Oliver Sacks is the Jane Goodall of neurology. He has spent his entire  professional career observing patients, dutifully recording in his notebooks, and publishing reports of his findings that illuminate how the mind works. Most of his published work tells personal stories of patient experiences. Most notably there is ‘The Man Who Mistook his Wife for a Hat’ (a man with visual agnosia) and ‘An Anthropologist on Mars’ (perceptions of people with autism).

In this TED Talk, Oliver Sacks explains Charles-Bonnet Syndrome –  a hallucination syndrome experienced by people who lose their vision. I was surprised to learn that up to 10% of people with vision loss experience Charles-Bonnet hallucinations, but only 1% of them report it because they are afraid of people assuming they  are going insane (which they are not).

Check it out, it’s fascinating:

I find human ancestry fascinating. How are we all related? What did my ancestors look like, and where did they live? What are the stories of our forbearers as they struggled for survival, made discoveries, and lived together?

Adam and Eve were African. That’s not a new discovery, but many people have never heard it. The immediate consequence is that you yourself, regardless of where you come from or where you live now, have African ancestors. The reason that we can be sure of that comes from population genetics.

Here’s a TED Talk that took place in my home-country, Tanzania, that explains in simple terms how you can be sure that you have an African heritage. The speaker is Spencer Wells, who is the director of the Genographic Project. They analyze DNA from indigenous people around the world, building a family tree for the human races. If you want to purchase the kit, you can actually participate in the project yourself by sending in your own DNA for analysis.

Here’s what I found interesting about this talk:

Adam and Eve never met each other. That’s because, by ‘Adam’, I mean the most recent common ancestor of all the men that are alive today (according to the biblical account, ‘Noah’ would have been a better name since all men are said to descend from him more recently than Adam). Correspondingly ‘Eve’ refers to the most recent common ancestor of all the women that are alive today (Noah’s wife).

Now men generally have more disproportionate reproductive success. That is, some men father many children while others father none. For example, Ghengis Khan had so many concubines that it is believed he is an ancestor to more than half the men on the planet (does that explain a lot to you ?). Women, on the other hand, are generally more evenly reproductively successful. The consequence of this difference between men and women, is that ‘Adam’ appears in our history far more recently than ‘Eve’. So much so, that they lived in completely different time periods and could never have met.

Another interesting realization about Adam and Eve, is that they weren’t the first “humans”. Far from it. The origin of our species dates much earlier, but we defined Adam and Eve as the most recent common ancestors. To find the actual first “humans” is an impossible task, given that evolution works along gradients making only gradual changes. It would be like trying to find the first moment that a child is “grown-up”.

Finally, Adam and Eve lived side-by-side with other non-human bipedal apes. Actually it’s been that way throughout our history. There has almost always been other walking, thinking hominids living with us. It’s a fair question to ask why there’s just our species left now. Did we kill-off, or out-compete the others?

Well, if you find ancestry like this interesting, I highly recommend Richard Dawkin’s book “The Ancestor’s Tale”. It takes you on a journey back to the most recent common ancestors of humans, apes, mammals, vertebrates, and eventually all of life.  It’s a beautiful book.

This was an entertaining TED Talk, if you like magical illusions!

The story of Earth’s origin captures my imagination. It is the grandest of epics, a comprehensive myth (in the sense of ‘myths’ being stories that define who we are), the most dramatic story ever told.

I strongly believe we need to tell this story more often! It surprises me how few people know its major scenes or actors – even among those who study the life sciences. Origins are more than history, they are more than biology – they define who we are. In our unavoidably secular, globalized society, here’s a myth that embraces us all. Children should grow up learning this tale, and re-tell it to their own children with all of the modifications added by modern science.

This particular telling is orchestrated by Frans Lanting, a photographer for National Geographic. Although humans are his heroes/heroines (he ends with a focus on mammals and primates), he draws satisfying attention to plants, insects, invertebrates, and algae – the players of any real consequence in this drama (humans appeared too late to matter much). I was a little disappointed that he gives air-time to the KT extinction (non-avian dinosaurs), but not to the much larger end-Permian extinction.

If you haven’t yet discovered TED.com, go check it out! But choose sometime when you don’t have much to do, because it is highly addictive. On this website, the world’s brightest minds give ‘TED Talks’ on their most creative ideas. Topic areas are unlimited – whatever your subject, you can find a TED Talk right up your alley! Seriously, check it out.

From time to time, I’ll feature a TED Talk here on my blog – one that I found particularly interesting / creative / inspiring. 

Vilayanur Ramachandran is a neuroscientist. In this TED Talk, he uses psychiatric case studies to explain some aspects of how the mind works.

@ Introduction: Now that’s a fascinating paradox! Can a human brain ever be fully understood… by a human brain?

@ Phantom limbs: Ramachandran’s idea of how important optical input is to “programming” the nervous system (seeing the phantom limb moving was enough to convince the brain that it was no longer paralyzed) made me think of another example from my anatomy professor. Stroke recoverers sometimes have trouble initiating muscle contraction. To walk, they can throw a crumpled piece of paper (or other aide) in front of them. Having the visual cue of a target to aim for for helps to initiate the muscle movements needed to get there.

@ Synesthesia: That’s a creative definition for creativity!