F Rosa Rubicondior: Birds
Showing posts with label Birds. Show all posts
Showing posts with label Birds. Show all posts

Wednesday 6 March 2024

Creationism in Crisis - Earliest Toothless Bird From 120 Million Years Ago


Imparavis attenboroughi, a 'strange bird' named after Sir David Attenborough, British broadcaster and naturalist
Fossil named “Attenborough’s strange bird” was the first of its kind without teeth - Field Museum

It seems every week is a bad week for creationists, yet the wackadoodle cult staggers on, albeit with dwindling numbers, managing as always to ignore anything that shows their childish superstition to be wrong.

On top of the recently-reported predatory marine lizard, from 66 million years ago, we now have the earliest bird without the teeth of its enantiornithine ancestors. The enantiornithines were a diverse class of avian dinosaurs that went extinct 66 million years ago following the meteor impact that killed most of the dinosaurs. Only the ornithuromorphs survived, for reasons not completely understood, and they gave rise to all modern birds.

Saturday 20 January 2024

Creationism in Crisis - Biologist Watch Dawinian Evolution Happen - No Magic Was Involved


How does one species become many? | Newsroom - McGill University

Classical (Darwinian) evolution theory explains diversification of one species into several by hypothesising that an advantageous trait in any given environment will convey a fitness advantage in that environment, so carriers of that trait will have more descendants than non-carriers. As the environment varies so the advantageous traits with vary.

Although the logic of that is indisputable, formal proof of it in terms of observing it leading to diversification is hard to come by for several reasons, not the least of which is that speciation can only really be identified retrospectively when a large enough population exists to be able to say this is a new species, and not just a variant. There was no way to predict that a given individual or small population would actually become a new species so no reason to watch what happened. I explained this some time ago in a blog post about monkey diversification, subsequently confirmed by observation.

So, to the consternation of creationists, an international group of biologists led by McGill University have set about providing the evidence to validate the hypothesis, and, to make matters worse for creationists, they did it using the Galápagos finch, also known as Darwin's finch, that gave Charles Darwin the idea of evolution by natural selection as the explanation for biodiversity. So, this work not only validates basic Darwinian theory but also validates Darwin's choice of an example of it.

The biologists’ findings, based on 17 years of observations, are published open access in Evolution and are explained in a McGill University press release:

Tuesday 5 December 2023

Creationism in Crisis - Evolution of Rock Doves & Domestic Pigeons


Rock dove, Columba livia.
The wild ancestor of the domestic or town pigeon
Redefining the Evolutionary History of the Rock Dove, Columba livia, Using Whole Genome Sequences | Molecular Biology and Evolution | Oxford Academic

A great deal is understood about how the many different varieties of domestic pigeon were produced ever since Charles Darwin used them to illustrate the role of selection in evolution. In this case, selection is human selection rather than natural selection, although the difference is a matter of semantics if you regard human selective breeders as part of the domestic pigeon's environment.

Incidentally, creationists should note that Darwin never claimed evolution always resulted in new species. As he showed with his selective breeding examples, it produced new varieties too. Some of these have become so far removed from their wild ancestors that they rank as subspecies, like the domestic pigeon, Columba livia domestica

Although the radiation of domestic varieties is now well understood, the wild ancestors, the rock doves, have received far less attention until now. Now a paper by a team led by Germán Hernández-Alonso of the Center for Evolutionary Hologenomics, The Globe Institute, University of Copenhagen, Copenhagen, Denmark, redresses that discrepancy by analysing the entire genomes of 65 historical rock doves that represent all currently recognized subspecies and span the species’ original geographic distribution. 3 of these specimens were from Charles Darwin's collection.

This works shows that rock doves have diversified into a number of subspecies across their range, stemming from a subspecies now restricted to a small coastal strip of Northwest Africa, C. livia gymnocyclus. One of these subspecies received a substantial ingression of genes from a related species, C. rupestris after it split from the West African population but before it became domesticated. The result is that C. livia gymnocyclus should now probably rank as a species in its own right, C. gymnocyclus.

