Sex on the beach

2 10 2018
Female green turtles (Chelonia mydas) spawning (top) and diving (bottom) on Raine Island (Great Barrier Reef, Queensland, Australia) — photos courtesy of Ian Bell. This species is ‘Endangered’ globally since 1982, mainly from egg harvesting (poaching conflict in Mexico for olive ridley Lepidochelys olivacea featured by National Geographic’s video here), despite the success of conservation projects (39). Green turtles inhabit tropical and subtropical seas in all oceans. Adults can grow > 150 kg and live for up to ~ 75 years. Right after birth, juveniles venture into the open sea to recruit ultimately in coastal areas until sexual maturity. They then make their first reproductive migration, often over 1000s of km (see footage of a real dive of a camera-equipped green turtle), to reach their native sandy beaches where pregnant females will lay their eggs. Each female can deposit more than one hundred eggs in her nest, and in several clutches in the same season because they can store the sperm from multiple mating events.

When sex is determined by the thermal environment, males or females might predominate under sustained climatic conditions. A study about marine turtles from the Great Barrier Reef illustrates how feminisation of a population can be partitioned geographically when different reproductive colonies are exposed to contrasting temperatures.

Fortunately, most people in Western societies already perceive that we live in a complex blend of sexual identities, far beyond the kind of genitals we are born with. Those identities start to establish themselves in the embryo before the sixth week of pregnancy. In the commonest scenario, for a human foetus XY with one maternal chromosome (X) and one paternal (Y) chromosome, the activation of the Sry gen (unique to Y) will trigger the differentiation of testicles and, via hormonal pathways, the full set of male characteristics (1).

Absence of that gene in an XX embryo will normally lead to a woman. However, in just one of many exceptions to the rule, Sry-expression failure in XY individuals can result in sterile men or ambiguous genitals — along a full gradient of intermediate sexes and, potentially, gender identities. A 2015 Nature ‘News’ feature echoes two extraordinary cases: (i) a father of four children found to bear a womb during an hernia operation, and (ii) a pregnant mother found to host both XX and XY cells during a genetic test – with her clinical geneticist stating “… that’s the kind of science-fiction material for someone who just came in for an amniocentesis” (2). These real-life stories simply reflect that sex determination is a complex phenomenon.

Three ways of doing it

In nature, there are three main strategies of sex determination (3) — see scheme here: Read the rest of this entry »





The Effective Scientist

22 03 2018

final coverWhat is an effective scientist?

The more I have tried to answer this question, the more it has eluded me. Before I even venture an attempt, it is necessary to distinguish the more esoteric term ‘effective’ from the more pedestrian term ‘success’. Even ‘success’ can be defined and quantified in many different ways. Is the most successful scientist the one who publishes the most papers, gains the most citations, earns the most grant money, gives the most keynote addresses, lectures the most undergraduate students, supervises the most PhD students, appears on the most television shows, or the one whose results improves the most lives? The unfortunate and wholly unsatisfying answer to each of those components is ‘yes’, but neither is the answer restricted to the superlative of any one of those. What I mean here is that you need to do reasonably well (i.e., relative to your peers, at any rate) in most of these things if you want to be considered ‘successful’. The relative contribution of your performance in these components will vary from person to person, and from discipline to discipline, but most undeniably ‘successful’ scientists do well in many or most of these areas.

That’s the opening paragraph for my new book that has finally been release for sale today in the United Kingdom and Europe (the Australasian release is scheduled for 7 April, and 30 April for North America). Published by Cambridge University Press, The Effective ScientistA Handy Guide to a Successful Academic Career is the culmination of many years of work on all the things an academic scientist today needs to know, but was never taught formally.

Several people have asked me why I decided to write this book, so a little history of its genesis is in order. I suppose my over-arching drive was to create something that I sincerely wish had existed when I was a young scientist just starting out on the academic career path. I was focussed on learning my science, and didn’t necessarily have any formal instruction in all the other varied duties I’d eventually be expected to do well, from how to write papers efficiently, to how to review properly, how to manage my grant money, how to organise and store my data, how to run a lab smoothly, how to get the most out of a conference, how to deal with the media, to how to engage in social media effectively (even though the latter didn’t really exist yet at the time) — all of these so-called ‘extra-curricular’ activities associated with an academic career were things I would eventually just have to learn as I went along. I’m sure you’ll agree, there has to be a better way than just muddling through one’s career picking up haphazard experience. Read the rest of this entry »





A gender-diverse lab is a good lab

18 09 2017

sexism

Another little expurgated teaser from my upcoming book with Cambridge University Press.

My definition of a ‘lab’ is simply a group of people who do the science in question — and people are indeed a varied mob. I’d bet that most scientists do not necessarily give much thought to the diversity of the people in their lab, and instead probably focus more on obtaining the most qualified and cleverest people for the jobs that need doing. There are probably few of us who are overtly racist, sexist, or otherwise biased against or for certain types of people.

But the problem is not that scientists tend to exclude certain types of people deliberately based on negative stereotypes; rather, it concerns more the subconscious biases that might lurk within, and about which unfortunately most of us are blissfully unaware. But a scientist should be aware of, and seek to address, these hidden biases.

I acknowledge that as a man, I am stepping onto thin ice even to dare to discuss the thorny issue of gender inequality in science today, for it is a massive topic that many, far more qualified people are tackling. But being of the male flavour means that I have to, like an alcoholic, admit that I have a problem, and then take steps to resolve that problem.

Read the rest of this entry »