Science & Nature Archive

Wednesday, November 6, 2013

Texas Science Textbook Adoption

Stand Up for Science TexasI haven't written about the Texas School Board in a while, but it's time to, again. On November 22nd, the school board will have the final vote to adopt the currently proposed textbooks and other instructional materials. Now so far, things appear to be going the right way for our students' educations. Despite some school board members appointing creationists and other idealogues to the textbook review panels, and those idealogues making recommendtions against sound science, the publishers haven't made any changes undermining science education. There's still full support for evolution and climate change, the two big controversial points for the extremists.

If the final vote approves the recommended materials without any last minute shenanigans, then our students will at least have good science textbooks. But, given the school board's past behavior, it doesn't hurt to send the members a gentle reminder to vote properly. If you would like to send such a reminder to your representative, the links below provide you the means to do so (and please remember to be polite).


Links to Take Action:


Links for More Information:


Links to Past Entries on This Site Related to SBOE or TEA:

Friday, September 6, 2013

Review of Ray Comfort's New Movie - Evolution vs. God, Part I

Ray Comfort's new movie, Evolution vs. God, is finally out on YouTube. I mentioned this movie a few weeks ago in the entry, Ray Comfort's New Movie - Evolution vs. God. At that time, the movie was only available by paying for a download, which I obviously wasn't going to do. Now that the movie's out for free, I actually took the time to watch it and write this review. By this point, I'm a little late to the party in my critique, and there are already pretty good reviews out there. But I figured I'd add my voice, especially given Comfort's special significance to this blog*. And since this review grew so long as I was typing it, I've decided to divide it into two parts. This first part covers the 'sciencey' portions of the movie.

But first, for anyone who's interested, I've embedded the video below.

My original expectations for the movie weren't far off the mark. Comfort still doesn't understand evolution, at all, despite all the years he's spent trying to debunk it. The movie also made extensive use of selective editing of interviews, arguments from semantics, misconstrued definitions, and Comfort's trademark series of leading questions on whether or not you're a good person. To be charitable, the movie did highlight a few real problems, sometimes inadvertently, sometimes on purpose. But overall, this movie is just one more example of Comfort's colossal lack of understanding of evolution, combined with his questionable ethics in trying to get his point across. And to be honest, I didn't particularly like the documentary style. The constant jumping from interviewee to interviewee, never showing any of them for long enough to give a detailed response, wasn't very engaging, and several times I found myself bored.

I'm going to try to review the movie pretty much chronologically, breaking up my review into the same topics that Comfort used. Since he didn't exactly use headings, and some transitions were a bit fluid, this will be a bit inexact, but still pretty close. I'll begin each section with a few examples before adding my commentary.

One note I'll add up here concerns Comfort's method of jumping so fluidly from one scene to the next. It was done in such a manner as to give the appearance of continuity, but without the viewer actually knowing what conversations were taking place. For example, he might ask one person a question, and then jump to several people giving answers. The impression is that he asked the same question of all the interviewees, but there's no way to be sure. Similarly, sometimes after a person gave a response, he would jump to another clip, where his statement or question seemed like a response to the previous person. And maybe he would have responded that way to the previous person, but you don't get to see their reaction, nor whether they would have had a reply of their own.

Meeting the Interviewees

The movie began by briefly displaying a Richard Dawkins quote ("Faith is the great cop-out, the great excuse to evade the need to think and evaluate evidence") with eerie background music, and then a short title sequence, before beginning in earnest by introducing the interviewees who would be shown responding to Comfort's questions throughout the movie. These began with the interviewees stating their religious positions - atheist, agnostic, or leaning that way, and confirming their belief in evolution. Next was a quote describing evolution, " 'Live Science' says of Darwinian Evolution: 'It can turn dinosaurs into birds, apes into humans and amphibious mammals into whales.' " with an authoritative voice over reading the quote verbatim. Following that was a professor giving a brief statement about evolution removing the need for the supernatural in explaining the origin of life, and then back to brief responses from interviewees, this time concerning whether evolution is a 'belief', when people started believing, their reasons for believing, the majors of the students he was talking to, etc. Just to give an idea of how fast all the cuts are in this movie and how superficial all the discussion is, everything mentioned in this paragraph was covered in just a little under 3 minutes.