First a little about the evolution of domestic pigeons:

Friday 17 November 2023

Creationism in Crisis - 120 Million-Year-Old Bird Footprints Trample on Creationist Mythology


One of the Early Cretaceous bird tracks that clearly shows all four toes, including the rear toe, or hallux. The track is nearly 10 centimeters wide and is similar in size and form to tracks made by modern-day green herons.
Photo by Melissa Lowery.
Birds set foot near South Pole in Early Cretaceous, Australian tracks show

Some more of that long history of 'pre-Creation' life on Earth was revealed a couple of days ago when an international team of researchers led by Professor Anthony Martin, of Emory University’s Department of Environmental Sciences, and including researchers from Monash University and the Museums Victoria Research Institute in Australia; the Benemérita Normal School of Coahuila in Mexico; and the Smithsonian Institution, published their discovery of 27 bird tracks which vary in form and size in Early Cretaceous rocks. The tracks range from seven to fourteen centimetres wide and resemble those of modern shore birds such as small herons, waders and oystercatchers.

The discovery is published open access in PLOS ONE.

They were found in the Wonthaggi Formation south of Melbourne. The rocky coastal strata mark where the ancient supercontinent Gondwana began to break up around 100 million years ago when Australia separated from Antarctica and are the oldest bird tracks so far found.

At the time, in the rift valley that was opening up between Australia and what was to become Antarctica, the valley would have contained rivers which were subject to drastic seasonal changes between very cold, winters and several months of perpetual darkness and relatively warm summers when the river flood plain would have been home to migrant waders.

The tracks were made in successive stratigraphic layers which suggests seasonal flooding followed by gentle covering with silt or sand which preserved the footprints.

The Wonthaggi Formation is famous for its variety of polar dinosaur bones, although bird-fossil finds are extremely rare. The Cretaceous strata of the formation has yielded only one tiny bird bone — a wishbone — and a few feathers.

Birds have such thin and tiny bones. Think of the likelihood of a sparrow being preserved in the geologic record as opposed to an elephant.

Professor Anthony Martin.

Tuesday 26 September 2023

Creationism in Crisis - Increased Complexity Does Not Always Mean Increased Diversity


Study shows birds that have evolved greater complexity are less biodiverse
Flamingoes and geese
High skeletal complexity, low species diversity
The creation cult has fooled its members into believing that evolution, as defined by science, always involves increasing complexity. They do this because it's easier then to argue that either greater complexity implies intelligent design because systems become 'irreducibly complex' or because it implies that science is claiming that new structures can arise by evolution which contravenes some half-baked notion about new information contravening the second law of thermodynamics by equating 'information' to energy in a closed system.

This claim is blatantly untrue, of course, as any study of parasites will show, since parasites normally evolve by loss of complexity and genetic information, as I reported recently, and repeatedly point out in my illustrated book, The Malevolent Designer: Why Nature's God is not Good, which, judging by the misleading, lying and hysterical 'reviews' on Amazon is still causing panic in the creationist cult.

If that claim of increasing complexity leading to increased structures were true, we would expect it to always lead to increased biodiversity, which is exactly what we often see, but the truth is not as black and white as creationist frauds need to present it to their simplistic dupes.

As a new study by researchers at the Milner Centre for Evolution at the University of Bath have shown, in birds, evolution often results in less diversity and greater specialisation, as species adapt to new niche opportunities or environmental change. Their findings are published, open access, in Nature Communications.

As the press release from Bath University explains:

Saturday 16 September 2023

Creationism in Crists - How Prey Perception Directs Evolution


Lapwing, green plover or peewit, Vanellus vanellus
Habitat geometry rather than visual acuity limits the visibility of a ground‐nesting bird's clutch to terrestrial predators - Hancock - 2023 - Ecology and Evolution - Wiley Online Library


If you're going to perpetuate your genes through time, you need to arrange things so the next generation doesn't get eaten, because that ends your gene line. To do that, you need to ensure you arrange things so any potential predator has difficulty finding the next generation, at least before they've managed to breed.

I appreciate these concepts are difficult for creationists to grasp, but a paper out today shows the importance of catering for the perception of potential prey on your offspring, if you want then to survive and breed.

It concerns the siting of lapwing nests and eggs.

