Tag Archives: evolution

Blog

Did cooking make us evolve?

campfireBecause there’s still got to be an optimistic sf story in here somewhere:

Harvard anthropologist Richard Wrangman theorizes that cooking with fire triggered hominids to evolve into humans. His experience in the wild led him to conclude that humans could never live on what chimpanzees eat. Cooking, he thinks, might account for the sharp rise in brain size, and the decrease in the size of teeth, that occurred about 1.6 million years ago in Homo erectus over its predecessor, homo habilis. It might explain our relatively small guts and weak jaws, not to mention certain preferences that seem innately human:

[O]ne of the fascinating things for me as I ventured into this was really learning about what hunters and gatherers eat—and it turns out that there are no records of people having a large amount of their food come from raw food. Everywhere, everyone expects a cooked meal every evening.

The problem is lack of evidence that people used fire that long ago. A lot of scientists believe cooking didn’t really start till only 500,000 years ago.

Lacking the proof for widespread fire use by H. erectus, Wrangham hopes that DNA data may one day help his cause. “It would be very interesting to compare the human and Homo erectus genetics data to see when certain characteristics arose, such as, When did humans evolve improved defenses against Maillard reaction products?” he says, referring to the chemical products of cooking certain foods that can lead to carcinogens.

Human origins have been in the news.  How and when we began is a source of wonder. Call me mammal-centric, but I found it impossible to look at the (eerily well-preserved) face of the newly unearthed lemur-like fossil without feeling a bit of kinship.

[Image: Campfire, P. Sto]

Blog

RepRap creates circuits

just-finishedA moment of history. The RepRap project has created circuits for the first time:

Ed and I have a final-year student – Rhys Jones – who’s working on RepRap for his MEng research project. He’s been taking the old idea of depositing metal in channels and an observation of Forrest’s and Nophead’s (that you don’t need a low-melting-point alloy because the specific heat of metals is so low that they shouldn’t melt the plastic anyway).

Also worth a look: Bruce Sterling points to Darwinian Marxism as a means of ensuring the proletariat gain possession of the means of production sans revolution.

[via the Yorkshire Ranter][image from the Reprap blog]

Blog

In defence of altruism – the unselfish gene

Is altruism a result of human societal values, or is it something innate that evolved biologically? Psychologist Dacher Keltner claims the latter may be the case:

Our research and that of other scientists suggests that the vagus nerve may be a physiological system that supports caretaking and altruism. We have found that activation of the vagus nerve is associated with feelings of compassion and the ethical intuition that humans from different social groups (even adversarial ones) share a common humanity. People who have high vagus nerve activation in a resting state, we have found, are prone to feeling emotions that promote altruism—compassion, gratitude, love, happiness. Arizona State University psychologist Nancy Eisenberg has found that children with elevated vagal tone (high baseline vagus nerve activity) are more cooperative and likely to give. This area of study is the beginning of a fascinating new argument about altruism—that a branch of our nervous system evolved to support such behavior.

If you want the opposite take (which, for what it’s worth, reads a lot less like the jacket copy for a spiritual self-help book), look no further than sf writer and biologist Peter Watts:

Men, like most male mammals, like to acquire resources. When they’re not especially horny, they’re as likely to go for furniture and big-screen TVs — i.e., major, nonportable items that remain in the home — as anything else. When they’re horny, however, they’d rather buy bling and fast cars — flashy stuff they can take on the road to attract mates. Also, when in a horny mood, they’re more likely to give publicly to panhandlers (also to indulge in risky/heroic behaviour). In other words, both conspicuous consumption and conspicuous generosity are just ways of attracting mates: hey baby, lookit me! I’ve got so much money I can just give it away!…

I wonder if we’ll ever be ale to answer this question definitively? Whether we’ll like the answer is another question entirely…

Blog

Lamarckism reassessed – can acquired characteristics be inherited?

Lamarckian evolutionary theory – the notion that acquired characteristics can be passed on to offspring – was dismissed (and roundly mocked) in light of Darwin’s theories of natural genetic selection. But new research shows that, in rodents at least, the environment in which a creature is raised can affect its offspring quite profoundly:

In Feig’s study, mice genetically engineered to have memory problems were raised in an enriched environment–given toys, exercise, and social interaction–for two weeks during adolescence. The animals’ memory improved–an unsurprising finding, given that enrichment has been previously shown to boost brain function. The mice were then returned to normal conditions, where they grew up and had offspring. This next generation of mice also had better memory, despite having the genetic defect and never having been exposed to the enriched environment.

If the same applies to humans, the implication is that an enriched nurturing environment – or, conversely, childhood abuse – could have effects that reach beyond generations.

It’s pretty much accepted that childhood poverty will have a negative effect on someone’s prospects as an adult, but if Lamarckism turns out to be valid we have an even stronger argument for striving to improve the lot of the world’s least fortunate. [via SlashDot]