I think you are discussing the differences between inherited things (you get your hair colour, height etc. largley from your parents, though training can increase things like speed) and learned things (like learning to write, or throw a ball). Powers, such as you describe, of course do not actually exist!

Hi Ahmed,

This is a really tricky question to answer as obviously we will not be able to find out any more information about the university than you will. I suggest you look around for several places that have MSc courses you might be interested in and e-mail the course tutor / organiser about their entry requirements. They will have had students from all over the world and be able to tell you what kind of rating they have for various universities and programs in other countries. Generally they are quite flexible, so I would not worry too much, but you can get a lot of this information if you ask directly the people who will make those decisions.

Best of luck.

There is not much difference between Tyrannosaurus and Tarbosaurus, they are very close relatives, though I doubt they could interbreed successfully. However, since they are very close, what is generally ture of one is pretty much true of the other in terms of general build and how they acted.

Let's be honest here - you have not actually asked a question but just listed a bunch of things. I guess you want me to tell you how true they are and most fall into the realm of 'possible but unknown'. There is a lot of exaggeration online and things often get very mixed up - just becuase someone once said something (even if it was a researcher) does not make it true.

How would you estiamte how loud a roar can be? We don't even know if they could roar, let alone how big their voice box was, or how powerful their lungs. Things like this are just pure fiction.

The largest specimens were probably around 8 tons, though most were rather smaller. They did have a tremendously powerful bite, but I'm a bit sceptical of some of the values put out there - it is hard to calcualte the true maximum bite force without a live animal, but they could certainly bite into solid bone effectively. I doubt the 'infectious bite' stuff - their teeth and jaws are not that different to many other dinosaurs or indeed other carnivores so I doubt there was anything special there.

There is no way they could hit 25 mph, it's a massive exaggeration, something more like 15 is much more realistic and even that might be pushing it according to some studies. Simialrly, they were not acrobatic, an 8 ton biped simply cannot turn that fast! Smacking another animal with its tail would do nothing to hurt the other one and probably knock themselves over - it was no weapon.

They did have good vision and a sense of smell, but the vibration thing came from a TV program and no peice of real science.

Their arms were small and relatively weak. I doubt they could lilft anyhting liek 200 kgs with them, that seems to be a major over-estimate, but quite how they did function is not clear - we don't know everything.

Tyrannosaurs may well have worked in groups, but there is no good evidence for it at the moment. Getting the information needed to work out something like this is very hard so we will have to wait and see.

Not all dinosaurs were large, some were very small at adult size (like a crow or chicken).

In order to work out exactly how large a hatchling was, we need to have an egg of that dinosaur and to be sure which species it came from. There are lots of dinosaur eggs, but few are found with parents or babies to make it clear which egg is which. As a result we can not do much more than make an educated guess in most cases.

A Protoceratops would be perhaps only 30 cm or so long at hatcling (that sounds a lot but much of it would be tail), a Velociraptor perhaps the same, and Gorgosaurus maybe twice that.

I am not sure what you mean by 'carnotosaur' do you mean Carnotaurus? A lot of your names are not spelled right so it's hard to be sure what you mean - I know a lot of these names are complicated and hard to spell (I make plenty of mistakes) but do try. 'Anyklosaur' is too general a term - that means any member of the group and it's a bit like saying 'deer' or 'shark' and so that would have varied a lot between species.

Hi there,

I'll have a go at this, but you are asking an awful lot of questions and most of them cannot easily be answered. You must remember that a lot of palaeontolopgical data is very ;limited and we cannot easily work out things about behaviour especially - a few bones do not often get you very far!

Protoceratops is a small dinosaur, but many of the specimnes seen in museums and in books are juveniles and only about half grown. An adult would be around 3 m or so in length and perhaps weight a couple of hundred kilograms. I do not think anyone has tried to estimate their speed, but given their build I doubt they were very fast.

At a push they might defned themselves by biting, but it would not be much of a defence against most predators. However, since carnivores typically target young animals, the adults were probably farily safe from attack most of the time. We as scientists don't try to look at who kills who or how they fought unless there is direct evidence from it (like stomach contents or bite marks) and trying to calcualte sizes and what it means for defence is basically impossible. So questions like how many would it take to kill another animal cannot be worked out and would have no scientific information so we don't even try, so there's little I can say about your later questions.