The northern lapwing, Vanellus vanellus, green plover or peewit (from their call), is a ground-nesting bird, which, until about 40 years ago was common in my part of Oxfordshire, UK. They formed vast flocks in the Autumn that would put on impressive displays as twilight approached, as they twisted and turned in flight (hence their name, lapwing) giving the flock a twinkling appearance as they exposed their white underwings, then twisted to hide them, confusing any potential predator such as peregrine falcons. Since then, they have been in rapid decline, probably due to habitat destruction and change in agricultural land management, and these vast flocks are no more.

Tuesday 22 August 2023

Creationism in Crisis - Urban Great Tits Have Beome Paler Than Their Rural Relatives


European great tit, Parus major.
Urban great tits have paler plumage than their forest-living relatives | Lund University

In an example of how the environment, and in this case probably the availability of different food items, can cause changes on which natural selection can act, a study by an international team or reserchers led by Pablo Salmón of Lund University, Sweden, has shown that great tits, Parus major living in an urban environment have paler breasts than those living in a forest environment.

Although this is probably not an evolutionary change, i.e., a change in the frequency of alleles in the population gene pools, as the cause is probably dietary difference, it illustrates how an environmental change can produce changes in features on which natural selection can act to bring about true evolutionary changes, and so begin the process of allopatric speciation.

Of course, there will be creationists who will misrepresent the scientific fact of evolution, either deliberately, or mendaciously in order to mislead others, who will dismiss this as "not evolution", not for the reason given above but because "they're still great tits/still birds" and haven't grown a new structure or turned into an unrelated taxon.

The research is explained in a Lund University press release:

Friday 18 August 2023

Creationism in Crisis - How Albatross' Beaks Evolved To Match Their Prey. No Magic Required


Wandering albatross, Diomedea exulans, widest wing-span of any bird

Image: picture-alliance/blickwinkel/K. Wothe
Thick ones, pointy ones – how albatross beaks evolved to match their prey

Just as Darwin's finch’s beaks did, albatross’ beaks have diversified as the different species diversified from a common ancestor, and the driving force is again the food they eat.

This is the finding of three biologists, Josh Tyler, a Postgraduate Research Student in the Department of Life Sciences, University of Bath, UK, Jane Younger, Lecturer, Southern Ocean Vertebrate Ecology, University of Tasmania, Australia and David Hocking, Adjunct Research Associate, Monash University, Australia.

And of course, it's bad news for creationists who have been fooled into thinking biologists are abandoning the Theory of Evolution in favour of their childish superstition with its belief in magic and supernatural deities.

The scientists have published their findings, open access in the journal Royal Society Open Science and have written about their research in The Conversation. Their article is reprinted here under a Creative Commons licence, reformatted for stylistic consistency:

Saturday 20 May 2023

Creationism in Crisis - How a 'Macro-Evolutionary' Change can be Produced by Changes to a Few Genes

Creationism in Crisis

How a 'Macro-Evolutionary' Change can be Produced by Changes to a Few Genes.
A transient change in expression of one gene (Shh) can produce a cascade of developmental events leading to the formation of feathers instead of scales


© UNIGE / Cooper & Milinkovitch
Sablepoot batams
Sablepoot bantams
Scales or feathers? It all comes down to a few genes - Medias - UNIGE

Lurk a while in any Evolution vs Creationism group in the social media and you can guarantee a creationist will try to argue that a given example of evolution which they have probably just deamnded be provided, and which conforms to the scientific definition of evolution - any change in allele frequency over time - is not real evolution because it wasn't 'macro-evolution' which they will define as a change in 'kind' or the evolution of a new species, even the evolution of new structures - whichever definition they think stands the best chance of winning.

I've been at this for long enough to remember how, when the early internet 'bulletin boards' on CompuServe had morphed into thriving debate 'forums', creationists would simply argue that there was no such thing as evolution, full stop! It simply never happened; not in the slightest. No Way! Everything was created exactly as it is today during 'Creation Week' a few thousand years ago! Any evidence to the contrary was a forgery by evil scientists or had been planted by Satan.

