Author Archives: tomhouslay
A popular science article causing something of a furore right now is journalist David Dobbs’ latest offering, ‘Die, Selfish Gene, Die‘. Dobbs attempts to lay out the case for the ‘extended modern synthesis’ as proposed by researchers such as Massimo Pigliucci, but – to me, at least – tries to cover too much ground and fails to make a coherent argument. Beware also the ‘controversial’ statements made to pique the reader’s interest; here, even the sub-heading claims that the content will overturn the central idea of Richard Dawkins’ famous book:
The selfish gene is one of the most successful science metaphors ever invented. Unfortunately, it’s wrong.
Dawkins has responded to this ‘adversarial journalism’ on his own blog; meanwhile, Jerry Coyne at ‘Why Evolution is True’ has written two lengthy pieces which go into rather more detail on the science:
Dobbs himself has written another two posts on the subject on his own blog, the first being a ‘clarification’ of his original piece. The second is a more direct response to Coyne’s writing. PZ Myers has also weighed in on Dobbs’ side, expanding on the science while claiming that pushback is from ‘people who don’t quite get the concept‘.
It’s worth reading all these to get a feel for the different ideas flying around, although reading ‘The Selfish Gene’ itself (or Dawkins’ later book, ‘The Extended Phenotype’) should be on your xmas list if you don’t own them already.
I also tried to follow a twitter conversation between the likes of Richard Lenski, Razib Khan, Josh Witten, Karen James, Emily Willingham, Joel McGlothlin, Aylwyn Scally… among others… but it all got a bit too intense for me! Hopefully someone will gather those tweets together under one internet roof, but that someone certainly isn’t going to be me.
I’m pretty sure we haven’t heard the last of this, so I’ll try to keep adding links as I find them. In the meantime, feel free to weigh in below in the comments section…
I’m also covering this on my own blog, so the update is copied verbatim from there:
It wouldn’t be a scientific debate on Twitter without a blaze of capslock hulkspeak. SMASH LINK TO READ
‘Die, Selfish Gene, Die’ has evolved: David Dobbs has, rather wonderfully, published a revised version of his article. While I’m sure many will still take issue with the ideas contained within it, it’s fantastic that he has taken all of the criticism and comments onboard and updated his article. The original version still exists online, and I’ve changed the link at the top of this post so that it is linked there. There is also another (!) version of the revised article with links inserted by Dobbs to show his sources.
Finally (for today, at least), I just saw a great post by Sergio Graziosi on the whole affair, discussing both the public understanding of evolution and the technical points of Dobbs’ article. It’s well worth a read.
The previous posts from our discussions on classic mating systems papers have shown how both empirical work and theory advanced knowledge of sex differences in the returns from relative investment in reproduction. In their 1977 paper, Emlen & Oring attempted to bring natural history observations and ecology into a general theory of mating systems evolution, and to discuss the ecological factors and selective forces that shape polygamous mating systems. Of particular relevance here is Trivers’ work on parental care, as the prevalence of polygamy is often related to whether one sex is freed from parental care duties (and thus have excess time and energy to seek additional mates).
‘Ecology, Sexual Selection, and the Evolution of Mating Systems’ was published 2 years after E. O. Wilson’s ‘Sociobiology’ had hit the shelves, and Emlen & Oring are careful to note early on that understanding mating systems requires the reader to abandon any thoughts of group- or species-level ‘adaptiveness’. Fitness is a measure of the reproductive success of an individual (or genotype) relative to other individuals (or genotypes) in the same or other populations, and so we must consider selection to be operating at the level of the individual . Intraspecific competition is a crucial aspect of sexual selection: essentially, when one sex becomes a limiting factor for the other, the result is an increase in intrasexual competition among members of the available sex for access to mates of the limiting sex. The authors hypothesise that an important cause of the differing intensities of sexual selection found both across species and between populations of the same species is “the ability of a portion of the population to control the access of others to potential mates”. This control may be enforced through physically excluding other members of the same sex from potential mates, or through controlling critical resources. Central to Emlen & Oring’s argument is a cost-benefit analysis: under what environmental circumstances is the defending of multiple mates, or of those resources necessary for gaining multiple mates, economically viable?
Two of the crucial components of this concept of an environment’s ‘polygamy potential’ are illustrated by the figure below, in which the height of the shaded area perpendicular to each diagonal line indicates the environmental potential for polygamy in relation to the spatial distribution of resources (on the x-axis) and the temporal availability of receptive mates (on the y-axis). Resource ‘clumping’ in space means individuals can monopolise critical resources, which always increases the potential for polygamy. Asynchrony of mate availability is required for polygamy, else the time to locate, attract or copulate will mean that other potential mates are no longer available. However, too much asynchrony means the cost of continual defence outweighs the benefits of gaining additional mates.
Another crucial piece of the sexual selection intensity puzzle is the realisation that the overall ratio of males to females in the population is less important than the operational sex ratio (OSR): the average ratio of fertilisable females to sexually active males at any point. The OSR is affected by spatial and temporal clumping of the limiting sex; the example given is of continuous long periods of male sexual activity alongside brief, asynchronous periods of female receptivity, producing a strong skew in the OSR.
The bulk of the paper outlines an ecological classification of mating systems, concentrating on whether and how access to potential mates and resources are controlled, and the effects of temporal and spatial clumping on the OSR. Detailed examples of mating system types are illustrated using examples of avian mating biology. Emlen & Oring also consider how changes in ecological parameters might disrupt the environmental potential for polygamy, and indicate that their framework should enable predictions of the form of mating system plasticity that occurs.
A rather low-key science drinks on this occasion, as the mid-semester break meant a number of people are away (including our Fearless Leader, who is swanning about in Finland right now). Stu and I were joined by Claudia, Gregor and Toby to discuss a diverse set of topics, ranging from where best to set up camp on Mull to why I have just ordered a pint of maggots through the internet. We also managed to talk some science, including a general discussion on the peer review process and how it works, as well as why it sometimes doesn’t. Gregor outlined his plans for his project for the statistics module he’s taking, in which he’s hoping to do some work on random forests – a machine learning technique involving ‘forests’ of decision trees that is useful for ‘small n large p‘ problems (that is, problems that are high-dimensional but have a low sample size). This means that Gregor will – like the best of us – get to spend the vast majority of his time glued to RStudio. Luckily for him, there is a wealth of information out there to help him get started. Even more luckily, it turns out that R users of random forest techniques also like to party.
Quick to spot a gap that needed filling in Stirling’s list of societies (I was going to try to make an ecological niche pun before realising that I’d probably need to read a bunch of papers first so as to make sure I didn’t make a scientifically inaccurate joke), Claudia has been helping to set up the new Stirling University Biology Society:
The Stirling University Biology Society was set up this year in order to increase each and every individual student’s chances of getting the job they deserve when they graduate. As well as this, some other Society aims are to have students helping each other with study sessions, to meet new people in the University (integrating both students and lecturers) and, of course, to have some top class fun!
We meet weekly to discuss any problem with our courses and to update on new Science. On top of this, we provide events such as trips to parks, conferences and expositions. We also invite special guest speakers to talk about their profession and perhaps give advice on how to get there yourself.
Finally, we offer students the opportunity to enhance their involvement in the subject of biology by registering with the national Society of Biology.
Head over to to the Stirling University Biology Society website to find out more!