Animals of an Indonesian Island

Animals of an Indonesian Island

Here is a selection of awesome animals I saw around Pulau Weh, an island just north of Sumatra, Indonesia:

• A flying lizard with a yellow skin flap on it’s neck and fan-like wings tucked away under its body. No known lizards have powered flight, so this flying lizard like all others was a glider, but some can travel hundreds of metres while losing only a couple of metres in height. The male had a blueish head and yellow neck which it was extending, possibly to display to the less impressive, but very well camouflaged, female that was slightly lower on the tree. A similar lizard from Bogor Zoological Museum

• Millions and millions of baby, translucent crabs migrating up the river, where we walked to find a waterfall on Pulau Weh. I’m not entirely sure why they were migrating, but we followed them as they crawled across the rocks (and each other) on either side of the river. Occasionally the stream of crabs hopped into the water and swam for a short while before clambering back onto a rock as the water became too fast and choppy.

 Crabs, crabs, crabs

• Monitor lizards swimming in the clear, aqua-marine ocean in front of our hut and basking in the sun. Then one chasing a rival off the rocks and into the sea as it asserted its authority over a territory.   Monitor lizard showdown

• Fruit bats flying between islands during and just following a storm. From our kayaks we saw around a dozen over a couple of hours. Soaring above us with a wingspan of around a metre, they flew between trees and then started munching on some fruit as they hung beneath the branches. With over 12,000 different species discovered so far, bats make up a fifth of the total number of mammal species on Earth! This they owe to their almost exclusive access to the large, nocturnal-flying niche. 

The last common ancestor of all living mammals* was a nocturnal insectivore that looked something like a shrew and lived alongside the dinosaurs around 140 million years ago.   Maybe it looked a little like this shrew I saw in West Java

This mammalian ancestor scraped by, living in the shadows, at a time when dinosaurs – reptiles – ruled the planet. But the Cretaceous-Tertiary (K-T) mass extinction 65 million years ago wiped out all of the dinosaurs, except the ancestors of modern birds. This allowed the mammalian clade to undergo massive diversification and to dominate the planet as it does today. 

The bat lineage separated from the rest of the mammals around 80 million years ago and, with the aid of flight and echolocation, has enjoyed huge success in colonising the world. Most bats use echolocation to navigate in the dark – they emit high-frequency sound which bounces off the environment and is detected by their ears, giving them a sound scape, a mental ‘image’ of the scene. Despite the saying, most bats are not blind, and many have very large eyes which they use instead of echolocation. Our fruit bats on Pulau Weh were frequently spotted in the late afternoon navigating by sight, which they exclusively use.

Unfortunately, I’ve since learnt that some local Indonesians fly barbed wire kites to bring down these majestic fliers to put them in a soup. Across Asia, many bat species have been pushed close to extinction through human hunting activity, though smoking out caves is a more common method of capture. This illustrates one of the biggest difficulties in conservation biology – educating and convincing local people to care for the long-term survival of a species, rather than over-exploiting it to extinction (as we’ve done time and time again across the continents).

*excluding the five species of monotremes, the egg laying mammals (echidnas and platypus of Australia), which diverged earlier, maintaining their reptilian oviparity.

• Moray eels, lobsters, octopus, barracuda, sting rays and more on two scuba dives off Pulau Weh. Plus countless numbers of other fish swimming in every conceivable direction around us. And the occasional tiny sting of a jellyfish, barely visible to the naked eye. 

• Cats, damn cats! On Pulau Weh in our 5 day visit we had the misfortune of seeing cats toy with and kill a praying mantis and a frog. 
 
 A similar, dead praying mantis

Domestic animals reach remote islands by deliberate and accidental introduction. And domestic cats are one of the most harmful alien species you can take to a remote island, especially in places that have no large mammals of their own. This is because the native community of species are not used to living alongside such predators. Without the strong selective pressure of mammalian predators, endemic island species are able to thrive while being relatively defenceless. But throw in a handful of cats and they can quickly eat their way through a huge proportion of the naive local species. 

Other invasive species that typically do serious damage to island fauna are rats, snakes, rabbits and toads. Not to mention the foreign parasites and diseases they bring with them, to which the local species have no immunity. It requires huge operations to try to rid an island of an invasive species, and often the efforts are in vain. Hence why there are such strict customs regulations in countries like Australia, where Johnny Depp recently took two un-quarantined, illegal-immigrant Yorkshire Terriers. 


