Genetic research is showing that certain types of crickets that live entirely in caves (in the Southern US) are more genetically diverse than their cousins who venture to the surface to forage.
It seems like this should be the other way around, since the foraging crickets are traveling more in the caves and out of the caves.
“The main issue is that Ceuthophilus leaves the cave to forage at night, whereas Geotettix doesn’t. That led us to hypothesize that perhaps Ceuthophilus was better at dispersing and might not show as much genetic structure,” said Jason Weckstein, PhD, associate professor in the Department of Biodiversity, Earth and Environmental Science at Drexel University’s College of Arts and Science. “In fact, what we found was the Ceuthophilus showed deeper — older — structure than Geotettix.”
The crickets in the study live in a variety of caves in central Texas, from which the team collected specimens and then analyzed their DNA.
Ceuthophilus are known to be trogloxenes, meaning that they live parts of their lives in caves. Species in the Ceuthophilus sub-genus lay their eggs and spend the day in caves but come out to forage at night.
Geottetix, meanwhile, are troglobites, which means that they spend all of their lives deep in caves. The team wrote that Geotettix have almost never been recorded on the surface outside a cave entrance.
Researchers have found a blind cavefish that can climb waterfalls. No, I am not making this up. The New Jersey Institute of Technology featured this story.
This research is reported in a March 24 Nature Scientific Reports article, “Tetrapod-like pelvic girdle in a walking cavefish,” by Brooke Flammang, Daphne Soares, Julie Markiewicz and Apinun Suvarnaraksha. Flammang and Soares, assistant professors in the NJIT Department of Biological Sciences, were assisted with the research by Markiewicz, an NJIT post-baccalaureate research volunteer in the Flammang lab at the university. Investigator Suvarnaraksha is a member of the Faculty of Fisheries Technology and Aquatic Resources of Maejo University in Thailand. The full text of their article is available at www.nature.com/articles/srep23711.
Flammang studies fish locomotion at the New Jersey Institute of Technology, so she’s used to seeing fish moving on land. She wasn’t surprised to see one that could push itself over rocks and through water gushing like a fire hose. But other “walking” fish hop forward by leaning on their pectoral fins like a pair of crutches, or flex and shimmy to wriggle over surfaces. This one was taking steps, moving one of its front fins in time with the back fin on the other side of its body, alternating in a diagonal two-step like a salamander. Flammang was incredulous. “I was like, ‘Fish can’t do that,’” she says. “That’s ridiculous.”
Climate change and spreading bat populations; what a topic! Europe is experiencing a impressive spread of the Kuhl’s pipistrelle and they think changing climate is increasing it’s habitable territory. Springer has the report:
The team collected 25,132 high-resolution records of where the bat occurred in Europe between 1980 and 2013. These were used in conjunction with various models to predict whether the colonisation of new areas over the years has been prompted by increased urbanisation or by changes in the climate.
When first recorded, Kuhl’s pipistrelle was typically found over large areas of North Africa, southern Europe and Western Asia. In southern Europe its distribution was originally confined to the Mediterranean basin. It extended east to the Balkans, west to the Iberian Peninsula and north to the Alps and western France. By the 1980s, the bat was also reported in northern France and Bulgaria. Slowly but surely it has spread to other countries, including the United Kingdom to the north and eastern regions such as the Czech Republic, Slovakia, Ukraine, Hungary, Romania, Bulgaria, Serbia and Poland.
Remains discovered in Qesem Cave, near Tel Aviv, shows that early humans had a taste for turtles.
Tel Aviv University researchers, in collaboration with scholars from Spain and Germany, have uncovered evidence of turtle specimens at the 400,000-year-old site, indicating that early man enjoyed eating turtles in addition to large game and vegetal material. The research provides direct evidence of the relatively broad diet of early Paleolithic people — and of the “modern” tools and skills employed to prepare it.
The research team discovered tortoise specimens strewn all over the cave at different levels, indicating that they were consumed over the entire course of the early human 200,000-year inhabitation. Once exhumed, the bones revealed striking marks that reflected the methods the early humans used to process and eat the turtles.
Research into how bats’ brains filter noise show that they are super good at sifting through a sea of sound, and focusing on their own chirp echoes.