Observable Evidence

Now it was time for another quote read by the authoritative voice, "A scientific method is based on 'the collection of data through observation and experimentation...' -Science Daily" Actually, that's not such a bad statement, but notice that he's quoting a popular news magazine. If you're going to play the definition game, here's another definition of science, this one from Wikipedia, "Science ... is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe. In an older and closely related meaning, 'science' also refers to a body of knowledge itself, of the type that can be rationally explained and reliably applied."

Here's where Comfort's mangling of science first comes into the documentary. He asked a man, "Could you give me some observable evidence that evolution is true, something I don't have to receive by faith. Some observable evidence." The man responded by saying to take a look at what happened 65 million years ago, and Comfort jumped in to say that something that happened 65 million years ago isn't observable. Fair enough from a strict point of view. That's not exactly evidence. But then the movie starts cutting to other interviewees, without showing exactly what questions they were asked, showing them discussing deep time, with Comfort periodically interjecting that that means it can't be observed. This was all followed by a quote from Richard Dawkins that our lives are too short to "see evolution going on", and a similar quote from Charles Darwin.

While talking to PZ Myers, Comfort described that there are different kinds - feline kind, canine kind, human kind. He then asked Myers, "Darwin said there'd be a change of kinds over many years, so could you give me one example of observable evidence of a change in kinds." Myers began discussing fossil evidence, and Comfort asked how long ago all these evolutionary changes took place. When Myers responded that it was around 60 million years ago, Comfort seamlessly jumped to another clip, stating "I don't want something I have to accept by faith. I want it to be observable." It wasn't a direct response to Myers, but it seemed to imply that Myers hadn't given observable evidence. He then moved on to showing students who couldn't provide any good observable evidence, and getting them to admit they had 'faith' in evolution.

Next it was back to PZ Myers again, who began discussing evidence from the genetics of stickleback fish. But when Comfort learned that they were still sticklebacks, his somewhat incredulous reply was, "They stayed as fish". He went on from there asking more people about 'observable' evidence of change in kinds, always objecting that since these changes take longer than a human lifespan, that they're not observable.

This whole section of the documentary is either dishonest, or Comfort really isn't thinking things through. Observable evidence of an event does not necessarily mean directly witnessing the event. And in no other aspects of studying history do we call it faith to accept something as true that we haven't directly observed. I'll use an example. Mesoamerican history really interests me. Civilizations like the Maya or the earlier Olmec are fascinating. But nobody has directly observed those civilizations. The 'observable evidence' that we do have is what archaeologists find when they go investigating sites. We didn't see the artist who made The Wrestler, nor did we see it in that distant time period, but it is an artifact that can be observed. Likewise, we never directly observed any inhabitants of Tikal, but the ruins themselves are observable evidence. It would be ludicrous to say that we accept the existence of those civilizations on faith. We accumulate the evidence we have to form the most likely picture of the past.

Evidence for evolution is similar. A fossil is observable evidence, even if we didn't see the organism while it was alive. Studying genetics is observable. Anyone can go out and replicate the procedures used by geneticists to verify that they get the same results. It may take a little reasoning to put all the evidence together into a coherent picture, but that's how science works. For example, have you ever directly witnessed the Earth orbiting the Sun? Nobody has. We're inside the system, and nobody has ever traveled 'above' the solar system to directly observe it. Heliocentric theory is based on studying the evidence that we can see, and then reasoning out the motions of the planets from that.

Besides, the type of direct observation Comfort is asking for is ludicrous. Evolutionary theory doesn't predict that one 'kind' will evolve into another 'kind' in any type of timescale that humans can directly observe. It's true that we have witnessed a few speciation events (see Talk Origins - Observed Instances of Speciation, but when Comfort talks of changing kinds, he's talking of much bigger changes. It's almost as if he wants to see a cat give birth to a dog. If I give Comfort the benefit benefit of the doubt here, maybe he's trying to argue that since a change of kinds can't be witnessed because it's such a slow process, it must therefore be taken on faith. He'd still be incorrect, but not so bad as expecting a cat-dog. Though, even giving him the benefit of the doubt here might be too generous, considering how ludicrous his arguments can be (for an example, scroll about halfway down this page for his strange interpretation of dog evolution.)

