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Missing Link Fossil Discovered
choongiri writes "The Guardian is reporting the discovery of a missing link of evolution. From the article: "Scientists have made one of the most important fossil finds in history: a missing link between fish and land animals, showing how creatures first walked out of the water and on to dry land more than 375m years ago.""
This link to bbc news includes a picture of the fossil.
How can you be a non-evolutionary biologist? To be a biologist, one must understand say... DNA, which then has the whole "gene thing." Organisms with DNA that codes for beneficial traits live on, and the rest die. Evolution.
Silence is golden... and duct tape is silver.
Doesn't look very tasty.
Don't Hate, Gestate
FYI: Most slashdotters are really niggers.
Richard Dawkins, Climbing Mount Improbable. pp 138-197.
With all due respect, Creationism is not used by many people in the way you use it.
You are right, there is nothing mutually exclusive about religion and evolution, or divine creation and evolution. There are many who believe in theistic evolution and there is nothing contradictory about it -- that God set up the laws of evolution, or even that he guides the process.
But Creationism is a word that, right or wrong, is used by both the general public and its most vocal proponents to mean a belief in a literal interpretation of the Biblical account of Genesis, and as such is incompatible with any evolutionary theory.
Recursive: Adj. See Recursive.
The probability of a fossil forming is actually pretty slim. First of all, the organism needs to be at least partially solid -- bones do the trick, or a nice big shell, but squishy invertebrates, for example, are extremely unlikely to leave any trace of their passing. The organism also needs to die under the correct conditions and stay there relatively undisturbed for millions of years until human scientists get around to digging it up.
:)
Given that billions and billions of species have existed on this planet, it's not surprising that we've found some fossils, most notably those of the dinosaurs (ie. big, numerous boney things that lived at a time when Earth was conveniently swampy), but that doesn't mean that there's even the slightest possiblity that we'll ever find the remains of everything that ever existed.
Also, I've read about scientists observing evolution in action. Sure, they're only going to be able to observe relatively small changes in their lifetimes, but that doesn't mean that the changes didn't happen... though they obviously don't have a complete fossil record to go along with their notes
According to Swedish radio this is not a direct ancestor to us. However this find is important since it is close to the trunk from which the mamals is derived.
Fox has some pictures of the model and sketches accompanying their article.
For sale: one sig space, gently used. Inquire for details.
Yes, beneficial mutations are often observed.
The Talk Origins FAQ I've linked to is comprehensive, easily searched, and quite objective. Even better, it points the way to more in depth books, articles, and sources--you can, if you choose, go from a one-page FAQ summary all the way to the primary evidence. Otherwise, I would recommend a book such as Ernst Mayr's "What Evolution Is." Much more difficult than the FAQ, and a tiny bit dated, but also much more rewarding.
1. There is a lot more about this just that it's "an animal that we haven't seen before". It's a tetrapod like we are. We've found aquatic tetrapod fossils, we've found land-based tetradpod fossils. This one is between the two. It has land-based features (i.e. lungs and strong limbs), and fish-based features (i.e. fins and scales). As such it falls between the two "groups" of tetrapods.
2. They didn't "assume" the time period. They looked in riverine rocks which are dated to having been deposited between 417 mil and 354 mil years ago to find the animal. They knew the time period it should come from (from the dates of aquatic and land tetrapods fossils), and they knew the type of environment it would be found in (riverine). So, they went to an area dated to that time period, that was riverine in those days, and found the fossil.
3. (Since you conflated two points in no 2), the point is that it doesn't resemble "some other animal", it resembles two other animals, a marine tetrapod and a land tetrapod. Ergo, transitional fossil.
I think you'll find that evolution is a lot more gradual than you give it credit for. The main reason that we expect to find "jumps" in the fossil record is precisely because it is gradual. To simplify, speciation is theorised to be "faster" for isolated species, since their smaller population allows for swifter distribution of advantageous genes. Once they expand beyond their range, if they have evolved enough advantages, they very quickly expand even further.
So, if we look everywhere on earth, except for at that original range, we will find a "sudden" appearance of that species. Even if speciation was not "swifter" in isolated populations, we would expect to find this. However, if we did ever find the original range (a VERY unlikely proposition), we would find the gradual fossil record for that species.
What IS surprising, is that there is no image - not even the obligatory 100-pixel-across thumbnail, which links to a lame-ass 200-pixel-across "Large Picture". I am very interested in seeing this thing - so where the bloody hell is it?
