It is 1825, nearing the peak of American whaling, and the seas are still crowded with whales. But hunting the mighty creatures means long, lonely stretches for whaling crews on voyages that could last for years.
It is a time before Sudoku, so sailors turn to scrimshaw – detailed etching on bone or ivory – to while away the hours. This skull of a rough-toothed dolphin, Steno bredanensis, becomes the canvass for images including potted plants, butterflies and flags. Sailing ships flank the back of the animal's head, while a checkerboard pattern marches along the mandible.
The origin of this piece is unknown, but it is thought to be the work of an American whaler working around 1825, judging by the flags depicted.
Cetaceans themselves can get creative, too. Some whales woo mates with love songs, and then cement their union with duetsSpeaker. Whales and dolphins could even be said to have their own cultures.
Whales can craft a story worthy of the most ambitious scrimshaw artist: their 25-centimetre long plugs of earwax can serve as detailed records of their life experiences.
(Image: AMNH/Elizabeth Nunan)
The scrimshaw skull is on display at an exhibition called Whales: Giants of the deep at the American Museum of Natural History in New York City.
Read more about whales and other ocean creatures in our mysteries of the deep sea topic guide.
It is a time before Sudoku, so sailors turn to scrimshaw – detailed etching on bone or ivory – to while away the hours. This skull of a rough-toothed dolphin, Steno bredanensis, becomes the canvass for images including potted plants, butterflies and flags. Sailing ships flank the back of the animal's head, while a checkerboard pattern marches along the mandible.
The origin of this piece is unknown, but it is thought to be the work of an American whaler working around 1825, judging by the flags depicted.
Cetaceans themselves can get creative, too. Some whales woo mates with love songs, and then cement their union with duetsSpeaker. Whales and dolphins could even be said to have their own cultures.
Whales can craft a story worthy of the most ambitious scrimshaw artist: their 25-centimetre long plugs of earwax can serve as detailed records of their life experiences.
(Image: AMNH/Elizabeth Nunan)
The scrimshaw skull is on display at an exhibition called Whales: Giants of the deep at the American Museum of Natural History in New York City.
Read more about whales and other ocean creatures in our mysteries of the deep sea topic guide.
Even the prettiest faces are built using junk. In mice, the shapes of the face and skull are finely tuned by junk DNA, so called because it was initially thought to lack function since it doesn't encode proteins. The same junk DNA sequences are found in humans, so they are probably also shaping our faces.
This finding could help us make sense of some congenital conditions, such as cleft palates, that can develop even when the genes that shape the face appear to be working normally.
There is a huge degree of variation in human faces but, as family resemblances show, the overall shape is heavily constrained by genetics. However, so far, geneticists have identified only a small number of genes that influence the shape. These explain just a tiny fraction of the variation seen in human faces.
According to Axel Visel of the Lawrence Berkeley National Laboratory in California and his colleagues, more variation is controlled by distant-acting enhancers. These are short sequences of DNA, in non-coding regions of the genome, that can influence the activity of the facial genes, even if they are a long way along the DNA strand.
"Enhancers are part of the 98 per cent of the human genome that is non-coding DNA – long thought of as 'junk DNA'," says Visel. "It's increasingly clear that important functions are embedded in this 'junk'."
Face enhancers
Visel and his colleagues used a technique called optical projection tomography, which allows them to build up a three-dimensional model of a developing mouse embryo and show how gene expression varies in each region. This revealed some 120 enhancers that were active in various regions of the developing face. To work out what the enhancers were doing, the team chose three and engineered three groups of mice to each lack one of them.
When the mice were 8 weeks old, the team compared their skulls and faces to those of a control group of mice with all enhancers intact. They found that each enhancer had a subtle effect on face shape. For instance, deleting one enhancer left mice with faces that were longer – but skulls that were broader and shorter – than the control mice.
It's an important study, says Lavinia Paternoster, a geneticist at the University of Bristol, UK, because it identifies the key areas of the genome for face shape. "Studies such as this will enable us to focus on regions of the genome that are more likely to harbour important genetic variants and hence might mean that we can identify these variants with smaller sample sizes than is usually necessary."
However, she thinks the junk DNA might not be as important as Visel suggests. She has performed one of the few studies so far to identify genes involved in facial morphology. She investigated the entire genome – including coding and non-coding regions – of thousands of individuals, and found little evidence that non-coding regions have a powerful effect on face shape. "I am in no doubt that some enhancers do harbour some genetic variants that will influence face shape," she says. "But they are not the Holy Grail of missing heritability."
Cleaving palates
None of these effects on face shape were dramatic enough to, say, cause a cleft palate. But several enhancers can act on a single gene, says Visel. So if some or all of these enhancers carry mutations, their cumulative effect might lead to such dramatic facial changes.
"There are many cases of craniofacial pathologies – including a significant number of cases of clefts of the lip or palate – that cannot currently be explained by mutations in protein-coding genes," says Visel. "Based on our studies in the mouse model, it is possible or even likely that in some of these cases mutations in enhancers play a role."