(posted in Birds)

I see your point David but I very much doubt it, it can still be efficient to climb up to things (look at monkeys), the real issue tends to be transport between high points, and so you need to have plenty of them around in a single area to make it effective as a mod of transport and we really don't have rock formations that act anything like trees, and even if so, they would not be very productive for plants and by extension things like insects or fruit, so there wouldn't be any resoruces to access.

(posted in Birds)

Wow, what a question! :) Cutting a long and complex story rather short, I'd say probably not becuase the vertebrates that have evolved flight (be it gliding, or powered flight, and so including things like bats, pterosaurs, flying squirrels, sugar gliders, flying frogs etc.) seem to have done so in trees. This makes a lot of sense - it's a very quick way to get from one tall structure to another, without the time, energy and dnager of going all the way down, along, and the back up again. Take away trees, and that environment and evolutionary selective pressure no longer exists, and rocks or cliffs are not really the same kind of thing and probably wouldn't produce the same results.

Quite simply Archaeopteryx is *both*. Birds are direct descendants of dinosaurs and so are dinosaurs (just as humans are both apes and mammals). Archaeopteryx is widley regarded as the first bird, but this means that it is also still a dinosaur.

There are some pneumatic bones in Archaeopteryx known so they are there as expected.

Hello,

This is something that does crop up from time to time, but the very simple answer is that pterosaurs already have a thumb. The four fingers seen (the three with claws and then the long wing finger) are the first four of the hand - the missing digit is the little or pinkie finger, and not the thumb. So the pteroid can't be a thumb, or they'd have two on each hand.

Here's a bit more about the identification of the pterosaur fingers: http://archosaurmusings.wordpress.com/2 … th-finger/

(posted in Evolution)

I think you'd struggle to call anyone who denied evolution to be a scientist at any level. After all, not only is the evidence overwhelming, but even the creationists concede that secies do change over time through selection pressures (hence the formation of bacterial resistance to antibiotics) even if they deny the magnitude of the effect they at least concded evolution by natural selection occurs. If your worst 'opponent' agress that much is right, it's hard to say anyone else could not argue with it, let alone someone claiming to be a sceintist or have a scientific approach.

I mailed Mike Habib himself about this and he was good enough to provide an additional response:


Thanks for the interest and excellent question. As Dave already noted, the "Heresies" site is not a recommended source. More specifically, the animations posted there actually have the situation reversed: quadrupedal launch provides a greater margin of error than biped launch.

Animal takeoff is initially ballistic (by leaping), and then the wings are engaged. Using all four limbs to leap necessarily provides more height and clearance than biped launch. Quad launch also has the advantage that the wings stay folded for the first phase of the launch, and so pterosaurs could simply land on all fours if they aborted the takeoff.

A biped pterosaur launch would not only provide far less clearance, it also requires that the animal pitch forward dangerously at the end of the leap in order to place the wings at an appropriate angle of attack. Birds have a very different shoulder and are not similarly constrained. So, in short, a missed bipedal launch would be far more dangerous than a missed quad launch for large pterosaurs.

The animations you discovered are not linked to any physics, they're just imagined trajectories. The artist has cheated, as it were, by making the quad launch very weak and the wing motions comparatively slow and ineffective. He has then made the biped launch ignore angle of attack issues for the wings, and he has assumed that maximum lift occurs as soon as the wings are engaged (which violates a basic principle of fluids). To be fair, if some pterosaurs did launch bipedally, it might look something roughly like what he has drawn. However, the quad launch would look rather more similar to his biped launch animation (instead of the rigged quad launch), except much more powerful.

Since you are interested in visualization, it should be noted that the data support quadrupedal launch, but don't tell us exactly what kind of quad launch was used. There are multiple versions that are all plausible. I have only ever figured one type in talks and papers.

As noted above, there's a huge number of factors that link to body size. Now certainly in marine animals large size does seem to often be associated with filter feeding though this is likely becuase it's an efficient way of picking up a lot of relatively high-energy foods so we see in in baleen whales but also giant sharks like the whlae shark and probably extinct giants too like Leedsicthys. It's not exclusive though, sperm whales are very large (bigger than many baleen whales) and are active predators rather than filter feeders, and giant sharks like 'Megalodon' would also have been active predators.

