De Lamater said not only can women expect to live nearly 10 years longer than men, they often marry older men.Between the possibility of a partner passing away and the odds of a divorce, De Lamater said it's becoming more and more common for people to be left behind later in life.(c) The long fuse model is based on dos Reis et al. (d) The short fuse model is based on Bininda-Emonds et al. (e) The majority consensus of recent molecular dating estimates is represented here by Meredith et al. Black circles show the crown origins for the 11 orders generally agreed upon as being Paleogene or older, in each case arranged from top to bottom: Xenarthra, Afrosoricida, Lipotyphla, Carnivora, Chiroptera, Perissodactyla, Artiodactyla, Primates, Scandentia, Rodentia, and Lagomorpha.(a) The hard explosive model is based on O'Leary et al. (b) The soft explosive model differs only by extending the earliest few placental superordinal divergences into the Cretaceous.Single point calibrations have in turn been superseded by multiple sets of calibration bounds or priors. The timing of placental mammal diversification remains especially contentious, with major recent studies reinforcing divisions between older, molecular-based estimates ( Meredith et al. 2012 ) and younger fossil-based estimates ( Wible et al. In the most extensively sampled phylogenetic analysis of living and fossil eutherians O'Leary et al. 1 a), in which all placentals arose from a single survivor of the KPg mass extinction.As a result, geological information, which formerly only gave a temporal scale to molecular branch lengths, now also substantially informs how rates of molecular evolution vary across the tree (see Ho and Phillips 2009 ; Magallón et al. I refer to this modern conception of relaxed clocks and multiple calibrations as “geomolecular dating.” Despite recent progress in modeling molecular sequence evolution, large apparent conflicts with far younger fossil records remain across the tree of life, such as for the diversification of metazoans ( Aris-Brosou and Yang 2002 ), and the origins of flowering plants ( Bell et al. Traditionally, however, paleontologists have favored a “soft” explosive model ( Fig.Richard Rathmann has missed the days of face-to-face interactions, so much so that he has even turned to the internet to meet up with single women in his age group."I find it's really hard to meet people. Rathmann and Hemming were two of 16 people who came out to the speed dating event, a sign that a more mature crowd is looking for ways to make a connection.John De Lamater, a professor of sociology at the University of Wisconsin-Madison who has studied the subject of senior relationships, notes that the age group is "rapidly growing" and is expected to double over the next 15 years or so.
Molecular dating has been transformed by relaxed clock methods that allow the rate of molecular evolution to vary across the phylogeny ( Sanderson 1997 ; Thorne and Kishino 2002 ; and see Welch and Bromham 2005 ). Direct reading of the fossil record suggests that eutherian mammals, including their crown group (placentals), underwent an extraordinary taxonomic and morphological diversification following the extinction of non-avian dinosaurs at the Cretaceous–Paleogene boundary (KPg), 66 Ma.
Here I consider the implications of this development.
I use fossil calibrations to test the accuracy of models of molecular rate evolution for placental mammals, and reveal substantial misspecification associated with life history rate correlates.
Black circles show the crown origins for the 11 orders generally agreed upon as being Paleogene or older, in each case arranged from top to bottom: Xenarthra, Afrosoricida, Lipotyphla, Carnivora, Chiroptera, Perissodactyla, Artiodactyla, Primates, Scandentia, Rodentia, and Lagomorpha.
(a) The hard explosive model is based on O'Leary et al. (b) The soft explosive model differs only by extending the earliest few placental superordinal divergences into the Cretaceous. Dark gray triangles show the pattern of superordinal divergences, beginning with the placental crown origin.