American Science Idol

A discussion on stress, neurodegeneration and individual differences led by Dr. Robert Sapolsky from the department of biological sciences at Stanford University.

What our genes tell us

This article by Malcolm Ritter address some interesting points when considering they “why” and “how” of cognitive differences between humans and animals.

Humans and chimps have evolved separately since splitting from a common ancestor about 6 million years ago, and their DNA remains highly similar — about 96 percent to almost 99 percent identical, depending on how the comparison is made.

Still, the number of genetic differences between a human and a chimp is about 10 times more than between any two humans, the federal genome institute says. It’s the differences — some 40 million — that attract the attention of scientists.

Scientists like Svante Paabo of the Max Planck institute for Evolutionary Anthropology who is quoted as saying

“I’m still sort of taken aback by how similar humans and chimps are” in their DNA. “I’m still amazed, when I see how special humans are and how we have taken over this planet, that we don’t find stronger evidence for a huge difference in our genomes.”

Geniuses everywhere

I’ve recently seen two programs on TV, “Ape Genius” and “Dog Genius” that examine animal intelligence and compare it with human capabilities. 

Check out this National Geographic video about a dog and his peculiar habits.

An article in Animal Cognition details and experiment conducted at the University of Vienna to investigate the performance of different species

 The ability to reason by exclusion (which is defined as the selection of the correct alternative by logically excluding other potential alternatives; Call in Anim Cogn 9:393–403 2006) is well established in humans. Several studies have found it to be present in some nonhuman species as well, whereas it seems to be somewhat limited or even absent in others. As inconsistent methodology might have contributed to the revealed inter-species differences, we examined reasoning by exclusion in pigeons (n = 6), dogs (n = 6), students (n = 6), and children (n = 8) under almost equal experimental conditions. After being trained in a computer-controlled two-choice procedure to discriminate between four positive (S+) and four negative (S?) photographs, the subjects were tested with displays consisting of one S? and one of four novel stimuli (S?). One pigeon, half of the dogs and almost all humans preferred S? over S?, thereby choosing either by novelty, or by avoiding S? without acquiring any knowledge about S?, or by inferring positive class membership of S? by excluding S?. To decide among these strategies the subjects that showed a preference for S? were then tested with displays consisting of one of the S? and one of four novel stimuli (S??). Although the pigeon preferentially chose the S?? and by novelty, dogs and humans maintained their preference for S?, thereby showing evidence of reasoning by exclusion. Taken together, the results of the present study suggest that none of the pigeons, but half of the dogs and almost all humans inferred positive class membership of S? by logically excluding S?.

Man vs Ape - social complexities

An interview with Rebecca Saxe, a cognitive scientist at MIT, sheds light on   humans’ unique ability to teach and interest passing along cultural knowledge and how it compares with other social animals.

Q: Is it true that there might be a brain region dedicated to this coordinating of two minds?

Saxe: Well, what we do know is that there are definitely regions in the human brain that seem to play special roles in social cognition—in seeing and thinking about other people. And different parts of your brain get involved in coordinating and reasoning about different kinds of social tasks. It appears that this kind of cooperation recruits a very specific part of your brain, right behind the middle of your forehead.

In the last five years, there’s been a huge explosion of research with new tools, new imaging tools, that make it possible to study the living, thinking human brain. And that’s allowed us to study the brain basis of all kinds of things that are uniquely human.

Bonobo whisperer

A video on NOVA’s website tells the story of Kanzi, a bonobo who learned and understands English without ever being directly taught language skills. The  27 year-old bonobo communicates with researchers at the Great Ape Trust in Iowa using lexigrams, or symbols representing words.

If there were a superstar within the bonobo community, Kanzi, which means “treasure” in Swahili, would certainly be it. Born in 1980, Kanzi came to Georgia State University’s Language Research Center at the age of six months. He is regarded as the first ape to demonstrate real comprehension of spoken speech.

Kanzi has been presented with a variety of carefully controlled tests which demonstrate his comprehension of speech. In these tests, spoken words are presented through headphones and Kanzi is requested to indicate the real object, the photo or the lexigram that the word represents. He is essentially 100 percent accurate on all words that are a part of vocabulary at any given age. Today, his vocabulary includes more than 500 words! His comprehension of spoken language is at least equivalent to that of a two-and-a-half-year-old child.

Kanzi’s achievements are not limited to language, but include tool use and tool manufacturing. Kanzi has shown skills as a stone tool maker and he is very proud of his ability to flake Oldowan style cutting knives. He learned to do this from Dr. Nick Toth, an anthropologist with The Stone Age Institute in Bloomington, IN. Kanzi’s stone knives are very sharp and he’s able to cut hide and thick ropes with them. He has also demonstrated his unspecified and musical skills, having played with Sir Paul McCartney and Peter Gabriel.

Dog Manners

Neuroscience

image courtesy of AJ Gazman

Using animal examples is a great way to explain biology and other scientific principles to children.  Elephants seem to be especially captivating to children, perhaps due to their gigantic size or unique anatomy. 

A little series published by the University of Washington “Neuroscience for Kids” uses findings from a recent study that suggest elephants are able to distinguish between different ethnic groups in Kenya as a way to introduce neuroscience and includes some other interesting facts.