Jsut shifting diet suddenly is unlikely to have much effect on size in the short term - if anything you might get smaller, if you are not used to and adapted for that food you might not get much of it, or be able to digest it effectively and so have less energy to put into growth.

I'm posting this across for Susie after problems with the submisson pages:

I teach in a primary school and I am embarrassed to be asking this question 
as I probably should know the answer.

Birds mostly build nests. Chicks hatch. Chicks are fed by parents until they 
can fend for themselves. Why does this not apply to hens? We buy fertilised eggs, we incubate them, they hatch but don't wait to be looked after, immediately fend for themselves.

Is it because we have bred this into our stocks ?

I presume free range hens build nests and lay eggs into them. Do the chicks 
wander off straight away?

Your help would be greatly appreciated. Need to be able to explain this to a 
group of 5 year olds (and every adult I have asked!)

I've not read through it, but I *very* very (and add a few more 'very's) much doubt the second link is right. While just becuase someone is wrong about one thing, doens't make them wrong about everything, I would point you to this (http://blogs.scientificamerican.com/tet … ution-com/) there are huge, huge problems with just about everything on that site you mention and associated ones.

My general fallback fro stuff like this online is quite simple - get it published. Mike Habib has a peer-reviewed PhD thesis on the subject (and published two papers on quad launch too, inlcuding one in PLOS ONE that is freely available online) and any serious challenge would need to have the same rigour applied to it. "Someone said online" is not much of an argument in science generally. ;)

I agree with David that you are not likely going to change the mind of the people you are arguing with, but there is *some* merit to it - you will likely learn a lot from it (how to refine arguments, use of evidence, how to make a convincing case, how others tend to argue, flaws in reasoning etc.) and there's lots of anecdotal evidence that while you won't affect those you are directly communicating with, many watching on the sidelines might well be swayed having not been exposed to the evidence before. That said, I wouldn't get too involved and take too much time on it - it will lead to frustration.

To take your point: For example - how would some salamanders choosing not to reproduce with other salamanders be evidence that mutations can cause evolutionary change from oak trees to humans?

Well that seems to take the assumption that oaks turn into humans, which since they don't and no biologist has said they would or could, rather makes it a strawman argument. Nor am I sure how mate choice in salamanders affects such mutations - certainly mate choice and influence the spread of mutations and thus response to selective pressures, and ultimately speciation (thought selection or drift), but I'm running out at that point.

As is all too common - what is being presented here is a false view of biology as an attack on it, or an attempt to show biologists can't prove it and therefore argue it is wrong. Since these people either don't, or don't want to, understand what evolution is or how it really works, arguing with false premises won't do anything, jsut point out it's a false start and thus irrelevant.

Finally, Finland. It certainly has moved around a fair bit at various times but for at least part of the Mesozoic it was above the water and would have been tolerable to dinosaurs. Don't forget dinosaurs basically got everywhere at one time or another and probably would have colonised almost every bit of land tht was exposed.

However, dinosaurs living there, fossils of those animals being produced, and then those fossils being found are all different things. Fossils don't always form nd various conditions can make it very hard for them to form and so make them rare. If the conditions are harsh, few animals may live there, and for example in places like rainforests, despite the huge numbers of naimals and plants, decay is so fast that dead animals and bones can rot before they might be buried. In the case of Finald, I think the main problem is that the rocks of the right ages are not available. Some 65 million years have passed since the dinosaurs went extinct and so many of the rocks formed then have moved, been destroyed, or are covered in other rocks. When these can be explored (such as in Montana) you might find many dinosaurs, but if they are buried under others, then you can't dig into them even if the bones are there (well unless, you plan to produce an entire mine, but that's not really practical).

I have checked a few sources and sorry, I have yet to find any dinosaur bones from Finald. A quick look at a map suggests that all the major areas of rocks on the surface are either the wrong type to hold fossils or the wrong ages for dinosaurs. Still, it's always possible that there are patches somewhere, or they might be found deep down (the first dinosaurs in belgium for example came deep from coal mines) so there may be a Finnish dinosaur one day.

