A new study suggests that whales and hippos had a common ancestor that was likely a land mammal

Hippos, whales, dolphins, and porpoises are all related but their skin evolution isn’t because of a shared ancestor…

In April, the American Museum of Natural History published a remarkable study in Current Biology about the “aquatic skin adaptations of whales and hippos” and how they actually evolved independently rather than through a “shared amphibious ancestor”.

Titled “Genomic and anatomical comparisons of skin support independent adaptation to life in water by cetaceans and hippos“, the paper analysed both cetaceans (whales, dolphins, and porpoises) and hippos’ skin and discovered 8 inactivated genes but none of them shared inactivating mutations. This suggests their adaptations to aquatic life were independent of each other.

“When you look at the molecular signatures, there is a striking and clear answer,” said study co-corresponding author and evolutionary genomicist Michael Hiller, from the Max Planck Institute of Molecular Cell Biology and Genetics and the LOEWE-Centre for Translational Biodiversity Genomics in Germany. “Our results strongly support the idea that ‘aquatic’ skin traits found in both hippos and cetaceans evolved independently. And not only that, we can see that the gene losses in the hippo lineage happened much later than in the cetacean lineage.”

This throws out the idea that hippos and cetaceans had an ancestor that gave them skin that helped them live in the water completely (cetaceans) and semiaquatically (hippos).

The mysterious migrations of North Pacific loggerhead turtles

A marine biology unknown has been revealed.

SchTechDaily investigated the migrations of loggerhead turtles from the North Pacific in April:

North Pacific loggerhead turtles’ years-long oceanic journeys remain poorly understood. Using data from satellite tracking and other techniques, scientists reveal a unique phenomenon that may explain the endangered migrants’ pathway.

Known as “the lost years,” it is a little-understood journey that unfolds over thousands of miles and as much as two decades or more. Now, a Stanford-led study illuminates secrets of the North Pacific loggerhead turtles’ epic migration between their birthplace on the beaches of Japan and reemergence years later in foraging grounds off the coast of Baja California. The study, published April 8 in Frontiers in Marine Science, provides evidence for intermittent passages of warm water that allow sea turtles to cross otherwise inhospitably cold ocean barriers. The findings could help inform the design of conservation measures to protect sea turtles and other migratory sea creatures amid climatic changes that are altering their movements.

Loggerhead turtles are the most abundant species of sea turtle in the United States but globally, they are otherwise threatened or endangered. They can live between 70 to 80 years with female loggerheads reaching maturity at about 35.

NOAA Fisheries has a great page on loggerhead turtles and how you can help to conserve their species.

The radioactive boar-pigs of Fukushima

Piggin’ hell!

I think the best word to describe this is “wild”. There are radioactive boar-pig hybrids living and thriving on the island of Fukushima.

ON MARCH 11, 2011, a magnitude 9.0 earthquake — the largest ever recorded in Japan — generated a tsunami that devastated the island nation. The tsunami also triggered an accident at a nuclear reactor in the Fukushima region of Japan, leading to the evacuation of 164,000 residents within a 20-kilometer radius of the reactor.

Among the evacuees were pig farmers who left their swine behind — fleeing from the threat of nuclear radiation.

According to research published Wednesday in the journal Proceedings of the Royal Society B, the absence of humans and the sudden release of pigs into the wild led to new boar-pig hybrids that are now reclaiming Fukushima — though researchers don’t know if these hybrids will last in the long run.

A similar thing has happened in Chernobyl where wolves and elk are living in the radioactive zone and new plants are growing where people can no longer live. This goes to show how resilient nature can be despite humanity’s best efforts to destroy it. But there’s a catch: what happens when people go back to Fukushima?

The eventual return of humans to Fukushima will likely challenge the boars’ ability to roam freely as well, potentially putting an end to the boars’ free reign over the land.

“We do not expect these adaption changes in boar, likely caused from the absence of people, to maintain in populations especially as [human] disturbance returns,” Anderson says.

For now, this sounder will continue to pillage and roam — as humans consider whether or not they are ready to return to the region they were forced to abandon.

Reminds a little of the cocaine hippos of Colombia.

Marine ecology has dark fish

What lies beneath… who knows?

It started with a tweet:

Imagine if ornithology was like physics where we had some sort of "dark birds" that represent 95% of all birds but we just had no way to detect them besides the effect they have on other birds.

And a follow up from Dr Andrew Thaler, deep-sea ecologist and population geneticist:

There's a globe-spanning layer of mesopelagic fish that is so dense it distorts SONAR. For decades we had no idea what created the Deep Scattering Layer or why it moved. We still know almost nothing about it.  It contains 65% of all fish biomass.  Marine Ecology has Dark Fish.

Now, I’ve written about a different kind of dark fish known as “vantafish” but these dark fish are extra special. According to Dr Thaler and this post from Phys.org, 65%–95% of all fish biomass may hide in a mesopelagic zone, an area between 100–1000m below the surface.

Professor Carlos Duarte, a marine biologist and Distinguished Professor at the King Abdullah University of Science and Technology, led a seven-month team circumnavigation of the globe collecting echo-soundings of mesopelagic fish where he found that they were able to detect nets from at least five metres making catches for biomass calculations difficult, hence the wide estimates.

(h/t @PublicStilli)

Study shows alligators can regrow their tails

Researchers hope their findings will help lead to discoveries of new approaches to repairing injuries and treating diseases in alligators.

Tl;dr: can alligators regrow their tails? Yes. Well, some of it.

According to a team of researchers from Arizona State University and the Louisiana Department of Wildlife and Fisheries, juvenile American alligators have the ability to regrow their tails up to 18% of their total body length.

An interdisciplinary team of scientists used advanced imaging techniques combined with demonstrated methods of studying anatomy and tissue organization to examine the structure of these regrown tails. They found that these new tails were complex structures with a central skeleton composed of cartilage surrounded by connective tissue that was interlaced with blood vessels and nerves. They speculate that regrowing their tails gives the alligators a functional advantage in their murky aquatic habitats.

In terms of what determined the length of regrowth, the team advised variations depended on “sex, age, or environment” due to reptiles being ectotherms and that “tail repair with regrowth in the alligator is a prolonged process.”

Overall, this study of wild-caught, juvenile American alligator tails identifies a distinct pattern of wound repair in mammals while exhibiting features in common with regeneration in lepidosaurs and amphibia.

Read and download the full paper on the Scientific Reports website.