how the Sahara became a desert

The Sahara isn't exactly the place where you would want to store your DNA for a few millennia and expect it to still be readable, so it was a bit of a sensation that researchers recently published the first genome-wide analysis of 7000-year-old DNA of humans who lived there, when it wasn't a desert yet. A good excuse to look a bit more closely at the "Green Sahara" and how it became the Sahara desert we know today. It also serves as a warning, as some places are at risk of desertification due to climate change.

The resulting feature is out now:

Becoming a desert

Current Biology Volume 35, Issue 10, 19 May 2025, Pages R357-R359

Restricted access to full text and PDF download
(contact me if you would like a PDF)

See also my Mastodon thread where I highlighted all CB features of 2025.

The thread for 2024 is here .

The Acacus Mountains in Southwest Libya, where archaeological excavations at sites such as the Takarkori Cave have revealed a rich fauna and human habitation during the African Humid Period. (Photo: Franzfoto/Wikimedia Commons (CC BY-SA 3.0).)

wonderful Welwitschia

The desert plant Welwitschia mirabilis has accompanied my writing for a while. It featured in my book Exzentriker des Lebens / Life on the Edge. The info in the books is mostly 1990s plant physiology. Now however, researchers have published a high quality genome structure of Welwitschia in comparison with its closest relative - which isn't very close. I've used the opportunity to also have a look at other plant life in deserts on other continents - in the context that the climate disaster will produce more extreme conditions for life to cope with, so we'd better understand how it does.

The resulting feature is out now:

How to survive in the desert

Current Biology Volume 31, Issue 17, 14 September 2021, Pages R1017-R1019

FREE access to full text and PDF download

See also my twitter thread with all 2021 features that are now in the open archives.

Welwitschia_mirabilis, Plate 5369 from vol89 (1863) Curtis's Botanical Magazine (source: wikipedia)

bonus illustration not included in my feature, as images in portrait format are awkward with the column format we use.

roll back malaria (again)

The global effort to roll back malaria has been a success for a while, but in the last three years, progress in disease reduction appears to have stalled. In my latest feature I am looking at the problems holding back the fight against the disease and at some potential solutions:

Fresh efforts needed against malaria

Current Biology Volume 29, issue 9, pages R301-R303, May 6, 2019


FREE access to full text and PDF download



The mosquito Anopheles gambiae, which transmits malaria in Africa and thereby causes hundreds of thousands of deaths each year, has been called the world’s deadliest animal. (Photo: ArtsyBee/Pixabay.)

fighting Ebola

Open Archive Day

A year ago, I published my second feature about Ebola virus disease, and since then the Democratic Republic of the Congo has suffered two further outbreaks of the disease. Scientific efforts geared up after the devastating outbreak in West Africa in 2014 are now beginning to bear fruit, and the past few weeks have seen some interesting developments in this field. Specifically, the hypothesis that wild bats are the natural reservoir from which outbreaks in the human population originate (especially if and when bat populations are disturbed eg by deforestation) has been strengthened by the discovery of Ebola in a West African bat. Also, there are further related filoviruses found in bats that could become a worry some day. A new genus of such viruses has now been discovered in bats in China. Meanwhile, the vaccine work is making progress, and researchers have this month reported that a candidate vaccine is safe and effective in monkeys.

And not to forget my feature is now freely accessible:

Preparing for the next Ebola epidemic

(and the first one from 2014, too, of course)

but if things continue to develop at this pace, I may have to write a third one soon ...



This is a Leschenault's rousette fruit bat (Rousettus leschenaultii) seen in a temple in Madurai, Tamilnadu, India. Researchers discovered a new genus of filoviruses in this species.
Credit: Rajesh Puttaswamaiah, Bat Conservation India Trust

mind Africa's genomes

Africa has been left behind by much of modern biomedical science and biotechnology, so it is always good to see when new initiatives aim to spread the benefits to this continent, as the newly launched NeuroGAP and NeuroDEV programmes for psychiatric genetics do. However, one also has to watch out very carefully, not to create the impression that Western scientists extract samples and scientific insights from the continent in a one-way system. Empowering local scientists and building capacity in situ have to be important parts of any such projects.

