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Why do the ancestors of birds still exist?

Why do the ancestors of birds still exist?



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If I am not mistaken, scientists believe that birds are evolved from reptiles. Why do the ancestors of birds (that is, reptiles) still exist?


Introduction to phylogeny

Short Intro to Speciation

Let's talk about speciation. Speciation is the process by which a single lineage split into two. This happens in a number of ways (allopatric vs sympatric vs parapatric, BDM model and others). I will consider a simple case of allopatric speciation below as it is the simplest one to understand (although not necessarily the process causing most speciation events).

Following the story of a lineage through its speciation events

Think of a population at time $t=0$. Let's call this speciesA(forAncestor). Imagine that an ecological change brings a barrier right in the middle of the range of this population ofA. Such a barrier could be originally caused by a fire, or a river that has changed direction or a mountain range "popping up". The two now isolated populations are free to diverge randomly through time. This is what we call a speciation event. Note that under this model, there is no necessary need for selection to explain speciation. Let's call the two diverging populationBandCwhich exist at time $t=1$.

Now, imagineCgoes under another speciation event and split into the populationsDandE. In the same time, populationBmay have changed quite a bit so that we might want to call themF. Here is a diagram of the situation

F D ----- E t=2 | | B ------------- C t=1 | A t=0

Ais an ancestor ofB,C,D,EandFand does not exist today.Bis an ancestor ofFbut does not exist today.Cis an ancestor to bothDandEand does not exist today. Let some more time pass by and you may eventually end up with the following tree

G ----- H K I ----- J t=3 | | | F D ----- E t=2 | | B ------------- C t=1 | A t=0

At time $t=3$, only speciesG,H,I,KandJexist today, the other are ancestors of current species. Let's expand this tree even further.

L ----- M N O P ----- Q t=4 | | | | G ----- H K I ----- J t=3 | | | F D ----- E t=2 | | B ------------- C t=1 | A t=0

You will note that lineageIwent extinct at some point between $t=3$ and $t=4$.

Naming subsets of the tree

Reptilia

I am now suggesting to give a generic name for all the lineages present in the tree we drew (which we call a phylogenetic tree by the way). Let's call them Reptilia. So all the speciesA,B,C,D,E,F,J,I,J,K,L,M,N,O,PandQare Reptilia.

Birds and Mammals

Now let's consider a subset of this tree. Let's consider the subset made of the speciesJ,PandQonly. Let's call them birds. Let's also call mammals the subset composed by the speciesG,LandM.

Lizards (and others)

Finally let's call lizards all reptilia that are not birds, nor mammals (in reality it would be more correct to call this group lizard_crocodile_turtles_snake_amphibians_tuatura). Of course, the right tree is much bigger! By the way, you can explore the tree of life yourself on OneZoom.org.

What is a taxon

By the way, a group of species is called a taxon (plur. taxa).

Monophyletic taxa

It might be straight forward to you that there is something fundamentally different between the groups that we called mammals, birds and reptilia to the one that we called lizards. Indeed mammals, birds and reptilia are called monophyletic as they are composed of a given ancestor and all its descendants. lizard on the other way is not monophyletic. A monophyletic taxon is also called a clade. Below is a graph representing what a monophyletic taxon is. It also uses the terms polyphyletic and paraphyletic to describe different types of non-monophyletic taxa

Concept of species

You might want to learn more about the issues behind the concept of species in the post How could humans have interbred with Neanderthals if we're a different species?

Concept of taxonomic ranks

What we decide to call a class, an order or a family is also somewhat arbitrary too. For example, we generally consider the monophyletic taxon Mammalia is a class. However, there is no non-arbitrary reason for calling Mammalia a class rather than Eutheria (eutheria = placental mammal).


Online resources

I suppose the above answered a big part of your question. You will be able to read all of what I just wrote (and much more) on any good introductory course to evolutionary biology. Consider having a quick look at Understanding Evolution by UC Berkeley for example as @MattDMo suggested in the comments.

Issues in your post

There are issues in your post that cannot be addressed in a single post (another reason for you to follow a quick intro course to evolution). Below I consider your post piece by piece mainly to point to some issues

Scientists believe

Terrible statement. By belief, we often refer to a non-justified belief, that is a belief about the world that is not justified (in science, the method of justification is called "the scientific method"). The statement, therefore, suggests that non-justified beliefs have a place in science while they don't. By being a little lose on the semantic, one could say that scientists "know" or they don't know but they don't believe without good reasons to believe.

that birds are evolved from reptiles

This is misleading (and it mislead you) because by "reptile" you think of a lineage that currently exists. Also, the expression "are evolved from" sounds very wrong. The expression "has evolved from" would be more correct.

evolution occur so that the organism can survive in the environment by developing new characters

This is wrong both in terms of the semantic (issue of causality when sayingso that) and in term of the definition of evolution. You seem to confound evolution with natural selection.

According to natural selection

Natural selection is a process, not an explanation. It is like saying "according to gravity". The semantic is wrong, you should say "according to the theory of gravity" or "according to the theory of evolution" (or eventually "according to the theory of natural selection").

According to natural selection, those with favourable variations will survive and those with unfavourable die

You seem to apply that statement to population-level fitness (which would be mainly wrong) rather than to fitness variance within a population.

Why do the ancestors of birds (that is, reptiles) still exist?

The ancestors of birds don't exist anymore. I hope that was made clear from the above explanations.

Why didn't they get eliminated by natural selection?

This sentence suggests that you do not really understand what natural selection is but this is a story for another time. You can learn about natural selection on Understanding Evolution by UC Berkeley.


Reptiles evolving from birds is an example of divergent evolution. This wiki article has more information. Essentially both birds and reptiles are still around because they both fill a niche. That is, birds and reptiles separated have a common ancestor, and at some point their evolution diverged. At that point, birdoids which better filled the "bird" niche had higher fitness, and reptiloids which better filled the "reptile" niche had higher fitness, so birds evolved to be more like birds, and reptiles evolved to stay reptiles.