Darwinian Evolution

This is closely related to the above discussion, but I want to make a different point. A bit later, Comfort asked Myers, "Can you give me an example of Darwinian evolution? Not adaptation or speciation, but a change of kinds." When Myers replied that he had been giving examples of a type of fish evolving into multiple distinct kinds of fish, Comfort again went back to his retort that "They're still fish." Myers also brought up Lenski's famous e. coli experiment (see The Loom - The Birth of the New, The Rewiring of the Old), and Comfort had the nerve to say, "That's not Darwinian evolution," and then a seamless transition into the next scene where he says "That's not a change in kind." He went on to say, "To summarize, the observable evidence you've given me for Darwinian evolution is bacteria becoming bacteria." He kept on harping on this topic, asking for an observed instance of one kind becoming another kind. There was a discussion on the Galapagos finches, and of course, Comfort's reply was "They're still birds", and that it therefore wasn't Darwinian evolution. He spent a fair amount of time showing students getting stumped again, not being able to instantaneously offer observed evidence of one kind changing into another. After insisting on this unrealistic expectation of evidence, he said that evolution therefore wasn't scientific, and showed the students he was able to get to go along with that statement, and then just a bit later students that he was able to convince that they were going on 'blind faith', with a repeat of the Dawkins quote from the start of the documentary.

First, it's a bit strange to keep harping on 'Darwinian' evolution 150 years after Darwin. Modern evolutionary theory is the modern synthesis. It owes much to Darwin's theory of natural selection, but it's more than that. It takes into account genetics, which Darwin didn't have a good handle on. It incorporates genetic drift, kin selection, Hardy-Weinberg equilibrium, and much that Darwin never even dreamed of.

Even if we were to pay homage to Darwin and refer to modern evolutionary theory as Darwinian evolution, Comfort doesn't seem to understand the real definition. Here's a biology professor's definition, "Biological evolution is the change that species (kinds of living things) undergo over time. More precisely, it is the change in the gene pools of living populations of species which occurs over time. A gene is a hereditary unit that can be passed on. A gene pool is the set of all genes in a species or population." That's pretty consistent with definitions I've seen elsewhere. All the examples described above, from the Galapagos finches, to stickleback fish, to Lenski's e. coli experiments, show changes in the gene pools of populations. Lenski's experiment is particularly exciting, because it shows an entirely new biochemical ability that developed in a population.

However, this is one of the areas where Comfort did highlight a legitimate problem - not enough people understand the evidence supporting evolution. However, contrary to Comfort's interpretation, this is not because the evidence doesn't exist, but rather because of the nature of our education system. So much of science education, especially in grade school and undergrad, is teaching concepts, with only a bit of the evidence of how we know those things. For example, I don't think that even Comfort doubts atomic theory, but how many people can explain the evidence for why atomic theory is true? How do you know we're composed of these weird particles called atoms, with a nucleus full of protons and neutrons, and electrons flitting about outside the nucleus?

Lungs AND Gills?

This next bit was actually part of the above discussion, but I wanted to pull it out on its own. Here's something Comfort actually said in the movie.

So did we have lungs or gills when we came out of the sea? ... If we came out of the sea, we had gills in the sea.

The reason this stands out to me is that he said nearly the same thing in a CD that I listened to years ago, the very CD that inspired me to start this blog. It's such an ignorant argument, implying that it would be silly for an animal to have both lungs and gills. But guess what, numerous such animals exist today, not just as inferences from the fossil record.

Here are a few animals with both gills and lungs:

And of course, many amphibians go through a metamorphosis, and so have gills and lungs at different stages of their lives.

Here are a few fish with vascularized swim bladders that can be used to breathe air:

And here are a few fish that have evolved independent means of breathing air:

Really, it seems quite useful for organisms to be able to breathe above and under water. And it's not as if it's a terribly rare trait. The list above contains quite a few vertebrates with that capability. And that's not even considering invertebrates (such as crabs). And further, some of the fish above, including lungfish and bettas, are actually required to breathe air - their gills can't get them enough oxygen to survive.

