Galapagos Islands: Unique Wildlife and Natural Paradise and the Evolution

“Galapagos is probably the best explored archipelago in the world, but it surprises us every
day with new discoveries,” says Jorge Carrión, Director of the Galapagos National Park.
The Galapagos Islands lie 1000 kilometers off the coast of Ecuador in the Pacific Ocean
and the equator line crosses the archipelago, to the north of the island of Isabela.
Galapagos is the second largest volcanic island area on the planet, surpassed only by
Hawaii. The most famous visitor was Charles Darwin, whose voyage led him to establish
his theory of evolution by natural selection. Nowhere else can you find such a diverse flora
and fauna in different stages of development in such a limited space. Many island species
are descended from mainland species, but have developed into new species in isolation.
Researchers and visitors have the opportunity to study the natural laboratory of evolution:

In the beginning of March 2024, the shield volcano La Cumbre 1476m / 4.842ft, which is
located on the island of Fernandina in the west of the archipelago, has been in eruptive
activity and the lava had reached the coast and was flowing bubbling into the sea.
https://www.galapagos.org/newsroom/lava-from-la-cumbre-volcano-eruption-has-reached-
the-sea/

The giant tortoise species living on the island of San Cristóbal genetically corresponds to
another species that had been considered extinct since the beginning of the 20th century,
according to a comparison of genetic analyses.
https://www.galapagos.org/newsroom/new-taxon-of-giant-tortoise-discovered-in-galapagos-
islands/#:~:text=New%20DNA%20analysis%20of%20century,organisms%2C%20or%20“ta
xon%2C”

Researchers observed on Daphne Major how a large male cactus finch mated with a
female of the medium-sized ground finch and produced fertile offspring. Forty years later,
there are around 30 offspring. This rapid speciation shows that evolution can happen faster
than expected.
https://www.princeton.edu/news/2017/11/27/study-darwins-finches-reveals-new-species-
can-develop-little-two-generations

Three new species of the blind spider genus Metagonia have been discovered in the lava
tunnels of Santa Cruz and Isabela. At the same time, new lichen species were described
on several islands.
https://bioone.org/journals/invertebrate-systematics/volume-36/issue-7/IS21082/Metagonia-
spiders-of-Galápagos–blind-cave-dwellers-and-their/10.1071/IS21082.short

In the Galapagos, land and marine iguanas normally have separate breeding seasons. On
South Plaza, however, these overlap slightly, so that late land iguanas may be forced to
mate with marine iguanas that have just arrived. Hybridization only occurs between male
marine iguanas and female land iguanas. Although hybridization is usually considered
negative, as it reduces the gene pool of a species and increases the risk of extinction, the
hybrid iguana on Galapagos is an exception. This rare species evolved through a natural
process without human intervention. https://galapagosconservation.org.uk/about-galapagos/islands/north-plaza-south-plaza/

And it was only at the beginning of May of 2024 that a new discovery made the
international press: a team of researchers apparently spotted a potential birthplace for
smooth hammerhead sharks off the island of Isabela.
https://www.galapagosscience.org/new-nursery-for-vulnerable-hammerhead-shark-
discovered-in-galapagos/

Galapagos Ocean Currents

We owe much of the biodiversity of the Galápagos the 3 ocean currents that converge
here: The South-Equatorial surface water current, the Peruvian/Humboldt current, and
the Cromwell Equatorial Sub current:

•  The South Equatorial surface water current flows east-west.
•  The Humboldt/Peruvian current brings in cold waters from the south as well as the tropical waters of the Panama current from the north.
•  The Cromwell current flows from the west, along the ocean bottom until it rises to the surface in the Galápagos. The Cromwell current brings in cold, nutrient-rich waters vital to many of the Galápagos Islands resident marine and terrestrial fauna.

History

The Galápagos Islands were discovered by chance on March 10, 1535, by Fray Tomas de
Berlanga. Strong ocean currents unexpectedly carried his ship to the islands’ shores after
17 days at sea. At the time, the Archbishop of Panama found the islands uninhabitable and
struggled to return to the mainland. Known as the “enchanted islands,” they earned this
nickname in the 16th century because they seemed to mysteriously appear and disappear.
This illusion was caused by the inaccuracy of early navigation tools, powerful ocean
currents, and the fog that often obscured the islands, making it difficult for privateers and
whalers to locate these “phantom islands.”