Evolution Made Ridiculous Flightless Birds Over and Over

Watching an ostrich sprint across the plain like a mean two-legged dust mop, you might think a mistake has been made. Surely this isn't one of evolution's prouder moments? But new genetic evidence says that the group of birds including ostriches, emus, and other ungainly birds all came from flying ancestors. They lost the ability to fly not once, but over and over again. Something must have been working. The ratites are a group of birds that includes the ostrich and emu, as well as the kiwi, rhea (like a smaller, South American ostrich), and cassowary (with a bright blue face and what looks like a toenail on its head). There were also the moa of New Zealand and the elephant bird of Madagascar—gigantic Big Bird types that went extinct within the past several hundred years, likely due to humans. The birds themselves are pretty obvious, but the story of ratite evolution "has always been a contentious issue," says Oliver Haddrath, an ornithology research technician and PhD student at the Royal Ontario Museum. Scientists have never been certain how ratites arose, or how they're related to each other and to more normal birds. In the 1960s and 1970s, Haddrath says, molecular evidence showed that the flightless ratites were closely related to birds called tinamous. Unlike the ratites, these small ground dwellers in Central and South America can fly (though they don't often choose to). At the same time, scientists realized that everyplace ratites live or used to live (Australia, South America, Africa) was a piece of land that once belonged to the supercontinent Gondwanaland. Perhaps the common ancestor of all ratites was a flightless bird on Gondwanaland that had already split off from its flying relative the tinamou. When the supercontinent broke up, the birds left standing on each bit of land could have evolved into different species. Since then, some evidence has supported this theory, while other studies have contradicted it. Haddrath and his coauthors approached the question using DNA from the extinct moa, as well as updated DNA-sequencing technology that let them gather large amounts of data at once. "We used over 1 million base pairs" of DNA, Haddrath says, "to test whether the tinamou was closer to the moa than the moa was to the emu and ostrich." At last, they would unearth the answers to the ratites' family secrets. They found that the tinamou isn't a distant cousin after all, but a sibling smack in the middle of the ratite family tree. This suggests that the common ancestor of the ratites and the tinamou could fly, and while the tinamou held onto this skill, the branches leading to other ratites became flightless again and again .

Since tinamous kept their ability to fly, every other branch in this tree probably also started with a flying bird. Technically, it's possible that the opposite is true: all the ratites and the tinamou evolved from one flightless ancestor, and the tinamou re-learned how to fly. But Haddrath says it's unlikely. "There are no known examples of a flightless bird species regaining flight," he says. Many kinds of birds other than the ratites have lost the ability to fly—penguins, some ducks, and so on—but none have gotten it back. Generally, it's "considered much easier to lose a trait than regain it," Haddrath says. The relationship between the tinamou and other ratites, for which Haddrath says there's "overwhelming evidence" in the DNA, was hidden by the shapes of the birds' bodies. "Most studies using skeletal features have concluded that the ratites are each other's closest relatives, and the tinamous are a distant cousin," Haddrath says. But it now seems that the demands of land-bound life made ratites' skeletons evolve in similar ways. This convergent evolution masked the birds' true relationships. Since so many birds have given up flying, it must be an easy trait to lose when it's beneficial, Haddrath says. For birds that are adapting to life on land, hanging onto the traits that let them fly may (ironically) weigh them down. As they lose flight they're free to evolve into the weird, walking species we know today. It's apparently a winning strategy—as long as humans don't arrive on their island to wipe them out.

Images: ostriches by Josh*m (via Flickr) ratite tree adapted from Baker et al.

Baker AJ, Haddrath O, McPherson JD, & Cloutier A (2014). Genomic Support for a Moa-Tinamou Clade and Adaptive Morphological Convergence in Flightless Ratites. Molecular biology and evolution PMID: 24825849

Postscript (5/26/14): Another study , published this month in Science , compared ancient DNA from elephant birds to DNA from modern ratites and came to the same conclusion: flightless ratites evolved several times, independently, from a flying ancestor. You can read more at Not Exactly Rocket Science or in the New York Times .


How birds lost their penises

In the animal kingdom, ducks and geese are famous for their extra-long penises. In fact, when extended, the usually coiled penis of the Argentine lake duck is longer than the bird itself. Most birds don't have such bragging rights, however: Males in 97 percent of bird species have tiny penises or lack them entirely. Instead, they shoot sperm into a female bird's body through an exit called a cloaca.

The absent bird penis is a head-scratcher for scientists who study animal reproduction. For animals in which eggs are fertilized inside the female body, sperm have a better chance of getting through if they're pipe-delivered within easy reach.

"Why lose an organ that seems so important to achieve this task?" Patricia Brennan, a researcher at the University of Massachusetts who studies the coiled duck penis, wrote to NBC News in an email.

Scientists have now identified the gene responsible for eliminating or reducing the bird penis, which begins to form in the embryo but disappears again before the bird hatches. The critical gene, called Bmp4, directs cells at the tip of the penis to die faster than they grow back. In birds with elaborate equipment — not just ducks, but emus and ostriches as well — Bmp4 is switched off, letting their penises grow to full size, as Martin Cohn and a team from the University of Florida explain in the Thursday issue of Current Biology.

The new study "now opens the possibility of exploring other instances of penis reduction in birds," Brennan, who was not involved with Cohn's research, explains.

Ducks have penises, but chickens do not. So Cohn and his team watched both chicken embryos and duck embryos grow before they hatched.

Scanning electron microscope images showed that the proto-penis in both species started out growing similarly, up until — in the case of the chicken — a silent kill order kicked in at the tip of the penis. After that, it began to shrink until it vanished almost to nothing. The team traced the directions back to the Bmp4 gene. When they turned off the gene in the embryonic chicks, penis growth continued. They also checked out emu embryos and found that they, like the ducks, lacked an active gene at the tip of the growing penis.

Cohn also examined an alligator embryo because, while reptiles and birds evolved from a common ancestor, reptiles wound up keeping their penises. Sure enough, the alligator lacked an active Bmp4 gene.

Mystery of the missing penis

Cohn sees penis loss in birds as "parallel" to the way snakes lose their limbs. Snakes start growing legs as embryos, but genetic factors kick in and inhibit their growth before they hatch. By slithering so successfully, legless snakes have found a niche. As to why evolution caused the penis in most birds to disappear: "This question still remains largely unresolved," Cohn writes.

Evolutionary biologists have proposed some tentative answers. William Eberhard, a staff scientist at the Smithsonian Tropical Research Institute, wrote to NBC News in an email that an elaborate penis in ducks and geese "might aid in copulation that occur[s] in the water." Another theory for uniquely shaped penises is to ensure creatures mated with members of their same species — the "lock and key" theory that mating would only be possible if the male and female bits fit together.

Others have suggested that the lost penis was a fallout of another adaptation. For example, it has been suggested that flying birds shed their penises as extra weight to make flight more efficient. But Brennan believes that is unlikely because "ducks have the large penises and they are some of the longest-distance migrants." Also, male birds that fly very little — like the moluccan scrubfowl and Australian brush turkey — seem to also have a tiny or nonexistent penis.

Brennan's favorite explanation is that it has to do with female choice. Mating behavior in many birds is forced. But when birds such as chickens mate via what's described as a "cloacal kiss," sperm can't enter a female unless she cooperates and turns her cloaca inside out. If she doesn't budge, fertilization won't happen.