Then, in the face of so much evidence, particularly the very large number of living and extinct species and the impossibility of them all being collected together in a few days, herded onto a wooden boat and surviving for a year, they began to concede that there had indeed been evolution, but only limited to evolution withing species, and evolution moreover at a phenomenal rate, far exceeding anthing proposed by biologists, so as to produce the millions of species from a few 'kinds' that survived the genocidal flood their putative creator had inflicted on its creation, just a few thousand years ago.

What creationists are doing is moving the goal-posts by redefining a well-understood scientific term to place it beyond what science actually claims, so they can demand evidence of something that no evolutionary biologist ever claimed - that a single mutation produced a new species or that one species gave birth to another in a single event, ignoring the fact that evolutionary biologists understand the evolution is normally a slow process which takes place in the species gene pool, with the instances of new species arising by, for example, hybridization, being rare exceptions, but nevertheless, natural processes, not requiring supernatural entities to explain.

So, ask a creationist now wedded to the notion that real evolution needs to be 'macro-evolution' to define a reptile 'kind' and a bird 'kind' and they will normally define a reptile 'kind' as having scales and a bird 'kind' as having feathers, ignoring the fact that paleontologists have discovered several feathered dinosaurs (reptiles).

Now, present a creationist with an example such as the one in this research paper, where changes to a small number of genes resulted in what they would define as 'macro-evolution', i.e., a change in 'kind' because that change in chickens results in them growing feathers where they normally grow scales, showing the feathers are simply evolved scales.

Wednesday 15 March 2023

Climate Emergency News - Large-Scale Failure of Entire Bird Population to Breed

Climate Emergency News
Large-Scale Failure of Entire Bird Population to Breed
Dronning Maud Land (Queen Maud Land), Antarctica

Extreme snowstorms lead to large-scale seabird breeding failures in Antarctica: Current Biology
Map of Antarctica showing Dronning Maud Land
Map of Antarctica showing Dronning Maud Land
South Polar skua , <i>Stercorarius maccormicki</i>, with nest containing two eggs
South Polar skua, Stercorarius maccormicki, with nest
According to a survey published, open access, yesterday in the Cell Press journal, Current Biology almost the entire breeding population of three seabirds failed to breed on important breeding grounds in Antarctica, due to unseasonably high snowfall in the Antarctic 'Summer' (December 2020-January 2022) when breeding normally takes place. The unusual weather is almost certainly due to man-made climate change.

The researchers found not a single nest of the South Polar skua, and only a handful of the nests of the Antarctic petrel, Thalassoica antarctica, and Snow petrel, Pagodroma nivea, on the main breeding ground of Dronning Maud Land (Queen Maud Land) in the Norwegian-administered sector of Antarctica.

According to information from Cell Press:

Friday 3 March 2023

Creationism in Crisis - Scientists Discover Flamingos Have Personalities Too

Creationism in Crisis

Scientists Discover Flamingos Have Personalities Too
The partner of one Caribbean flamingo helps it out in an argument with another pair
Caribbean flamingo, Phoenicopterus ruber
Credit: Paul Rose

1 of 6
Caribbean flamingos with chicks

© Claudio Contreras Koob/naturepl.com
2 of 6
Nesting flamingos

© Claudio Contreras Koob/naturepl.com
3 of 6
Flamingos bathing

© Claudio Contreras Koob/naturepl.com
4 of 6
Flamingos bathing

Klaus Nigg, National Geographic Image Colection
5 of 6
Flamingo chick

© Claudio Contreras Koob/naturepl.com
6 of 6
Chick being fed

© Claudio Contreras Koob/naturepl.com
Flamingos form cliques with like-minded pals - News

According to Creationist superstition, humans are specially created as a different form of life from the rest of creation and so are the only species capable of experiencing 'higher' emotions such as love and friendship, or of being able to empathise with other members of the same species. This superstition is vigorously maintained, probably because the cult leaders understand that it makes their dupes feel special enough, so they stick with the cult and reject any idea which seems to reduce their over-inflated sense of self-importance.

The superstition is maintained despite the growing number of examples of other species having these 'human' emotions, such as this example of flamingos forming friendship and mutual support groups depending on their personality. Flamingos with similar personalities prefer to associate together and will even defend one another if attacked by a member of another group.

