Cormorants prove Charles Darwin’s hypothesis on plants


This video from Taiwan says about itself:

The Cormorants (1 of 4)

9 March 2010

The [great] cormorant is a large water bird with black plumage. It has a wingspan of about 100 centimeters. From the Ussuri River region of Siberia and the northern-east region of China they fly to spend about five months in Kinmen; they do not embark on their return journey to the breeding grounds until April the following year.

The cormorant is equipped with webbed feet, a strong bill, easily wet-able feathers and a special flexible pouch on its throat, making the bird an efficient catcher of fish. Highly gregarious, the cormorants like to feed and roost in large numbers. They also fly in line formations. Every year the entertaining antics and sheer number of these birds attract many visitors, both domestic and abroad, to Kinmen.

From Biology Letters:

Great cormorants reveal overlooked secondary dispersal of plants and invertebrates by piscivorous waterbirds

Casper H. A. van Leeuwen, Ádám Lovas-Kiss, Maria Ovegård, Andy J. Green

4 October 2017

Abstract

In wetland ecosystems, birds and fish are important dispersal vectors for plants and invertebrates, but the consequences of their interactions as vectors are unknown. Darwin suggested that piscivorous birds carry out secondary dispersal of seeds and invertebrates via predation on fish.

We tested this hypothesis in the great cormorant (Phalacrocorax carbo L.). Cormorants regurgitate pellets daily, which we collected at seven European locations and examined for intact propagules. One-third of pellets contained at least one intact plant seed, with seeds from 16 families covering a broad range of freshwater, marine and terrestrial habitats.

Of 21 plant species, only two have an endozoochory dispersal syndrome, compared with five for water and eight for unassisted dispersal syndromes. One-fifth of the pellets contained at least one intact propagule of aquatic invertebrates from seven taxa. Secondary dispersal by piscivorous birds may be vital to maintain connectivity in meta-populations and between river catchments, and in the movement of plants and invertebrates in response to climate change. Secondary dispersal pathways associated with complex food webs must be studied in detail if we are to understand species movements in a changing world.

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Carnivorous plants and Charles Darwin, part two


Carnivorous plants, 11 August 2017

As I wrote in the first part of this report, on 11 August 2017, before we went to the carnivorous plants exhibition in the botanical garden, we went to a lecture in Leiden University about carnivorous plants and Charles Darwin. The lecture was by Norbert Peeters. The title of the lecture was Darwin’s little shop of horrors.

All photos on this blog post, of slides shown during the lecture, are cell phone photos. The slide the photo of which is on top of this blog post describes carnivorous plants as ‘living flypaper‘.

Carnivorous plants through a microscope, 11 August 2017

In his book on carnivorous plants, Darwin also included pictures of plant details as seen through a microscope.

Sundew leaf, on 11 August 2017

Like this enlarged picture of a sundew leaf.

Drosera leaves, 11 August 2017

In a letter to botanist Hooker, Darwin wrote that sundew (Drosera) ‘leaves are first rate chemists’.

Darwin to Lyell, 11 August 2017

Darwin acknowledged that carnivorous plants should make people question the rigid hierarchical separation between plants and animals, which, as we saw, Linnaeus and others had advocated. In a letter to Charles Lyell, he wrote: ‘By Jove I sometimes think Drosera is a disguised animal!’

Utricularia, 11 August 2017

Darwin studied the aquatic carnivorous plant Utricularia (bladderwort) as well. In that, his correspondence with United States botanist Mary Lua Adelia Davis Treat (1830-1923) helped.

Mary Treat, 11 August 2017

Venus flytrap

Darwin also studied the Venus fly-trap.

Nepenthes, 11 August 2017

And Nepenthes pitcher plants. Frenchman Étienne de Flacourt had described Nepenthes pitcher plants for the first time in 1658. He thought the pitchers were flowers. Georg Everhard Rumphius (1627-1702), a German Dutch East India Company employee staying on Ambon island corrected that, noting the pitchers were leaves. In fact, carnivorous plants’ flowers are often at a distance from their prey catching leaves, to prevent the plants from eating their own pollinating insects.