Growing a penis is a developmentally error-prone business, a "process that goes wrong far too often in humans," Cohn explained, citing tube defects in 1 in 125 boys. But the penis is also among the most diverse organs found in vertebrates: Birds that do have penises inflate them not with blood, as humans do, but with lymph — the milky substance that that soaks our cells. Mammals such as bears, cats and sea lions have a bonelike structure to help stiffen theirs. And snakes? Well, snakes have two.

More on bizarre animal sex:

An earlier version of this story misidentified Patricia Brennan's position as a researcher at the University of Maryland. She is a researcher at the University of Massachusetts.

In addition to Martin Cohn, Ana Herrera, Simone Shuster and Clair Perriton also contributed to "Developmental Basis of Phallus Reduction during Bird Evolution" in the journal Current Biology.

Nidhi Subbaraman writes about science and technology. Follow her on Facebook, Twitter and Google+.


Archaeopteryx : An Early Bird

It has long been accepted that Archaeopteryx was a transitional form between birds and reptiles, and that it is the earliest known bird. Lately, scientists have realized that it bears even more resemblance to its ancestors, the Maniraptora, than to modern birds providing a strong phylogenetic link between the two groups. It is one of the most important fossils ever discovered.

Unlike all living birds, Archaeopteryx had a full set of teeth, a rather flat sternum ("breastbone"), a long, bony tail, gastralia ("belly ribs"), and three claws on the wing which could have still been used to grasp prey (or maybe trees). However, its feathers, wings, furcula ("wishbone") and reduced fingers are all characteristics of modern birds.


Cast of the Berlin specimen of Archaeopteryx lithographica, from the collections of UCMP.
Original at Humboldt University, Berlin.

As you can see, Archaeopteryx certainly had feathers, although whether these feathers were used for regulating its body temperature or for flight is a matter still open for debate. Feathers may have originally evolved for insulation and then been co-opted into flight. The origin of flight, and the actual flight capabilities of Archaeopteryx, are debated. Two models of the evolution of flight have been proposed: in the "trees-down" model, birds evolved from ancestors that lived in trees and could glide down, analogous to today's flying squirrels. In the "ground-up" model, the ancestors of birds lived on the ground and made long leaps. For more information, see our new exhibits on vertebrate flight and avian flight.

The flight stroke may have originated as an extension of the grabbing forearm motions that smaller, agile theropods such as Deinonychus may have used to grab and hang on to prey. As you know if you've ever cut up a chicken, living birds (except for flightless birds like the ostrich and kiwi) have a keeled sternum to which the large, powerful flight muscles attach. Archaeopteryx, however, had a comparatively flat sternum. Although it is currently thought that Archaeopteryx could sustain powered flight, it was probably not a strong flier it may well have ran, leaped, glided, and flapped all in the same day.

Some years ago, the British astronomer Sir Frederick Hoyle and colleagues proposed that Archaeopteryx was a clever forgery. Check out Archaeopteryx -- Is This Bird A Fraud?, an excellent essay that not only reviews the evidence for and against fraud, but assesses various theories of how this creature lived.


Why do women have orgasms?

The reason for the female orgasm has long eluded scientists. Men need them for reproduction women don't. So why do female orgasms exist?

Scientists studying this issue are divided, said David Puts, a biological anthropologist at Penn State University. Some scientists think female orgasms are totally purposeless. But evidence suggests that they may have once helped (and perhaps still help) us survive and reproduce.

One theory holds that women have orgasms because men have them, said Kimberly Russell, an ecologist at Rutgers University in New Jersey. Some researchers argue that female orgasms exist because as fetuses, we all start out with the same basic parts, regardless of sex. Orgasms in women, like nipples on men, just happen to stick around.

"It might be an anatomical bonus," she told Live Science. In this scenario, the orgasm didn't evolve specifically for females, and it might not serve a specific evolutionary function for them.

But there's a problem with the argument that orgasms have no function, said Patricia Brennan, an evolutionary biologist at Mount Holyoke College in Massachusetts. It's not adaptive for our bodies to devote too much energy to traits, like nipples, that aren't beneficial. These traits tend to disappear or become less pronounced over time. That's far from the case for female orgasms, she said. According to the Kinsey Institute, female orgasms tend to last longer than male orgasms and can occur multiple times in a row &mdash something that's rare in men. In other words, female orgasms use a lot of energy for a trait that supposedly has no function, she said.

Plus, there's nothing diminished about the anatomical structures involved in the female orgasm, Brennan noted.

The clitoris, a highly sensitive part of the female genitals that has a key role in orgasms, is homologous to the penis. Like male and female nipples, they grow from the same anatomical structure. But contrary to popular belief, Brennan told Live Science, "a clitoris is not just a mini penis."

The human clitoris has &ldquostructures that are incredibly well developed,&rdquo Brennan said. "To me, that screams selection."

There are multiple theories about how, exactly, the female orgasm helped our ancestors pass on their genes. Although women don't need to have an orgasm to conceive, some research suggests that wasn't always the case. Many female mammals, including rabbits and cats, ovulate only when they mate. Based on an analysis of how traits have been passed down through the tree of life, one study published in the Journal of Experimental Zoology found that our female ancestors probably needed orgasms in order to reproduce.

But again, this theory doesn't explain why orgasms stuck around in women, Brennan said.

"If orgasms evolved for some adaptive reason, but they're no longer adaptive, they should have disappeared. And clearly they haven't gone away," Brennan said.

Some research suggests that orgasms still create the perfect conditions for conception &mdash even if they're not necessary to ovulate. One study found that women who had orgasms close to when their male partner did actually "upsucked" more sperm into their bodies compared with women who had orgasms much earlier or later than their partner. Scientists have even tried to draw correlations between the number of orgasms a woman has and the number of children she has. But the evidence for these hypotheses is shaky and doesn't draw a direct causal link between orgasms and conception, Puts told Live Science.

Plus, these theories leave a major question unanswered, Russell said. What if the orgasm has nothing to do with reproduction? What if, instead, it evolved only for pleasure?

Sex doesn't have to feel good for reproduction to take place, Russell said. "We know this from looking at animals! Sex can be very uncomfortable and still gets done," she said. But culturally, the idea that sex might be for more than just babies is somewhat of a taboo topic, Russell said.

Sex that feels good for both males and females has an important social role, Russell said. It relieves stress and helps partners bond. Ancestral humans might have engaged in sex to create more cohesive groups, smoothing over conflict and cementing their social network. We see these behaviors in other primates, like bonobos, who might use sex to help dispel a fight over a tasty piece of fruit or even a clan rivalry, the BBC reports. It follows from this argument that evolutionarily, female orgasms might have acted as a kind of social glue.

That pleasure alone is enough to make a trait adaptive goes against popular conceptions of why sex, and orgasms, exist. But for Brennan, it makes perfect sense. "To experience pleasure &mdash that seems evolutionarily like a good idea," she said.