As for your second question, you are essentailly asking how these things are grouped together, and this is a real fundamental of taxonomy and systematics. Essentially it comes down to both similarlites and differences, we can use similarities between species to grouo them together, and use differences to separate them out from one another.

So for example, ornithischians all have the bird-hip condition, and have a predentary bone, a toothless tip to the jaws, a special palprebal bone over the eye, and don't have penumatic bones (invaded by airsacs) among others, so we can use these features to unite them together into a group.

The sauropodmorphs and theropods do look very different when you compare something like Tyrannosaurus to Diplodocus, but go back to the Triassic and their ancestors and oldesst relatives were very simialr indeed to the point that several species have moved around in various analyses and it is not always clear to which group they might belong. These two big clades can be united by the presence of penumatic bones (or at least starting to develop them, various sauropodomoprhs have only some cavities on the surfaces of bones, but later on these penetrate the bones fully), the saurischian pelvis, and enlarged thumb and some other features of the hands and feet.

Note than in both cases, these things may eventually change. The saurischains of chourse originally have a saurischian-type hip, but eventualy some of the theropods modified this and ended up with something that look much more like those of the ornithischians, hence the true birds, having, well, bird-hips! Evolution does change things over time and key features can be lost or modified, but that doesn't change their position (whales have lost their fur but are still mammals, snakes have lost their legs but are still close relatives of lizards).

Finally, you can unite the two big clades together as members of Dinosauria becuase they share some features in common, notably the shape of a big crest of bone on the humerus (upper arm bone) a flange of bone on the pelvis, and the shape of the ankle. All dinosaurs have these and non-dinosaurs don't have them, allowing us to group these together.

Hello, there's three distinct questions here and the answers are quite long and complex, so just to keep it all stright I'll post several answers here to make it easier for people to follow and read.

So, first off, might Baryonyx be a young Spinosaurus? In short, no. We do indeed see changes between species as they grow and changes, but we do also know what kinds of features tend to change like this and which don't and some of the differences we see between these genera are the kinds that do not usually change (or if they do, only a very little). For example, Baryonyx has around twice as many teeth as Spinosaurus, since even if it was a young version, baryonyx would have to be the equivalent of a teen-ager, it suddently has to loose half it's teeth and change the shape of its head really quite quickly and that's not something we've ever seen in any other dinosaur. Also as dinosaurs grow, certain parts of the skull and skeleton start to fuse together, so we can generally tell, even from a few bones if an animal is a baby, a youngster, or close to being an adult and full grown, and Baryonyx is very much a near-adult, so it's unlikely to suddently get much bigger and change, it's nearly finsihed growing. Finally, these animals are separated in both and time and space, we should be finding 'adult' bits of Spinosaurus where we find Baryonyx and bits of this when and where we find Spinosaurus if this was the case and this doesn't happen.

I've written a bit more about this problem here: http://archosaurmusings.wordpress.com/2 … -taxonomy/

Hello,

a great question and as usual it throws up one of the big problems with this kind of issue. Personally I'm absoluitely sure that large carnivorous theropods ended up fighting on occasion both over mates and things like territory. If nothing else there were dozens and dozens of species over a huge range of time, space and different environments and it's pretty unlikely that *some* didn't end up being highly terratorail or aggressive and fighting. It's very common in modern species and would expect to be in anceint ones.

The real question then is can we say which species did this and do we have direct evidence for it, and then it goes from being a simple 'yes' to a very complex 'sort-of / maybe'. We do have evidence of theropds with injuries inflicted by other theropods, including by close relatives and it's reasonable to presume that in a few cases these were by other members of the same species. *what* they were fighing about however is impossible to know for a single incident - was it a fight over food, or over a mate, or territory, or just bad luck that two chanced upon each other and were desperate and tried to kill one another for food? All are possible, and while some are more likely than others, pulling it all apart and working out which pretty much can't be done.

So, in short, complicated, but I hope this helps explain it a bit.

(posted in Birds)

I wonder if you may have seen a nightjar. They are about that size and although well camoufalged, can be quite pale on the front and would be seen low in the trees and critically are often quite active at night.

There are a number of different species out there but I know they are in the region. Hope this helps.

Hi Nico, Errr, I'm really not sure you have actually asked a question here that we can answer. My guess would be you mean, 'is there any evidence for giant humans'?