“With so many stimuli in the world, the brain needs a filter to determine what’s important,” said Melville J. Wohlgemuth, the lead author and a postdoctoral fellow in the Krieger School of Arts and Sciences’ Department of Psychological and Brain Sciences. “The bat brain has developed special sensitivities that allow it to pick out sounds from the environment that are pertinent to the animal. We were able to uncover these sensitivities because we used the perfect stimulus — the bat’s own vocalizations.”
The researchers experimented with five big brown bats, playing them a variety of sounds while monitoring their midbrain activity. They played recordings of natural chirps, the actual sounds bats made as they hunted. They also played artificial white noise and sounds between the two extremes. All of the sounds were identical in amplitude, duration and bandwidth.
Although sensorimotor neurons in the bat midbrain reacted to all of the sounds, the neurons involved in stimulus selection, those that guide orienting behaviors, responded selectively to a subset of the natural chirps.
Inspired by the blind cave fish, researchers at the Singapore-MIT Alliance for Research and Technology (SMART) [新加坡-麻省理工学院科研中] have developed Micro-Electro-Mechanical Systems (MEMS) flow sensor so tiny and sensitive that it can be implanted into the IV or intravenous set-up, to aid in regulating the velocity of the fluid flow with minimal intervention by the nurses, thereby reducing their workload while increasing their productivity by 30%; and significantly decreasing the complications of drug infusion via IV therapy. These sensors can also be incorporated into marine underwater robots, lending them sensitivities to wakes, akin to the blind cave fish itself, so that the robots can manoeuvre in a highly energy-efficient manner.
This release has made waves in the news: bat wings influencing the creation of new drones:
A team of researchers led by Professor Bharathram Ganapathisubramani at the University of Southampton, in England, have been experimenting with adjustable bat-inspired membrane wings that also vibrate as air passes over them. They’ve mounted these wings onto a micro air vehicle that uses them (along with ground effect) to zip across water fast and efficiently.
These membrane wings aren’t just flexible, they’re also controllable. They incorporate electroactive polymers that respond to voltage by changing the wing’s stiffness, allowing you to dynamically adjust the wing shape and “dramatically” altering their performance.
Read the full article at Creative Planet Network. Be warned, I am using Safari and had a lot of trouble getting the article to scroll correctly.
In my underground wanderings I have on one occasion stumbled upon what we believed to be hydrosulfuric acid. It is pretty nasty stuff. The room, deep in a mine, was eerily decorated with odd formations and crystalline growths, and had pools of blood red liquid on the floor. We discovered several dead bats and decided to get out of there, though our gas detector was not reading anything out of the ordinary.
A 10 year study has just discovered some answers about how organisms can live in these harsh conditions. For example, the Atlantic Molly.
The tiny Atlantic molly can live in small puddles of toxic or nontoxic water. Using genomic tools, the researchers compared gene expression of the mollies living in toxic hydrogen sulfide environments with those mollies living in nontoxic environments just a few yards away.
They found that the fish have a two-pronged approach to survival: They become inert to the toxins that enter the body and they are able to detoxify hydrogen sulfide more efficiently.
Hydrogen sulfide shuts down energy production in cells by interfering with specific proteins. The fish combat this challenge by using anaerobic metabolism, which is an alternative — although much less efficient — way to produce energy and does not involve oxygen.
The scientists found that about 170 of the fish’s 35,000 or so genes were turned on, or upregulated, to detoxify and remove the hydrogen sulfide. The poison invades the fishes’ bodies, but their changed proteins help the fish break down the hydrogen sulfide into nontoxic forms and excrete it.
Two new hominin fossils have been found in a previously uninvestigated chamber in the Sterkfontein Caves, just North West of Johannesburg in South Africa.
The two new specimens, a finger bone and a molar, are part of a set of four specimens, which seem to be from early hominins that can be associated with early stone tool-bearing sediments that entered the cave more than two million years ago.
“The specimens are exciting not only because they are associated with early stone tools, but also because they possess a mixture of intriguing features that raise many more questions than they give answers,” says lead researcher Dr Dominic Stratford, a lecturer at the Wits School of Geography, Archaeology and Environmental studies, and research coordinator at the Sterkfontein Caves.
– See more at: http://www.wits.ac.za/news/latest-news/research-news/2016/2016-02/sterkfontein-caves-produce-two-new-hominin-fossils.html#sthash.dNY2KWcH.dpuf