# The History of Flowering Plants: Phylogenetic Reconstruction
--- class: top, left # Review a few definitions from first year - Taxonomy -- - Phylogeny -- - Evolution -- - Gene -- - Allele --- class: inverse, middle, center ## Evolution can be precisely defined as any change in the frequency of alleles from one generation to the next - Curtis and Barnes 1989
--- class: inverse, middle, center
Units can be either time ("time-tree") OR amount of change (esp in DNA code) This is a fossil-dated "time-tree"--the grey dough-nuts are 50 million years --- ## A few useful things about phylogenies - Phylogenies are imperfect: it is a statistical estimate of the true history -- - Trees have: "branches" and "nodes" (branch lengths can be meaningful or not) -- - Nodes in a phylogeny can be named (e.g., Myrtaceae) or un-named. So all taxonomy is the naming of the nodes on a tree -- - Traits evolve along particular branches (we usually can't tell where on a given branch) -- - Systematists are always improving phylogenies (we'll teach you the current understanding, but it *will* change) -- - Phylogenies are still useful even if they only contain a subset of species --- # Here is a partial phylogeny of candy bars
---
--- class: center, middle, inverse # There is some useful stuff to know about the plant phylogeny ---
--- #What is a family? Why are they useful?
Note: how weird is it that taxonomy was devised *before* we knew about evolution? --- class: inverse, middle, center
--- class: center, middle, inverse #IMPORTANT PLANT FAMILIES FOR *YOUR* FOOD
--- class: center, middle, inverse # 1. Poaceae (the grasses)
--- class: center, middle, inverse # 2. Fabaceae (the beans)
--- class: center, middle, inverse # 3. Brassicaceae (lots of greens)
Brassica oleracea --- class: center, middle, inverse # 4. Solanaceae (lots)
--- class: center, middle, inverse # 5. Amaryllidaceae (monocot)
--- class: center, middle, inverse # 6. Rosaceae
--- class: center, middle, inverse #Anyone eat a plant for lunch not in those 6 families? --- class: center, middle, inverse
--- # *Theobroma cacao* in the Malvaceae
--- class: center, middle, inverse
Cauliflory --- # Take Home Messages - A phylogeny is a data-based estimate of the true evolutionary history - Sources of data to build a phylogeny are DNA and fossils - Units can be either time ("time-tree") OR amount of change (esp in DNA code) - Taxonomists are always improving phylogenies (we'll teach you the current understanding, but it *will* change) - Nodes in a phylogeny can be named (e.g., Myrtaceae) or un-named. So all taxonomy is a subset of phylogenetics. - Families (named nodes) are a useful filing cabinet for learning plant (and food) diversity - Get familiar with the phylogeny of plants to help build you filing cabinet to organize plant diversity --- ## Challenge: draw a phylogeny that includes every plant that all of you ate today: 1. Add three traits to the phylogeny 2. Add Families to the phylogeny resources: http://www.mobot.org/MOBOT/research/APweb/ USE THE INTERNET; THE INTERNET IS YOUR FRIEND