Methods

Desiccation Tolerance: Phylogeny and Phylogeography Kristin Jenkins*, Shaily Menon**, and Gabriella Pinter^

*NESCent, **Grand Valley State University, ^University of Wisconsin - Milwaukee

References

Occurrence data for Anastatica hierochuntic:

o Downloaded from the Global Biodiversity Information Facility (gbif.org). o Of 127 available occurrence points, only 68 were georeferenced with latitude and longitude information.

Environmental layers: Precipitation and temperature from the IPCC climate dataset

Niche Modeling:

Maximum Entropy (Maxent)

Maxent principle is to estimate the probability distribution such as the spatial distribution of a species.

Maxent uses entropy as the means to generalize specific observations of presence of a species, and does not require absence points

A representation of the Maxent model for Anastatica hierochuntica can be seen in Figure 5.

Warmer colors show areas with better predicted conditions. White dots show the presence locations used for training.

Introduction Results

Figure 4. Rainfall Volume. Source: GapMinder.org.

Figure 1. Tortula ruralis. Source: Wikimedia.org. Figure 2. Selaginella lepidophylla

http://en.wikipedia.org/wiki/File:Rose_of_Jericho.gif

Desiccation tolerant plants:

o Survive dehydrationo Survive in dormant state for extended time period o Survive rehydration

Figure 3a. Evolution of desiccation tolerance. Source: Oliver et al. 2000 Plant Ecology.

Figure 3b. Convergent evolution of desiccation tolerance among vascular plants. Source: Oliver et al. 2000 Plant Ecology.

Desiccation tolerant in vascular plants:

o Seedso Polleno Sporeso Osmotic stress

Desertification is a sustainability problem:

o 40% of the earth’s surface is affectedo 38% of the world’s population is affectedo These are areas of low productivity due to

o lack of watero depletion of soilo loss of soilo delicate systems

Examples of desiccation tolerance species include:

o Xerophyta humiliso Tortula ruraliso Selaginella lepidophylllao Anastatica hierochuntica

Anastatica hierochuntica:

o Family Brassicaceaeo Common Name: Rose of Jerichoo Distributional range includes Northern Africa (Algeria, Egypt) and Asia (Arabian peninsula – Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, UAE, Yemen, and Western Asia – Iran, Iraq, Israel, Jordan, Syriao Most famous “tumble weed”, Palestinian tumble weed, resurrection planto After rainy season, plant dries up, leaves drop and branches curl into a tight ball, and ‘dies’o Wetted again in rainy season, the ball uncurls, fruit opens, and disperses the seeds, which germinate within hours if enough water is available

We tested the following hypothesis:

o Exploration of the phylogeography will enhance ongoing molecular phylogeny studies on the evolutionary relationships of desiccation tolerant plants

Oliver et al. 2000. The evolution of desiccation tolerance in land plants. Plant Ecology.

Phillips et al. 2006. Maximum entropy modeling of species’ geographic distributions. Ecological Modeling.

Figure 5. Maxent model for Anastatica hierochuntica.