Why creationists are out of time with history and science

O ne very positive aspect of the digital world for scientists is that there are various websites that track citations and mentions of research papers and link them together. This can be an excellent way of finding out who is using your research and, of course, to flag up papers you might not have known about and may not have otherwise seen.

However, one quirk is that some sites and articles that are styled like formally written and reviewed research papers are often picked up by the searching algorithms. In my case that means I occasionally get notifications that a less-than-scientific source has been citing my work: in particular creationist websites.

It is something of an issue that working on dinosaurs and their near relatives draws in this group. My assumption has always been that as dinosaurs and fossil reptiles are popular with the general public - although most people don’t know much about them - it’s an obvious avenue to use to try and persuade people of your point of view. Any reasonable-sounding argument might be convincing to a non-expert. It’s notable that creationists never seem to target research on, say, very ancient fish or insects, or recently extinct horses, and focus only on the charismatic dinosaurs, pterosaurs, marine reptiles or certain big mammals such as mammoths. Of course, writing about something convincingly and getting it right are different matters entirely.

Recently, I spotted a short creationist essay that had cited a paper of mine on various recent pterosaur finds and which was supposed to be some kind of response to an article written for the Observer. The creationist piece attempted to argue that these new discoveries helped support the idea that these pterosaurs were made by a creator. Oddly enough, I was left rather unconvinced, not least because of the obvious mangling of some fairly simple and very well-known history that contradicts the arguments presented in some delightfully ironic ways.

For a long time, pterosaurs were regarded as rather inept fliers and little more than unusual gliding reptiles, but this view has been overturned with more modern studies. In his piece on how our understanding has changed with new research, palaeontologist Dr Mark Witton wrote in the Observer that in the past, pterosaurs had been regarded as little more than “gargoyles with lanky limbs”. Our valiant creation-support correspondent then asks “Was th[is] description… a result of mere evolutionary speculation? Based on seeing pterosaur fossils occur in strata below other flying vertebrates, perhaps evolutionists reasoned that pterosaurs evolved first and therefore represented evolution’s initial, clumsy attempts to produce large flyers.”

Ah. Now, you see, there are a fair few issues here. Although the idea of changing species had been around for many years, there’s a good reason that biologists give so much credit to Darwin and On the Origin of Species for laying down the foundations of natural selection and ideas about changes over time. Darwin’s work was published in 1859, but pterosaurs were discovered around 1780 (see Wellnhofer, 2008 a point made in Witton’s piece but mysteriously overlooked). Early thoughts about them could therefore hardly have been influenced by “evolutionists” as there can’t really have been many around. Indeed, early researchers had considered pterosaurs might be marsupials and amphibians, or perhaps swimming animals (Wellnhofer, 1991) before most settled on flying reptiles.

Copper engraving of the holotype fossil of Pterodactylus antiquus from 1784 Photograph: Cosimo A. Collini

We know now that pterosaurs predate the earliest birds in the fossil record by something in the region of 80 million years, but, again, in Darwin’s time this wasn’t known. In fact, shortly after the On the Origin of Species was published, the legendary “first bird” Archaeopteryx was discovered in the Solnhofen limestones of Bavaria. Pterosaur enthusiasts will know this place well, as almost all of the well-preserved pterosaurs known at that time came from the same Jurassic age rocks, so the oldest-known birds and oldest-known pterosaurs were largely contemporaries as far as the Victorians were concerned (the first Triassic pterosaurs were not identified until the 1970s).

This theory would have been well known to those working on these animals at the time. Sir Richard Owen, grandfather of the natural history museum in London and brilliant anatomist worked on the first specimen of Archaeopteryx (Owen, 1863) and described a number of pterosaur specimens, so would have been well aware that many pterosaurs came from the same beds as this early bird. Moreover, both Owen and Canon William Buckland who worked on the first well-preserved British pterosaur Dimorphodon (Buckland, 1835 Owen, 1857/9), were both creationists! Owen was a staunch opponent of Darwin and his ideas (Cadbury, 2000), yet it was Owen who most influenced the early ideas about dinosaurs, and indeed pterosaurs, as reptile-like and not especially agile or able locomotors.

Although Owen, Buckland, and many other early naturalists were Christians and also creationists (though that term then as today covers a multitude of positions), their consideration that pterosaurs were created rather than evolved had little bearing on their interpretations of pterosaur biology. It was more to do with the simple observation that these animals were reptiles. Since at that time the understanding of reptilian animals was that they needed heat to get moving and suffered in the cold, the assumption was that pterosaurs would have been gliders at best and incapable of prolonged bird-like activity (Wellnhofer, 1991).

Oddly enough, the one early vocal dissenter to this view at the time considered pterosaurs to be the ancestors of birds (a position we now know is incorrect) and hence pushed for a theory of active flight (Seeley, 1901). Recent discoveries show that pterosaurs had an insulating layer of fur-like fibers on the body support the idea they were relatively “hot blooded” (Kellner et al., 2009) - as indeed were many dinosaurs -and we have tons of evidence that even the largest pterosaurs were active powered fliers (Unwin, 2005).

Collectively, then, the few simple lines of text quoted above from the creationist essay effectively misrepresent the timing of pterosaur discoveries, who was working on them, their then known age relative to birds, the scientific ideas of the time and how these aligned. The writer then tries to pass these errors off on “evolutionists”, who either didn’t actually exist at the time, or who weren’t involved, as it was the creationists who were making the running on pterosaur research. It’s quite an achievement, really, to be so wrong is so many ways on so simple a subject in so few words. All of this information is freely available, much of it is in multiple books on pterosaurs (Wellnhofer, 1991), early dinosaur discoveries (Cadbury, 2000), and online sources (like Pterosaur.net ) and even in places that the author cited (Witton’s own book - Witton, 2013).

Now, of course, creationism as a concept fails utterly in the face of the most basic of sciences, and of course our understanding of things changes over time as new evidence appears and new techniques are brought to bear on finds and theories. But it is especially galling that our modern understanding of pterosaurs, brought about entirely by formal scientific research, has been taken as correct position by a twenty-first-century creationist, and then used to attack outdated ideas as being obviously incorrect. The implication that we would have arrived at this modern take had it not been for those wrong-thinking “evolutionists” is magnificently incorrect. It is scientific researchers who got us here, not you those outmoded ideas you are sneering at as having come from incorrect preconceptions came from your philosophical ancestors, not ours.

Buckland, W. 1835. On the discovery of a new species of Pterodactyle in the Lias at Lyme Regis. Transactions of the Geological Society of London, series 23: 217-222.

Cadbury, D. 2000. The dinosaur hunters. Fourth Estate, London.

