Chapter 8 Plant Systema,cs and Evolu,on

Transcription

1 Chapter 8 Plant Systema,cs and Evolu,on Lecture Outline: Evolu,on explains the unity and diversity of organisms on Earth Fossils, Lamarck s first theory of evolu,on, and Darwin s voyage Darwin s theory: adapta,on and natural selec,on Ar,ficial selec,on in agriculture Darwin s observa,ons and 2 major inferences Evolu,on of pest resistance Carolus Linnaeus, systema,cs and binomial classifica,on The evolu,onary history of the land plants

2 Evolu4on The overarching theme in botany and biology hip://evolu,on.berkeley.edu

3 Key observa4ons of life 1. Organisms are well suited for life in their environment. 2. Living organisms share many characteris,cs (example = DNA). This demonstrates the unity of life. 3. The Earth has a rich diversity of living organisms.

4 Fossils are evidence for evolu,on Archaefructus sinensis, the oldest angiosperm fossil (125 MYO) Cooksonia pertoni, the oldest plant fossil (425 MYO)

5 Ar2ficial selec2on of agricultural species demonstrates evolu,on

6 Ar2ficial selec2on of agricultural species Terminal bud Lateral buds Cabbage Flower clusters Brussels sprouts Leaves Cauliflower Kale Stem Broccoli Flowers and stems Wild mustard Kohlrabi

7 Lamarck ( ) was one of the first to propose a mechanism for evolu,onary change

8 There is grandeur in this view of life [in which] endless forms most beau,ful and most wonderful have been, and are being, evolved. Charles Darwin, On the Origin of Species Orchid wasp mimic Ophrys apifera

9 Charles Darwin was the first to demonstrate a mechanism of evolu,on with evidence NORTH AMERICA ATLANTIC OCEAN GREAT BRITAIN EUROPE The Galápagos Islands Fernandina Isabela Pinta Marchena Santiago Pinzón Santa Cruz Florenza Santa Fe Genovesa Daphne Islands San Cristobal Española PACIFIC OCEAN SOUTH AMERICA Andes Cape Horn Tierra del Fuego Cape of Good Hope AFRICA Equator AUSTRALIA Tasmania New Zealand Darwin s important ques,on: Could a new species arise by the gradual accumula,on of adapta4ons to different environments?

10 Evolu,on by natural selec,on natural selec2on = A process in which organisms with certain inherited characteris,cs are more likely to survive and reproduce than are organisms with other characteris,cs. What counts in natural selec,on is not "survival of the fiiest" but a ques,on of reproduc,on the extent to which any par,cular type can outbreed its compe,tors.

11 Darwin s 1 st observa4on: Members of a popula,on oeen vary greatly in their traits Konza Prairie, KS

12 Darwin s 2 nd observa4on: Traits are inherited from parents to offspring Gregor Mendel s seminal breeding experiments with pea plants

13 Darwin s 3 rd observa4on: Species produce more offspring than the environment can support. Owing to lack of food or other resources, many of these offspring do not survive. Puffball fungus with spore cloud Dandelion (Taraxacum officinale) seed dispersal

14 Darwin s 1 st inference: Individuals whose inherited traits infer high survival and reproduc,on in a given environment leave more offspring. Darwin s 2 nd inference: This unequal ability of individuals to survive and reproduce will lead to the accumula2on of favorable traits in the popula,on over genera,ons.

15 cojon armyworm Evidence for evolu,on: Insect resistance to Bt coion Bruce E. Tabashnik, J.B.J. Van Rensburg,and Yves Carriere. Field- Evolved Insect Resistance to Bt Crops: Defini,on, Theory, and Data. J. Econ. Entomol., 102(6): (2009)

16 Natural selec4on: important points 1. Natural selec,on is an edi,ng mechanism, not a crea,ve force. 2. Natural selec,on favors traits that increase fitness in the current, local environment.

17 Natural selec4on Main ideas of Darwin s book, the Origin of Species: 1. descent with modifica2on explains life s unity and diversity 2. natural selec2on brings about the match between organisms and their environment Charles Darwin

18 Systema2cs = an approach to classifying the diversity and determining the evolu,onary rela,onships of living and ex,nct organisms

19 Carolus Linnaeus

20 Hierarchical Species: mul2flora classifica4on Genus: Rosa Rosa mul<flora Family: Rosaceae Order: Rosales Class: Magnoliopsida Division: Magnoliophyta Kingdom: Plantae Bacteria Domain: Eukarya Archaea

21 Scien,fic Names Species have binomial (two part) names Sugar Maple Acer saccharum Common name Scien4fic name Genus Specific epithet Binomial names should be underlined or italicized.

22 Names of higher taxa (genera and above) are uninomials e.g., Quercus - The genus of oaks Aceraceae - The family of maples The names of families and above are capitalized but not italicized.

23 The Categories of the Linnaean Hierarchy and their Standard Endings (example: Common wheat) Rank Standard Ending Example Division - phyta Magnoliophyta (Flowering plants) Class - opsida Liliopsida (Monocots) Order - ales Poales (Grasses, bromeliads, sedges) Family - aceae Poaceae (Grasses) Genus Triticum (Wheat) Species Triticum aestivum (Common wheat) aestivum developing in summer

24 Lecture Review, Chapter 8 Define evolu,on and adapta,on. Describe Lamarck s theory, and explain why it has been rejected. Describe Darwin s theory of natural selec,on and contrast it with ar,ficial selec,on. List and explain Darwin s observa,ons and two inferences. Define systema,cs. What evidence is used to construct an evolu,onary tree? What is hierarchical classifica,on? What is Carolus Linnaeus contribu,on to science? Provide examples of standard endings for plant Divisions, Classes, Orders, and Families. What are the major groups of land plants? From what common ancestor did all land plants evolve?