So perhaps rather than looking for mutations in the genes, we should be focusing on mutations in the enhancers that influence those genes.
"This will certainly help us to understand the underlying causes of these defects better, and will eventually help in the diagnosis, possibly also prevention or treatment of such conditions," says Visel.
This finding could help us make sense of some congenital conditions, such as cleft palates, that can develop even when the genes that shape the face appear to be working normally.
There is a huge degree of variation in human faces but, as family resemblances show, the overall shape is heavily constrained by genetics. However, so far, geneticists have identified only a small number of genes that influence the shape. These explain just a tiny fraction of the variation seen in human faces.
According to Axel Visel of the Lawrence Berkeley National Laboratory in California and his colleagues, more variation is controlled by distant-acting enhancers. These are short sequences of DNA, in non-coding regions of the genome, that can influence the activity of the facial genes, even if they are a long way along the DNA strand.
"Enhancers are part of the 98 per cent of the human genome that is non-coding DNA – long thought of as 'junk DNA'," says Visel. "It's increasingly clear that important functions are embedded in this 'junk'."
Face enhancers
Visel and his colleagues used a technique called optical projection tomography, which allows them to build up a three-dimensional model of a developing mouse embryo and show how gene expression varies in each region. This revealed some 120 enhancers that were active in various regions of the developing face. To work out what the enhancers were doing, the team chose three and engineered three groups of mice to each lack one of them.
When the mice were 8 weeks old, the team compared their skulls and faces to those of a control group of mice with all enhancers intact. They found that each enhancer had a subtle effect on face shape. For instance, deleting one enhancer left mice with faces that were longer – but skulls that were broader and shorter – than the control mice.
It's an important study, says Lavinia Paternoster, a geneticist at the University of Bristol, UK, because it identifies the key areas of the genome for face shape. "Studies such as this will enable us to focus on regions of the genome that are more likely to harbour important genetic variants and hence might mean that we can identify these variants with smaller sample sizes than is usually necessary."
However, she thinks the junk DNA might not be as important as Visel suggests. She has performed one of the few studies so far to identify genes involved in facial morphology. She investigated the entire genome – including coding and non-coding regions – of thousands of individuals, and found little evidence that non-coding regions have a powerful effect on face shape. "I am in no doubt that some enhancers do harbour some genetic variants that will influence face shape," she says. "But they are not the Holy Grail of missing heritability."
Cleaving palates
None of these effects on face shape were dramatic enough to, say, cause a cleft palate. But several enhancers can act on a single gene, says Visel. So if some or all of these enhancers carry mutations, their cumulative effect might lead to such dramatic facial changes.
"There are many cases of craniofacial pathologies – including a significant number of cases of clefts of the lip or palate – that cannot currently be explained by mutations in protein-coding genes," says Visel. "Based on our studies in the mouse model, it is possible or even likely that in some of these cases mutations in enhancers play a role."
So perhaps rather than looking for mutations in the genes, we should be focusing on mutations in the enhancers that influence those genes.
"This will certainly help us to understand the underlying causes of these defects better, and will eventually help in the diagnosis, possibly also prevention or treatment of such conditions," says Visel.
Like a softly glowing robin's egg, the nucleus of a cultured kidney cell seems to lie in a nest of microtubules, as seen at 100-times magnification. The shot is among the spectacular entrants in this year's Nikon Small World competition, which since 1974 has recognised the best pictures taken using a microscope.
All cells with a membrane-bound nucleus also have microtubules – hollow filaments of protein that aid in various tasks, from cell division to locomotion. This surreal vision of a lab-grown monkey cell was submitted by Mariela Loschi of Buenos Aires, Argentina.
(Image: James Burchfield/Nikon Small World 2013)
Another image shows the explosive dynamics of sugar transport in fat cells, seen in a living cell thanks to a microscope technique called total internal reflection fluorescence. It was made by James Burchfield at the Garvan Institute in Sydney, Australia. Stay tuned for the contest winners, which will be announced 30 October, and in the meantime tour a gallery of our favourite shots from last year's competition.
All cells with a membrane-bound nucleus also have microtubules – hollow filaments of protein that aid in various tasks, from cell division to locomotion. This surreal vision of a lab-grown monkey cell was submitted by Mariela Loschi of Buenos Aires, Argentina.
(Image: James Burchfield/Nikon Small World 2013)
Another image shows the explosive dynamics of sugar transport in fat cells, seen in a living cell thanks to a microscope technique called total internal reflection fluorescence. It was made by James Burchfield at the Garvan Institute in Sydney, Australia. Stay tuned for the contest winners, which will be announced 30 October, and in the meantime tour a gallery of our favourite shots from last year's competition.
Nearly three percent of the world's oceans – an area slightly larger than Europe – now lies within designated marine protected areas, according to new data from the International Union for Conservation of Nature (IUCN). This is a significant increase from 2010 when the area protected was just 1.2 per cent. However, many of the new protected zones may be of little value in terms of conservation.
