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CAN CHIMPANZEES COOK FOOD?A new study suggests that humans’ cogni ve capacity for cooking is also shared by chimpanzees. This includes a preference for

cooked food, the ability to understand the transforma on of raw food into cooked food, and even the ability to save and transport

food over distance for the purposes of cooking.

The fi ndings suggest that those abili es emerged early in human evolu on, and that aside from control of fi re, chimps may

possess all the requisite cogni ve skills to engage in cooking. The study is described in

a June 3 paper in Proceedings of the Royal Society B.

“It is an important ques on when cooking emerged in human evolu on,” says

Felix Warneken, co-author with Alexandra Rosa from the Psychology Department at

Yale University. “If our closest evolu onary rela ve possesses these skills, it suggests

that once early humans were able to use and control fi re they could also use it for

cooking.”A number of earlier studies have hypothesized that cooking played a key role

in human evolu on by making food easier to digest and enabling early humans to

extract more energy from their diet. In trying to understand the evolu onary origins

of cooking, however, those earlier studies largely focused on what is clearly a cri cal

aspect of cooking – the control of fi re.

According to Warneken and Rosa , “Obviously, chimps can’t control fi re, but

we were trying to hypothesize about some of the other aspects of cooking, like the

causal understanding that if you put this raw food on the fi re it creates cooked food,

or at the extreme end of our study, the ability to plan. What’s par cularly interes ng

about cooking is it’s something we all do, but it involves a number of capaci es that,

even without the context of cooking, are thought to be uniquely human.”

To explore those ques ons, researchers presented chimps at the Jane Goodall

Ins tute’s Tchimpounga Chimpanzee Sanctuary in Republic of Congo with two devices

– a “cooking device” that turned raw into cooked slices and a “control device” that

le it unchanged. During the cri cal test, chimpanzees saw raw sweet potato go into

both, but had to choose one device before seeing its (possibly transformed) contents.

Warneken and Rosa explain that nearly every chimp reliably picked the cooking

device, sugges ng they quickly understood the transforma on that was at work.

It was the last experiment, however, that truly revealed chimps’ capacity for cooking. To their surprise, the researchers found

that a number of chimps, when given a raw piece of potato, chose to essen ally cook it by placing it in the “cooking device” and

receiving a cooked piece of food in return.

While the study supports the no on that cooking behavior emerged early in human history, Warneken and Rosa said it may

also suggest a new account for humans’ control of fi re. Though the assump on had long been that humans controlled fi re before

they began using it for cooking, Warneken and Rosa suggest that cooking may have given early humans a reason to control fi re.

“Why would early humans be mo vated to control fi re?” Rosa asked. “I think cooking might give you a reason. We know

wild chimps will observe natural fi re, and they even some mes seek out and eat cooked food le behind by it. The evidence from

our cogni ve studies suggests that, even before controlling fi re, early hominins understood its benefi ts and could reason about the

outcomes of pu ng food on fi re.”

ANIMAL CROSSINGS

NOTHING puts a damper on a road trip like an accidental collision with a deer. For Jochen Jaeger, a professor in Concordia University’s Department of Geography, Planning and Environment, improving roadkill preven on is best approached through experimenta on.

In a study recently published in the Journal of Environmental Management, Jaeger and a group of co-authors from interna onal universi es show that protec ng animals from speeding vehicles

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(Photo: Shadab Khan)

SCIENCE REPORTER, OCTOBER 2015 10

(www.npr.org)

SCIENCE REPORTER, OCTOBER 201511

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FINICKY CATS – THERE’S A REASON

CAT taste receptors respond in a unique way to bi er compounds

compared with human receptors, according to research published in

the open access journal BMC Neuroscience. The study represents the

fi rst glimpse into how domes c cats perceive bi erness in food at a

molecular level, and could explain why cats are some mes such picky

eaters.Domes c cats have a reputa on of being rather unpredictable

in their dietary choices. This could be explained by their percep on

of bi er, which diff ers from that of other mammals due to varia ons

in their repertoire of bi er receptors. It is the goal of many

pharmaceu cal and food manufacturers to iden fy compounds that

either block or alter bi er percep on, to create a more palatable

product.The teams at AFB Interna onal and Integral Molecular studied

the behavior of two diff erent cat bi er taste receptors in cell-based

experiments, inves ga ng their responsiveness to bi er compounds,

and comparing these to the human versions of these receptors.

TAS2R38 is a bi er taste receptor in humans of which some people

have ‘supertaster’ variants that give them an extreme sensi vity to

bi er compounds, explaining some people’s strong aversions to broccoli

and brussels sprouts.