All pictures from this article were taken by me, except the crab photo, which was taken by my travelling companion Samuel Holdway. 

I’m Migrating to Australia!

I’m currently travelling from West to East across Indonesia with a friend, inspired by the migration path taken more than 50,000 years ago by the ancestors of Aboriginal Australians, and many others (see map below).

 The sea was around 100 metres lower than today, as lots of water was locked up in ice, so their coastal migration route looked a little different than ours (see high-def map). It’s unlikely that any single individual crossed the entirety of Indonesia in the migration wave I’m attempting to recreate, as they would have been walking for the most part and the distance is over 5,000 kilometres!! But over many generations that’s just what they did, along with a great deal of sea crossings. However, I’ve got things to get on with in my life so I’m taking public transport to make the crossing over around 3 months, getting to Australia sometime in August (hopefully).

Keep an eye out for some geeky tales from the trip that I hope you’ll enjoy.


Sources

First map photographed by myself in Sangiran Museum of Human Evolution in Java, Indonesia.

Second map: Maximilian Dörrbecker http://commons.m.wikimedia.org/wiki/File:Map_of_Sunda_and_Sahul.png

The Goals of a Gene: Should We Help Our Selfish Genes?

You’ve probably heard that genes want to make copies of themselves, and try to ensure survival and reproduction of their host so they make it into the next generation. These anthropomorphic phrases are useful shorthand for biologists, as most genes act as though they selfishly wish to reproduce, and it is easier for us to think about them if we imagine that they have intentions. However, it can be misleading and warp some people’s ideas of evolution if they believe genes are literally selfish, for example.

Genes have absolutely no desires, and therefore no will to get themselves replicated. It would be just as accurate (or inaccurate) to describe genes as wanting to cease to exist and have no further copies of themselves made. In reality, the reason the genes we see today are here is because of the fact that they are good at building survival machines and reproducing. It is simply the case that those genes that were most successful in reproducing became more common and survived this far, and it now appears as though those genes actually want to continue to reproduce into the future. What appears to be purposeful design (genes that are good at replicating themselves indirectly via survival machines) is actually just the result of billions of years of cumulative evolution that has favoured the best replicators, generation after generation.

There is a big difference between genes, without any motives, and individual survival machines, which follow goal-driven patterns of behaviour in order to (ultimately) reproduce. Genes are made up of a sequence of DNA, a code which can be read and translated into functional proteins that build up and create a working organism. Without a nervous system and capacity to think, it is clear that genes cannot truly have motives or goals. However, genes programme organisms to have proximate goals such as eating, mating and surviving. Emotions as we know them are our genes motivating our minds to do (or not to do) something. But genes are given no motivation and being successful is just something that occurs if their effect is to encode a survival machine that is well suited to reproducing in its particular environment.


It is interesting to be a human being, and ponder about our evolutionary past and its effects on our behaviour. We know that most of our actions exist to increase the spread and therefore success of our genes, but we have no qualms about thwarting them. Our genes don’t have a sense of happiness so we needn’t feel bad about doing it. But it seems inescapable to conclude that our genes created us to propagate them as much as possible. So are we somehow misbehaving or overruling them when we use birth control or adopt children?

The distinction to be made is whether we view genes as wanting to do something in future, or simply as the result of evolutionary history. Our genes did not create us so we could aid their replication. They created us because their lineage happened to be highly successful at replicating since life began on this earth! And they were successful because they had the effect of building appropriate survival machines. We needn’t try to help them, as they aren’t trying to do anything themselves. They simply exist due to the past successes of their lineage.

Genes drive our behaviour in ways that generally increase their chances of replication. However, we are not precisely motivated to replicate our genes – if we were there’d be long lines for donating to sperm banks and we wouldn’t use contraception. We’re actually motivated to find happiness by eating tasty foods, having sex with attractive partners, having friends, finding love, raising happy children and to have fun, satisfy our curiosity and find meaning in our lives. We’re programmed by our genes but we don’t seek to replicate them, we instead follow our human desires and goals wherever they may lead us.

