Strategies of Life

Chapter 20 Great Idea:

Living things use many different strategies to deal with the problems of acquiring and using matter and

energy

h"p://www.youtube.com/watch?v=uBuPiC3ArL8  

h"p://www.youtube.com/watch?v=fIOUD1XFBeA  

h"p://www.youtube.com/watch?v=HE6XUcq4g38   AgouL  and  Brazil  nuts  

Chapter Outline •  The Organization of Living Things •  What is Life? •  Classifying Living Things •  Survival: A New Look at the Life Around

You •  Strategies of Fungi •  Strategies of Plants •  Strategies of Animals

The Organization of Living Things

Ways of Thinking about Living Things

•  Levels – Biosphere – Ecosystem – Community – Population – Organism – Anatomy and physiology – Cellular – Molecular

•  All levels complement each other

Study  an  Ant  

What Is Life?

The Characteristics of Life •  High degree of order and complexity •  Part of larger systems of matter and energy •  Life depends on chemical reactions in cells •  Life requires liquid water •  Organisms grow and develop •  Regulate energy use •  Share same genetic code, code is heritable •  All living things are descended from a common

ancestor

Organisms Need Energy

Organisms Grow and Develop

Classifying Living Things

EvoluLon  

Chapter 25

Great Idea: All life on Earth evolved from single-celled organisms

by the process of natural selection.

h"p://www.youtube.com/watch?v=HE6XUcq4g38  EvoluLon  of  skin  color  

Chapter Outline •  The Fact of Evolution •  Chemical Evolution •  Natural Selection and the Development

of Complex Life •  The Evolution of Human Beings

The Fact of Evolution

The Fact of Evolution •  Evolution – Ongoing process of change

•  Scientists accept evolution as fact – Debate various theories

The Fossil Record •  Fossils – Organism’s hard parts preserved

•  Turned to rock •  Replaced by minerals

•  Fossil record – Fossils found, catalogued, and analyzed – Shows transitions – Incomplete

The Fossil Record – cont. •  Three key ideas – Older fossils more different – Increasing complexity with time – Most species have gone extinct

Wide Variety of Fossils

Fossil Trilobites

The Biochemical Evidence

•  DNA – Evidence for evolution – Changes slowly – Also compare amino acid sequences

•  Cytochrome c – Humans and chimps identical – Rattlesnake 86% overlap

Evidence from Anatomy: Vestigial Organs

•  Vestigial organs – Internal features – No useful function

•  Examples – Appendix: humans – Wings: penguins – Hind legs: whales

Wings of a Penguin Are Vestigial Organs

Evolution of skin color h"p://www.youtube.com/watch?v=QOSPNVunyFQ  

Cataloging Life •  Linnaean classification

–  Shared characteristics

•  Hierarchy –  Kingdom –  Phylum –  Class –  Order –  Family –  Genus –  Species

•  Binomial nomenclature

ClassificaLon  of  Life  

Classifying  Life  -­‐  cont.  

•  Kingdoms – Monera – Protista – Fungi – Plants – Animals

Five-Kingdom Classification

Monera

Protista

Different  Division  of  Life  

•  Carl Woese – Molecular genetics – Three domains

•  Bacteria •  Archaea •  Eucaryea

Science by the Numbers •  How many

species are there?

Species Estimation

Classifying Human Beings

•  Kingdom: Animals •  Phylum: Chordates – Subphylum: vertebrates

•  Class: Mammals •  Order: Primates •  Family: Hominid •  Genus: Homo •  Species: sapiens

Primates

The Characteristics of Life •  High degree of order and complexity •  Part of larger systems of matter and energy •  Life depends on chemical reactions in cells •  Life requires liquid water •  Organisms grow and develop •  Regulate energy use •  Share same genetic code, code is heritable •  All living things are descended from a common

ancestor

Implications of Linnaean Classification (physical similarities)

•  Use of DNA •  Similarity depends on time and change •  Classification results from real events

Survival: A New Look at the Life Around You

Survival: A New Look at the Life around You

•  Autotrophs •  Heterotrophs •  Dealing with complexity- specialized

organs vs. collection of similar cells •  Two basic tasks of life – Obtain and distribute molecules for energy – Reproduce

Strategies of Fungi

Strategies of Fungi •  Growth – Filaments – Decomposers

•  Structure – Mass of filaments

•  Reproduction – Break filaments – Asexual reproduction •  Spores

Fungi-formerly classified as plants molds..mushrooms…yeast

Fungi – cont. •  Lichens (live in extreme environments) – Two interdependent species

Science in the Making •  The discovery of

penicillin – 1928 – Alexander Fleming

Strategies of Plants

The Simplest Plants •  Phylum: Bryophytes •  Structure – No roots – Photosynthetic

•  Reproduction – Sexual – Asexual

Bryophytes  

Vascular Plants •  Phylum: vascular plants •  Structure – Roots, stems, leaves – Control water loss

•  Reproduction – Seedless – Gymnosperms (seeds---no flowers) – Angiosperms (flowers and seeds) •  Sexual and asexual

Design of Vascular Plants

Angiosperm

h"p://youtu.be/RuYrFwDuYn0  

Reproduction of plants…

•  The  Brazil  nut  is  a  hard  shelled  seed  from  the  Brazil  nut  tree.  The  Brazil  nut  tree,  also  known  as  the  castana  tree,  is  from  the  Neotropics,  spread  out  from  southern  Mexico  into  southern  Brazil.    The  Brazil  nut  represents  only  a  single  species  in  of  the  genus  BertholleLa.    Although  there  is  considerable  variaLon  in  fruit  size  and  shape  and  number  of  seeds  per  fruit,  there  is  no  jusLficaLon  for  recognizing  more  than  one  species  of  BertholleLa.  

