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>Date: Wed, 19 Jul 1995 19:09:52 PDT
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>From: Daniel Blackburn <[log in to unmask]>
>Subject: abstractions
>To: "katherine a. dettwyler" <[log in to unmask]>
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>
>Dear Kathy:
>
>Here is the Mamm. Rev. abstract, along with my mail and home page
>addresses.  Please feel free to post this and/or my previous message as you
>deem appropriate.
>
>**********
>
>Blackburn, D.G. (1991). Evolutionary origins of the mammary gland.
>Mammal Review 21: 81-96.
>
>Abstract: Because the mammary gland has no known homologue among the extant
>reptiles, attempts to reconstruct its evolution must focus on evidence from
>living mammals.  Of the numerous structures that have been hypothesized to
>have given rise to the mammary gland, only three remain as plausible
>progenitors: sebaceous glands, eccrine glands, and apocrine glands.
>Ancestral mammary glands usually are assumed to have produced a copious
>watery secretion like that of human eccrine sweat glands.  However, in terms
>of anatomy, physiology, development, and topographic distribution, mammary
>glands are more similar to apocrine and sebaceous glands than to typical
>eccrine glands.  Nevertheless, each of the three populations of cutaneous
>glands exhibit specializations unlikely to be primitive for the mammary
>gland.  The mammary gland probably either predated full differentiation of
>mammalian cutaneous glands, or more likely, evolved as a neomorphic mosaic
>that combined the properties of apocrine and sebaceous glands.
>Consequently, ancestral, prototypic lacteal glands may have had the
>capacity to synthesize and secrete small amounts of organic substances, as
>do sebaceous and apocrine glands of living mammals.
>
>**********
>For reprints, write to:
>
>Daniel G. Blackburn, Department of Biology, Life Sciences Center
>Trinity College, Hartford, CT  06106  USA
>
>
>or email:
>[log in to unmask]
>
>
>For abstracts of other papers, visit DGB's home page at:
>
>http://shakti.trincoll.edu:80/~blackbur/
>
>
Katherine A. Dettwyler, Department of Anthropology, Texas A&M University
e-mail [log in to unmask], specialist in infant feeding and health
co-editor of Breastfeeding: Biocultural Perspectives