Rumphius called Nepenthes in Dutch kannekes kruyd, little jug plants.

Rumphius did not know yet the insectivorous function of the pitchers. He did note that a small crustacean species lived in them, staying alive. This was forgotten: in 1987 two zoologists claimed they had discovered that crustacean’s lifestyle for the first time. In 2004, Rumphius’ earlier description was rediscovered.

In 1874 Hooker, advised to do so by Darwin, did experiments with Nepenthes plants, establishing they were carnivorous; just in time for Darwin’s 1875 Insectivorous plants book.

Sarracenia, 11 August 2017

Darwin did not experiment with Sarracenia pitcher plants, but wrote he suspected they were carnivorous as well.

Sarracenia minor, 11 August 2017

Darwin’s United States correspondent Mary Treat wrote:

From all appearance the terrible Sarracenia was eating its victim alive. And yet, perhaps, I should not say ‘terrible,’ for the plant seems to supply its victims with a Lethe-like draught before devouring them.

The Lethe, in ancient Greek mythology, was a river in the underworld making those who drank from it forget everything.

Evolution, 11 August 2017

Norbert Peeters concluded his lecture with a quote by Theodosius Dobzhansky:

Nothing in Biology Makes Sense Except in the Light of Evolution

Norbert Peeters, 11 August 2017

Peeters’ last slide was about his own presence on the Internet.

Carnivorous plants and Charles Darwin, lecture report


Norbert Peeters, 11 August 2017

On 11 August 2017, before we went to the carnivorous plants exhibition in the botanical garden, we went to a lecture in Leiden University about carnivorous plants and Charles Darwin. The lecture was by Norbert Peeters, on the left of this photo. The title of the lecture was Darwin’s little shop of horrors.

All photos on this blog post, mainly of slides shown during the lecture, are cell phone photos.

Today, Darwin’s best known book is On the Origin of Species. However, Peeters said, during Darwin’s life his best sold book was his 1875 Insectivorous plants.

Before Darwin, people either thought carnivorous plants did not exist; or they looked at them with fascination often mixed with exaggeration of how big carnivorous plants’ prey was.

In 1768, for the first time live Venus flytrap plants were brought from North America to England. In a 1770 book, John Ellis described them. He named the genus Dionaea, a Greek name for the goddess of beauty Aphrodite (Venus in Latin).

Venus fly-trap from Ellis' description

Ellis strongly suspected Venus flytraps were carnivorous. He wrote so to the most famous naturalist of the eighteenth century, Carolus Linnaeus, sending dried specimens with his letter.

However, Linnaeus did not believe that carnivorous plants existed.

Linnaeus, 11 August 2017

In support of that view, Linnaeus quoted the Bible, Genesis 1:30:

And to every beast of the earth, and to every fowl of the air, and to every thing that creepeth upon the earth, wherein there is life, I have given every green herb for meat: and it was so.

So, Linnaeus interpreted the Bible as saying that animals eat plants, not the other way round.

In this, Linnaeus was in a tradition, as pictured in this 17th century book, of seeing reality as a hierarchical ladder. God on top, humans below God. On the lower end, stones, etc. Plants one step below animals, forever unable to catch up with them.

Hierarchy, 11 August 2017

Linnaeus made tremendous contributions to systematic biology, still relevant today. However, comparable to earlier naturalists like Scheuchzer, he was still what would now be called a ‘creationist‘. He opposed the idea of evolution, in his own eighteenth century advocated in rudimentary form by Buffon, and later elaborated by Darwin, including as an explanation for the origin of carnivorous plants, as we shall see.

The poet Thomas Moore (1779-1852) reacted to the newly discovered Venus flytrap with the lines:

The Lord deliver us!
Think of a vegetable being “carnivorous!”

