Questions for Simon The Scientist

Following on from my last request for feedback, I’ve now got a new request for you awesome people: Questions. Many of my posts were inspired by a single question that someone asked me casually in conversation, which I attempted to answer in a rambling and lengthy reply. Later I realised I could do a much better job at answering it, which many more people might like to hear, so I took to the keyboard/touchscreen. So below are most of the questions I’ve attempted to answer thus far on this blog, as inspiration for you to fire away with any questions of your own in the comments section.

Should gay people be allowed to adopt?

What’s wrong with incest?

How the hell does cloning work?

Can religion co-exist with modern science?

Are ‘green’ products always superior?

Are humans special compared to the rest of the animal kingdom?

Shouldn’t we all be environmentalists?

Are we supposed to help our genes?

Is it unlucky to get cancer?

What’s the point trying to save the environment? It’s basically already screwed.

Post your own question below and I’ll do my best at answering it for you and everyone else who might be interested.

Thanks and you’re welcome!

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Blogging Feedback

I’ve been writing this blog for about 18 months now and I’d be interested to know which posts my readers have found the most interesting. Generally I’ve found the greatest response to those ideas that were inspired when talking or debating with people.

If you could leave a comment below with the title of your favourite post(s), with maybe a short explanation of why you liked it, it would be greatly appreciated!! That way I can write more about what you want to read about.

Many thanks kind readers!

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.

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

The Problem With Incest

Humans find the idea of incest disgusting and thus avoid mating with close relatives. Most people have a vague understanding that children born to closely related parents are likely to have physical or mental abnormalities, like the royal family of years gone by and some of that dodgy village down the road. This is known as inbreeding depression. But why does it occur? Surely it is beneficial to give children not only half of your set of genes, but also some that your sibling or parent shares with you, thus passing more than 50% of your genes to the next generation. Inbreeding ought to allow you to maximise the proportion of your genes in the next generation, the ‘goal’ of reproduction. Unfortunately, for most animals on this planet there are severe problems with inbred offspring that outweigh any benefits in terms of propagating their genes.

To understand inbreeding depression you must first have some basic knowledge of errors that occur when genes are copied or repaired incorrectly, called mutations. Every time cells divide they must copy all of their genetic material using microscopic ‘machinery’, and these are subject to the occasional error, which can result in a new version of a gene. Additionally, mutations can arise due to environmental damage through radiation, heat or chemical agents. These mutations become permanent features in the genetic lineage of a given cell, hence those that appear in the germ line (egg and sperm cells) are passed from parent to offspring eternally down the generations.

Within a single cell a mutation happens at a completely random point in the genome, effecting any of the ~25,000 genes. In most cases the mutation is not expressed, as there are two copies, called alleles, of each gene. And mutations usually result in a recessive allele, meaning it is submissive and masked by the ‘normal’, dominant allele, which works as usual. Therefore, any person with a random recessive mutation is unaffected and a ‘carrier’ for the genetic disorder associated with faults in that particular gene.

Most individuals inherit between 3-5 random recessive mutations and when they mate with an unrelated person in the population there is a very low probability that they are both carriers of the same mutation. This means that their children are pretty much guaranteed to inherit at least one healthy, working version of each gene. However, when closely related people mate they are likely to share mutations they’ve inherited from a common ancestor, meaning each of their children would have a 1 in 4 chance of receiving both faulty versions of a particular gene, giving them a genetic disorder. As most people carry multiple mutations (and these are likely to be shared by related parents) the chance that their child will have genetic abnormalities becomes seriously high.

So that is inbreeding depression: the accumulation of faulty versions of genes in descendants of closely related sexual partners, where they are shared through common ancestry.

Note: Not all mutations are harmful; most are in fact neutral, producing no effect on the protein and function of the gene. And while some mutations are harmful, a small but important subset result in improved function of a gene, and this is a crucial way in which new adaptations can arise.

Should Same-Sex Couples Be Allowed To Adopt?

Of course they should. But I was at a wedding last weekend and found myself listening in to a heated argument that centred on whether or not gay men should be allowed to adopt and raise children. The opposition to said rights was shocking in his distorted understanding and use of the principles of evolution and what is natural, in defending his position. He passionately argued that since gay men could not naturally produce a child together they should never be provided with this opportunity. “It’s not natural, it’s not natural”, he kept repeating. He is right about the impossibility of two men conceiving a child, however his beliefs were a perfect example of the naturalistic fallacy, as I pointed out to him. This fallacy is easily simplified as ‘the misunderstanding that everything that’s natural is good, and everything that’s unnatural is bad’. Infanticide, rape and war are all perfectly natural components of many animals’ societies, including our own, but this does not mean that they are right or good. As an intelligent and moral species we can see that these behaviours are terrible and should be penalized in order to reduce their occurrence.

Coming back to the topic of having children, many heterosexual couples find that they are unable to conceive naturally, but IVF treatment allows them the joy of bringing a child into this world. The process is as unnatural as you can imagine, and using a Darwinian moral compass they should be denied this right along with homosexual couples. But nobody in their right mind uses this compass and falls for the naturalistic fallacy so completely that they would seek to deny the right to have children to anyone, regardless of sexual orientation.

That being said, this man’s beliefs ran further still and he went on to argue that homosexuals in general were not natural since they couldn’t reproduce. This simply isn’t true. Being homosexual is partly genetic and there are no right and wrong genotypes; there are many variations each with their own advantages and disadvantages, depending on the environmental conditions. Being homosexual usually results in less offspring but may allow greater care of nieces and nephews, resulting in overall greater fitness. The frequency of male and female homosexuals worldwide is far higher than would be predicted, given the fact that they don’t directly pass on their genes. So it is probable that their relatives (who share their genes) have a corresponding increase in reproductive output, which their homosexual kin lose, thus maintaining the genes for homosexual orientation. There is absolutely nothing unnatural about homosexuals. And there’s nothing unnatural about homosexuals raising children that aren’t their direct descendents. If there were evidence suggesting future psychological problems for adopted children then this would need considering, but there is no grounds for denying these rights by virtue of it being unnatural.

This is a classic case of people twisting and distorting principles of natural selection in order to justify their prejudices. Some people dislike homosexuals so they try to demonize them and limit their rights as human beings. It is the exact same principle as eugenics that the Nazi’s infamously took to extremes. But the idea is completely flawed. There is no right set of genes that make up a human or any other animal, so there can be no perfect specimen to try to breed towards. Any person advocating or subjugating a particular race or trait is simply imposing their opinion with absolutely no scientific evidence to support it. And we must not take such behaviour lying down.

The Unbelievers: Science Trumps Religion

The Unbelievers

Watched a documentary today called The Unbelievers which follows Richard Dawkins and Lawrence Krauss as they tour the world speaking about science and religion. They are trying their best to promote the open discussion (and abandonment) of religion, instead of it being protected as a taboo subject we are just expected to accept and live with. Why should all other aspects of society and culture be open to criticism and scrutiny while religion gets a free pass?

This film simply promotes the rather sensible idea that reason and evidence should guide our beliefs, rather than just old, fictitious stories, taken on faith. By using the scientific method we can hone in on the truth and discover the incredible wonders of the universe, and of our own lives. Science is willing and able to change as new discoveries are made; it doesn’t hold a position and refuse to budge out of fear and blindness. We may not yet have answered all of life’s questions convincingly but that doesn’t mean we need to cop out and cry miracle!