Picture courtesy of New Scientist.
Re: showing how creatures first walked out of the water and on to dry land more than 375m years ago
Not so. Arthropods (millipedes and centipedes etc) first conquered the land around 500 million years ago and were walking around long before this newly-discovered beastie. Their fossilised footprints have been found. "The oldest body fossil of a land animal is a 430-million-year-old millipede."
"Our own ancestors, fish-like amphibians, first lumbered ashore a mere 370 million years ago. There they found a world teeming with plants and giant creepy crawlies."
Reduce, reuse, cycle
> What IS surprising, is that there is no image
i cleID=000A040D-36A2-1434-B6A283414B7F0000
Lots of other places covered the story, some do have pictures.
http://news.google.com/news?q=Tiktaalik+roseae
e.g. http://www.sciam.com/article.cfm?chanID=sa003&art
rant
There is nothing magic in the evolution of both neural pathways and biomolecules. Brains are made for plasticity: co-evolving a neural pathway along with the sensory organ sounds like the lesser problem to me. While eyes must evolve a plethora of new tissues, differentiation signals etc., neurons are just there, they just need to grow and wire up in the right way. A simple arc reflex of the kind "if light, then avoid" or "if it moves, then attack" probably requires just a few neurons firing (remember Valentino Breitenberg...) , would be extremly easily selected by evolution, and would be of tremendous advantage.
On the other hand, the evolution of proteins also is nothing magic IMHO, although it is the newest field of evolutive theory, as of today. Proteins are so chemically long and complex that is easy for them to be able to bind almost anything, at least with low specificity. Evolving specificity by selection alone is easy -in fact, it is something readily done every day both in your immune system and in biochemistry labs.
-- Patent no.123456: A way to personalize
So you're saying that because your belief system cannot conceive of anything before time t, therefore all times before t are meaningless?
No. Others have used the 'north pole' analogy. 'Before the Big Bang' is akin to 'north of the north pole': it's simply an empty statement. Not part of the coordinate system. Undefined.
Here's another puzzle for you: what part of England is a thousand miles from the sea? What do you mean, there's no such place? You mean that just because your belief system can't conceive of places in England further from the sea than distance d, therefore such places are meaningless? Same goes with "external." The whole universe was contained in this ball of energy so there is no "internal" or "external." So the whole question is absurd and moot.
The moment you posit a ball you also have to admit a bounding surface (to wit, a 3-sphere). And when you admit a bounding surface, shying away from what is on the other side of that boundary is intellectual cowardice.
A 3-sphere? No, no, no. Nothing of the sort. A 4-sphere, possibly, in which case the 3-surface would be the space of our universe and the radial directions would correspond to the forward and backward time directions (btw, another analogy for you, what's below the centre of the earth? You mean that because your belief system can't imagine locations > r kilometres down, means all depths below r are meaningless?). An infinite flat expanse of 4-space, also quite plausible. And there are other interesting geometries proposed based on quirks of the microwave background; it's still an open problem in cosmology.
The trouble with these discussions is that it's rather hard to speak meaningfully about these things without using general relativity. Thus you get these rather woolly analogies, translating the clear and precise equations into ambiguous and inaccurate English.
Real Daleks don't climb stairs - they level the building.
The fish that crawled out of the water
For anyone looking for more info plus a picture of Tiktaaaaaahtingy check:
http://en.wikipedia.org/wiki/Tiktaalik
I'm always impressed how fast wiki is with its updates, whoot!
.sigh
That's just too bad for the normal person. Time doesn't work like you think, that's just a plain fact. Read up on your relativity. Time really does vary in just the way Einstein described. Time is not a given, a priori, absolute, it's just one more feature of the universe. All other arguments, such as "what is north of the north pole", are not related to this problem. They describe other definition problems.
They describe definition problems that are quite closely analogous to the one at question. Someone with a naive idea of a flat, x-y Cartesian coordinate system would be confused by the idea that there is no 'north of the North Pole': is there a wall there? A barrier followed by some kind of unplace? What's beyond the North Pole?
Similarly, someone with a pre-Einsteinian notion of how time works has a problem. They think - as your 'normal person' does - that time just is. But that doesn't make it so. In the geometry of the classical Big Bang, the zero point - the singularity - really is very similar to that of the North Pole.