The Hopeless Hopeless

Last night I met someone who frustrated me a lot. He seemed to be an educated man but when I mentioned saving water his response was essentially “There’s no point as it won’t change anything, it won’t go to poor people who actually need it.” His stance likely represents a large chunk of society, a group of people who believe that trying to do anything about very large, global problems such as climate change and water and food shortages is useless, as what can one person possibly hope to achieve?

These hopeless people are not denying that the problems exist, they are fully aware of them. And this makes me very angry at their incredibly pessimistic outlooks. I’m all for being skeptical – there are no doubt many ways we can attempt to solve a problem that will not work. But taking a look at a big problem and then declaring it hopeless is simply pathetic.

Back to climate change. There is a consensus, an overwhelming tsunami of evidence that backs the fact that humans have caused and are causing dramatic climate change, most notably in the past few hundred years. It’s clear that this is mainly down to the burning of fossil fuels, destruction of forests and agriculture (especially meat production), to fuel and feed our 7.3 billion-strong population. Just as there were small steps and changes in lifestyle that got us to this point, we can now take small steps to reduce our impact through what we consume and what we waste.

It’s pretty simple: we produce and consume more water, meat, plastic and energy than ever before. And we waste huge amounts of these resources, which we simply cannot afford to do. Our planet will not allow it. Certainly not for 7 billion people.

But the situation is far from hopeless! Even the most basic adjustments that reduce the excess food, water and energy that are currently wasted can have a tremendous positive impact on our environment. The only problem is that there are too many hopeless individuals out there who are too pessimistic and selfish to take some responsibility and join the rest of us in doing something good.

Finally, back to the man who sparked my anger. He’s probably right that saving water in a rich country is not going to magically provide a poorer country with much-needed water. But the world doesn’t care for our country borders – we all share one planet! Reducing water consumption in one country takes a little strain off that precious resource and ensures there is enough to go round for everyone. And minimizing emissions of greenhouse gases is literally felt across the globe.

 

Our situation is not hopeless unless we think it is. Be positive and make little changes to reduce waste. It’s an easy first step.

Thanks,

The Environment

Cancer Misconceptions

There are a number of misconceptions I believe some people have about cancer, which I thought I would attempt to clear up.

  1. All cancers are alike
  2. We should find a cure for cancer soon
  3. Getting cancer is unlucky
  4. Cancer is a man-made disease

 

1. All cancers are alike

By using the term cancer we tend to think of it as a single illness, with a range of risk factors, such as smoking, eating unhealthily, drinking alcohol to excess and being exposed to radiation. But from a biological standpoint, cancers vary hugely, with over 200 types of cancer, and subtypes that vary drastically. All cancers are the result of abnormal cell growth. Normally, growth of our cells is controlled by oncogenes, promoting it, and tumour suppressor genes, inhibiting it. But occasionally a mutation will arise in a critical gene, which various safeguard mechanisms attempt to identify – so they can correct the mistake or else instruct the cell to self-destruct. However, very occasionally a mutation is missed by the safeguards (or the mutation is in a gene for the safeguards themselves!) and the abnormal cell can start growing uncontrollably; replicating, spreading, mutating and evolving as cancerous tissue1.

Almost all cancers are caused in this way, but the precise genetic fault that causes the cell to start growing abnormally and avoid self-destruction can be one of many thousand, or even million! As with any existing complicated system, the vast majority of changes will be detrimental to its function. Even in the same tissue type, there can be numerous different kinds of cancers, with very different causes. But cancers can start to grow in any tissue type in the body, and these usually differ substantially from one another. This brings us on to misconception number 2.

 

2. We should find a cure for cancer soon

Cancers vary widely in their causes and this means that there will never be a ‘cure for cancer’. Compared to most diseases cancers are incredibly difficult to treat because the cause is the body’s own cells, growing uncontrollably. Once it has begun there is almost no stopping it, as the body is unable to recognise the cancerous tissue as being a threat, as it has the “self” marker that foreign pathogens causing other diseases lack. Attempts at fighting the cancer by doctors are similarly thwarted – it is difficult to target the abnormal cells alone, hence why chemotherapy typically causes harmful side effects.