I've tried to gain a balanced perspective of all this in my latest feature, which is out now:

Mind the genome diversity gap

Current Biology Volume 28, Issue 7, 2 April 2018, Pages R293–R295

FREE access to full text and PDF download




Sites in South Africa, Ethiopia, Kenya and Uganda are involved in the projects.
Credit : Susanna M. Hamilton, Broad Communications

revisiting Ebola and Marburg

I wrote a feature about Ebola Virus Disease three years ago, when the largest Ebola epidemic so far was still happening in West Africa. I recently came across a structural study of the Ebola virus capsid and so I thought it would be a good time to revisit this disease and see how the experience from the 2014 epidemic and progress in fundamental science can help to avert or at least manage further epidemics.

As an alumnus of Marburg University, I also had to mention Ebola's closest relative, which is known as, you guessed it, Marburg virus, as it was discovered in that town.

Read all about these viruses in my feature which is out now:


Preparing for the next Ebola epidemic

Current Biology Volume 28, Issue 2, pR51–R54, 22 January 2018


FREE access to full text and PDF download





Have a photo of Marburg town, much nicer than the eponymous virus. (own photo, taken 2013).

primate problems

There are around 500 primate species on our planet. Two thirds of them are threatened with extinction, because one, Homo sapiens, isn't quite as wise as the binomial name suggests. In my latest feature I have discussed some of the threatened species and the problems they are facing:

Primates in peril

Current Biology Volume 27, Issue 12, pR573–R576, 19 June 2017



OPEN access to full text and PDF download




Ring-tailed Lemur (Lemur catta) at Berenty Private Reserve in Madagascar. Source: Wikimedia

arthropods at work

Both insects and spiders tend to have a bad press, so I collected up some examples of how insects make positive contributions to our world, apart from the pollinators which I have covered on numerous other occasions. And to round it up I've thrown in the recent study estimating how many insects end up being eaten by spiders. The feature is out today:

How insects shape our world

Current Biology Volume 27, Issue 8, pR283–R285, 24 April 2017

FREE access to full text and PDF download



Fairy circles in Namibia have caused lively debates. Recent modelling suggests that both feedback regulation of plant growth and competition between insect states play a role in creating these patterns. I just love this photo from Jen Guyton, check her website www.jenguyton.com for lots more amazing wildlife photography.

save the elephants

Elephants have been in the news a lot recently, with two international conservation conferences calling on countries to ban all internal ivory trade in line with the international trade ban that has already been in force for decades. The reason is a new crisis in poaching and ivory trading, caused this time by buyer interest from China.

Read my take on the situation here:

The plight of the pachyderms

Current Biology Volume 26, Issue 19, R865–R868, 10 October 2016

Restricted access to full text and PDF download
(will become open access one year after publication)

Confiscated ivory items displayed ahead of the first official ivory crush held by the US Fish and Wildlife Service in 2013. (Photo: Gavin Shire/USFWS.)

pee-back time

The round-up of German pieces published in June covers African genomics, gene editing, and advanced materials reflecting urine from the much peed-upon walls of St. Pauli district in Hamburg.

Crispr-Cas: Gen-Schere weckt Neugier, Hoffnungen und Ängste
Chemie in unserer Zeit Volume 49, Issue 3, page 158, Juni 2015
Abstract and restricted access to full text.
related content in English

Blickpunkt Biowissenschaften: Afrikas Genome
Nachrichten aus der Chemie 2015, 63, 647-649
related content in English

Ausgeforscht: Clochemerle 2.0
Nachrichten aus der Chemie 2015, 63,751

the trouble with animals

It's all very well having animals around as food or for company, but the trouble is that we pick up diseases from them, and those can be deadly, especially in the initial phase after jumping across to our species. At the end of the year in which Ebola hit the headlines for months, I've discussed the wider problem of zoonotic disease and the lessons to be learned from the failure to tackle Ebola in time to stop it running out of control.

Our shared burden of diseases

Current Biology Volume 24, Issue 24, pages R1139–R1141, 15 December 2014 Open access

(I can send PDF "reprints" on request, and the article should become freely accessible one year after publication)

Vénus noire

review of the film

Vénus noire by Abdellatif Kechiche (France 2010)

This film from the auteur of Cous cous (La graine et le mulet) and this year’s Palme d’Or winner Blue is the warmest colour (La vie d’Adèle) tells in epic breadth the sufferings of Sarah Baartman, one of the African women shown around as a curiosity ("the Hottentot Venus") in European cities at the beginning of the 19th century.

While mentions and images of the historical Venuses are familiar to many, I think they remained curiosities so far. The film very successfully lifts the human being caught up in this show off the page and makes her experience of hopes, disappointment and exploitation the focus of the story. With the benefit of living in a (slightly) more enlightened age, we can see that she is beautiful, intelligent, and talented in ways that the contemporary audiences – neither the workers in London nor the aristocrats and scientists in Paris – could hardly fathom.