Compared with the human TAS2R38 receptor, the cat version was

10-fold less sensi ve to a key bi er compound PTC and did not respond

at all to another bi er compound PROP.

Like its human counterpart, the cat bi er taste receptor Tas2r43

was ac vated by bi er compounds aloin (found in the aloe plant) and

denatonium (used to deter children and pets from consuming chemicals

such as an freeze) but responded diff erently to the compounds. The cat

receptor was less sensi ve to aloin and more sensi ve to denatonium

than the human receptor. It also diff ered from the human taste receptor

by being insensi ve to saccharin, an ar fi cial sweetener that tends to have a bi er a ertaste in humans.

The team also found that probenecid, a known inhibitor of human bi er taste receptors, also worked on both cat

taste receptors, preven ng s mula on when in the presence of PTC, aloin and denatonium.

The team says that these insights and further study could be instrumental in formula ng appe zing food for

household cats as well as designing masking agents to enhance the acceptability of medica ons.

(www.abc.net.au)

doesn’t have a one-size-fi ts-all solu on. Instead, a more detailed understanding of preven ve measures should be gained through scien fi c experiments.

The study looks at the key ques ons asked by road planners. The fi rst ques ons are the most fundamental: Does a certain type of crossing structure work be er than another? What type and size of crossing structures should we use? How many crossing structures are needed on a certain stretch of road?

“Now that preven ng roadkill has become a concern for both protec ng biodiversity and increasing driver safety, planners want to know what types of preventa ve construc ons will result in the least collisions possible — ideally, none at all,” says Jaeger. “It’s also important to see we can learn more eff ec vely about the features that can improve their performance.”

But with animals ranging from mice to moose, these mi ga on measures can’t be the same in all situa ons. Indeed, they should include a range of op ons, such as: • Animal detec on systems • Wildlife warning signs • Measures to reduce traffi c volume,

speed and/or noise • Temporary road closures • Wildlife crossing structures

• Wildlife fences and • Modifi ed road designs.

Making the right comparisons is

par cularly important when studying how well the measures work. For example, comparing diff erent types and sizes of crossing structures under similar condi ons, and inves ga ng the changes in road mortality when changes are made to the size of a par cular measure, e.g., an increase or reduc on of its width.

The study iden fi es a set of feasible experiments and recommends that researchers and road planners collaborate as early as possible in any given road project to implement the op on that will be the most informa ve, given the project’s constraints.

Does a certain type of crossing structure work better than another? What type and size of crossing structures should we use? How many crossing structures are needed on a certain stretch of road?

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SUSUMU Tonegawa and team at the Picower Ins tute of Learning, Massachuse s Ins tute of Technology have reported (Science, 29 May 2015, 348/6238;DOI: 10.1126/science.aaa5542) successfully bringing back memories that appeared to be lost forever but were hidden in the brain, ready to be reawakened with the right light signal. The scien sts’ experiments in mice hopefully would one day allow doctors to revive memories in pa ents suff ering from Alzheimer’s disease or amnesia.

It was believed that during the learning process neurons in the brain are able to reinforce their mutual connec ons so as to fi x las ng memories. The team managed to fi x a ‘label’ (known as learning-dependent cell labeling) onto neurons called ‘memory engrams’ in brain cells involved in forming a specifi c memory.

Through gene c engineering they modifi ed the brains of a set of mice to produce some extra neurons. As

OPAH – WORLD’S FIRST WARM-

BLOODED FISH!WE know that all fi sh are cold blooded. But Opah (Lampris gu atus), also known as the Moon Fish, has been found to be the one and only warm-blooded fi sh in the en re fi sh family. Opahs distribute warmed blood throughout the body including to the heart.

Dr. Nicholas Wegner et al. of the Southwest Fisheries Science Center run by the Na onal Oceanic and Atmospheric Administra on (NOAA) stumbled upon this unique warm-blooded feature of the fi sh which sets it apart from other fi sh. Their fi ndings have been published in the May 2015 issue of Science.

Scien sts from the NOAA discovered that Opahs, which are massive being almost the size of a car tyre, generate heat as they swim in the cold waters of the twilight zone of the ocean. The fi sh appears to produce the heat by constant fl apping of its pectoral fi ns. The heat is distributed throughout their unique or special disc-shaped body by means of special blood vessels. A special “counter-current heat exchanger” in their gills minimises heat loss, allowing these master predators of the deep

RETRIEVING LOST MEMORIES WITH LIGHT!memory is formed when neurons fi re they release red colored proteins that can be seen under a microscope, allowing the researchers to tell which cells were part of the engram. They also inserted a gene that made the neurons to fl ash up when lit by blue laser light. This technique is known as optogene cs in which the brain’s hippocampus region is s mulated by laser light.