Flamingos are highly gregarious and can be seen in groups ranging from a half dozen to many thousands. I have seen small flocks of maybe a dozen in Andalucia, Spain and in Kuwait, larger flocks of several thousand in the Camargue, France and probably tens of thousands on the Limasol Salt Lake, Akrotiri, Cyprus.

The research in question was carried out on a captive population of Caribbean flamingos at the Wildfowl & Wetlands Trust, Slimbridge, Gloucestershire, UK, by two scientists from Exeter University.

The research is explained in an Exeter University news release:

Wednesday 1 March 2023

Creationism in Crisis - Scientists Find New Clues to How Hummingbird Diversity Evolved

Creationism in Crisis

Scientists Find New Clues to How Hummingbirds Evolved Coloured Feathers
Pink-throated Brilliant, Heliodoxa gularis
© Carlos Calle Quispe
16 April 2017

Pink + pink = gold: hybrid hummingbird’s feathers don’t match its parents | Field Museum
The gold-throated hybrid, center, with its parent species H. branickii (left) and H. gularis (right).

© Kate Golembiewski, Field Museum

When scientists from the Field Museum of Natural History, Chicago, Illinois, USA, discovered a hummingbird with an iridescent gold throat, they thought they had discovered a new species, but DNA evidence revealed that it was a hybrid between two closely related species - the Pink-throated Brilliant, Heliodoxa gularis and the Rufous-webbed Brilliant, H. branickii.

The problem was that the two parent species both had pink throats, so you might expect a hybrid to have a pink throat also, not glittering gold.

Saturday 25 February 2023

Creationism in Crisis - How Did Birds Get Their Wings? They Evolved of Course!

Creationism in Crisis

How Did Birds Get Their Wings? They Evolved of Course!

Fossilised propatagium, labeled ppt in image
©2023 Yurika Uno and Tatsuya Hirasawa CC-BY

Musculoskeletal system of the avian left wing in ventral view. A, B, Propatagium (A) and forelimb muscles (B). C, D, Synchronous actions between the elbow and wrist joints, at an extension via the function of the musculus (m.) propatagialis (C) and at a flexion via the interlocking wing-folding system (D)
How birds got their wings | The University of Tokyo

Another gap was slammed shut by science recently and, once again, no gods were found.

The gap was in our knowledge of how exactly birds wings evolved; now two Japanese scientists from the Department of Earth and Planetary Science, Tokyo University's Graduate School of Science, Yurika Uno & Tatsuya Hirasawa, have shown that the key structure, known as the propatagium, evolved out of an analogous structure in non-avian dinosaurs.

Creationists hoping to find evidence that the Theory of Evolution is being increasingly rejected by mainstream scientists will be disappointed to find not a scrap of evidence in this paper that the TOE is other than alive and well and providing an explanation for the observable facts as well as predicting what the scientists would find and informing their research. This paper is not about whether birds’ wings evolved, but how and from what starting point.

The Tokyo University news release explains the research and its significance:

Sunday 12 February 2023

Creationism in Crisis - Now Cockatoos Have Been Seen Choosing Tools For A Task

Creationism in Crisis

Now Cockatoos Have Been Seen Choosing Tools For A Task
Goffin's cockatoo not only makes tools but selects the right ones to take to work
Source: Natural History Museum
©SunyawitPhoto/Shutterstock

Experimental set up
Platform and table setups during experiment 3
(A) Walking phase.
(B) Horizontal flight.
(C) Vertical flight.

Cockatoos know to bring along multiple tools when they fish for cashews -- ScienceDaily

Imagine you're a Creationist fraud trying to convince your credulous cult that a magic man in the sky made humans specially and flattering your target marks by citing our high intelligence as evidence of our difference, as though we are the only species to have something that makes us unique (like every other species has). Then along come a bunch of clever scientists and shows that another, very distantly related species, a cockatoo, is also highly intelligent.

The conclusion any sensible person is going to draw from this is that intelligence is not unique to humans but is an evolved trait that has arisen in many distantly related species such as octopuses, bees, birds, and several mammals. That it has arisen independently can be concluded from the fact that it is a relatively rare trait. If it had evolved from a remote last common ancestor of cephalopods, insects, birds and mammals it would be almost universal in the animal kingdom, not unusual.