However, all this is somewhat academic, since quantum effects come into play before we get to that point. Instead of the smooth curvature of spacetime Einstein gives us, we have a boiling froth; quite what that does to causality near the zero point is not well understood at all.
Real Daleks don't climb stairs - they level the building.
There's always more to the story:
http://www.canada.com/vancouversun/news/story.htm
Religion is the opium of the people. Evolution is the opium of scientists.
... the scientist ... said it was 'one of many' missing links to the evolution of land animals from fish, but certainly not the only one.
;-), a fairly accurate reconstruction is possible. This is more useful than a pile of fragments of different individuals who may have lived centuries apart.
Yup. Much of the reason this one gets so much attention is that it is nearly complete. Other than not knowing how long its tail was (and what color its skin was
Plus, it's a species that wasn't known before. That's always useful information.
Those who do study history are doomed to stand helplessly by while everyone else repeats it.
You're thinking of the fundies. Catholics don't subscribe to a literal read of the bible.
ad logicam Claiming a proposition is false because it was presented as the conclusion of a fallacious argument.
http://images.google.com/images?q=Tiktaalik+roseae &hl=en&btnG=Search+Images
i'm sure i could find more if i tried
I would have to agree that if this find is as important as Archaeopteryx, it's not all that important.
It used to be that evolutionists believed Archaeopteryx (fancy word for "ancient wing" or "ancient bird"), was a link between reptiles and birds. Many evolutionists no longer believe this. Closer examination of its fossilized remains revealed perfectly formed feathers on aerodynamically designed wings capable of flight. Its leg and wing bones were thin and hollow. Its supposed "reptilian features" are found in birds today. And it does not predate birds. Fossils of other birds have been found to have lived in the same period as Archaeopteryx.
Religion is the opium of the people. Evolution is the opium of scientists.
Then: causation or event chronology
Than: comparison
I think you've got a fundamental confusion with what evolution is, what the theory says and how it works.
why are there still some species left that are considered lower down on the evolutionary chain?
There is no lower or higher on the evolutionary chain, nor is there transitionary forms. There are species which exist now, species which have existed and those which may exist. There are species that are older, "lower", because they have proved fit for their environments. There are species that evolved later, normally not a direct line of decent, that are fit for *their* environment. I don't know if you've read a good book on evolution but it covers this, pretty basic stuff.
A blog about stuff.
Sigh. No.
You don't understand the method. Observation is observation of some fact or state of affairs that we want to explain. In evolution, those facts are things like the fossil record, the diversity of life on earth, and the very particular character of that life. "Observation" is not a requirement that we see things with out eyeballs, or even the part where we draw conclusions. It's the set of circumstances that we are trying to explain. That's why it comes first. It's TESTING where we find out if the explanation was correct or not.
And that's where you go wrong again. Testing in evolution is testing any given piece of evidence to see if it confirms or disconfirms the theory. If you don't think evolutionary biologists run tests or use evidence to confirm or disconfirm their claims, then you don't know anything about the field.
IF evolution is true, then all other sorts of things MUST be true. Are they true, or not? We test, and find out. We gather evidence and compare it to those theoretical requirements. Does it hold up? Yes, it does: in fact it holds up in spectacular and exacting detail.
If what you were saying were true, then forensic science wouldn't be science either. But, unfortunately for your post, it is science. I don't think you're liable to find any textbook on the scientific method that would actually support what you are saying.
"Well, not really. It COULD be something totally unique."
Well, yes, except that morphologically it fits in at only one place and time into the tree of life. As you can read from the article, no one is saying that it is a direct ancestor of modern life, because we cannot know, as you note, it's particular future. But we CAN tell its past and from what orders of life it came, and its existence tells us all about what sorts of creatures were around and what they were like on this particular branch of the tree that led to modern land animals.
"We breed dogs with all sorts of other types of dogs, sometimes wolves, coyotes, and even Jackals and Hyenas (all in the "canis" family) and we always get offspring that are DOGS!"
I hate to break it to you, but if you think that evolution suggests something different, you are mistaken. Your exclamation is about as silly as saying "but if you breed two mammals together, we always get MAMMALS!"
Evolution is cladistically conservative. New species branch out from old categories: they do not replace or exit them. Just as all the species that will descend from dogs can still be grouped as "dogs" (because they will all still share the same traits that distinguished dogs from all other forms of life).
Of course, your statement is wrong anyway. There are plenty of canis that cannot interbreed already. It might even be the case with some domestic dogs: it's just that we've never really seriously tried.
