Biology

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An Amazing Thing

This is from Sasha Sagan, daughter of Ann Druyan and Carl  Sagan, remembering a time from her childhood when she began to understand mortality. Her parents told her: 

“You are alive right this second. That is an amazing thing,” they told me. When you consider the nearly infinite number of forks in the road that lead to any single person being born, they said, you must be grateful that you’re you at this very second. Think of the enormous number of potential alternate universes where, for example, your great-great-grandparents never meet and you never come to be. Moreover, you have the pleasure of living on a planet where you have evolved to breathe the air, drink the water, and love the warmth of the closest star. You’re connected to the generations through DNA — and, even farther back, to the universe, because every cell in your body was cooked in the hearts of stars. We are star stuff, my dad famously said, and he made me feel that way.

My parents taught me that even though it’s not forever — because it’s not forever — being alive is a profoundly beautiful thing for which each of us should feel deeply grateful. If we lived forever it would not be so amazing.”
 

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Biology: The Science of Exceptions

[Edit:  Every year, I get a large number of visitors from Nepal and Bhutan on this post. Welcome, everyone. I’m just curious why this seems to happen every year at the same time. Could someone please let me know? It would help me understand how this site is being used, particularly if it’s for educational purposes. Thank you.]

Biology is sometimes referred to as “the science of exceptions.” A few recently reported examples from the study of animal behavior (i.e., ethology) help to bolster that reputation.

The first instance has probably received the most attention simply because it’s just so cool. It’s a video from Russia of some type of wild corvid (others have said it is most likely a hooded crow) that appears to snowboard down a roof. It does this multiple times by sliding on a small unidentified object under its feet, picking it up with its beak when it gets to the bottom of the roof, then flying back to the top to do it again. See for yourself.…

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Part 1. Humans are (Blank) -ogamous

“(A)s our forebears adopted life on the dangerous ground, pair-bonding became imperative for females and practical for males. And monogamy – the human habit of forming a pair-bond with one individual at a time – evolved.” (Helen Fisher 2004: 131)

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“Several types of evidence suggest our pre-agricultural (prehistoric) ancestors lived in groups where most mature individuals would have had several ongoing sexual relationships at any given time. Though often casual, these relationships were not random or meaningless. Quite the opposite: they reinforced crucial social ties holding these highly interdependent communities together.” (Chris Ryan & Cacilda Jethá 2010: 9-10)

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 “We are not a classic pair-bonded species. We are not a polygamous, tournament species either…. What we are, officially, … is a tragically confused species.” (Robert Sapolsky)

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The above three quotations were selected to illustrate the range of views that exist on the evolution of human sexual and mating behavior. This is not a trivial matter. To primatologist Bernard Chapais: “The central puzzle of human social evolution… is to explain how promiscuity was replaced by the pair bond” (that is, assuming the pair-bond has gained complete ascendancy). But it’s about more than our ancestors’ mating behaviors. Lurking in the background is the notion that our ancestral behavioral patterns impact current ones, via phylogenetic inertia. Additionally, how we view the past is important because, rightly or wrongly, we have a tendency to associate what is natural with what is good (but note well the naturalistic fallacy). For both of these reasons, the past matters.

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One Planet. One Species. Homo sapiens.

“One planet, one experiment.”
………………..— Edward O. Wilson. 1992. The Diversity of Life.

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Hadzabe men (wikimedia commons)

The BBC has compiled what looks to be an absolutely visually stunning television series, titled ‘Human Planet.’  The footage is said to contain video from 80 different locations, highlighting the relationship of humans to various ecological conditions.1 The description from the website:

Uniquely in the animal kingdom, humans have managed to adapt and thrive in every environment on Earth. Each episode takes you to the extremes of our planet: the arctic, mountains, oceans, jungles, grasslands, deserts, rivers and even the urban jungle. Here you will meet people who survive by building complex, exciting and often mutually beneficial relationships with their animal neighbours and the hostile elements of the natural world.”

Have a look for yourself at the preview:

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A Human Biology of War: The Proximate and the Ultimate

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On the surface, it may not be so clear where war, health, and evolution intersect. From the perspective of biological anthropology, many have called for a holistic, transdisciplinary approach to human biology and health which considers the environment as the totality of its evolutionary, ecological, and social components, including social inequality (Little and Haas 1989; Thomas et al. 1989; Wiley 2004).

Girl in Darfur refugee camp (source: Colin Finlay)

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More than a decade ago, Leatherman and Goodman (1998) suggested that biological anthropologists put more effort toward better understanding what they termed the ‘biology of poverty.’ In this sense, poverty is an ‘environment’ that may induce consistent, but obviously varying, biological responses depending upon local circumstances. Similarly, war can be conceived as a biological environment. At least in the short term from an evolutionary point of view, wartime conditions may be as biologically challenging as some of the classic ecologically extreme environments faced by humans (circumpolar, tropical, high-altitude, desert, etc.) (Clarkin 2010).

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The Power of Love

Infant rhesus monkey with terrycloth ‘mother’

As social animals, we need to be around others. Virtually everything we do is social – trade, eating meals, watching sports in stadiums or movies in theaters, religious services, education, the internet, etc. Even war is a social activity. No human being on the planet is completely self-sufficient. Being social is more than utilitarian, however; it is also biologically and psychologically necessary. For example, one of the most severe forms of punishment in prisons is solitary confinement.

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One Big Family

Evolutionary tree, Darwin’s notebook

Whether you like it or not, you are, in fact, my cousin. We can verify this through a couple of complementary lines of argument, one working forward in time, the other working backward. First, we know that all human beings comprise a single species, Homo sapiens. In 2005, Ian McDougall and colleagues reported in the journal ‘Nature’ that the oldest fossils belonging to our species were dated at 195,000 years old, and were discovered in Omo, Ethiopia. We all share this common point of origin as our lineages have intertwined and diverged over the last 8,000 to 9,000 generations or so.

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