SciBlogs

Archive April 2012

Matuka-moana – the white faced heron Brendan Moyle Apr 30

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A photographic study of the relatively common white-faced heron. While the bird is often found around coastlines and estuaries, getting close enough to take photographs is always a challenge.

#1 The Good Side


#2 The Eyes Have It


#3 Quizzical


#4 A Good Look


#5 Hiding in Plain Sight


Matuka-moana – the white faced heron Brendan Moyle Apr 30

No Comments

A photographic study of the relatively common white-faced heron. While the bird is often found around coastlines and estuaries, getting close enough to take photographs is always a challenge.

#1 The Good Side


#2 The Eyes Have It


#3 Quizzical


#4 A Good Look


#5 Hiding in Plain Sight


White-Fronted Terns Brendan Moyle Apr 24

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Sometimes the best camera and lens is simply the one you have with you. These shots were taken with my 70-200/2.8, which has the advantage of tracking subjects quickly but at the expense of some reach.

The white-fronted tern is a common sea bird in NZ but these shots were taken at Punakaiki (Pancake Rocks) on the West Coast. So they're a little out of my way :)

Soar


Fishing


(I think that's a garfish it's caught?)

White-Fronted Terns Brendan Moyle Apr 24

No Comments

Sometimes the best camera and lens is simply the one you have with you. These shots were taken with my 70-200/2.8, which has the advantage of tracking subjects quickly but at the expense of some reach.

The white-fronted tern is a common sea bird in NZ but these shots were taken at Punakaiki (Pancake Rocks) on the West Coast. So they're a little out of my way :)

Soar


Fishing


(I think that's a garfish it's caught?)

Are You Qualified To Discuss Evolution? Brendan Moyle Apr 24

15 Comments

The theory of evolution has alas, never been without controversy, largely as it appears, its conclusions are unpalatable to many. As a biologist, I'm often pretty enthusiastic about the whole theory of evolution thing. The idea that we are related to every other animal on this planet is profound and amazing. Nonetheless, sometimes I wonder if there's any point trying to discuss the theory with some people. If I had a dollar for every time a creationist gave me the correct definition of evolution…well, I still wouldn't be able to afford a coffee. So the quiz below is a rough guide for anyone who thinks they're qualified to discuss evolution.

Quiz
Question 1
The definition of evolution is
A) The change in the frequency of genes (traits) in a population of organisms over time due to selection and drift.
B) There are many definitions of evolution that cover distinct natural phenomena (macro- versus microevolution, origin of life etc).

Question 2
The 2nd Law of Thermodynamics
A) allows for a decrease in local entropy even if global entropy increases so long as energy can be supplied to the system.
B) means evolution is impossible

Question 3
A scientific theory is
A) a system of ideas held as an explanation for a group of facts or phenomena; confirmed by observation or experiment, and accepted as accounting for known facts on which it depends.
B) An unproven hypothesis lacking evidence.

Question 4
The age of the earth is
A) About 4.5bn years
B) About 6,000 to 10,000 years

Question 5
The biological model of abiogenesis describes
A) the successive, step-wise process by which molecules combine to make primitive cells able to replicate, in an open thermodynamic system.
B) the sudden emergence of fully-formed organisms in a closed thermodynamic system (i.e. spontaneous generation)

Question 6
Fossil evidence of evolution
A) is supported by many sequences showing the transition of arrays of traits through the geological column
B) still doesn’t exist because the gaps and missing links are so many.

Question 7
The probability of evolution occurring is
A) based on a Markov statistical process with many trials, implying a very high likelihood.
B) practically impossible because the odds are akin to a tornado tearing through a junkyard and assembling a Boeing 747.

Question 8
Evolutionary Biologists
A) claim that humans once shared the same ancestor as other apes.
B) assert that people evolved from monkeys.

Question 9
In evolutionary biology, speciation is typically a process where
A) adaptations gradually accumulate and spread through a population until it is distinct from others.
B) entire new species appear as offspring of an existing species.

Question 10
Evolution is
A) an interactive system where random events- like mutations- end up being sorted by a (non-random) selection process.
B) an entirely random process where everything happens as a chain of coincidences.



If you’re getting mostly B’s for this quiz, then you’re not qualified to discuss the theory of evolution. You have obviously drawn most of your knowledge from non-scientific sources and your conception of evolution has little resemblance to the actual theory.