Intelligent Design

Just for reference, it's now just about 14 minutes into the documentary.

So, with his ludicrous demands for observable evidence of one kind changing into another out of the way, he moved on to discussing Intelligent Design (ID). He started off by asking people to make a rose. And when people responded that they couldn't, his inane response was "Hang on. Now it's not intelligently designed, so you should be able to whip me up a rose real quick." What type of sense does that even make? Simple vs. complex doesn't denote intelligently designed vs. natural. A hammer is intelligently designed. It's also very simple, and I'd have no problem making one. A geode is naturally occurring, but I couldn't make one of them.

He transitioned from that into saying that nobody can make something from nothing, not even a grain of sand. That's not what evolutionary theory even says. Creation ex nihlo is a religious concept. Evolutionary theory starts up with the universe already existing.

Next was another example of how badly he represented the scientific understanding of the history of the universe, "There was nothing in the beginning, a big explosion of nothing, it become something. It became into a rose, and giraffes and horses and cows." It's as if he's trying to represent the history of the universe as the big bang leading directly to fully formed organisms, completely ignoring the expansion of the universe, stellar evolution, the formation of our solar system, abiogenesis, and finally biological evolution.

Vestigial Traits

Next came a discussion of "vestigials". The student he was interviewing said it was a left over organ with no use, and Comfort jumped on that 'no use' part. In particular, he pointed out that tail bones anchor tendons, ligaments and muscles, and that the appendix is actually a part of the immune system. Since I've already played the definitions game once in this entry, let's do it again and take a look at how Meriam Webster defines 'vestige'. This is the second definition given, the one with the biological connotation:

a bodily part or organ that is small and degenerate or imperfectly developed in comparison to one more fully developed in an earlier stage of the individual, in a past generation, or in closely related forms

Where does that definition say no function at all? It doesn't, because that's not what vestigial means. Many body parts have multiple functions. For example, our larynxes allow us to breathe, but they've also been co-opted for communication (speech). Same with tongues, though for them it's eating and speaking. Our hands have many, many functions.

If you go back far enough, our ancestors had tails. Those tails did all the normal functions tails do - especially balance in our simian ancestors, and also providing an anchor point for tendons, ligaments and muscles. At some point, our ancestral line lost their tails - probably due to a change in locomotion through the trees where they weren't as important. But all those tendons, ligaments and muscles for our leg muscles still needed anchoring points. Evolution doesn't do a whole lot of creating new parts from scratch, but rather modifying existing features. So, as our ancestors lost their tails, they couldn't lost the parts that anchored tissues for the legs, so they couldn't lose those bones entirely. And we still have that vestige of the past - a short 'tail' that's not even long enough to poke out through our skin. It still has a function, but it is "small and degenerate" compared to our simian ancestors.

As far as the appendix, I'll direct readers to the TalkOrigins article, The vestigiality of the human vermiform appendix: A modern reappraisal. Comparing the human appendix to the caecum of other animals, it's pretty clear that the human index is greatly reduced. It also seems rather unnecessarily complicated for the limited functionality it might have (though even any functionality is disputed).

And of course, appendices and coccyges aren't the only examples of vestigial organs. While the following article may not be the scientifically rigorous, it does provide some good examples, Top 10 Useless Limbs (and Other Vestigial Organs).

---

At this point, just over 17 minutes into the movie, or about halfway through, Comfort's pretty much done with any discussion of science. So, that makes for a good breaking point for this review. Look forward to Part II, which will focus more on religion, in about a week.

Continue Reading: Part II

Monday, July 29, 2013

Response to Global Warming Denialist E-mail - Volcanoes and Global Cooling

Global WarmingSomeone recently asked me to fact check an e-mail for them, so I've decided to post that response here. The e-mail was supposedly quoting Ian Plimer, a geologist and professor at the University of Melbourne, and a noted climate change denialist. For anyone interested, I've posted that e-mail in its entirety below the fold.