The short answer is 'no'. Yes some people are exceptionally tall (look at basket ball players!) and if you have a big population, espeically with modern health and medicine, it's not a big surprise we do see very tall humans occasiaonlly in the modern world. Also, some genetic issues can cause people to grow very tall (such as agromegly) though these also typicall produce some key changes to the skeleton and make it obvious the person had this problem (e.g. a very large lower jaw).

So, are there, were there, any 'races' or tribes or groups of giants in history or prehistory? No, none that we know of at all. Nothing of a consistent group of tall or very tall people (that is say, consistently in the realm of say 2.5 m plus, let alone soemthing extraordinary like 3 m) in the historical or fossil record. Only the occasional tall human that most often had some growth problem or similar issue leading to great height.

The term 'rhamphorhynchoids' is one that effectievly refers to the non-pterodactyloid pterosaurs, and so denotes all of the species that comae before the pterodactyloids. The rhamphorhynchids are a more narrow group that are just a few species that are closely related to the genus Rhamphorhynchus (a bit like the difference between 'cats' and 'big cats', they have very simialr names, but one is a sub group of the other).

As for the others, these do basically have a set order: -ines lie withing -idae and those within -oidea. To Tyrannosaurus (genus) is within the Tyrannosaurinae, but also within Tyrannosauridae, and then also Tyrannosauroidea! These also have captial letters at the start as they are techncial scientific terms, and a 'common' form would be tyrannosaurine, tyrannosaruid and tyrannosauroid.

Well all cobras are venomous and thus potentially deadly to humans, especially if they are young, old or infirm. However, obviously the degree of danger varies depending on how aggressive the animals are, how much venom they typically inject, and how toxic it is. Collectively though the obvious answer would be the spitting cobras, since they generally shoot venom at a target rather than biting, and while the venom can cause blindness if not treated, that's obviously rather less severe than a bite from a more toxic animal.

A lot of reptiles do have some nasty bacteria in their mouths, if you get a bite that draws blood a good wash with some soap or anti-bacterial agent is a good idea, but generally they are pretty harmless. Even the venomous lizards David mentions do not have especially strong toxins are are not too much to worry about (not that I'd test that by getting bitten).

Someone named Paul has written to us and suggested the following:  I know what this thing because I have a   dead one. That is of the kind of insect, but not the sex of insect. The picture is of a female dobsonfly. I have a male. The difference if the males huge jaws,used for mating.

(posted in Mammals)

I think you can argue that animals that have lost their legs don't have them. Whales and dolphins and manatees have little more than some bits of the hips remaining of their hindlimbs so don't have knees, but that's a rather special case and more 'not having legs' than not having knees.

Hello,

i know of preserved skin in various hadrosaurs including Edmontosaurus, but this is the first I have heard of things in the nasal cavity. As such, I really cna't help I'm afraid.

Dave

As with your last question,it's incredibly hard to say. For a start we have very little of this animal preserved, but even going from other near relatives it is difficult to be precise. What we can say is that many troodontids were probably among the fastest of dinosaurs - they were small and lightweight and had the leg proportions that indicate fast movers as well as specialised bones in the feet that would have allowed them to be quite efficient too. Hope this helps.

Hi Randy,

These are good phoots but it's a very hard thing to judge so I'm not certain I'm right but this doens't look like any coprolite that I've ever seen. It does have something of ana organic quality to it, but many rocks do and I suspect it's simply a coprolite-looking stone rather than a genuione find.

Hopefully someone else will add a bit more.

No need for any kind of donation, thouhg the offer is most welcome, thanks.

Hi,

well there's an awful lot there and some complex issues but I'll try and get through it effectively.

First off I'd disagree with the logic of extending male brood care through coelurosaurs. While we do have a couple of males on nests of dinosaur eggs, that hardly means males were the only or primary care givers - a great many birds share responsibility, so it's entirely possible that the sample so far are males only by change becuase we happened to have sampled male borooders, or have simply not yet caught the females on the nest (or indeed our test of male-femlae ness may be flawed).