"Third, they simply claim that this previously undiscovered creature is something "in transition" from one being to another when this is the first one found. How do they know that it's not just a unique creature that died out (ie: gone extinct)."
You're mixing up claims about this specific species with what a transitional fossil actually is. Transitionals are creatures that have the distinctive and otherwise unique features of both an earlier group (in this case lobed fishes) and a later group (in this case tetrapods). We know that this creature was related to the tetrapods because it has several features that are unique to tetrapods or otherwise related to tetrapods, while at the same time being identifiably Stegocephalian. As point of fact, you are also still a Stegocephalian. Just as you are: a tetrapod, an amniote, a synapsid, a therian, a eutherian (what you think of as a mammal), a primate, an ape, and a sapien sapien. If you mated with someone and produced offspring, I could scream "BUT THEIR BABY IS STILL A EUKARYOTE!" I would be right: but it wouldn't make a lick of difference in disproving evolution.
The problem is that you misunderstand evolution.
"There's no way to prove that this was an "adaption" to moving from water to land - else, why do animals like ducks still lay eggs"
I don't know what you mean by why. They lay eggs because all descendants of the early amniotes have eggs with amniotic fluid. Including humans.
"(or the platypus, et al)"
Platypi are monotremes, a group of therians (one of three, the other two being the placentals and the marsupials). Therians as a rule lay eggs. But their "eggs" are not like bird eggs. They are almost as if someone gave birth without first breaking the placenta: the "egg" is thin and membranous like a placenta, and it hatches almost immediately.
"and some mammals (whales, dolphins, seals, etc) live entirely in the water (but not breathe in the water like fish and some reptiles) bear live young like mammals if this is indeed an evolutionary change..."
Cetaceans very obviously tetrapods returned to the water. As such, they bear all the distinctive features of their tetrapod, amniote, euthreian, and so on ancestry, but have modified these features for life in the water. The features they have are not some random grab bag of features. They are all mammal features. Even the fact that they've "lost" their back limbs is deceptive: in the embryonic stage they still grow back limbs (which are then reabsorbed!). Sometimes, they are actually born with limbs (an atavism: just like when humans are born with tails), which happen to be in just the right place and hooked up to their vestigial pelvic girdle in just the right way... to be a tetrapod.
Dawkins acn't be blamed for not covering every concievable single subject in one book, especially one written for laypeople. Discussing bio-chemistry is pretty hard when you can't guarantee that your audience knows much about chemistry, cell cycles, genetics, etc.
However, I must say that I find the incredulity a bit weird. It would be strange if light sensitivity _wasn't_ part of the nervous system. After all, lots of organic chemicals are sensitive to, and react differently to light. Those reactions would be a quite and predictable natural trait to select for.
"Also, Dawkins never really gets around to addressing the issue of how complicated protein molecules like hemoglobin could have come into being through only random mutations and non-random natural selection, an question which, as Dawkins himself mentions, a number of people have some problems with."
Again, you expect him to explain every single issue you can think of in a popular book, without using chemistry? The evolution of hemoglobin has been discussed extensively, but since it's a chemically complex protein, understanding it takes a heck of a lot prior knowledge of things like protein folding and interactive bio-chem.
Creationists have facts, too. Just look at humanity as it exists today. How could pedophiles have evolved (there's no evolutionary advantage to having sex with someone who is too young to bear offspring). How can the fetish of stomping small creatures to death have come into being through evolution? No, humans as they exist today could only have been the product of a cruel and twisted god.
Do you seriously not see the reproductive advantage of killing any rat, mouse, spider, scorpion, ant etc. on sight? I have delegated that task to my cat, because I am smarter than my ancestors, but I think it's a good instinct to have for a relatively stupid species with very vulnerable offspring and a habit of storing food.
I don't really see how trying to impregnate unsuitable candidates would be a disadvantage. Since we are not very good at judging sexual maturity the pedophile might get lucky, certainly if he is a low ranking male in a chimp-like hierarchy. Many animals (dogs, rabbits) also mate with everything that moves.
More generally: evolution selects genes, and morality is not the criterium for selection. "Fitness" is also a moving target in a changing environment. There is no way we can make a connection between genes and complex behaviours like pedophilia or killing. We don't know whether there is a specific genetic factor at all, and we can't judge how this genetic factor works out positively in other circumstances.