On top of this, a single cancer tumour has a whole succession of mutations, varying by location in the tumour, plus a tendency to mutate rapidly. Treatments can be aimed at the genetics of a sample unrepresentative of the entire tumour, and drug resistance can quickly emerge if a drug fails to destroy every cell quickly enough. As with other diseases that can evolve resistance to antibiotics, cancers can quickly mutate and overcome our most effective treatments2. Doctors compensate by administering a huge dose and combination of different drugs during chemotherapy, reducing the odds that the tumour will become resistant to the treatment. Unfortunately, the large dosage also contributes to the severe side effects that many cancer patients experience.

It is likely that many cancers will prove to be incurable, but by concentrating our efforts on the most common killers, we may hopefully be able to cure some of them in future. However, I think it is unlikely that cancers will ever stop being a leading cause of death. If you look at causes of death over the past couple of hundred years you can see that cancers have increased hugely. This rise in cancers can be attributed to people living longer due to improved sanitation, nutrition and medical care. No longer are infants lucky to make it to their teenage years, and no longer are adults lucky to make their 60th birthday. But unfortunately cancers become much more likely in old age, and this leads us on to misconception number 3.

 

3. Getting cancer is unlucky

The average life expectancy in the UK today is 81, which by the standards of any of our ancestors is incredibly long! While we are no longer likely to die from infectious diseases like diarrhoea, pneumonia and tuberculosis, which killed many of our ancestors, we are now more prone to developing a cancer. The reason for this is simple; cancers are caused by genetic mutations and these accumulate over time from mistakes in DNA copying (in cell cycles) and exposure to environmental risk factors. Now that we are lucky to live longer lives, we are much more likely to get and die from cancer.

According to Cancer Research UK, 1 in 2 people in the UK born after 1960 will develop cancer in their lifetime2. So getting cancer is just as unlucky as losing a coin toss. However, it should be recognised that lifestyle and environmental risk factors play a vital role too. Behaviours such as smoking, drinking, failing to exercise, eating a poor diet and getting sun burnt can vastly increase your chances of developing a cancer. So you obviously shouldn’t think of cancer as inevitable and throw caution to the wind!

While cancer is terrible as it takes many of us to our graves, it is actually a sign that we are living long lives in the first place. It should be noted that some cancers do strike people while they are young, but these are quite rare cases (less than 2% of all UK cancer cases are in under 25’s2). Why are cancers more common when we are older? Because there was a strong selective pressure for people to live to rear offspring, and to care for those offspring until they reached reproductive age in turn. So there was a strong pressure for people not to get cancer and die at a young age, before passing on their genes – those that failed left no offspring and those that succeeded were our ancestors. In contrast, the selective pressure on our ancestors to stay alive and be free of disease into old age was very relaxed. If a genetic disease doesn’t strike until we are 50, then it won’t be rapidly selected out of the population, as our children will already be passing on our genes!

All organisms face a trade-off in allocating energy to different aspects of their lives – growth, reproduction and maintenance (immune system and repair). Natural selection has led to strategies that produce optimal allocations of their resources, on average, resulting in a maximum possible number of strong, healthy offspring (biological fitness). The body spends energy defending itself against environmental, as well as genetic, factors that can trigger cancer, such as sunlight, viruses, bacteria and carcinogens. It pays to invest large amounts of energy supressing mutations that could lead to cancer in early and reproductive years, but the payoff to this maintenance reduces dramatically post-reproduction3.

There are so many different possible forms of cancer that we could get, and our chances increase rapidly as we age. Unfortunately, it is not bad luck if you get cancer and die from it in old age; that is how many of us can expect to die. Improved nutrition and medicine are allowing us to live longer and longer lives, and it is estimated that a third of all babies born today in the UK will live to be over 1004. However, even with great advances in genetic therapies, cancers will always be a huge difficulty to overcome; one that we may never be able to beat. So it is possible that many of us will live for over 100 years, but it is not very likely that we’ll be able to stay free of cancer forever.

 

4. Cancer is a man-made disease

This is absolute nonsense. The entirety of multi-cellular life has the ability to get cancer, and many other animals do get cancer; if they are lucky enough not to get injured, diseased or eaten before they get old.

A more accurate statement is that cancer is more common in modern times. Some environmental risk factors for cancer such as smoking, drinking alcohol, eating unhealthily and air pollution are no doubt more common in modern society. But the main reason cancer is more common is that we live longer lives; our bodies deteriorate with exposure to carcinogens and our cellular defences against cancer can’t protect us forever.