How then do you fool a sensible person into thinking humans are unique with a unique design which includes high intelligence, when the evidence shows otherwise? Well, you don't, of course. As a dedicated confidence trickster and fraud, your target market is the lower few percentiles of the IQ curve and those whose thinking ability has been inhibited by theophobic psychosis, also known as religious fundamentalism, an acute anxiety disorder normally caused by mental abuse in childhood, so you simply ignore the evidence, confident that they are very unlikely to read it, but if they do they won’t understand its significance and will wave it aside because it doesn’t support them.

You will have targeted that demographic specifically because of their inability to evaluate complex evidence and draw valid conclusions from it, or to change their minds from those opinions foisted on them by childhood conditioning and maintained by the terror of thinking they could be wrong under the watchful eye of an invisible mind-reading sky bogeyman who has a uniquely terrifying punishment waiting for doubters.

So here then is an account of how a species of bird, the Goffin's cockatoo, Cacatua goffiniana, not only quickly learns to use two different tools to solve a problem with a two-stage solution, but then remember what tools it needs for the task and selects them to take with it when leaving to perform the task.

Wednesday 30 November 2022

Creationism in Crisis - Old World Flycatchers’ Family Tree Mapped

Old World flycatchers’ family tree mapped - Uppsala University, Sweden
European robin in snow
European robin, Erithacus rubecula
Photograph: Tomas Carlberg
In yet another casual refutation of the plaintive Creationist assertion that the Theory of Evolution (TOE) is about to be overthrown by their childish Bronze Age superstition, scientists from Uppsala and Gothenburg Universities, Sweden and Florida University, USA, have produced a family tree of the Old World flycatchers - a family of birds that includes the European Robin.

In doing so, they found not the slightest hint that the TOE is inadequate to explain the observations. In fact, as expected, it is entirely consistent with what they found.

As the article in Uppsala University news by Elin Bäckström explains:

Wednesday 19 October 2022

Malevolent Designer News - Now Creationism's Divine Malevolence is Also Killing Birds With a Virus!

What is avian flu, the disease afflicting viral TikTok emu Emmanuel?
Barnacle geese on Islay
Barnacle and white fronted geese arriving on the Island of Islay from Greenland.
Source: RSPB
The COVID-19 pandemic caused by variants of the SARS-CoV-2 virus is not the only viral pandemic the world is currently experiencing. Many of the world's birds, both domesticated and wild are dying from a virus known as avian flu that is related to the virus that causes influenza in humans. Like the SARS-C0V-2, virus, the avian flu virus comes in a variety of versions and mutates to give successive waves of infection and reinfection. Also like the SARS-CoV-2 virus, avian flu is zoonotic. Two varieties in particular, H1N5 and H7N9, can be caught by humans and can cause us serious illness and even death. Not all variants kill their bird victims; some will just make them very unwell. In the case of domestic hens, it will reduce egg-laying, causing economic damage to egg producers.

The UK bird charity, the Royal Society for the Protection of Birds (RSPB) is also reporting devastation in some UK wild bird populations, especially waterfowl and seabirds.

In the following article, Professor Marta Hernandez-Jover, Professor in Veterinary Epidemiology and Public Health at Charles Sturt University, Australia, explains what avian flu is, and what measures are being put in place in Australia to prevent outbreaks. Australia is fortunate in that migratory geese, one of the main avian orders that spread the virus, do not migrate to Australia. The article from The Conversation is reprinted under a Creative Commons License, reformatted for stylistic consistency. The original article can be read here:

Friday 9 September 2022

Unintelligent Designer News - When Yesterday's Soltion to the Problem You Created Earlier, is Today's Problem Waiting To Be Solved

These female hummingbirds evolved to look like males — apparently to evade aggression | UW News
Female white-necked jacobin hummingbird with male-like plumage
Female white-necked jacobin hummingbird with male-like plumage
Irene Mendez Cruz
If you share the childish creationist belief in intelligent [sic] design, you must accept that the designer behaves like an amnesiac or an idiot, constantly discovering that the solution it designed to solve yesterday's problem is today's problem waiting to be solved. The result is an almost infinite number of examples of arms races and their results to be found throughout nature. An offshoot of this process is various forms of mimicry, where one species comes to resemble another because that helps protect it from a predator on both.