The lead-in to the body of the article was, "Where Does the Carbon Dioxide Really Come From?" After a bit of ranting about Priuses, CFL bulbs, and the like, it got to its main point - that volcanoes supposedly spew out far more carbon dioxide than any human contributions. It even made the claim:

...when the volcano Mt Pinatubo erupted in the Philippines in 1991, it spewed out more greenhouse gases into the atmosphere than the entire human race had emitted in all its years on earth.

Just a bit later, the e-mail claimed that the Earth has been cooling for the last century:

It's because the planet has COOLED by 0.7 degrees in the past century and these global warming bull artists got caught with their pants down.

So, in response to the person who asked me to fact check this e-mail, I responded in three parts, as detailed below.


Correct Attribution/Credentials?

On the first level of fact-checking, I didn't find the actual source of this quote from Plimer. All I could find were reprints of this e-mail. So, I'm not sure if he actually wrote it (and given the tone, I would hope not), but it does appear consistent with claims of his I've found elsewhere. As far as his background, that's simply copied-and-pasted from Wikipedia, so it's probably correct.


Volcanic Emissions vs. Human Emissions:

Plimer is way off base here. I found many, many different sites dealing with this. Here are two of the better ones:

That first link contains these two tables, so that you can compare annual volcanic CO2 emissions to human emissions. It also contained the emissions for a couple notable eruptions, Mt. St. Helens and Mt. Pinatubo. Annual human caused CO2 emissions are on the order of 134 times higher than total annual volcanic emissions (which includes submarine volcanos), and about 700 times higher than what was released by the one-time event of Mt. Pinatubo erupting.

Yearly CO2 emitters Billion metric tons per year (Gt/y)
Global volcanic emissions (highest preferred estimate) 0.26
Anthropogenic CO2 in 2010 (projected) 35
Light-duty vehicles (cars/trucks) 3
Approximately 24 1000-megawatt coal-fired power stations * 0.22
Argentina 0.2
Pakistan 0.18
Saudi Arabia 0.44
 
CO2 emission events  
Mount St. Helens, 18 May 1980 0.01 Gt
Mount Pinatubo, 15 June 1991 0.05 Gt
Number of Pinatubo-equivalent eruptions equal to annual anthropogenic CO2 700
Number of Mount St. Helens-equivalent eruptions equal to annual anthropogenic CO2 3500


Global Cooling?

I've seen similar claims of global cooling a few times before, but usually on shorter time scales. It almost always comes down to cherry-picking data. Here's an article dealing with a similar claim made by David Rose last year, and another article dealing with longer term trends.

Below is a good graph from the first article. It clearly shows a long term warming trend over the past several decades. But it's not a perfectly smooth line, and there are outliers both above and below the general trend. So, if you cherry-pick, as they show in the animation, and choose an appropriate (or rather, inappropriate) time period, you can say there's been cooling over that short term period, and then naively extrapolate that short term cooling to saying that it's a long term cooling trend. But when you look at the larger data set over several decades, it's clear which way the trend is going.

Global Warming Trends

The second article dealt with longer term trends, addressing the e-mail's specific claim of cooling over the last century. Below is a graph from that article, showing the temperature anomaly for the past 11,000 years. I clearly shows that the rate of change right now is much higher than it's been than at any other point in that period, and a clear warming trend for the past century.

Marcott Graph

So, this e-mail contained nothing but the bogus claims I've come to expect from the climate change denialists. I really don't understand this mindset. Problems don't disappear just because you ignore them. Burying your head in the sand won't make global warming go away. We've already had to face some consequences of a changing climate, and rather quickly, we're going to have to start dealing with the more profound effects. Why not own up to it and start working on solutions now?

Continue reading "Response to Global Warming Denialist E-mail - Volcanoes and Global Cooling" »

Monday, July 22, 2013

Sketching Art Masterpieces from Memory

Some of my fellow engineers and I watch the show, Brain Games, on the National Geographic Channel (I highly recommend watching the show if you haven't seen it, yet). On one episode, they performed an experiment based on the study, The Science of Cycology, by Rebecca Lawson. Subjects were given a basic, incomplete layout of a bicycle, showing just part of the frame, the wheels, the seat, and the handlebars, and then asked to fill in the rest of the drawing with the pedals, chain, and completing the frame. Below is a copy of the basic layout that they were given.