 

Special thanks to Jonathan Lockett, my cancer expert, for his technical knowledge and tips.

 

  1. Casás-Selves, M., & DeGregori, J. (2011). How cancer shapes evolution, and how evolution shapes cancer. Evolution4(4), 624–634. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3660034/
  2. Cancer Research UK http://www.cancerresearchuk.org/cancer-info/cancerstats/keyfacts/Allcancerscombined/
  3. Aktipis, C., & Nesse, R. M. (2013). Evolutionary foundations for cancer biology. Evolutionary applications6(1), 144-159. http://www.athenaaktipis.com/Home_files/AktipisNesse2013.pdf
  4. Office for National Statistics http://www.ons.gov.uk/ons/rel/lifetables/historic-and-projected-data-from-the-period-and-cohort-life-tables/2012-based/sty-babies-living-to-100.html

Why Are Environmentalists A Rare Breed?

There was a time when every man, woman and child was at heart an environmentalist. Their lives directly depended on rivers for water, land for food, animals and the sea for meat, forests for fuel and building material, and so on. Our ancestors were not perfect; many overexploited resources as we do today, sometimes resulting in the collapse of entire societies, e.g. Easter Island. This is a clear example of failing to estimate the long-term effects of consuming natural resources – typical of our species on a global scale in modern times. But hunters and gatherers had and still have a closeness to the environment that meant they understood just how greatly they depended on it, unlike the majority of the world today.

2015/02/img_5210-0.jpg
We simply couldn’t exist without a healthy environment, so shouldn’t we all be environmentalists? These kids have the right idea – plant some trees!

 

The industrialisation of agriculture has led to a fundamental disconnect between the production of essential goods like food, water and fuel, and the consumption of them. The average person no longer appreciates or even acknowledges the role of the environment in their life, since a small fraction of society produces the sustenance for everyone else. Most of us are ignorant to the intricacies of generating consumable calories from the soil, as the supermarket is our first contact with food. And we’re similarly oblivious to the chain of events leading to electrical outputs that power most of our activities. So it is no wonder that environmentalists are rare; the average person has little respect, understanding and appreciation for the natural world, which, quite literally, provides every requirement for our lives.

To put it as plainly as possible, energy comes from the sun and is harnessed by plants and microorganisms in the sea. We rely on plants to convert the sun’s energy into a form that we can eat, or we eat animals that have converted and concentrated it into more usable calories. To power our technologies and industry we burn fossilised stores of organic matter; dead trees that were buried and put under immense pressure over millions of years, turning them into coal, gas and oil. Unfortunately, it’s difficult to see the link between turning our washing machines on, driving our cars, buying meat and vegetables from a shop or heating up/cooling down our homes, and the negative environmental effects of these actions. Hence why it is so difficult for people to change their behaviour in order to lessen their impact, as they don’t clearly see or understand the relationship between what they consume and the environment.

We’ve become scarily distanced from the environment by living in our concrete urban areas and gathering dinner from shelves; food that’s biotic origins are often hard to determine. This means that great effort must be made to encourage environmentalist attitudes in current and future generations, since our present lifestyles and eating habits fail to promote a green conscience.

If we want to move forward into a greener world we need to start by teaching our kids about where food really comes from, and about the importance of complex ecosystems and forests in maintaining a healthy, liveable climate. One of the best ways to do this is to simply get them outside and enjoying what nature has to offer. The great outdoors is where our species has been educating its children for millions of years, before we started mass-destruction of the planet’s wilderness, so perhaps we’d do well to try to recreate this method of learning. There’s also good evidence that quality of life and happiness improves with increased connection to our wild, ancestral homes.

Why should we be environmentalists?
We’re threatening our planet and our only home by driving climate change, deforestation and mass species extinctions. These are all tough, pressing problems that we are responsible for and which require immediate and effective action. We’re poorly equipped to combat these problems because most of us lack the attitudes of an environmentalist – we don’t value the very thing we depend on to survive. Only by actively encouraging these attitudes do we stand a chance of saving our planet.

 

Inspiration for this post came from ‘The Omnivore’s Dilemma – A Natural History of Four Meals’ by Michael Pollen, which investigates the true costs of industrial-scale agriculture on society. I highly recommend it.