Either way, it's hard to say anything much about differences between theropods and crocodilians. We are happy that non-avian dinosaurs mostly included some form of parental care of eggs and probably hatchlings too, as this is near universal in crocs and birds, as well as seeing support for it in theropods. Separating out finer details and shifts really requires huge amounts of more data than we currently have.

As for degrees of care, again it's very hard to say. I think there are some correlated with other factors we might use to being to work at this, but it's very hard to say. As with crocs and unlike birds, young theropods were clearly relatively independent (they could move around freely, and could eat without help) so how to tell when the parents stop helping is all but impossible to tell.

Fianlly I'm not convinced by brood parasitism as a decent explanation for this (data pending of course). Not that it's impossible but it is very rare - few species engage in it, and the odds of this being one seem low at best simply from the odds. How on earth you would effectively demonstrate it would reply on demonstrating the age of the individulas, evidence from egss shells of two different species and other things too, but that still wouldn't rule out annother species using the nest of a first later on.

A great question! Depending on how much venom has been extracted, in the short term the snake will have little or none left, but it will generate more over time. Venom is produced in special glands and the back of the head and if snakes are used regularly for venom extraction, these glands can grow very large as the snake has to produce more venom more often.

I'd tentatively suggest that it does also help at least occasioanlly, thus providing positive reinforcement of the behaviour. If something has jiggled or worked loose, then a tap or slap might restore a connection (especially in electronics) or free up soemthing jammed (in mechancial devices) at least temporarily.

I'm broadly with David and the original question though, it's a fairly basic respose to anger and frustration, though I suppose since it's not a human this might mean that a) you turn to violence because reason and discussion are impossible with an inanimate object, and b) since it's not human, some of the cultural / social rules are suspended and you can vent a bit more freely.

Very interesting area for discussion though, great question.

It's hard to say the exact speed of any extinct animal, but at least with the adult of large sauropods the answer is basically "slow". Even their top speed would be little more than a fast walk, and they would not have been able to break into a trot or canter let alone a run so they would have been one of he slowest things around on land at that time, though a big stride length does compensate at least a little.

I doubt we can narrow it down too much, but it's a parasitoid wasp of some form. The absolutely huge ovipositor (the 'stinger') and the narrow wings plus the curled antennae give it away. These wasps inject their eggs into other things like caterpillars and spiders and the eggs hatch and larvae eat their way out killing the host. All rather nasty, but they are often good at taking out pest species so are rather useful to have around.

You do know your fish teeth better than me, so I'm happy to defer. :)

Actually I'm pretty sure it's a tooth plate from a ray. It's an absolute whopper though must have been a big fish - that's a cool find.

That's a lot of question, but I think it ultimately boils down to something close to this "how much inaccuracy is acceptable when it comes to a documentary?", or perhaps "how much artistic license can you have before you stop being a factual program?". This is of course a major issue with any and all documentaries and comes from a number of issues namely that 1) researchers almost never get final say on what happens, and even when they have a lot of input can be overruled, 2) the people making the show often don't or can't understand the complexities of thew subjects, and 3) there are always edits, mistakes, confusion, time abnd budget constraints and other issues.

You also have to respect the fact that, to a degree, a documentary or factual program does have to get across the point to the audience, and they have to sell their show / get an audience and there will have to be compromise there to best reach the right audience. In short, nothing will ever be perfect and you will never have everyone happy, even under ideal conditions (I can still point to you to researchers who will say birds are not dinosaurs, so with something this fundamental and basic being argued about, you can see how there are going to be issues with pretty much any program).

Based on my experience and what I've had from colleagues, what tends to grind therefore is not so much that mistakes are made or that compromises are inevitable (we may not like it, but there it is), but that there tend to be mistakes when they were pointed out in advance, or specific instructions / explanations were overruled as not exciting enough. Being told that it doesn't matter if it's right, they are not / won't going to use it, spells a lack of respect for both the science and the audience. Similarly setting up an artifical 'debate' between researchers (when one holds some minority and overturned view) gives a very false impression of things.

Personally I think a lot of the time the wording is the issue. Saying "This animal was a scavenger" is rarely true in that we don't have good evidence, but saying "this animal likely scavenged", or better yet "we have excelelent evidence that this animal scavenged sometimes, and maybe a lot" is a few more words, is not hard to understand and yet is a world away in terms of actual accuracy and interpretation of the real science.

