Twin Studies

1. Write 1-2 paragraphs explaining:
What is a twin study?

Why are they conducted?

How are they conducted?
2. Write a 2-3 paragraph summary of a twin study that you find through internet research.
Who conducted it?

Briefly explain the procedure and who was used as participants.

What were the conclusions?

Were there any problems or limitations with this study?

3. Write a 2-3 paragraph summary of another twin study that you find through internet research.

Who conducted it?

Briefly explain the procedure and who was used as participants.

What were the conclusions?

Were there any problems or limitations with this study?







You can turn this in handwritten or typed. If you would like, you can e-mail your answers to me at: bdougherty@amschool.org

Are Animals People?


by Dave Munger

The recent fatal attack of a SeaWorld trainer by the orca Tilikum has led to renewed questions about how humans should deal with potentially intelligent animals. Was Tilikum’s action premeditated, and how should that possibility influence decisions on the animal’s future treatment? Orcas, like their close relatives, dolphins, certainly seem smart, though researchers debate just how intelligent these cetaceans are and how similar their cognition is to humans. Should we ever treat such creatures like people? For centuries it seemed obvious to most people what separated them from other animals: Humans have language, they use tools, they plan for the future, and do any number of things that other animals don’t seem to do. But gradually the line between “animal” and “human” has blurred. Some animals do use tools; others solve complicated problems. Some can even be taught to communicate using sign language or other systems. Could it be that there isn’t a clear difference separating humans from other life forms? Last week, Brian Switek, a science writer who blogs about biology and paleontology, found a study demonstrating that tool use in chimpanzees isn’t a new phenomenon. For decades, scientists have been observing chimps using sticks and other objects as tools. They have even seen chimps modifying these tools and transporting them for anticipated use in the future. But until recently, there had been no evidence that tool use among chimps had a very long history. Wild chimpanzees in the Tai National Park in Côte d’Ivoire have been observed using stones as hammers and anvils for cracking large nuts. A team led by archaeologist Julio Mercador found evidence that these tools were being used as long as 4300 years ago: Ancient stones shaped similarly to those being used today as tools. Their research was published in PNAS in 2007. ©2005-2009 Seed Media Group LLC

Picking our brains: Why are some people smarter?


by David Robson

At Einstien's autopsy in 1955, his brain was something of a disappointment: it turned out to be a tad smaller than the average Joe's. Indeed, later studies have suggested a minimal link between brain size and intelligence. It seems brain quality rather than quantity is key. One important factor seems to be how well our neurons can talk to each other. Martijn van den Heuvel, a neuroscientist at Utrecht University Medical Center in the Netherlands, found that smarter brains seem to have more efficient networks between neurons - in other words, it takes fewer steps to relay a message between different regions of the brain. That could explain about a third of the variation in a population's IQ, he says. Another key factor is the insulating fatty sheath encasing neuron fibres, which affects the speed of electrical signals. Paul Thompson at the University of California, Los Angeles, has found a correlation between IQ and the quality of the sheaths (The Journal of Neuroscience, vol 29, p 2212). We still don't know exactly how much genes contribute to intelligence, with various studies coming up with estimates ranging from 40 to 80 per cent. This wide range of estimates might have arisen because genes contribute more to IQ as we get older, according to a study published last year. By comparing the intelligence of 11,000 pairs of twins, Robert Plomin of King's College London found that at age 9, genes explain 40 per cent of the variation, but by 17 they account for roughly two-thirds (Molecular Psychiatry, DOI: 10.1038/mp.2009.55). © Copyright Reed Business Information Ltd.

Clever Crows, Complex Cognition?
by Gisela Telis

Called “feathered apes” for their simianlike smarts, crows use tools, understand physics, and recognize themselves and humans. But new research suggests that the brainy birds may be even smarter than was previously thought. Given a complex problem and an assortment of tools, New Caledonian crows came up with a creative solution that hints at higher-order thinking. A native of New Caledonia and the Loyalty Islands in the Pacific Ocean, the New Caledonian crow makes tools from sticks or leaves and uses these to draw tasty grubs from hollows in trees. That in itself wouldn’t be so impressive—even some insects use tools this way—but the crows also combine tools when they needed to. In a 2007 experiment conducted by graduate student Alex Taylor and colleagues at the University of Auckland in New Zealand, the crows used a shorter stick to grab another that was long enough to get food outside their reach. This kind of action seems to indicate insight or reasoning. But not everyone was convinced, says Taylor. “Some scientists suggested the tools became valuable in themselves because they were associated with food,” he says. That would mean the birds sought each stick because they wanted it, not because they understood the stick’s potential function. The distinction, although subtle, marks the difference between high- and low-level learning, and it speaks to a central question of cognition research: How do you determine whether an animal is thinking through its actions, or simply learning through association a series of behaviors and combining them? © 2010 American Association for the Advancement of Science

Brain research brings wonders and worries

By Judith Horstman

What ethical concerns will arise from new technology and medicine that can reveal our thoughts and enhance our brains?

Back in the 1980s a young Congressman from Tennessee named Al Gore was chairman of a subcommittee on science and technology. That oversight and investigations subcommittee was wrestling with troublesome questions surrounding organ transplantation. A new anti-rejection drug, cyclosporine, had raised survival rates for recipients to 80 percent, a tremendous advance in life-saving medical technology that resulted in a massive demand for donor organs – already in short supply – and set off a flood of legal, moral and ethical issues. Kidneys were being sold and bought from living donors, the wealthy were getting to the head of waiting lists after making huge donations to hospitals, and desperate parents were launching media campaigns for hearts, livers and lungs for their dying children. In the most notorious and bizarre case, a baboon heart was transplanted into a 7-month-old infant, Baby Fae, who did not survive. Gore's subcommittee waded into this morass and produced landmark legislation: The National Organ Transplant Act prohibited the sale of human organs and set up a policy and structure for allocation of donor organs. More legislation followed and so did more bioethical issues, such as those involving embryonic stem cells, gene therapy, and the ownership of your own body tissue and genes – and foreshadowed the increasingly complex ethical issues to come. © Copyright The Sacramento Bee.