A case in point, but one with a slight twist, is the fact that one in five females of the white-necked jacobin hummingbird, Florisuga mellivora, have bright 'male' plumage instead of the usual duller ‘female’ plumage, however, they still have the lighter female bodyweight and have female patterns of behaviour.

Males of the species have dazzling blue-and-white plumage, as do all juveniles. Males are also aggressive in defending their territory and food sources. About 80% of the females develop a duller, green and white plumage as they mature. This pattern, where males are brightly coloured and the females are duller is common in birds, where males display to defend their territory and to attract a mate, while the females which don’t need to display to attract a mate, can afford to be duller and more difficult for predators to see.

So ,the question is, why do about 20% of F. melliflora hummingbird develop a 'male' plumage while retaining a lighter female body and behaviour? This was the question scientists from Cornell University, Ithaca, NY, USA, Columbia University, New York, NY, USA and the University of Washington, Seattle, WA, USA set out to answer.

The answer turned out to be an unusual case of mimicry, where the females are not mimicking another species for protection, but males of the same species. This works because the males are bullies and cowards, and tend to pick on the light-weight females while avoiding picking a fight with other males and with juveniles (which also seem to be getting protection against the cowardly males by, unusually for birds, having adult ‘male’ plumage as juveniles).

As the news release from Washington University explains:

Tuesday 17 May 2022

Evolution News - How the Environment Made a Difference with Penduline Tits

Eurasian penduline tit, Remiz pendulinus
Chinese penduline tit buries eggs to prevent them from blowin’ in the wind | Science Linx News | Science LinX | University of Groningen

First off, if you came here attracted by the title, hoping to see something about large busty substances, you're in the wrong place. This is about a couple of closely related birds known as the Eurasian and Chinese penduline tits and about how subtle differences in their environments can cause differences in behaviour that act as barriers to hybridisation and so reinforce the evolving divergence into different species. If you're so shallow as to be looking for the former on line, you're probably too shallow to be interested in the latter.

The Eurasian penduline tit, Remiz pendulinus, is so called because males build a relatively large, dangling (penduline) nest on the end of thin willow branches or reeds, often over water. He then tries to attract a female to use the nest and, if she approves, he mates with her, and she begins to lay a batch of eggs over the next 14 days but won't permit the male to enter the nest. This choice of location is probably to make it difficult for predators to reach the nest.

The strange thing is each day she covers the eggs in the bottom of the nest before going off to feed herself. This is thought to be due to inter-sex rivalry because either one or the other parent is going to take responsibility for the incubation of the eggs and rearing the chicks and the female needs the male to hang around to mate with her and the male needs her to stay and use his nest so his offspring are in the eggs she lays.

When the batch of eggs is complete, the female, more often than not, incubates them and the male leaves to find another mate, but frequently, it's the female who leaves the male to do the incubation and rearing. Very occasionally, neither parent takes responsibility, and the nest and eggs are abandoned. But the male won't start to incubate the eggs until the batch is complete. Burying the eggs is thought to be an evolved strategy for keeping the male interested until the batch is complete.

Chinese penduline tit, Remiz consobrinus
However, a closely related species, the Chinese penduline tit, Remiz consobrinus, has a different pattern of behaviour. The make builds the next in the same way and in a similar position to his Eurasian cousin, and attracts a female to use it. However, she doesn't exclude him from the nest but they both roost in it together at night, and both sexes share responsibility for incubation and rearing the chicks. But, like her Eurasian cousin, the female Chinese penduline tit still assiduously buries her eggs every day. The question is, if this isn't due to inter-sex rivalry as with the Eurasian species, what is it due to? The answer has turned out to be due to subtle environmental differences.

To investigate this difference and the lack of aggression between the sexes by which the Eurasian female keeps the male from entering the nest while she is laying her batch of eggs, Jia Zheng, who had completed her master’s degree under Professor Zhengwang Zhang, from Beijing Normal University, and was now completing her PhD at the University of Groningen, conducted a number of experiment to test out various hypotheses.