Kellner, A.W.A., Wang, X., Tischlinger, H., Campos, D.A., Hone, D.W.E. & Meng, X. 2009. The soft tissue of Jeholopterus (Pterosauria, Anurognathidae, Batrachognathidae) and the structure of the pterosaur wing membrane. Proceedings of the Royal Society, Series B, 277: 321-329.

Owen, R. 1863. On the Archaeopteryx of Von Meyer, with a description of the fossil remains of a long-tailed species from the lithographic stone of Solnhofen. Proceedings of the Royal Society of London, 153: 33–47

Owen, R. 1857/1859. On the vertebral characters of the order Pterosauria (Ow.), as exemplified in the genera Pterodactylus (Cuv.) and Dimorphodon (Ow.). Proceedings of the Royal Society of London, 9: 703-704

Seeley H G 1901, Dragons of the Air: an account of extinct flying reptiles, London, New York.

Unwin, D.M. 2005. Pterosaurs from Deep Time. Pi Press, New York.

Wellnhofer, P. 1991. The Illustrated Encyclopedia of Pterosaurs. Salamander Books, Ltd., London, 192 p.

Wellnhofer, P. 2008. A short history of pterosaur research. Pterosaur papers in honour of Peter Wellnhofer. Zitteliana B, 28. p7-19.


Looking for LUCA, the Last Universal Common Ancestor

Around 4 billion years ago there lived a microbe called LUCA — the Last Universal Common Ancestor. There is evidence that it could have lived a somewhat ‘alien’ lifestyle, hidden away deep underground in iron-sulfur rich hydrothermal vents. Anaerobic and autotrophic, it didn’t breath air and made its own food from the dark, metal-rich environment around it. Its metabolism depended upon hydrogen, carbon dioxide and nitrogen, turning them into organic compounds such as ammonia. Most remarkable of all, this little microbe was the beginning of a long lineage that encapsulates all life on Earth.

If we trace the tree of life far enough back in time, we come to find that we’re all related to LUCA . If the war cry for our exploration of Mars is ‘follow the water’, then in the search for LUCA it’s ‘follow the genes’. The study of the genetic tree of life, which reveals the genetic relationships and evolutionary history of organisms, is called phylogenetics. Over the last 20 years our technological ability to fully sequence genomes and build up vast genetic libraries has enabled phylogenetics to truly come of age and has taught us some profound lessons about life’s early history.

For a long time it was thought that the tree of life formed three main branches, or domains, with LUCA at the base —eukarya, bacteria and archaea. The latter two— the prokaryotes— share similarities in being unicellular and lack a nucleus, and are differentiated from one another by subtle chemical and metabolic differences. Eukarya, on the other hand, are the complex, multicellular life forms comprised of membrane-encased cells, each incorporating a nucleus containing the genetic code as well as the mitochondria ‘organelles’ powering the cell’s metabolism. The eukarya are considered so radically different from the other two branches as to necessarily occupy its own domain.

However, a new picture has emerged that places eukarya as an offshoot of bacteria and archaea. This “two-domain tree” was first hypothesized by evolutionary biologist Jim Lake at UCLA in 1984, but only got a foothold in the last decade, in particular due to the work of evolutionary molecular biologist Martin Embley and his lab at the University of Newcastle, UK, as well as evolutionary biologist William Martin at the Heinrich Heine University in Düsseldorf, Germany.

Bill Martin and six of his Düsseldorf colleagues (Madeline Weiss, Filipa Sousa, Natalia Mrnjavac, Sinje Neukirchen, Mayo Roettger and Shijulal Nelson-Sathi) published a 2016 paper in the journal Nature Microbiology describing this new perspective on LUCA and the two-domain tree with phylogenetics.

Ancient genes

Previous studies of LUCA looked for common, universal genes that are found in all genomes, based on the assumption that if all life has these genes, then these genes must have come from LUCA . This approach has identified about 30 genes that belonged to LUCA , but they’re not enough to tell us how or where it lived. Another tactic involves searching for genes that are present in at least one member of each of the two prokaryote domains, archaea and bacteria. This method has identified 11,000 common genes that could potentially have belonged to LUCA , but it seems far-fetched that they all did: with so many genes LUCA would have been able to do more than any modern cell can.

Bill Martin and his team realized that a phenomenon known as lateral gene transfer ( LGT ) was muddying the waters by being responsible for the presence of most of these 11,000 genes. LGT involves the transfer of genes between species and even across domains via a variety of processes such as the spreading of viruses or homologous recombination that can take place when a cell is placed under some kind of stress.

A growing bacteria or archaea can take in genes from the environment around them by ‘recombining’ new genes into their DNA strand. Often this newly-adopted DNA is closely related to the DNA already there, but sometimes the new DNA can originate from a more distant relation. Over the course of 4 billion years, genes can move around quite a bit, overwriting much of LUCA’s original genetic signal. Genes found in both archaea and bacteria could have been shared through LGT and hence would not necessarily have originated in LUCA .

Knowing this, Martin’s team searched for ‘ancient’ genes that have exceptionally long lineages but do not seem to have been shared around by LGT , on the assumption that these ancient genes should therefore come from LUCA . They laid out conditions for a gene to be considered as originating in LUCA . To make the cut, the ancient gene could not have been moved around by LGT and it had to be present in at least two groups of archaea and two groups of bacteria.

“While we were going through the data, we had goosebumps because it was all pointing in one very specific direction,” says Martin.

Once they had finished their analysis, Bill Martin’s team was left with just 355 genes from the original 11,000, and they argue that these 355 definitely belonged to LUCA and can tell us something about how LUCA lived.

Such a small number of genes, of course, would not support life as we know it, and critics immediately latched onto this apparent gene shortage, pointing out that essential components capable of nucleotide and amino acid biosynthesis, for example, were missing. “We didn’t even have a complete ribosome,” admits Martin.

However, their methodology required that they omit all genes that have undergone LTG , so had a ribosomal protein undergone LGT , it wouldn’t be included in the list of LUCA’s genes. They also speculated that LUCA could have gotten by using molecules in the environment to fill the functions of lacking genes, for example molecules that can synthesize amino acids. After all, says Martin, biochemistry at this early stage in life’s evolution was still primitive and all the theories about the origin of life and the first cells incorporate chemical synthesis from their environment.

What those 355 genes do tell us is that LUCA lived in hydrothermal vents. The Düsseldorf team’s analysis indicates that LUCA used molecular hydrogen as an energy source. Serpentinization within hydrothermal vents can produce copious amounts of molecular hydrogen. Plus, LUCA contained a gene for making an enzyme called ‘reverse gyrase’, which is found today in extremophiles existing in high-temperature environments including hydrothermal vents.

