The Citrus-Primate Connection

greenhouse_citrus_webAround 5000 species of mammals inhabit the Earth today, and almost all make their own Vitamin C from simple sugar. Your dog doesn’t need orange juice to live a scurvy-free life.

Human ancestors, and most other primates, lost the genetic ability to perform this impressive biochemical feat around 61 million years ago [1]. How did they/we survive?

Short answer – don’t know (yet).  It’s accepted that these primate ancestors were insectivores. Insects, in general, do not contain high levels of Vitamin C [2]. But, insects do like hanging around flowers, fruits, and leaves. An insect could be noshing on some C-rich fruit (insects do require Vitamin C for development and reproduction) when the primate ate it. Or the primate could accidentally eat plant material while aiming for the insect.

What about other Vitamin C deficient mammals – Guinea pigs and bats? Guinea pigs… and fruit bats… certainly get plenty of Vitamin C in their diet. What about insect-eating bats? Well, maybe they aren’t as Vitamin C inept as we thought [3]. And, we deficients may be able to survive on less Vitamin C and/or recycle the little we do ingest [4].


  1.  Lachapelle M.Y. and G. Drouin. 2011. Inactivation dates of the human and guinea pig vitamin C genes. Genetica 139:199–207. 
  2. Kourimska L. and A. Adamkova. 2016. Nutritional and sensory quality of edible insects. NSF Journal. 4:22-26.
  3. Troadec, M. and J. Kaplan. 2018. Some vertebrates go with the GLO. Cell. 132(6)921-922.

Appalachian Trail Overlook

travelsketch_frombarn800The most amazing aspect of the human species (Homo sapiens) is our power to change our environment. Using this capacity, we’ve created societies in almost every corner of the Earth. We construct islands, create inlets and waterways, and move dunes to secure a coastal view. We cut tremendous forests and construct remarkable dams. And we eliminate entire mountains in our search for ores and coal. We even change the temperature and weather patterns of our planet.

This may sound bleak, but I don’t see it that way. With so much influence and ingenuity, we can protect our planet. We have the power to reduce and repair environmental impacts. It all begins with awareness, resolve, creativity… and responsibility.

Mind the wisdom of Spiderman’s Uncle Ben: “with great power comes great responsibility.”