The mice were fi rst given a mild electric shock when they entered a chamber so that they learnt to fear it and avoid it in future. Some selected mice were then administered a drug that prevented the neurons from forming strong connec ons. This made the mice to forget any link between the chamber and an electric shock. The scien sts were therefore able to induce in the mice, amnesia or loss of memory.

The red proteins were used as indicators by the team to fi nd out which neurons had been involved in storing the ‘fear’ memory in the mice. Using

blue light they managed to reac vate these par cular ‘fear’ neurons. When the memory engram was reac vated the mice recalled their ‘fear’ and avoided the chamber as before.

These fi ndings suggest that once the mice learned a task, a trace of that memory remains hidden in the brain. The human tendency is to think that we have completely ‘forgo en’ something as we are unable to access it or retrieve it. These hidden memories can now be retrieved.

Many persons have experienced suddenly recalling something, which they had once completely forgo en, when they get a signal or ‘cue’ like seeing something or hearing a sound or smelling some scent. This is similar to data on hard discs Some selected mice were administered a drug that prevented the neurons from forming strong connections. This made the mice to forget any link between the chamber and an electric shock.

The massive Opah being netted (Picture credit: NOAA

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oceans to keep their body temperature above the water temperature prevailing in the twilight zones.

According to the researchers, the pectoral fi ns of the Opah were found to be well-insulated by a thick layer of fa y ssue and the constant fl apping helped it to trap the warmth. The fi sh uses this heat to keep its heart, brain and other organs warm while it swims to cold depths of hundreds of meters.

The design of the Opah’s gills was described to be somewhat similar to that of a car’s radiator. When blood is pumped into the gills to collect oxygen loss of heat is minimised by a dense intertwined network of blood vessels called a rete mirabile, which is La n for “a wonderful net”. At the surface of the gills, blood picks up oxygen and loses warmth. But as it passes back through the sponge like rete mirabile it regains some heat from the s ll warm blood arriving from the fi sh’s body.

The scien sts came to this amazing discovery of the Opahs unusual internal system a er analysing samples of gill ssues of fi sh caught off the coast of USA.

This unique “whole body endothermy” of the Opahs results in the fi sh being a fast swimmer, having a be er vision and a quick response system compared to other fi sh that thrive in the deep cold water of the ocean. The Opahs have an edge in be er survival chances and since it can warm its body it is a be er and effi cient predator and can even zero in and catch quick swimmers like the squid. It can also migrate long distances.

The Opah does not swim in schools and is found in the oceans off the USA, Australia and few other countries. They are a huge and colourful fi sh having an average weight of 90 kg. Some Opahs are said to weigh a massive 270 kg! It has a diameter of 3 feet and it can some me grow up to 6 feet long.

Contributed by Mr Shakunt Pandey, Address: ‘Lake Utsav’, P-331 Parnashree Pally, Flat No. 3A, 3rd Floor, Kolkata-700060; Email: shakuntpan33@gmail.com/shakunt_soumya@rediffmail.com

The Opah (Picture credit: NOAA)

and fl ash memories that just remain even a er they have been ‘forma ed’. The data

can be later retrieved using sophis cated so ware.

The researchers also report that mice which were not injected with the “forge ulness drug” developed stronger connec ons between neurons in the memory engram. In the case of the mice given the drug, their neuron connec ons were not any stronger than connec ons that exist between neighboring cells that were not involved in storing the memory. The researchers suggest that strengthened neuronal connec ons are not essen al for forming new memories but might be important for retrieving memories.

This research would help people suff ering from amnesia and those pa ents in early stages of Alzheimer’s disease by reac va ng their brain cells. The scien sts hope they can help these people before brain ssues deteriorate and develop into demen a. The same technique may one day be used to help people suff ering from trauma c shock leading to temporary amnesia or memory loss in an accident.

Contributed by Haridas Panicker, Panapallil, Koipuram PO-689531, Pathanamthitta District, Kerala; Email: omharisai@gmail.com

Opahs, which are massive being almost the size of a car tyre, generate heat as they swim in the cold waters of the twilight zone of the ocean. The fi sh appears to produce the heat by constant fl apping of its pectoral fi ns.

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