Explanation
Question 1- The theory of evolution is the scientific explanation for the diversity of life. This rules out the origin of life or big-bang cosmology. The theory we use is termed the modern synthesis and has its origin in the 1930s. This brought together genetics, paleontology and Darwin’s model into one theory. The terms micro and macro-evolution are creationist shibboleths that have no currency within biology.

Question 2- It’s astonishing to find that some people still believe that thermodynamics disproves evolution. This is based on the claim that simple molecules can’t become more complex. This however happens all the time in biology. In photosynthesis, simple molecules of water (H2O) and carbon dioxide (CO2) combine to form more complex carbohydrates (C6H12O6). All you need is an energy source to sustain this system. In biology, we call that energy source the sun. It powers evolution too.

Question 3- The scientific definition of a theory is different to the popular use of the term theory. If you don’t know what the scientific definition of a theory is, you’re probably not qualified to discuss evolution. Laws are different again. Theories don’t eventually become laws. If you look at the theory of evolution you’ll see that laws embedded into it (e.g. Hardy-Weinberg, 2nd Law of Thermodynamics). Laws and theories also serve different function. In fact, a theory has the highest standing in science.

Question 4- The age of the earth is not in dispute because several scientific disciplines have independently yielded the same result. It’s an old earth. A young earth is contrary to all the evidence we’ve accumulated and would necessitate the violation of so many natural laws, life would be rendered extinct (molten earth, mutational meltdown etc).

Question 5- Technically biological hypotheses of the origin of life are not part of the theory of evolution. Nonetheless Pasteur did not prove abiogenesis was impossible when he disproved spontaneous generation. Abiogenesis is hypothesised to occur in systems where energy is available to keep driving the process. And rather than forming cells in one giant leap of coincidences, the evidence is that the process occurred as a series of steps where cellular-components form abiotically and combine gradually.

Question 6- This isn’t 1859 anymore. We have millions of fossils including some very good sequences detailing gradual evolution (e.g. Eocene Adapidae). And missing link has no scientific meaning. It is a popular but non-scientific term beloved by 1950s B-movie writers, newspaper headline composers and creationists. In biology we look to map out a matrix of traits that undertake transitions in the fossil record. That’s what evolution is. It’s about populations and traits.

Question 7- Again this is technically more to do with abiogenesis than the theory of evolution. It takes the Hoyle/Wickramasinghe critique from the mid-1980s (they were proposing a panspermia alternative at the time) and the junkyard metaphor Hoyle employed. Again, it’s statistically meaningless and biologically vacuous. It’s meaningless because it models the creation of complex biological molecules as one giant step, rather than a Markov-chain (series of steps, building on each prior success). It’s biologically vacuous because it says it’s all random rather than building on the principles of biochemistry and physics of self-ordering systems. It’s akin to saying salt crystals form when sodium and chlorine atoms combine randomly, rather than as an organised lattice driven by chemical bonding.

Question 8- Nope, biologists don’t say we evolved from (modern) monkeys. The evidence from genetics, molecular biology, anatomy etc is that we shared an ancestor with other apes (and earlier other primates). This common-ape ancestor would not have looked like a chimp or a gorilla as these apes have evolved from the same ancestral species as us.

Question 9- There seems to be a notion that biologists claims that species emerge suddenly as distinct biological entities. The whole ‘crocoduck’ creationist parody is an excellent of this type of fallacious thinking. Actually, we don’t claim that such clean breaks occur quickly and dramatically. This is why the appearance of neanderthal DNA in the human genome isn’t a great surprise to us. Things tend to happen gradually. Even in the punctuated equilibrium model, rapid speciation events still take 50,000-100,000 years to occur.

Question 10- Darwin’s important discovery was that natural selection was part of the evolutionary process. And as such it’s not actually random. That’s why the term selection appears in ‘natural selection’. Mutations and recombination may generate randomness and variability but that’s only part of evolution. Natural selection sorts these variations by eliminating the adverse ones.

Playing the ecotourist Brendan Moyle Apr 18

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After my seminar on Friday at Otago University, I squeezed in a quick trip to the Otago Peninsular on Saturday before the flight left. This was hosted by a charming and friendly colleague from Otago, who shares my interest in things wild and natural.

