks
a believer in evolution through should be examined not only for
natural selection. Darwin was earth, but the whole contents of
perplexed as to how the lizard their alimentary canals dried out
(Lacerta dugesi), earthworms and and placed on damp pure sand
snails had arrived in the Açores. under a small bell-glass to see
He asked Furtado specifically if any seeds are present which
to determine if the lizard’s eggs would germinate. If so, grow
could survive in seawater. The any plants and name them.
truth is probably much more Thirdly, as described above,
prosaic, however: all could have Darwin knew that seeds from the
arrived, except for the endemic New World occurred regularly
leptaxine snails (van Riel et al., on Açorean beaches and he used
2005) via human interventions. this fact as the raison d’etre for his
Indeed, Chaves (1949), provides experiments on the survival of
an introduction date of 1860 for seeds and other plant pieces in
the Macaronesian lizard although seawater. Thus, when asking his
this seems highly improbable. friend Joseph Hooker for seeds
Paginação_21.indd 65 19-01-2012 11:51:2366 AÇOREANA 2011, Suplemento 7: 39-71
to be collected from Hitcham in ding of the forces that created
Suffolk, England, he specifically the archipelago and how they
requested that they include became colonized show us what
those from plants also known to is important with regard to mari-
grow in the Açores. ne conservation in the Açores.
Hence, although Darwin’s vi- The predominant rocky shores,
sit to the Açores was not initially washed by oceanic currents are
inspiring, the islands subsequen- probably going to provide us
tly became so for him. Similarly, with only a few, if any, examples
he laid down the initial basis for of endemic species. There may
our understanding of how the similarly be few endemic spe-
Açorean flora and fauna was cies making up the communities
obtained. Finally, however, and of other intertidal habitats. In
although the word conservation one or two places in the Açores,
was not in Darwin’s vocabulary however, there are intertidal,
(in the natural history sense), his lagoonal, wetlands. In particu-
researches upon and understan- lar, Fajã dos Cubres and Fajã de
FIGURE 16. An illustration showing the origins of mankind from Paradise – Lemuria
– located in the Western Indian Ocean. The frontispiece to Ernst Haeckel’s History of
Creation (1876).
Paginação_21.indd 66 19-01-2012 11:51:23MORTON: DARWIN, THE ATLANTIC AND THE AÇORES 67
Santo Cristo, both on São Jorge, nued to argue that human evo-
the marsh at Lajes on the island lution consisted of exactly 22
of Pico and, especially, the quar- phases, the 21st (back in time),
ry at Cabo da Praia on Terceira, being the ‘missing link’ and re-
have much to reveal about how presenting a halfway step betwe-
such isolated communities have en apes and humans. But, that
become established – a question our origins were still in Paradise
that Darwin was deeply concer- (Figure 16). Clearly, even this
ned with, but who never saw enlightened contemporary of
these little habitats in the Açores. Darwin, still felt the need to ack-
In particular, the modern quarry nowledge the Christian orthodox
at Cabo da Praia, on Terceira, view of Genesis. But the illustra-
because it is isolated from sea, tion represents more, because its
except via the surrounding ba- image of human evolution still
saltic rock wall filter could tell resonates today in the minds of
us much about the origins of the some, generations later, and high-
Açorean biota and, more interes- lights the continuing struggle
tingly, how its representatives between science and faith for the
have obtained purchase on the soul of humanity and haunts the
islands. progress of humankind towards
In his understanding of the a more tolerant world.
evolution of life, Darwin also In the context of island
discovered important facts con- evolution, however, and espe-
cerned with the evolution of cially in the comparatively new
the Earth, thereby achieving the geological context of the Açores,
marrying of biology and geo- the researches of Charles Darwin
logy, that is, the unification of remain unchallenged and are
the history of life on Earth and, critical to our understanding
finally, the rejection of the bi- of island biogeography. And it
blical account of creation. It is his seminal discoveries that
i s i nteres tin g th ough , th a t have, in turn, led to a better
despite meeting, believing in understanding of the need for
evolution through natural se- conservation not only on land,
lection and supporting Darwin, but also on the riparian edge
Ernst Haeckel (1834-1919), the of the sea, especially on island
great German anatomist, em- archipelagos where new found
bryologist and illustrator, conti- life clings precariously.
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