The Groningen University News release explains how she went about it:

Wednesday 13 April 2022

Unintelligent Designer News - How the Genetics of Egg Mimicry in a Brood Parasite Could Cause Their Extinction

Cuckoo finch egg in zitting cisticola nest.
Scientists crack egg forging evolutionary puzzle

There has been some serious forgery going on in the world of evolution!

And, despite any hopes the thought of that might raise in the deluded minds of creationists, I'm not talking about human forgeries such as the famous Piltdown skull hoax, but natural forgeries produced by the natural force of evolution by natural selection.

The forgeries in question are the way brood parasite birds' eggs mimic those of the hosts.

I wrote about this very phenomenon in my popular, illustrated book, The Malevolent Designer: Why Nature's God is not Good, in which I said:
Cuckoo Finches and Arms Races.
The cuckoo finch or parasitic weaver, Anomalospiza imberbis of East Africa is an obligate brood parasite on other birds of the Cisticolas and Prinias families. As we have seen with the earlier brood parasites, this has resulted in the inevitable evolutionary arms race as the parasitized hosts evolve strategies to reduce the depredation and the cuckoo finch evolves ways to circumvent the defence strategies of its intended hosts.

The strategy adopted by the tawny-flanked prinia, Prinia subflava, is to change the colours of its eggs more quickly than the cuckoo finch can and to produce eggs in an array of colours with markings that the prinia recognises as its own, almost like a signature.

Cuckoo finch, Anomalospinza imberbis


The red-faced cisticola, Cisticola erythrops, on the other hand, while not varying the colour of its eggs has evolved to be better at spotting the cuckoo finch’s eggs and removing them. Another species, the rattling cisticola, Cisticola chiniana which might be expected to be an ideal host for the cuckoo finch appears to have won the arms race and is not parasitized at all (89).

Now one of the zoologists I cited in that section of my book, Professor Claire Spottiswoode from the Department of Zoology, Cambridge University, England, UK and the FitzPatrick Institute of African Ornithology, University of Cape Town, South Africa, along with Professor Michael Sorenson of the Department of Biology, Boston University, Boston, MA, USA, and others, has published an open access paper in PNAS which addresses the following questions:

Sunday 10 April 2022

Evolution News - How Amazonian Biodiversity Arose

Population genomic structure in six codistributed Amazonian bird species groups. For each species, results of the best k value for STRUCTURE analysis of split datasets (left) and example replicates of the t-distributed stochastic neighbor embedding (t-SNE) analysis (right) are shown. Colored bars underneath the STRUCTURE plots and circles on the t-SNE plots are colored on the basis of major interfluvial regions in map 1 (top left). Map 2 (top right) shows the topography of the study region within the dark red box, where yellow contours represent the 250- to 300-m elevational zone demarcating dynamic lowland (>250 m; shaded in blue) from relatively stable upland (>300 m; shaded in red) basins. Map 3 (top right inset) shows precipitation during the driest annual quarter (76), with high precipitation in gray, low precipitation in red, and a strong cline across the middle to lower reaches of the rivers draining the Brazilian Shield (plotted using QGIS).

Study: Rivers Contribute to Amazon Rich Biodiversity | AMNH

The major driver of evolutionary diversity is environmental change because it is the environment the species finds itself in that selects for fitness to survive and reproduce in that environment. This is why species can superficially look as though they are designed to suit their particular environment.

So, it is not surprising that a group of scientists led by Dr. Lukas Musher of the American Museum of Natural History’s Richard Gilder Graduate School found that changes in the local environment in the Amazon River basin are what led to the rich biodiversity in the Amazon Rain Forest. What was surprising, however, was the fact that it was dynamic changes in the courses of the many small tributaries to the Amazon that were the major factor and that proliferating bird species were the result, despite the fact that small rivers do not present major barriers to flying birds.

The team also discovered that this dynamic system had produced several local micro-species along the banks of these rivers, which are vulnerable to extinction.

From the American Museum of Natural History press release:
One of the most contentious questions in evolutionary biology is, how did the Amazon become so rich in species?

A new study focused on birds examines how the movements of rivers in the Amazon have
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