Two-domain tree

Martin Embley, who specializes in the study eukaryotic evolution, says the realization of the two-domain tree over the past decade, including William Martin’s work to advance the theory, has been a “breakthrough” and has far-reaching implications on how we view the evolution of early life. “The two-domain tree of life, where the basal split is between the archaea and the bacteria, is now the best supported hypothesis,” he says.

It is widely accepted that the first archaea and bacteria were likely clostridia (anaerobes intolerant of oxygen) and methanogens, because today’s modern versions share many of the same properties as LUCA . These properties include a similar core physiology and a dependence on hydrogen, carbon dioxide, nitrogen and transition metals (the metals provide catalysis by hybridizing their unfilled electron shells with carbon and nitrogen). Yet, a major question remains: What were the first eukaryotes like and where do they fit into the tree of life?

Phylogenetics suggests that eukaryotes evolved through the process of endosymbiosis, wherein an archaeal host merged with a symbiont, in this case a bacteria belonging to the alphaproteobacteria group. In the particular symbiosis that spawned the development of eukarya, the bacteria somehow came to thrive within their archaeal host rather than be destroyed. Hence, bacteria came to not only exist within archaea but empowered their hosts to grow bigger and contain increasingly large amounts of DNA . After aeons of evolution, the symbiont bacteria evolved into what we know today as mitochondria, which are little battery-like organelles that provide energy for the vastly more complex eukaryotic cells. Consequently, eukaryotes are not one of the main branches of the tree-of-life, but merely a large offshoot.

A paper that appeared recently in Nature, written by a team led by Thijs Ettema at Uppsala University in Sweden, has shed more light on the evolution of eukaryotes. In hydrothermal vents located in the North Atlantic Ocean — centered between Greenland, Iceland and Norway, known collectively as Loki’s Castle— they found a new phylum of archaea that they fittingly named the ‘Asgard’ super-phylum after the realm of the Norse gods. The individual microbial species within the super-phylum were then named after Norse gods: Lokiarchaeota, Thorarchaeota, Odinarchaeota and Heimdallarchaeota. This super-phylum represents the closest living relatives to eukaryotes, and Ettema’s hypothesis is that eukaryotes evolved from one of these archaea, or a currently undiscovered sibling to them, around 2 billion years ago.

Closing in on LUCA

If it’s possible to date the advent of eukaryotes, and even pinpoint the species of archaea and bacteria they evolved from, can phylogenetics also date LUCA’s beginning and its split into the two domains?

It must be noted that LUCA is not the origin of life. The earliest evidence of life dates to 3.7 billion years ago in the form of stromatolites, which are layers of sediment laid down by microbes. Presumably, life may have existed even before that. Yet, LUCA ’s arrival and its evolution into archaea and bacteria could have occurred at any point between 2 to 4 billion years ago.

Phylogenetics help narrow this down, but Martin Embley isn’t sure our analytical tools are yet capable of such a feat. “The problem with phylogenetics is that the tools commonly used to do phylogenetic analysis are not really sophisticated enough to deal with the complexities of molecular evolution over such vast spans of evolutionary time,” he says. Embley believes this is why the three-domain tree hypothesis lasted so long – we just didn’t have the tools required to disprove it. However, the realization of the two-domain tree suggests that better techniques are now being developed to handle these challenges.

These techniques include examining the ways biochemistry, as performed in origin-of-life experiments in the lab, can coincide with the realities of what actually happens in biology. This is a concern for Nick Lane, an evolutionary biochemist at University College of London, UK. “What I think has been missing from the equation is a biological point of view,” he says. “It seems trivially easy to make organic [compounds] but much more difficult to get them to spontaneously self-organize, so there are questions of structure that have largely been missing from the chemist’s perspective.”

For example, Lane highlights how lab experiments routinely construct the building blocks of life from chemicals like cyanide, or how ultraviolet light is utilized as an ad hoc energy source, yet no known life uses these things. Although Lane sees this as a disconnect between lab biochemistry and the realities of biology, he points out that William (Bill) Martin’s work is helping to fill the void by corresponding to real-world biology and conditions found in real-life hydrothermal vents. “That’s why Bill’s reconstruction of LUCA is so exciting, because it produces this beautiful, independent link-up with real world biology,” Lane says.

The biochemistry results in part from the geology and the materials that are available within it to build life, says Martin Embley. He sees phylogenetics as the correct tool to find the answer, citing the Wood–Ljungdahl carbon-fixing pathway as evidence for this.

Carbon-fixing involves taking non-organic carbon and turning it into organic carbon compounds that can be used by life. There are six known carbon-fixing pathways and work conducted over many decades by microbiologist Georg Fuchs at the University of Freiburg has shown that the Wood–Ljungdahl pathway is the most ancient of all the pathways and, therefore, the one most likely to have been used by LUCA . Indeed, this is corroborated by the findings of Bill Martin’s team.

In simple terms the Wood–Ljundahl pathway, which is adopted by bacteria and archaea, starts with hydrogen and carbon dioxide and sees the latter reduced to carbon monoxide and formic acid that can be used by life. “The Wood–Ljungdahl pathway points to an alkaline hydrothermal environment, which provides all the things necessary for it — structure, natural proton gradients, hydrogen and carbon dioxide,” says Martin. “It’s marrying up a geological context with a biological scenario, and it has only been recently that phylogenetics has been able to support this.”

Astrobiological implications

Understanding the origin of life and the identity of LUCA is vital not only to explaining the presence of life on Earth, but possibly that on other worlds, too. Hydrothermal vents that were home to LUCA turn out to be remarkably common within our solar system. All that’s needed is rock, water and geochemical heat. “I think that if we find life elsewhere it’s going to look, at least chemically, very much like modern life,” says Martin.

Moons with cores of rock surrounded by vast global oceans of water, topped by a thick crust of water-ice, populate the Outer Solar System. Jupiter’s moon Europa and Saturn’s moon Enceladus are perhaps the most famous, but there is evidence that hints at subterranean oceans on Saturn’s moons Titan and Rhea, as well as the dwarf planet Pluto and many other Solar System bodies. It’s not difficult to imagine hydrothermal vents on the floors of some of these underground seas, with energy coming from gravitational tidal interactions with their parent planets. The fact that the Sun does not penetrate through the ice ceiling does not matter — the kind of LUCA that Martin describes had no need for sunlight either.

“Among the astrobiological implications of our LUCA paper is the fact that you do not need light,” says Martin. “It’s chemical energy that ran the origin of life, chemical energy that ran the first cells and chemical energy that is present today on bodies like Enceladus.”

As such, the discoveries that are developing our picture of the origin of life and the existence of LUCA raise hopes that life could just as easily exist in a virtually identical environment on a distant locale such as Europa or Enceladus. Now that we know how LUCA lived, we know the signs of life to look out for during future missions to these icy moons.

