https://gregladen.com/blog/2008/03/19/which-came-first-the-mammalian/ Wed, 19 Mar 2008 20:10:14 +0000 hourly 1 https://wordpress.org/?v=6.4.8 https://gregladen.com/blog/2008/03/19/which-came-first-the-mammalian/#comment-5302 Wed, 19 Mar 2008 20:10:14 +0000 http://scienceblogs.com/gregladen/2008/03/19/which-came-first-the-mammalian/#comment-5302 All this reminds me of another interesting set of facts. I’ve heard that a marsupial embryo has a thin, permeable shell that sure looks like a vestigial egg shell. The shell dissolves away a few days before the marsupial is born. Also, marsupials have a vestigial egg-tooth for the no-longer-needed task of breaking out of the egg. The egg tooth is absorbed back into the embryo shortly before birth.If I’ve told this story correctly, it’s yet another good thing to bother creationists with.

]]> https://gregladen.com/blog/2008/03/19/which-came-first-the-mammalian/#comment-5301 Wed, 19 Mar 2008 19:18:14 +0000 http://scienceblogs.com/gregladen/2008/03/19/which-came-first-the-mammalian/#comment-5301 Matt: Yes, and this is discussed in the paper, though I did not highlight it because there is a confusing issue that they do not adequately address and that I cannot adequately critique. There is evidence that eggs in the echidna are secondarily evolved. Maybe.

]]> https://gregladen.com/blog/2008/03/19/which-came-first-the-mammalian/#comment-5300 Wed, 19 Mar 2008 18:25:47 +0000 http://scienceblogs.com/gregladen/2008/03/19/which-came-first-the-mammalian/#comment-5300 If I recall correctly the Duck Billed Platypus both lays eggs and lactates, albeit not through a breast as normally found in mammals but rather a modified sweat gland.This would seem to support the idea that lactation appeared before placentas.

]]> https://gregladen.com/blog/2008/03/19/which-came-first-the-mammalian/#comment-5299 Wed, 19 Mar 2008 18:16:57 +0000 http://scienceblogs.com/gregladen/2008/03/19/which-came-first-the-mammalian/#comment-5299 Oh, yes, it is!

]]> https://gregladen.com/blog/2008/03/19/which-came-first-the-mammalian/#comment-5298 Wed, 19 Mar 2008 17:23:44 +0000 http://scienceblogs.com/gregladen/2008/03/19/which-came-first-the-mammalian/#comment-5298 I guess because many others are blogging about it (e.g. PZ).

]]> https://gregladen.com/blog/2008/03/19/which-came-first-the-mammalian/#comment-5297 Wed, 19 Mar 2008 16:52:46 +0000 http://scienceblogs.com/gregladen/2008/03/19/which-came-first-the-mammalian/#comment-5297 Why do you say that?

]]> https://gregladen.com/blog/2008/03/19/which-came-first-the-mammalian/#comment-5296 Wed, 19 Mar 2008 16:39:06 +0000 http://scienceblogs.com/gregladen/2008/03/19/which-came-first-the-mammalian/#comment-5296 This is a popular article!

]]>