The total surface area of the African elephant cerebral cortex is 6,300 square cm. The surface area of the human cerebral cortex is 2,500 square cm

Cerebral cortex is the outer layer of the cerebral hemispheres in the brain that controls conscious experience and is responsible for perception, emotion, thought, and planning.

Novel ways elephants communicate

photo courtesy of  Greg George

It is believed that elephants use low frequency signals transmitted through the ground as a means of communication.  A current theory is that elephants are able to sense the vibrations through pressure-sensitive nerve endings, Pacinian corpuscles, in their feet and —Meissner’s corpuscles that detect infrasonic vibrations - in the tip of their trunks.

 Scientists Katy Payne, Joyce Poole and their colleagues discovered that elephants emit a variety of infrasounds—calls too low in pitch to be heard by most humans. In 1989, Payne and her colleagues conducted a landmark experiment at a waterhole in Etosha demonstrating that these powerful infrasonic rumbles contain specific messages that can be heard and understood by other elephants more than 2 miles away.

This article contains information on the progression of seismic communication research in elephants and evidence supporting the idea that elephants use low frequency signals to communicate a variety of information from predator warnings to reproductive cues.

Elephants on the pill

Actually more of a vaccine, contraception for elephants is a proposed alternative to killing elephants in order to maintain and control population growth.

Research efforts are ongoing to determine the best approach for delivering contraceptives and what type should be used.  There are many considerations, like not repeatedly disrupting elephant groups, creating situations that are very stressful for the elephants, the safety of people administering the contraceptive and costs associated with treatment.

An abstract from an article published in the Journal of the South African Veterinary Association summarizes a current project:

The goal of programmes to provide contraception for elephants should be to formulate an approach that does not require the relocation or immobilisation of the same individual year after year, which would be long-lasting and cause minimal disruption to social and reproductive behaviour. The programmes should be simple to administer, safe and cost-effective, and must meet the objectives defined by managers in the field. An immunocontraceptive programme was initiated in a small free-roaming population of elephants at the Greater Makalali Private Game Reserve in Limpopo Province in 2000 to determine whether the porcine zona pellucida (pZP) vaccine can successfully control population sizes. Further objectives were to determine implementation costs and efficiency through a multi-faceted approach. We have demonstrated that immunocontraception meets the objectives set by managers in the field. Minimal social disruption was observed over the course of treatment, with the mode of delivery (ground or aerial vaccinations) determining the degree of stress within herds and speed of resumption of normal movement patterns. Aerial vaccinations resulted in the least disturbance, with target herds being approachable within a day. In 2005, implementation costs were R880-R1000/elephant/year, inclusive of darts, vaccine, helicopter and veterinary assistance. Irrespective of the source or method of vaccine delivery, a non-pregnant elephant is rendered infertile from 1st vaccine administration. The sooner immunocontraception is implemented, the sooner population growth rates can be controlled. pZP contraception is a realistic alternative management tool, particularly if used as part of a long-term management strategy. Mass-darting from the air eliminates the need for detailed individual histories of each elephant or for employing a person to monitor elephants. Thus, implementation of immunocontraception in larger populations is feasible and practical.

 This excerpt from an article in the Journal of Development of Biologicals sheds some light on how the contraceptive works

Of the many targets for such vaccines, several sperm-associated antigens have been proposed for antibody-mediated intervention before fertilization but the very abundance of antigen to be neutralized has been a barrier. Zona pellucida antigens associated with the surface of the oocyte have also been targeted and used successfully for control of ‘wild’ elephant populations but worries concerning immunopathologically-mediated tissue damage have been mooted

 This link provides more information on some of the research into the vaccine’s effectiveness.

Okay to hunt elephants?

photo coutesy of Brian Snelson  

Successful conservation efforts are resulting in new problems as the swelling number of elephants may exceed what parks can support.  The South African government recently lifted the ban on killing elephants as a last resort in controlling the population.  According to an article in the Guardian

Amid words of protest and expressions of relief environment minister Martinus van Schalkwyk announced the elephant had been a victim of its own success with numbers growing from 8,000 to nearly 20,000 in national parks and private reserves in just over a decade.

 Supporters of culling point to growing difficulties in managing elephants in the country’s biggest and most famous game reserve, Kruger National Park. It has more than 12,500 elephants, 5,000 more than is sustainable, according to park officials. Ecologists say the animals’ huge appetites and fondness for “habitat re-engineering” - reducing forests to flatland by uprooting trees and trampling plants as they feed and roam - threaten the park’s biodiversity. 

However, elephants endear a lot of support from South Africans and the rest of the world because of their perceived gentle nature and the strength of their social bonds.  Some conservation groups, and animal rights advocates oppose lifting the restriction and approaching the situation as a numbers game.

Michele Pickover of Animal Rights Africa, which has threatened to urge a tourist boycott if culling goes ahead, said there was no scientific proof that the killing of elephants was necessary or even effective in controlling the population.

“This is a sad day for the country. Elephants are being treated as commodities by the government and game managers,” she said.

This article from National Geographic in 2004 gives more background on the debate, which has been going on for years and has included the voices of many different groups:  parks managers, game rangers, academics, community leaders, and the representatives of animal rights groups.