species: primates

A Whale of a (Milk) Tale

A Whale of a (Milk) Tale

Blue whales, along with other species of baleen whales, are remarkable for their ability to put on massive amounts of blubber during pregnancy. What may be even more remarkable, however, is their ability to quickly transfer that stored energy to their developing calf during lactation, all while consuming little, if any, food. But not all whales share this intense lactation strategy. The toothed whales (the evolutionary "cousins" of baleen whales) are the tortoise to the baleen whales' hare, taking the slow and steady approach to milk production that is reminiscent of humans and other primate species. Why don't the baleen whales pace themselves a bit more? Or, alternatively, why don't the toothed whales pick up some speed? The evolution of two such dramatically different strategies in these closely related marine mammals can only be understood in the context of the species' entire life course. After all, evolutionary success is not about winning a sprint, but successfully playing the long game. Read More...

Evolving Motherhood: When to Wean Part I

Evolving Motherhood: When to Wean Part I

The “evolved” age of weaning is a topic of debate not only among the general public but clinicians and scholars as well. Weaning, however, is not an event—it is a process. When that process begins and how long mothers and infants negotiate milk transfer varies across mother-infant dyads. Additionally, adaptations reflect the selection of traits in ancestral populations; changing ecological conditions can lead to a mismatch between adaptations and current ecological conditions. What was once adaptive in landscapes roamed by early humans may not be the best fit in contemporary urban and suburban environments. And lastly, for these types of behavioral biology traits, there is no precise “one size fits all” adaptive threshold. Read More...