A 1940s psychologist named Robert Tryon wondered if rats could be bred to complete a maze more competently, and after seven generations of selective breeding he succeeded. That classic experiment is still shaping our thinking about the age-old question of nature versus nurture when it comes to human intelligence and behavior.
The real problem with eugenics and selective breeding is that you are by necessity limiting your gene pool and therefore genetic diversity. While you are able to breed for select desired traits you often also get traits that you don’t want.
Even if you can keep from getting any undesired traits your new breed will lack the genetic diversity of the old breed. This means that an environmental or biological factor (like a virus) has a higher chance of being able to wipe out the whole of the new breed. Genetically diverse populations are more resilient against extinction because their genetic diversity makes them more adaptable as a group.
Many neuroscience studies in animals involve some type of short-term (or acute) manipulation of the brain, followed by behavioral tests. When manipulations of a specific brain circuit are followed by behavioral changes, neuroscientists generally conclude that the circuit contributes to the behavior that’s been changed.
But brain circuits are very densely packed and highly interconnected, so it’s hard to manipulate one without influencing others. This makes it particularly challenging to know if the behavioral effects are caused by the part of the brain that was targeted or by some other part that happens to be closely connected to it.
A paper published in Nature shows that short-term alterations and long-term damage can have different effects on behavior. The findings raise a significant caution about the cause-and-effect nature of manipulating the brain and provide a reminder that the brain can sometimes work its way around damage.
Pet rats are wonderful. They’re smart, playful, affectionate, and often hilarious. I think it’s important to distinguish between the kind you willingly keep your home, and the wild kind (especially the huge city-dwellers).
If you’re as fair-skinned as the average northern European, you only need about 20 minutes per day. All you have to show is an area of skin about the size of your face.
Without vitamin D from sunlight exposure, lactose assists with the use of calcium. So, cultures with easy access to leafy greens plus sunlight or fish, calcium is taken care of and milk has no advantage. Cultures without access to leafy greens, sunlight or seafood need dairy either as a source of calcium, lactose, or both. You can read more about it in a previous post.
IT MIGHT look like an amputated rat forelimb, but the photo above is of something much more exciting: the limb has been grown in the lab from living cells. It may go down in history as the first step to creating real, biologically functional limbs for amputees.
Awesome, they’re leveraging the approach used to grow lungs. They’ve got issues to address, like circulation and nerves… But I count that has problems they’d probably like to have 😉
The possibility of a natural limb means no need for immuno-suppression drugs, no need for powering, no degradation of the body where the limb attaches/anchors… This is seriously good news for amputees.