Seeing her strength in the face of adversity is uplifting, but watching her European audiences and the males that exploit her is very uncomfortable if you happen to be white and/or male. The underlying curiosity for people who are different from one’s own is of course not a bad thing, but without respect for the otherness it can have devastating effects.

I find it rather puzzling and depressing that this film didn’t get a UK release (not even on DVD - I bought mine in France, and amazon UK offers an import version). In many ways the London episode (where anti-slavery campaigners even try to liberate Baartman from her employer in a court case) is the less depressing part of the story.

Image from amazon.co.uk

food security and climate change

Last month, I attended a discussion meeting on food security and climate change at the Royal Society, London. As in other areas, it appears that change is going to hit those people hardest who are already in a precarious situation and can least afford to protect themselves. However, I also heard of some approaches promising efficiency improvements with very simple means, such as clever combinations of crops.

I've summarised some of the things I learned there in a feature which appears in this week's issue of Current Biology:

Food security in the times of climate change
Current Biology, Volume 23, Issue 1, R1-R4, 7 January 2013
doi:10.1016/j.cub.2012.12.

Full text and free access to PDF file.

don't play with food

Following the deregulation of the finance markets in the early 00s (whose bright idea was that?), finance people have discovered food commodities as a new toy to play with, and the prices have become unpredictable and decoupled from the real world parameters such as supply and demand. While the guilty parties deny that their gambling has any impact on the real world, experts increasingly believe that speculation does drive real people into real hunger.

For more info about this scandalous situation (and some of the science behind it, including, again, herding), read my feature in today's issue of Current Biology:

Don't play with food
Current Biology, Volume 21, Issue 19, pages R795-R798, 11 October 2011
doi:10.1016/j.cub.2011.09.037

summary and free access to pdf file

On the same issue, the World Development Movement (also mentioned in my feature) have today issued a press release:

450 economists call on G20 finance ministers to stop speculation fuelling hunger

a poisonous surprise

Oxford Zoologist Fritz Vollrath is famous for his work on spiders, but sometimes his team also gets involved in finding out amazing things about larger animals, such as rats storing poison in their fur. They have a paper out today, here's an excerpt from the press info:

For many years mystery has surrounded the sudden collapse, sometimes followed by death, usually at night, of dogs in north-eastern Africa. Typically, if the dogs do not die at once, they lose co-ordination, froth at the mouth and show symptoms of acute distress. In some rural areas elders or hunters might identify a wooly grey rodent as the culprit and warn that the rat is extremely poisonous. New research has confirmed that warning.

The Crested Rat, Lophiomys imhausi, 40-50 cm. long, looks quite innocuous as it clambers about in rocky, wooded valleys in Kenya and the Horn of Africa. If disturbed the long fur on its flanks parts to expose a vivid black and white pattern around a leaf-shaped tract of peculiarly specialized hair. Just how specialized the hair is and how well designed each hair is to hold and dispense poison has been revealed by a group of East African and Oxford scientists.

The group have identified the toxin, which comes from Poison-arrow trees of the genus Acokanthera, long celebrated for an extract from their bark and roots which, when applied to an arrow-head, can fell an elephant.

The scientists have observed the rat gnaw Poison-arrow tree bark directly from the plant, chew it and then deliberately slather the resulting colloid onto the flank hairs. These hairs are designed to rapidly absorb the colloid, acting like a lamp wick. The poison,Ouabain, is well-known as a heart-stopping cardiac glycoside and for centuries doctors have used minute doses of Ouabain to stimulate weak hearts.

The Crested Rat is the only mammal known to sequester plant toxins in this way. When more is known about the chemistry and genetics of the Crested Rat’s immunity to and use of Ouabain there may well be applications for human medical therapies.

In 1974 the senior author, East African Jonathan Kingdon, first advertised the mystery of a poisonous rat and invited further study. It has taken nearly 40 years for the mystery to begin to be solved.

A poisonous surprise under the coat of the African Crested Rat.
Jonathan Kingdon, Bernard Agwanda, Margaret Kinnaird, Timothy O’Brien, Christopher Holland, Thomas Gheysens, Maxime Boulet-Audet and Fritz Vollrath

Proc. R. Soc. B published online before print August 3, 2011, doi:10.1098/rspb.2011.1169

full text (open access)

we're all Africa

It doesn't happen that often that I get the chance to use a quote from Shakira in my writing, so I jumped at the opportunity to open my article about African genomics with a reference to last year's Fifa World Cup and its official tune, which includes the spoken words at the end: "We're all Africa."