Cycology Skeletal Layout

This may at first appear to be a simple task, but it turns out to be surprisingly difficult for a large number of people. If you want to see what types of drawings Lawson got from the test subjects, follow that link above to read her paper (it's not terribly long, and you can jump ahead to the interesting parts, anyway). If you really want to play along, try it for yourself before following the link.

The study listed errors in frame, pedals, and chain independently, so I'm sure there was some overlap in the errors, and I'm unsure what that overlap was, but nearly half of the drawings had the chain drawn incorrectly to where the bike wouldn't work. In other words, at least around half of the drawings were wrong. If some people got the chain right but made mistakes in other parts, then the number is even higher.

The hypothesized reason is that our memories really aren't as good as we think they are. While we all know a bicycle when we see one, and think we have a good memory of just what a bicycle looks like, the truth is that many of us remember only just enough to recognize the bicycle, but not much detail.

Of course, us engineers in the office had no problem drawing a bicycle from memory. In fact, we didn't even need the skeletal layout to start off with. We could all just draw it from a blank sheet. But I didn't think this was exactly representative. For one, we're all mechanical engineers (if you count aero as a subset of mechanical), so this is exactly the type of thing we pay attention to. For another, with our bent towards mechanical design, we don't actually have to remember what the bike looks like. We can just remember a few details, and then fill in the rest as we go to make a functioning product. That's the type of thing we do on a daily basis.

So, we got to talking about another way to test Lawson's hypothesis. Was there something else that we should be familiar with, that we would recognize instantly, to try drawing from memory. And we decided that art masterpieces were the perfect objects. These are things you see repeatedly throughout your life. And we couldn't use our mechanical aptitude to fill in details. We had to rely on memory.

Before I go on, I'll list the pieces that we attempted to draw. If you want to have some fun, try drawing them for yourself before you scroll on further (or before you click on the links).

[Intentional blank lines to leave some space so that you don't accidentally see the real versions if you want to draw them yourself.]

.

.

.

.

How did we do? Pretty poorly, and not just on artistic merit. I don't have copies of every sketch that we did, since the other engineer who was trying it was doing his sketches on a white board and had to erase each one to have a clean canvas for the next masterpiece. But I was doing mine by pencil on scratch paper, so I at least have all of mine. Below are my sketches and one of his, followed by the real masterpiece.

The Mona Lisa

Jeff's Mona Lisa Sketch The Real Mona Lisa

The Scream

Jeff's The Scream Sketch The Real The Scream

The Persistence of Memory

Jeff's The Persistence of Memory Sketch
Martin's The Persistence of Memory Sketch
The Real The Persistence of Memory

We may have gotten a few of the big details right, but we really missed a lot when it came to filling it in. We both missed many details in the Mona Lisa, even something as prominent as her hands. Neither of us had the extra people or the sailboats in The Scream. And my Persistence of Memory was particularly dismal (the other engineer's was pretty good, but he admitted to having painted a copy of it in an art class).

I can think of another permutation on this, actually similar to what Lawson did in another section of her study - multiple choice. How many of us would be able to pick the correct version of a masterpiece given multiple similar choices (either through alterations, or probably even more difficult, through the time honored tradition of hand painted reproductions).

Anyway, while this post is nominally related to Rebecca Lawson's study, and our anecdotes fall in line with what she's proposing, the real reason I posted this was because it was fun. Get together with some friends and try doing this for yourself. Pick a masterpiece, try sketching it from memory, and then compare your sketches to each other and to the real thing. If you're like us, you'll be surprised at how little you can remember, but you'll have fun doing it.

Monday, July 15, 2013

Which Came First, the Chicken or the Egg?

Which Came First, the Chicken or the Egg?Jerry Coyne recently started a thread on his website in the entry, The Eternal Question, asking his readers to weigh in on the question, 'Which came first, the chicken or the egg?'. Some of his commenters left answers I largely agreed with, and I even added my own two cents in response to one comment, but I thought I'd leave my full thoughts here.