It's always a challenge wondering how much camera gear to bring on such expeditions, especially with the vagaries of domestic air-travel. I opted not to weight myself down. My main gear was a DSLR with a (carbn-fibre) monopod, and a 300mm prime + 1.4x TC. I figured (or hoped) we'd see mostly birds so the reach would be ideal. Plus this is still a combination I can work with hand-held. There's no acute need to be carrying tripods.

I pondered the second camera option- do I take a lens for some scenic work- if I did, should I take another DSLR to avoid switching lenses? But what I decided was I'd take my NEX-5 instead. I've been pretty impressed with it to date- it's compact yet produces some very nice images (the big sensor helps immensely).

So out on Sandfly Bay on Saturday morning I relied upon the NEX-5 as my wide-angle. I even shot- which I don't usually do- in jpeg format with the camera. And once again, the camera didn't disappoint.

#1


#2


#3


Playing the ecotourist Brendan Moyle Apr 18

No Comments

After my seminar on Friday at Otago University, I squeezed in a quick trip to the Otago Peninsular on Saturday before the flight left. This was hosted by a charming and friendly colleague from Otago, who shares my interest in things wild and natural.

It's always a challenge wondering how much camera gear to bring on such expeditions, especially with the vagaries of domestic air-travel. I opted not to weight myself down. My main gear was a DSLR with a (carbn-fibre) monopod, and a 300mm prime + 1.4x TC. I figured (or hoped) we'd see mostly birds so the reach would be ideal. Plus this is still a combination I can work with hand-held. There's no acute need to be carrying tripods.

I pondered the second camera option- do I take a lens for some scenic work- if I did, should I take another DSLR to avoid switching lenses? But what I decided was I'd take my NEX-5 instead. I've been pretty impressed with it to date- it's compact yet produces some very nice images (the big sensor helps immensely).

So out on Sandfly Bay on Saturday morning I relied upon the NEX-5 as my wide-angle. I even shot- which I don't usually do- in jpeg format with the camera. And once again, the camera didn't disappoint.

#1


#2


#3


A Tale of Two Species Brendan Moyle Apr 11

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On Friday afternoon I'm giving a seminar at Otago University entitled "A Tale of Two Species"

Here's the abstract:
Tigers and the salt-water crocodile share many similar features. Both have had their populations reduced to a remnant due to economic factors, both are apex predators that generate human-animal conflicts, yet also produce goods considered to have high value. The paradox is that despite the tiger receiving most attention and conservation resources, it is the saltwater crocodile that has experienced the most dramatic recovery. Wild tiger numbers in Asia however, are still in decline. The crocodile recovery can be attributed to an elegant and strategic property rights solution. The factors behind this recovery are elaborated. In the same vein, the property-rights regime implemented for tigers has exacerbated rather than reversed the decline of this iconic species.

The kind of intriguing thing is how two apex predators- ranging over many countries- both starting as endangered in the 1970s (both listed in Appendix I of CITES)- took such a divergent path in their recovery. What makes it even more intriguing is the one species that was lavished with resources has done far worse. This seems a bit counter-intuitive so I'm going to try answering that question on Friday.

A Tale of Two Species Brendan Moyle Apr 11

4 Comments

On Friday afternoon I'm giving a seminar at Otago University entitled "A Tale of Two Species"

Here's the abstract:
Tigers and the salt-water crocodile share many similar features. Both have had their populations reduced to a remnant due to economic factors, both are apex predators that generate human-animal conflicts, yet also produce goods considered to have high value. The paradox is that despite the tiger receiving most attention and conservation resources, it is the saltwater crocodile that has experienced the most dramatic recovery. Wild tiger numbers in Asia however, are still in decline. The crocodile recovery can be attributed to an elegant and strategic property rights solution. The factors behind this recovery are elaborated. In the same vein, the property-rights regime implemented for tigers has exacerbated rather than reversed the decline of this iconic species.

The kind of intriguing thing is how two apex predators- ranging over many countries- both starting as endangered in the 1970s (both listed in Appendix I of CITES)- took such a divergent path in their recovery. What makes it even more intriguing is the one species that was lavished with resources has done far worse. This seems a bit counter-intuitive so I'm going to try answering that question on Friday.