Biology Reference
In-Depth Information
utionary shifts in ecology and performance, exaptive or adaptive, are detectable using
the same rationale with which we infer changes in anatomy.
Simply put, attributes of diverging lineages that are lacking in close relatives prob-
ably arose in their common ancestor—the upright walking and savanna-dwelling life-
styles, for example, characteristic of australopithecines and us but not of chimps,
bonobos, and gorillas. Whether such comparisons prove that ancient selection fixed
those traits in a population seems largely a matter of taste; for many evolutionists that's
the only plausible conclusion, whereas others, myself included, prefer sticking to what
ds and moloch
are
correlated with feeding in open areas, and the rock-loving Chilean
ant specialist can't refute the hypothesis that the others' spines
are
antipredator ad-
aptations. Komodo monitors do take deer and pigs, but ancestral varanids ate small
items. So perhaps their raptorial jaws and mammal-like endurance originated for wide-
foraging and rapid capture, regardless of prey size.
25
My data from field observations and museum specimens addressed interesting ques-
tions. The probationary years at Berkeley zoomed by, and, thanks to supportive col-
leagues there and elsewhere, I cleared academia's “publish or perish” hurdle. Studying
desert lizards led to research on snake ecology, venoms, and parental care, topics that
still captivate me; arid lands also afforded tranquillity and a sense of going wild, even
though I never lacked water or traveled far on foot—only years later would I read hor-
rific accounts of dying of thirst in Mexico's Gran Desierto and, while backpacking in the
Barranca del Cobre, come to more viscerally appreciate my own adaptive shortcomings.
In the meantime, there were plenty of ups and downs outside of science, and where bet-
ter to ponder them?
In May of 1985, freshly tenured and preoccupied by my dad's sudden passing, I was
helping Claudia Luke with her doctoral research at Pisgah. We were walking along
chatting, hot and hungry from a morning of chasing lizards, when only a dozen yards
ahead an enormous magenta coachwhip materialized on the gravel track. Named for
the braided look of their scales, with birdlike eyes, these lightning-fast creatures occur
in habitats as diverse as pinewoods and desert scrub. More than most other serpents,
they defy control—I've ripped the knees out of jeans diving for one on a paved road,
been stabbed by a yucca while grabbing for another. In hand, they're prone to thrash
wildly, strike at one's face, and if all else fails go limp and feign death.
This coachwhip looked like a piece of dazzling pink Hula-Hoop, and capturing it
was instantly paramount. There was a split second of evaluation, as if we doubted the
creature's existence, followed by an explosion of action; everything was over in seconds.
We stumbled and scrambled while the coachwhip seemed to fly, not always touching
earth. As I charged full tilt, the snake shot down a sandy embankment, then up an es-
carpment. Claudia cut diagonally toward the high rocks, trying to prevent its escape,
but my feet slipped backward and I pitched through a somersault. Luckily my head was
cushioned by a creosote bush at mid-roll as arms and legs tumbled over lava chunks.
I lay as I landed, propped on one elbow, and in an affectedly calm voice asked, “Did
you get that snake?” Claudia shot me a skeptical grin as I passed from clarity to confu-
sion, from relict obsession with the coachwhip to startling pain. Really addled now, my