Venus flytrap, 11 August 2017

Now, from denial to fascination mixed with exaggeration.

Tree eating humans, 11 August 2017

In Victorian England, there were fictional stories, as well as stories claiming to be non fictional, about plants eating people; like a tree in Madagascar supposedly feeding on humans.

Today, we know that the biggest animals eaten by carnivorous plants are mice. And even that size is too much for most of today’s about 680 carnivorous plant species.

This video from the USA says about itself:

20 January 2017

While the carnivorous cravings of most flesh-eating plants are limited to small insects, one exception is the pitcher plant. It can consume anything that fits in its mouth–including a mouse!

However, Peeters said, twentieth century films like The Little Shop of Horrors and The Day of the Triffids continued the nineteenth century stories of carnivorous plants being dangerous to humans.

The little shop of horrors, 11 August 2017

Though about 1800 much was still unknown about carnivorous plants, they fascinated many people. Empress Josephine of France and President Thomas Jefferson of the USA owned Venus flytraps.

Since Darwin’s 1860s-1870s experiments with carnivorous plants, we know much more about the Venus flytrap.

Peeters illustrated that by playing this 2009 BBC video.

The video says about itself:

Life – Venus Flytraps: Jaws of Death – BBC One

Hungry Venus flytraps snap shut on a host of unfortunate flies. But, despite its name, flies aren’t the flytrap’s only meal. As long as its prey is roughly the right size and touches two of its hairs within twenty seconds, the plant will dine on any insect or spider that comes its way. Glands in the lobes then secrete enzymes that break the dinner down into a digestible soup. Ten days later, the trap pops open to reveal nothing but a dried out husk.

Thanks to Darwin and others, we now know more about the European carnivorous plant sundew than centuries ago.

Sundew has liquid droplets on it. Many other plants have dew droplets on them early in the morning. These evaporate as the sunshine gets stronger. In sundew, they don’t evaporate. People thought the sundew droplets were a peculiar kind of dew resistant to warmth; hence the plant’s name ‘sundew’.

Erasmus Darwin, 11 August 2017

In the late eighteenth century, Erasmus Darwin, the grandfather of Charles Darwin, said the sundew droplets were not dew. He correctly thought they had to do with insects. He did not know yet they had to do with eating these insects though.

Insectivorous plants, 11 August 2017

Erasmus Darwin’s grandson Charles experimented with carnivorous plants. In 1875, the results of these experiments were published in his Insectivorous plants. Why did plants become carnivorous? Because they grew in soils with few nutrients, Charles Darwin pointed out. They needed other sources of nutrients. In the course of evolution, carnivorous plants developed mechanisms to lure, catch and digest arthropod prey.

Sundew leaf, 11 August 2017

Like this specialized sundew leaf from Darwin’s book.

Carnivorous plants' traps, 11 August 2017

Peeters pointed out there are three kinds of carnivorous plants’ traps. Traps snapping tight, glue traps and pitcher traps.

The sequel of this will come on this blog. So, stay tuned!

‘Darwin’s Backyard’ chronicles naturalist’s homespun experiments. Breeding pigeons, growing orchids and other hands-on work provided evidence for the theory of evolution. By Sid Perkins, 10:00am, August 24, 2017.

Attenborough on Darwin and the Galapagos


This June 2016 video says about itself:

Charles Darwin‘s Galapagos Discovery – #Attenborough90BBC

Sir David retreads Charles Darwin’s footsteps to follow how he made the discovery of evolution on the Galapagos Islands.

See also here.

David Attenborough reads Charles Darwin


This video from Britain says about itself:

Sir David Attenborough Reads Charles Darwin#Attenborough90BBC

9 May 2016

Sir David reads the final paragraph of The Origin of Species by Charles Darwin.

Charles Darwin’s writings on the Internet


This 2012 video is called Evolution – Part 1 of 7 – Darwin’s Dangerous Idea (PBS Documentary).