Because, you see, considering the facts that we all came from Africa at one point, sooner or later, that most of human genetic diversity is found between African populations, not between "races", and that a large part of the global disease load weighs down on Africa, it really is quite weird that the new investigation of personal genomes so blatantly followed the money rather than the scientific interest in sequencing lots of males of European descent before even beginning to include some token people of different origin (or even gender).

Obviously, I have phrased this sentiment much more diplomatically in my feature and I also report on several initiatives which aim to empower Africans to take part in the genome revolution and also to reap the medical and economic benefits from it.

My feature is out today in Current Biology:

African genomes
Current Biology, Volume 21, Issue 13, R481-R484, 12 July 2011
doi:10.1016/j.cub.2011.06.047

Summary and limited access to PDF file



Shakira performing "Waka waka: This time for Africa" at the closing ceremony of the 2010 World Cup.

It's my turn to speak

review of

Swallow
by Sefi Atta
Interlink books 2010

The book opens with a dialogue between two friends on the bus, on their way to work, after narrowly escaping a possible accident. Rose talks a lot, and preferably about what her friend Tolani should do with her life and her boyfriend, while Tolani herself only gives laconic replies. Both face an uphill struggle trying to survive in the chaotic metropolis of Lagos, Nigeria, in a society dominated by men who tend to be unreliable, molesting, or even criminal.

Tolani doesn’t appear to be very good at getting her way through dialogue, even though there is a lot of it going on. Somehow, it never goes her way, and she always ends up swallowing her pride. Her employers kick her around, her useless boyfriend squanders her savings, her mother tells her everything except what she needs to know, and her friend Rose signs the pair of them up for a trip as drug mules, which, again, requires Tolani to swallow her pride, not to mention a condom filled with cocaine.

With its colourful representation of everyday life in Nigeria, this short novel (like Atta’s debut, Everything good will come) is very engaging - at least in the short term, for 10 or 20 pages. I especially enjoyed the swipes at us western people (“oyinbo” seems to be the Yoruba equivalent to “gringo”), such as: “… oyinbos write theories about things they can’t understand, and by the time they finish, you can’t understand either, even if they’re writing about you.” (p. 167) However, given the very slow pace of the progress our heroine makes, the reading experience is also a little bit frustrating in the longer term. This may very well be intentional, reflecting the frustration that this woman suffers every day. (Atta's debut novel was a coming of age story, so there naturally was a bit more of direction to it.) Only in the very last paragraph she seems to have picked herself up. “It’s my turn to speak,” she says. About time, too.



amazon.co.uk

neanderthal debate

Also in this week's issue of Current Biology (apart from those 3 pieces by me) is an interesting dispatch on the Neanderthal genome, raising the issue that our insufficient understanding of genetic diversity within sub-Saharan Africa may mean there are other explanations for the genome results than those favoured by Pääbo et al.

Essentially, if African diversity was already geographically segregated at the time the Neanderthals migrated towards Europe, their similarity could simply mean that they derived from the same sub-group of Africans as the later Homo sapiens migrants that settled the rest of the world. If I understand it correctly, this would mean however, that the genetic differences within Africa should be as large as those between modern humans and Neanderthals, which is not what has been observed.

The authors also offer a more complicated model, involving human emigration from Africa, mixing with Neanderthals, return to Africa, and then emigrating again, which in my eyes falls victim to Ockham's razor, as it is needlessly complicated.

But anyhow, I agree that one should sequence a lot more African genomes, seeing that most of human diversity is between Africans, not between the groups wrongly labelled as "races".

Reference:

Neandertal Genome: The Ins and Outs of African Genetic Diversity
Jason A. Hodgson, Christina M. Bergey and Todd R. Disotell

Current Biology, Volume 20, Issue 12, R517-R519, 22 June 2010

summary and link to pdf file

one goal

there will be absolutely no football coverage on this blog, but here is one goal I can relate to:



You can join 1goal here or follow their tweets.

PS - I pinched the photo from Wendy's blog.

PPS: While I'm at it, I'll also throw in a video of Shakira's appearance at the opening ceremony:

ethics of data sharing

I have recently started to work for the Welcome Trust Centre for Human Genetics (WTCHG) which is based at Oxford University's Old Road Campus. The first feature I wrote for their website is now online:

How to control access to sensitive DNA information

It is about the MalariaGEN project, which works with sensitive DNA data from participants in Africa and therefore had to develop new ways of controlling access to that data.