Basically, I don't think you can have a perfect science show. Even with an infitite budget, things will change fatser than you can accommodate the research to make the program, and some ideas will be too complex or contentious to communicate effectievly to a broad audience. However, I do think many places could do a lot better than they do at the moment, and hopefully things can improve.

(posted in Evolution)

This certainly does exist at least in theory, though I'm struggling to think of a specific example. The obviously place to look are in 'ring species' that have something of this effect, though there are few good, real, examples of this that have been thoroughly assessed.

Note that we don't just define species by who they can breed with - this is only one definition (see the essay in our 'From the Lab' section for more), and even incompatible species can breed on occasion (you do get fertile mules, just very rarely).

The other thing to note here is that jsut because animals look the same doesn't mean that they are. They have different colours, but critically different beak shapes and that means each is better adapted to a different food source - there is some competition, but they largely do not overlap in their requirements, so they can exist as separate species. There are tons of ecological niches for smaller species (hence there are bazillions of beetles, but not many antelope) so there are somewhat inevitably a number of small finches, tits and birds like robins that superficially look simialr, but are different.

(posted in Research and Careers)

I'd add to this that lots of people move between jobs and with so few positions, you might well dip in and out between various biology-related fields and others.  many people need to take a year or two out to earn money to support their studies or do a Masters of PhD part time, and so it can be a long road to even getting a PhD, let alone a permanent position.

(posted in Mammals)

Oh. Err, yeah drop bears are NOT real. They do not exisit, they are a fictional creation - a local joke much like the haggis in Scotland.

Hope this helps. :)

I have heard the same idea going around, but I don't think I've seen it formally laid out in a scientific paper. Assuming it is true (and it's plausible at least) then it's possible it would have an effect on physiology and thermal regulation, but that doesn't rule out mammals as comparisons (I think there's more useful data to come from a multi-ton mammal, than a tens of kilos bird like an ostrich in many circumstances given the colossal mass of many dinosaurs) jsut that we need to be more careful with what comparisons we make and how that data is used.

I'm not aware of any standard term like this in commun use in the scientific literature. I think researchers would simply refer to them as 'newborns' or 'juveniles'.

(posted in Evolution)

You also seem to think evolution is random, it is not: mutations to traits are random, but selection on those is non-random.

(posted in Fossils)

Only just found this! I am a palaeontologist who has worked on the dinosaur-bird transition and I'd call it one of the best understood and scientificalyl best supported ideas of it's kind in palaeontology. Basically, birds are literally living theropod dinosaurs. The case is every bit as convincing as humans being mammals or ostriches being birds.

There is not a lot to say about the counterclims so much as that they obviously ignore or skip over huge amounts of data, and have to keep changing radically every time now discoveries add more information - not generally a good sign!

(posted in Fossils)

Just to add, there are absolutely tons of transitional forms known from fossils. Some of the best known are the origins of humans, the origins of whales and the origins of birds. All are documented by numerous fossils showing clear progressions in anatomy (and even behaviour) over time and changing from one form inot another. You can almost watch a whale's legs vanish over time, the hands turn into flippers and the nostrils move back and turn into a blowhole!

Well some of the old ones are clearly 'just' a part of the language (flocks of pigeons, herds of cows, schools of fish, pack of dogs and so on), and at least some are clearly recent inventions which might well have been done for a bit of fun or mischief (a 'crash of rhinos' apparently), but to my knowldge there's no real biological meaning behind them. Biologists will pretty much jsut use 'flock' for anything in the air, herd or flock for big groups of herbivores, schools for things in the sea and with the odd smattering of common terms like 'pride of lions' or 'pod of whales', but that's about it for collective nouns. I'd imagine the pseron to ask is actually an atymologist or linguist. That probably doesn't help you too much, but the answer is I think, not biological.

Agree totally with Paolo it's a sacrum (that is, the bit of the spine that the pelvis attaches to) and it's certainly mammalian. Judging by the woodgrain and so on, my guess would be that it's under about 10 cm across, making it sizeable but hardly huge. Perhaps a sheep or simialr, though Paolo will know much better than me.

I don;t think they drink water (i.e. consume water as an entity as it were), but get their water from their food. But they certainly don't live *without* water.