From the American Museum of Natural History in the USA:

Project to Digitize Darwin’s Writings on Evolution Nearly Halfway Complete

by AMNH on 11/24/2014 02:36 pm

Tracing the evolution of Charles Darwin’s thoughts about evolution is becoming an increasingly accessible project, thanks to a growing cache of publicly available digitized Darwin manuscripts on the Museum’s site.

As of today—the 155th anniversary of the publication of Charles Darwin’s On the Origin of Species—the Museum’s Darwin Manuscripts Project has made available 12,000 high-resolution and color images of manuscript pages, drawings, book abstracts, and other writings, complete with transcriptions that decipher the famous naturalist’s handwriting. By June 2015, the Museum will host more than 30,000 digitized documents written by Darwin between 1835 and 1882.

“These notebooks, marginalia, portfolios, and abstracts were the basis for eight of Darwin’s books, beyond the Origin, that set down, enlarged, and defended the theory of evolution by natural selection,” said Darwin Manuscripts Project Director David Kohn. “In these writings, you can see Darwin as a thinker, a keen-eyed collector, an inspired observer, and a determined experimenter.”

The Darwin Manuscripts Project has been publishing Darwin’s writings since 2007, but the publication and interpretation of the entire corpus will make it possible for visitors to trace the gradual gestation and long maturation of Darwin’s theory of evolution by natural selection. The project involves a close collaboration with Cambridge University Library, which holds Darwin‘s archives, and the Darwin Correspondence Project. Content is being simultaneously published by the Cambridge Digital Library.

The 12,000 documents accessible on the site now cover the 25-year period in which Darwin became convinced of evolution; discovered natural selection; developed explanations of adaptation, speciation, and a branching tree of life; and wrote the Origin.

Darwin’s work in creating the Origin of Species encompassed much more than just setting pen to paper and writing the epochal book,” Kohn said. “The Origin was the mature fruit of a prolonged process of scientific exploration and creativity that began toward the end of his Beagle voyage, which first kindled Darwin’s interest in evolution, and that continued to expand in range and deepen in conceptual rigor through numerous well-marked stages.”

The remainder of the manuscripts, which will be available in June 2015, will pick up in the year the Origin was published—1859—and will include the full record of Darwin’s massive experimental research program to substantiate the power of natural selection until his death in 1882.

Most influential academic books, according to Britons


This video is called The Genius of Charles Darwin – HD Full Length (All 3 Episodes).

There is not only a National Bird election in the Netherlands. There was also another election in Britain.

From daily The Independent in Britain today:

These five books have been named as the most influential academic texts of all time

Posted 2 hours ago by Louis Doré

The most influential academic books in history have been revealed in a public vote.

Charles Darwin‘s On the Origin of Species from 1859, which founded evolutionary biology, was named the most influential academic text ever written.

The study was voted for by 26 per cent of the public in an online poll of over 900, to mark the inaugural Academic Book Week.

The top five were:

1) On the Origin of SpeciesCharles Darwin
2) The Communist ManifestoKarl Marx and Friedrich Engels
3) The Complete Works of William Shakespeare
4) The RepublicPlato
5) Critique of Pure Reason – Immanuel Kant

Also shortlisted were:

The Second Sex by Simone de Beauvoir
Ways of Seeing by John Berger
Silent Spring by Rachel Carson
The Meaning of Relativity by Albert Einstein
The Female Eunuch by Germaine Greer
A Brief History of Time by Stephen Hawking
The Uses of Literacy by Richard Hoggart
The Prince by Niccolò Machiavelli
The Naked Ape by Desmond Morris
Nineteen Eighty-Four by George Orwell
The Rights of Man by Thomas Paine
Orientalism by Edward Said
The Wealth of Nations by Adam Smith
The Making of the English Working Class by EP Thompson
A Vindication of the Rights of Woman by Mary Wollstonecraft

The poll was organised as part of a series of events and competitions throughout the UK, conducted by the Arts and Humanities Research Council in conjunction with the British Library, between 9-16 November.