species: mammals

Tasmanian Devil Milk Provides Powerful Antibacterial Proteins

Tasmanian Devil Milk Provides Powerful Antibacterial Proteins

The Tasmanian devil is best known for being a swirling, growling, trouble-making cartoon character. But the marsupial mammal's reputation is about to get a complete makeover, thanks to new research on the function of proteins secreted in their milk and their skin. 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...

A Tale of Fats, Fish, Dolphins, and Dairy

A Tale of Fats, Fish, Dolphins, and Dairy

For decades, we have been warned about the evils of saturated fats in our food. We have heard that this whole “family” of fats increases our “bad cholesterol,” and hence increases our risk of cardiovascular and metabolic diseases. Recently, however, this widely accepted mantra has been challenged by growing evidence that some saturated fats, such as milk fats, do the exact opposite: they appear to reduce our risk of many diseases, including type 2 diabetes. While scientists debate the mechanisms involved, the changing view on saturated fats is underpinned by a new study of some unexpected contenders: dolphins (1). Read More...

Milk-On, Milk-Off

Milk-On, Milk-Off

If we could travel along a chromosome, we would find genes arranged in clusters. Sometimes the genes within the cluster have some shared function, but other times they seem to be randomly organized. Lactation biologists have often wondered how the mammary gland turns on lactation and keeps the milk flowing when needed. In a recent study by Danielle Lemay and her colleagues1, they investigated the potential role of gene cluster arrangement and coordinated control of lactation. Interestingly, they found that the clusters of lactation genes may be more relevant to which genes are turned off during lactation rather than which are turned on. Read More...

Mega Milk Composition Analysis

Mega Milk Composition Analysis

Fifty years ago Devorah Ben Shaul published the seminal paper "The Composition of the Milk of Wild Animals" (1963). She had spent ten years aggregating published papers of milk composition as well as directly analyzing dozens of species' milks. Eyeballing the data from 101 species, Ben Shaul posited that the composition of milks--the percent fat, protein, and sugar--did not necessarily cluster by the evolutionary history of taxonomic groups (a.k.a. phylogeny). She noted that "grizzly bear milk and kangaroo milk had virtually the same basic milk composition" (p. 333). Therefore, Ben Shaul approached milk from the perspective of environment and nursing behavior. She posited that milks clustered in relation to the degree of maturity at birth, maternal attentiveness and nursing frequency, and the exposure to water and ambient temperature. To learn more about milk composition among mammals, read this. Read More...