In 1832, the island was incorporated into Ecuadorian territory. The Galapagos National
Park was established in 1959 and the Charles Darwin Research Station on Santa Cruz
Island in 1964. The Galapagos Archipelago was recognized by UNESCO as a World
Heritage Site and Biosphere Reserve in 1978. In 1998, the waters around the islands were
declared a marine reserve. The southern part of Isabela is designated as a wetland of
international importance (Ramsar Convention).

The Galápagos Islands were formed over five million years ago due to tectonic activity
occurring over a “hot spot,” a zone where hot magma rises from the Earth’s lower mantle.
As the tectonic plate drifts over this spot, new islands are continually created. The
westernmost islands, Isabela and Fernandina, are still actively forming today.

The archipelago consists of 18 main islands, 3 smaller islands and around 107 rocks and
islets. The islands are inhabited by around 25,000 people, and all of them live on the
islands with fresh water: San Cristóbal, Santa Cruz, Isabela and Floreana.

Fauna

The first islands were initially completely isolated. Nevertheless, over time many species
found their way across the sea to the islands, where they found a new habitat thanks to
their adaptability. Half of the birds and most of the classified reptile species are endemic to the Galapagos
Islands. The most symbolic animal is the giant tortoise, after which the Galapagos Islands
are named in Spanish. There are also the Galapagos penguins, which probably reached
the islands with the Humboldt Current from Antarctica. There is also the only wingless
cormorant, the Galapagos albatross and the land birds: Galapagos buzzard and
Galapagos barn owl, the four species of mockingbirds and not forgetting the many species
of Darwin’s finches …

The Galápagos Islands are home to a variety of native animal species, some of which also
inhabit the South American coast. These include the flamingo, blue-footed and red-footed
boobies, Nazca booby, shearwater, brown pelican, frigate birds, and various species of
gulls. Since the islands were never connected to the mainland, there are few native
mammals. Most land mammals, like mice, bats, rats, dogs, cats, and goats, were
introduced by humans. Marine mammals, however, play a much larger role in the islands’
ecosystems, with sea lions, fur seals, dolphins, and whales being prominent. The
surrounding waters are also rich with sharks, turtles, rays, and an array of colorful fish.

Flora: Plant Pioneers in an Evolving Landscape

The flora of the Galápagos Islands had a challenging journey to reach this remote
archipelago, carried by birds, winds, or natural rafts. Once there, these plants adapted to
the unique environment, reflecting the islands’ geological youth, with species still evolving
into new varieties. Around 35% of the native plant species are endemic to the Galápagos,
with up to 614 native species and 825 introduced ones. Many plants form their own
endemic genera, such as the “sunflower tree” Scalesia. They all form complex ecosystems at different altitudes.

Vegetative Zones of the Galápagos

1. Littoral/Coastal Zone Located at the ocean’s edge, this zone features salt-tolerant plants like mangroves, which support both marine and bird life. Four different mangrove species can be found throughout the islands: black mangroves, button mangroves, red mangroves, and white mangroves. Mangroves protect coastlines and provide habitats for young marine species.
2. Arid Zone
   Covering the majority of the islands, this zone is dominated by cacti like the prickly pear, essential to giant tortoises and land iguanas. The prickly pear cactus is a primary dietary component of the giant tortoises and land iguanas, and the two animals have unwittingly served as seed carriers and introduced the cactus onto several islands. Other hardy plants like Galápagos lantana and Palo Santo trees thrive here.
3. Transition Zone
   Connecting the arid lowlands with the moist highlands, this zone boasts the greatest diversity of plants, with species like the endemic pega pega shrub and hardwood matazarno.
4. Scalesia Zone
   The “rainforest” of the Galápagos, this zone at higher elevations is named after the giant Scalesia trees, which reach up to 60 feet and support mosses, orchids, and ferns.
5. Zanthoxylum or Brown Zone
   Dominated by the “cat’s claw” tree and draped in brown lichens, this zone has been impacted by agriculture but remains an important vegetative area.
6. Miconia Zone
   Found only on San Cristóbal and Santa Cruz at elevations around 975m / 3,200 ft, this zone is home to the rare Miconia shrub, now endangered due to invasive species and cattle grazing.
7. Fern-Sedge or Pampa Zone
   At the highest elevations, this lush zone is blanketed in ferns, grasses, and orchids, creating a stark contrast to the arid zones below. Pools of water attract moisture-loving plants during the rainy season.

These distinct vegetative zones illustrate the incredible adaptability and diversity of plant
life in the Galápagos, offering a living laboratory of evolution in action.