The short answer is that evolution is a gradual process that occurs among entire populations, and species are such a fuzzy concept, that it doesn't even make sense to think of a first chicken or a first chicken egg*.

One of Coyne's commenters suggested that even if the line is arbitrary, you should be able to draw it somewhere. What if you set up your dividing line such that there was a single last mutation responsible to shift a genome from an almost-but-not-quite-chicken to a true chicken? And that mutation finally appears in one organism, so presto, it's a chicken. But if you think about this threshold a bit more, it doesn't make sense. Imagine that your first chicken grows up, finds a mate, and reproduces. Since the chicks get half of their genetic material from each parent, and the division is random, somewhere around half of the 'first chicken's' offspring will get the mutation that defined it as a chicken, and around half will have the old version of that gene. So only half of its offspring would be 'true chickens' - there would be brothers and sisters that were different species! And then all those chicks would grow up and have their offspring, and on and on, and you'd end up with a breeding population composed of a mix of almost-but-not-quite-chickens and true chickens. That's just silly, and doesn't even meet the biological definition of a species.

In reality, species is a very fuzzy concept. The biological species concept is the one most used for sexually reproducing animals. Wikipedia gives a definition for it as follows.

A biological species is a group of individuals which can breed together (panmixia). However, they cannot breed with other groups. In other words, the group is reproductively isolated from other groups.

So, any organism will always necessarily be the same species as its parent. It's only after generations of reproductive isolation that two groups will gradually change to be sufficiently different that they won't be able to interbreed.

There are some interesting modern examples that show how even the biological definition of species can be difficult. One is polar bears and grizzly bears. They can, in fact, interbreed to create fertile offspring. But they don't usually do so naturally. So, it's not that the reproductive isolation has to be complete. It just has to happen little enough that the gene pools don't do too much mixing. How much is too much? Who knows. That's one of the grey areas.

A very interesting case is what's known as a ring species. These are animals that have a range that encircles some type of barrier. A classic example is the Larus gull, which lives in a band around the Arctic Ocean. If you start with the European Herring Gull which lives mainly in Great Britain, it can mate with the American Herring Gull to the west. And they do this often enough that their gene pools mix, which indicates that they're merely subspecies, not completely different species. And if you go west from there, the American Herring Gull can mate with the East Siberian Herring Gull. And you can keep going west, with the groups being able to interbreed, all the way until you get to Lesser Black-backed Gulls, which live mainly in Europe but which also stray into Great Britain. But guess what, the Lesser Black-backed Gulls in Great Britain don't mate with the European Herring Gulls on the same island. So how do these animals get classified as a species? There's one large interbreeding population right now, which would indicate one species. But what if all of the subspecies were to go extinct except for Lesser Black-backed Gulls and European Herring Gulls? Would they instantly become two new species?

Perhaps a more familiar example is dogs. Everybody knows that dogs can interbreed. That's where muts come from. But what if some super-villain were to come along and kill every breed of dog except for Chihuahuas and great Danes? Now, I know that technically you could probably give them a hand to do the deed and make puppies, and they might even be fertile. But, if left to their own devices, they'd be two pretty effectively isolated breeding populations. (I suspect this page is either a joke or an urban legend, but it still reveals the difficulties that would be involved). So, given the current dog population, chihuahuas and great Danes are part of the same species. But there's no way they would be considered the same species if they were the only dogs left in existence.

Given that species is such a fuzzy concept to begin with, it makes no sense to think of a 'first' of any species. There are gradually changing populations, and there's no point where you can pick one organism as being a different species from its parent.

So, the next time you hear someone ask, 'Which came first, the chicken or the egg?', you can tell them to go learn some biology before asking such a silly question that doesn't have an answer.

Image Source: Brain Pickings


*I'm assuming that the question implies it's a chicken egg. It doesn't make much sense to ask which came first, the chicken or the dinosaur egg, because then there's no conundrum at all.

Updated 2015-02-26: Slightly reworded 3rd paragraph for better flow.

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