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Quantum speciation

In some modes of speciation the first stage is achieved in a short period of time. These modes are known by a variety of names, such as quantum, rapid, and saltational speciation, all suggesting the shortening of time involved. They are also known as sympatric speciation, alluding to the fact that quantum speciation often leads to speciation between populations that exist in the same territory or habitat. An important form of quantum speciation, polyploidy, is discussed separately below.

Quantum speciation without polyploidy has been seen in the annual plant genus Clarkia. Two closely related species, Clarkia biloba and C. lingulata, are both native to California. C. lingulata is known only from two sites in the central Sierra Nevada at the southern periphery of the distribution of C. biloba, from which it evolved starting with translocations and other chromosomal mutations (see above Chromosomal mutations). Such chromosomal rearrangements arise suddenly but reduce the fertility of heterozygous individuals. Clarkia species are capable of self-fertilization, which facilitates the propagation of the chromosomal mutants in different sets of individuals even within a single locality. This makes hybridization possible with nonmutant individuals and allows the second stage of speciation to go ahead.

Chromosomal mutations are often the starting point of quantum speciation in animals, particularly in groups such as moles and other rodents that live underground or have little mobility. Mole rats of the species group Spalax ehrenbergi in Israel and gophers of the species group Thomomys talpoides in the northern Rocky Mountains are well-studied examples.

The speciation process may also be initiated by changes in just one or a few gene loci when these alterations result in a change of ecological niche or, in the case of parasites, a change of host. Many parasites use their host as a place for courtship and mating, so organisms with two different host preferences may become reproductively isolated. If the hybrids show poor fitness because they are not effective parasites in either of the two hosts, natural selection will favour the development of additional RIMs. This type of speciation seems to be common among parasitic insects, a large group comprising tens of thousands of species.


Here's What It Would Be Like If Dinosaurs Were Around Today

BERLIN, GERMANY - DECEMBER 17: Visitors look at the original skull, which, due to its weight, had to . [+] be exhibited separately from the skeleton, of Tristan the Tyrannosaurus Rex on the first day Tristan was exhibited to the public at the Museum fuer Naturkunde (Natural History Museum) on December 17, 2015 in Berlin, Germany. (Sean Gallup/Getty Images)

What would happen if dinosaurs roamed the earth today? originally appeared on Quora - the knowledge sharing network where compelling questions are answered by people with unique insights.

Answer by Ben Waggoner, Ph.D in Integrative Biology, paleontologist, and evolutionary biologist, on Quora:

Massive devastation of trendy Manhattan wine bars.

Okay, first of all, one subgroup of dinosaurs is still roaming the Earth today: the birds. So dinosaurs poop on your car, visit your feeders, and feed you well on Thanksgiving. But I assume you meant what would happen if the extinct, non-bird dinosaurs could somehow roam the Earth today.

That raises the point that different dinosaur species lived at different times and places. Tyrannosaurus never feasted on Stegosaurus, for example, because Steggy lived something like 100 million years before Rexy ever existed. Tyrannosaurus never got to taste Giraffatitan because they not only lived 80 million years apart, they lived on separate continents. (This is one of my beefs with Jurassic Park Dilophosaurus, the critter that spit poison in Wayne Knight's face, lived about 120 million years and 6000 miles away from Velociraptor, the critters that ate Bob Peck.) So if all the extinct dinosaurs suddenly started roaming the Earth together at the same time . well, you'd have utter ecological chaos, as the Velociraptors discovered that their tactics for hunting Protoceratops were ineffective against unfamiliar Ankylosaurus, and Triceratops found out that it had no idea how to dodge Allosaurus. You might as well turn some polar bears, bison, tree sloths, and kangaroos loose on the Serengeti plain.

But let's keep it simple. Suppose we could magically transport a decent sample of the dinosaurs from one place and time into the present day. Let's pick up a herd of duckbills—say, Edmontosaurus or Maiasura—and a herd of Triceratops, a few smallish predators like Dakotaraptor, and a couple of Tyrannosaurus. All of these lived in the same general area (western North America) in the same general time frame (late Cretaceous). So we plop all of these down in North America today, and .

There were flowering plants in the Late Cretaceous, but they didn't yet dominate the landscape. The typical landscape in Cretaceous North America seems to have been "fern savannas"—somewhat like prairies, but dominated by small ferns, not grasses—broken up by tracts of forests dominated by conifers, ginkgos, ferns, and cycads. There were flowering plants, including decent-sized trees, but again, nothing like the diversity we have now.

And here's the problem: Modern flowering plants have had

100 million years to evolve anti-herbivore defenses, and just to evolve complex chemistry in general. We don't know enough about dinosaur biochemistry to know exactly what they would find poisonous. Suffice it to say that as soon as the herbivores started eating the local plants, they would be exposed to a whole range of chemicals that they had no adaptations to handle. They might not even have the sensory receptors to taste them.

The actual effects are anyone's guess. The simplest case would be that the herbivores would get sick and die, like modern sheep or cows in the West that eat death camas or lupine. Some might end up tripping out, like humans eating ergot-infected rye or jimsonweed, or livestock eating Oxytropis or Astragalus "locoweeds". Survivors might fail to lay viable eggs, or lay eggs that would hatch into deformed offspring—like sheep and goats eating false hellebore and giving birth to lambs and kids with cyclopia.

The carnivorous dinosaurs might have easy pickings for a while, as they feasted on dead or incapacitated herbivorous dinosaurs. This wouldn't last long, though. Sooner or later, Tyrannosaurus rex has to find living prey, or possibly fresh carrion, depending on whether it was a predator or scavenger (that's another story). There were mammals alive at the same time and place as T. rex, but none very big—and for all we know, modern mammal flesh might be unpalatable. But recall that birds belong within the dinosaurian clade. T. rex may run out of Triceratops to eat, but if it can find large, relatively slow birds to munch, it might survive for a while, assuming that it can run fast enough to catch them (a controversial question). A T. rex that was lucky enough to find a turkey farm would probably eat the birds like so much popcorn. The few ostrich ranches in the America West could find their business nipped in the bud, if by "nipped" you mean "messily dismembered."

The herbivores would be equally hard to manage. Imagine: a herd of Triceratops eats a patch of Datura stramonium and promptly levels downtown Bismarck, North Dakota, hallucinating like a Grateful Dead show gone horribly wrong. Twitching, retching, slobbering duckbills collapse across I-94, blocking traffic into Fargo for hours, after getting into a patch of Apocynum cannabinum (hemp dogbane). A photo of a poor baby Edmontosaurus whose mamma tried hellebore, with a single eye and adorably deformed face, threatens to displace the "I Can Has Cheezburger?" cat as the most viral meme on the Internet .

