Eric Hagen

• Doctor of Philosophy
• Postdoctoral Fellow at University of Toronto

Background Since the mid-twentieth century, it has been argued by some that the transition from diploidy to polyploidy is an “evolutionary dead end” in plants. While this point has been debated ever since, multiple definitions of “dead end” have been used in the polyploidy literature without sufficient differentiation between alternative uses. Sco...

Premise The proportion of polyploid plants in a community increases with latitude, and different hypotheses have been proposed about which factors drive this pattern. Here, we aimed to understand the historical causes of the latitudinal polyploidy gradient using a combination of ancestral state reconstruction methods. Specifically, we assessed whet...

Last year, a study published in Biology Letters by Thompson and Ramírez-Barahona (2023) argued that, according to analyses of diversification on two massive molecular phylogenies comprising thousands of species, there is no evidence that angiosperms (i.e., flowering plants) were affected by the Cretaceous-Paleogene mass extinction. Here I show that...

What grows where? Knowledge about where to find particular species in nature must have been key to the survival of humans throughout our evolution. Over time, and as people colonised new land masses and habitats, interactions with the local biota led to a wealth of combined traditional and scientific wisdom about the distributions of species and th...

Polyploidy, the state of having more than two full sets of chromosomes, has been hypothesized to provide several evolutionary advantages to flowering plants including increased ability to resist pathogens and parasites. However, studies comparing pathogen resistance in conspecific and congeneric diploids and polyploids have produced mixed results....

Premise of the Study The proportion of polyploid plants in a community increases with latitude, and different hypotheses have been proposed about which factors drive this pattern. Here, we aim to understand the historical causes of the latitudinal polyploidy gradient using a combination of ancestral state reconstruction methods. Specifically, we as...

The evolution of annual or perennial strategies in flowering plants likely depends on a broad array of temperature and precipitation variables. Previous documented climate life‐history correlations in explicit phylogenetic frameworks have been limited to certain clades and geographic regions. To gain insights which generalize to multiple lineages w...

Drosophila sechellia is a dietary specialist fruit fly that evolved from a generalist ancestor to specialize on the toxic fruit of Morinda citrifolia This species pair has been the subject of numerous studies where the goal has largely been to determine the genetic basis of adaptations associated with host specialization. Because one of the most st...

Taphonomic processes may filter in a biased manner the tiny fraction of leaves preserved as fossils. A common perception is that large leaves are underrepresented; this is based both on intuition (large leaves are more likely to break apart) and some observations of extant vegetation. Characterizing leaf area correctly is critical for reconstructin...