The IUCN, which yesterday released the latest official map of marine protected areas (MPAs), defines a protected area as "a clearly defined geographical space, recognised, dedicated and managed, through legal or other effective means, to achieve the long-term conservation of nature with associated ecosystem services and cultural values". In practical terms, this can mean implementing measures to restrict the amount of fishing and mineral exploitation that can take place in the waters, for example.
The rapid increase in coverage of MPAs means that the world should soon be able to meet the UN Convention on Biological Diversity target of having 10 per cent of the oceans protected. "It's encouraging to see the progress we've made so far," said Carl Gustaf Lundin, director of the IUCN's Global Marine and Polar Programme. "If we continue to increase this area by one per cent each year, we should be able to reach the agreed 10 per cent by 2020."
Antarctic talks
We may get even closer to meeting the target when the results of negotiations to create huge marine reserves around Antarctica – which would include some of the world's last remaining pristine waters – are announced next week. The MPAs being discussed in Hobart, Australia, would introduce a ban on fishing in the spawning areas of some species and put limits on the amount of fish caught elsewhere. If the proposals being discussed are agreed on, the global protected area will jump by about another percentage point.
But a preoccupation with the size of MPAs is counterproductive, says marine conservationist Bob Pressey from James Cook University in Townsville, Australia. "It's the wrong measure." He says conservation only occurs when a threat, such as species loss from overfishing or pollution, has been mitigated. Many of the protected areas do not enjoy sufficient enforcement.
The largest network of marine reserves in the world is around Australia, and was significantly added to in 2012. Pressey points out that many of those areas allow oil and gas exploration, while others allow recreational fishing.
Motivated by numbers
The focus on the 2020 target means governments are motivated to protect the low-hanging fruit – large areas that are of little conservation value or that are not under any threat, Pressey says.
"If you look at the no-take zones [off Australia], you find them way offshore in deep water and you find them in areas with no oil or gas interest," he says. "In the world map, we see a repetition of that. The big MPAs are remote as hell," he says.
Hugh Possingham from the University of Queensland, who together with Pressey built the open-source software that countries use to design MPAs, agrees. "We don't want countries just bragging about the size and percentages. There's more to this than size," he says. One important factor is that an example of each type of ecosystem in a country's waters should be protected, such as mangrove forests or salt marshes, but this effort is often perverted by commercial interests, he says.
Pressey says the Antarctic MPAs currently being negotiated would be a valuable addition because of the region's important biodiversity – the Ross Sea, for example, boasts orcas, minke whales, seals, Adélie and emperor penguins – and the threat the area faces from overfishing.
The IUCN, which yesterday released the latest official map of marine protected areas (MPAs), defines a protected area as "a clearly defined geographical space, recognised, dedicated and managed, through legal or other effective means, to achieve the long-term conservation of nature with associated ecosystem services and cultural values". In practical terms, this can mean implementing measures to restrict the amount of fishing and mineral exploitation that can take place in the waters, for example.
The rapid increase in coverage of MPAs means that the world should soon be able to meet the UN Convention on Biological Diversity target of having 10 per cent of the oceans protected. "It's encouraging to see the progress we've made so far," said Carl Gustaf Lundin, director of the IUCN's Global Marine and Polar Programme. "If we continue to increase this area by one per cent each year, we should be able to reach the agreed 10 per cent by 2020."
Antarctic talks
We may get even closer to meeting the target when the results of negotiations to create huge marine reserves around Antarctica – which would include some of the world's last remaining pristine waters – are announced next week. The MPAs being discussed in Hobart, Australia, would introduce a ban on fishing in the spawning areas of some species and put limits on the amount of fish caught elsewhere. If the proposals being discussed are agreed on, the global protected area will jump by about another percentage point.
But a preoccupation with the size of MPAs is counterproductive, says marine conservationist Bob Pressey from James Cook University in Townsville, Australia. "It's the wrong measure." He says conservation only occurs when a threat, such as species loss from overfishing or pollution, has been mitigated. Many of the protected areas do not enjoy sufficient enforcement.
The largest network of marine reserves in the world is around Australia, and was significantly added to in 2012. Pressey points out that many of those areas allow oil and gas exploration, while others allow recreational fishing.
Motivated by numbers
The focus on the 2020 target means governments are motivated to protect the low-hanging fruit – large areas that are of little conservation value or that are not under any threat, Pressey says.
"If you look at the no-take zones [off Australia], you find them way offshore in deep water and you find them in areas with no oil or gas interest," he says. "In the world map, we see a repetition of that. The big MPAs are remote as hell," he says.
Hugh Possingham from the University of Queensland, who together with Pressey built the open-source software that countries use to design MPAs, agrees. "We don't want countries just bragging about the size and percentages. There's more to this than size," he says. One important factor is that an example of each type of ecosystem in a country's waters should be protected, such as mangrove forests or salt marshes, but this effort is often perverted by commercial interests, he says.
Pressey says the Antarctic MPAs currently being negotiated would be a valuable addition because of the region's important biodiversity – the Ross Sea, for example, boasts orcas, minke whales, seals, Adélie and emperor penguins – and the threat the area faces from overfishing.