And a herd of Maiasaura, starving and desperate, wanders into Manhattan and discovers a wine bar decorated with lush ferns and rare tropical cycads. Minutes later, the wine bar is flattened, its greenery devoured. Newly invigorated by their first decent meal in weeks, the Maiasaura rampage from one fern bar to the next. Hundreds of Wall Street middle-management flunkies who were hoping to score that night are severely inconvenienced.

This question originally appeared on Quora - the knowledge sharing network where compelling questions are answered by people with unique insights. You can follow Quora on Twitter , Facebook , and Google+ . More questions:


So you think you saw a seagull? Think again because they don't exist

CLOSE

Hikers to Indian Head in the Adirondacks come with packs, water, good boots and a new must-have item: advance reservations. (May 28) AP Domestic

I received an email recently that really caught my attention.

It came from a young lady who lives in a small town in Kansas. And she wanted to know how a wild turkey could lay a clutch of 15 or 20 eggs over the course of as many days and yet hatch them all in one day?

And that simple question brought back fond memories of my time spent learning about wildlife biology, a subject that has always fascinated me.

With the majority of birds, the time between ovulation (when the soft parts of the egg form inside the female bird) and actually laying the egg takes around one day, give or take a few hours. That means most birds, from chickens and turkeys (both wild and domestic) to sparrows and goldfinches, follow this rule.

But how many eggs any bird will lay “in total” depends solely on the species in question.

Geese and seagulls have a hard time finding food along the Oak Creek Parkway near Grant Park in South Milwaukee, Tuesday, April 17, 2018. Birds are having a tough time finding food, especially migrating birds like robins, purple martins and other birds who can't find food with so much snow on the ground. (Photo: Rick Wood/Milwaukee Journal Sentinel)

And, there are wide variations in the overall number of eggs any species will lay. Emperor penguins will lay only one egg, and keep it warm between their feet. Robins almost always lay four eggs, while Eastern phoebes may lay from three to six eggs (which can really crowd their tiny nests).

Bald eagles may lay two or three eggs, but often only one “eyass” will survive (more on that later). And great horned owls almost always lay two eggs, with both babies surviving most of the time.

Most wild ducks and geese, on the other hand, might lay 6 to 18 eggs during each breeding season.

But the young lady’s question really deals with “incubation.” And that time period varies with virtually every individual species, and sometimes within a species.

With wild turkeys, the female (hen) somehow knows when to begin laying eggs, as well as when no more eggs will be laid by her. At one egg per day, that usually means from 8 to 18 eggs. And once she is done with the laying, she still does not have to begin incubation immediately.

As long as the air temperature does not drop below 34 degrees (with most birds), the hen can delay beginning to incubate the eggs for several days or even a week or more. When she does begin, she instinctively knows to stay with the nest during the night and longer if the days are cool. She will leave the nest for short periods to feed, and she may do this several times each day.

And here is the good news. Once the eggs begin to hatch, most if not all of the chicks will be free of their shells within two or three hours.

And generally, they will remain under the hen for that night. But they are precocious little tykes, and they are able to follow the hen wherever she leads.

Baby animals in the wild: If you care, leave them there

What every hiker needs to know: It's no walk in the park

Bald eagles were mentioned earlier. And while most broods consist of two or three young eaglets, it is a sad fact that the largest eaglet will often force its sibling(s) out of the nest. Most biologists believe this is to get more of the food the parents bring.

In nests where the parents bring lots of food, the two or three youngsters often survive together to fledge (take wing), generally within one or two days of each other.

And while I am on the topic of baby birds, often one will leave the nest too early. It is helpless, and if a human happens along and sees it, quite often their initial instinct is to pick it up and render aid if they can.

The best course of action if this happens is to leave it alone. The parents probably know where it is and will keep on feeding it until it can fledge. If the nest is nearby you can carefully pick it up and put it back there.

Do not worry about leaving human scent on any baby bird that appears to have fallen from its nest. It may not be a commonly known fact, but virtually all birds have either a reduced olfactory sense (sense of smell) or none at all. They use their other senses, but really have no need for a sense of smell.

With respect to mammals, this is not the case.

It is actually very dangerous to even touch any mammal babies. Even if the mother was laying dead in the road, did she have some disease before she was killed that was transmitted to her young? You can never answer that question, so why take a chance that your entire family might suffer from? Instead, contact the DEC, tell them what you have seen, and let the experts handle that problem.

While on the subject of birds and their strange behaviors or habits, here are some more things you may not have known.

For instance, did you know that flamingos are not really pink? They are actually born gray, their natural color. It is their diet that causes them to “change” their color to pink. Their primary food sources are brine shrimp and blue-green algae, and it is those two foods that contains a natural pink dye and it turns their feathers pink.

Zoo keepers learned this fact the hard way. Back in the late 1800s and all the way to around 1920 or so, they had no clue as to why those birds could not maintain the “pink” (wild flamingos) color.

Then some scientist discovered that canthaxanthin, the natural pink dye in their diets in the wild, was missing in captive birds. By adding that substance to their food, they gradually brought the pink color back to captive flocks.

Just about everyone knows that a hummingbird is the only bird species that can fly backward. It is essentially a living helicopter in that respect.

But did you know that a hummingbird’s eggs are around the size of a garden pea? And they can lay three to five eggs, but the overwhelming number of eggs laid is four, with only one nesting per year for most species.

Swifts are another incredible bird species. They are among the most adroit fliers in the entire bird world, being surpassed (possibly) only by several albatross species. They spend almost all of their lives on the wing, only taking 40 to 50 days off (partly) to build their nest and raise their young until they fledge.

They don’t even take the time to teach their young how to catch insects on the wing. The young observe the adults and emulate their hunting techniques.

These are truly amazing critters. They eat, drink and even mate while flying, stopping only to feed the youngsters once they hatch. Many experts agree that swifts probably fly in excess of 400 miles every day!

Over the eons of their existence they have learned to use their saliva and bits of mud to build their nest on almost any flat, sheltered surface, but their preference is inside buildings such as open barns.

There are four species of swifts that nest in North America. They are the black, Vaux’s, white-throated and chimney swifts. The first three nest across the western states, and the chimney swifts nest all across the east.

By the way, the black swift migrates to Brazil where it spends the winters, an estimated distance of over 4,000 miles! Each way! Wow!

Did you know that penguins can fly? They may not be able to go airborne, but they can fly under water where they also hunt for small fish such as sardines and some crustaceans. And their most dangerous enemies are leopard seals and Orcas (killer whales).

And here is one more fact that is interesting (and it has won me more than a few “ginger ales.”) There is no such thing as a “seagull.” There are ring-billed gulls, greater black-back gulls, kemp gulls, and many other species of gulls, but no seagulls.

In fact, there are around 48 different (recognized) species of gulls around the world, but not even one species is called a seagull. Just thought you would like to know.