The evolution of milk secretion and its ancient origins

Jun 29th, 2015
Studypool Tutor
Academy of Art University
Price: $30 USD

Tutor description

Lactation has an evolutionary origin and biological context within which its secretory processes and milk constituents evolved.

Word Count: 13646
Showing Page: 1/14
animalAnimal (2012), 6:3, pp 355368 & The Animal Consortium 2011doi:10.1017/S1751731111001935The evolution of milk secretion and its ancient originsO. T. OftedalSmithsonian Environmental Research Center, Smithsonian Institution, Edgewater, MD 21037, USA(Received 8 August 2011; Accepted 8 September 2011; First published online 14 October 2011)Lactation represents an important element of the life history strategies of all mammals, whether monotreme, marsupial, oreutherian. Milk originated as a glandular skin secretion in synapsids (the lineage ancestral to mammals), perhaps as early as thePennsylvanian period, that is, approximately 310 million years ago (mya). Early synapsids laid eggs with parchment-like shellsintolerant of desiccation and apparently dependent on glandular skin secretions for moisture. Mammary glands probably evolvedfrom apocrine-like glands that combined multiple modes of secretion and developed in association with hair follicles. Comparativeanalyses of the evolutionary origin of milk constituents support a scenario in which these secretions evolved into a nutrient-richmilk long before mammals arose. A variety of antimicrobial and secretory constituents were co-opted into novel roles related tonutrition of the young. Secretory calcium-binding phosphoproteins may originally have had a role in calcium delivery to eggs;however, by evolving into large, complex casein micelles, they took on an important role in transport of amino acids, calci

Review from student

Studypool Student
" all I can say is wow very fast work, great work thanks "
Ask your homework questions. Receive quality answers!

Type your question here (or upload an image)

1819 tutors are online

Brown University





1271 Tutors

California Institute of Technology




2131 Tutors

Carnegie Mellon University




982 Tutors

Columbia University





1256 Tutors

Dartmouth University





2113 Tutors

Emory University





2279 Tutors

Harvard University





599 Tutors

Massachusetts Institute of Technology



2319 Tutors

New York University





1645 Tutors

Notre Dam University





1911 Tutors

Oklahoma University





2122 Tutors

Pennsylvania State University





932 Tutors

Princeton University





1211 Tutors

Stanford University





983 Tutors

University of California





1282 Tutors

Oxford University





123 Tutors

Yale University





2325 Tutors