•  It  is  the  only  species  in  the  genus  BertholleLa  and  can  be  found  in  the  Amazon  forests  of  Brazil,  Bolivia,  Peru,  Columbia,  the  Guianas,  and  Venezuela.  The  Brazil  nut  tree  reach  heights  of  about  150  feet,  their  trunk  can  be  about  8  feet  in  diameter  and  can  live  about  500  years.  This  tremendous  tree  only  has  branches  and  leaves  at  the  top  third  of  the  tree.  The  branches  can  span  a  hundred  feet  providing  a  canopy  over  other  rain  forest  vegetaLon.  The  leaves  of  the  Brazil  nut  tree  are  long,  green  and  waxy.  At  the  end  of  the  leaf  is  a  yellow  orchid.  This  flower,  when  pollinated,  produces  the  fruit  that  contain  the  Brazil  nuts.  

•  Flowering  happens  during  the  dry  season  and  conLnues  into  the  wet  season.    Dry  season  is  very  important  for  Brazil  nuts,  they  grow  naturally  only  in  areas  with  a  4-­‐month  dry  season.    In  the  eastern  part  of  Amazonian  Brazil,  the  flowering  starts  near  the  end  of  the  rainy  season  in  September  and  runs  into  February.    October,  November,  and  December  are  when  the  Peak  flowering  happens.  

•  Cross-­‐pollinaLon  is  required  for  seed  set  in  Neotropical  Lecythidaceae.    The  Brazil  Nut  tree  depends  on  bees,  and  bats  to  pollinate  the  flowers  and  begin  the  fruit  and  seed  development  of  Lecythidaceae.  

•  The  large  shelled  fruit,  similar  to  a  coconut,  takes  about  14  months  to  mature.  The  fruit  is  about  4-­‐6  inches  in  diameter  and  can  weigh  up  to  4  pounds.  The  shell  of  the  fruit  is  about  a  quarter  of  an  inch  thick  and  inside  clustered  together  are  between  12-­‐24  brazil  nuts.  

•  Brazil  nuts  are  primarily  harvested  from  wild  trees  during  six  month  period  in  the  rainy  season.  The  fruits  weigh  between  0.5  to  2.5  kilograms  and  contain  about  20  seeds.  The  brazil  nut  trees  are  so  tall  that  harvesLng  the  fruits  consists  of  gathering  the  fruit  afer  they  fall.  Once  the  fruit  falls,  it  has  to  be  gathered  quickly  since  they  are  suscepLble  to  fungal  a"ack,  and  animals  also  carry  the  fruit  away.  

h"p://youtu.be/fIOUD1XFBeA   h"p://youtu.be/mZYmkd2FGUc  

Brazil-­‐Nut  Tree  Symbiosis  Gregory  Cello    Rainforests  are  characterized  by  a  unique  vegetaLve  structure  consisLng  of  several  verLcal  layers  including  the  overstory,  canopy,  understory,  shrub  layer,  and  ground  level.  One  of  the  largest  trees  in  the  rainforest  that  makes  up  a  large  porLon  of  the  canopy  is  the  Brazil  nut  tree  (Bertholle(a  excelsa).  These  trees  are  dependent  on  several  animal  species  for  their  survival  such  as  the  agouL,  a  ground-­‐dwelling  rodent,  for  a  key  part  of  their  life  cycle.  The  agouL  is  the  only  animal  with  teeth  strong  enough  to  open  their  grapefruit-­‐sized  seed  pods.  While  the  agouL  eats  some  of  the  Brazil  nut's  seeds,  it  also  sca"ers  the  seeds  across  the  forest  by  burying  caches  far  away  from  the  parent  tree.  These  seeds  then  germinate  and  form  the  next  generaLon  of  trees.  For  pollinaLon,  Brazil  nut  trees  are  dependent  on  Euglossine  orchid  bees.  Without  these  large-­‐bodied  bees,  Brazil  nut  reproducLon  is  not  possible.  For  this  reason,  there  has  been  li"le  success  growing  Brazil  nut  trees  in  plantaLons  as  they  only  appear  to  grow  in  primary  rainforest.    

Strategies of Animals

Major Animal Phyla

Invertebrates •  Invertebrates – No backbone – Most diverse animals

•  Arthropods – 70% of known animal species

•  Structure – Exoskeleton

Arthropods

Three Main Body Segments in Insects

Vertebrates •  Organization – Ocean to terrestrial

•  Evolution – Earliest fish – Bony Fish – Amphibians – Reptiles – Birds – Mammals

Modern Fish

Mammalian Family Tree

Thinking More about Life’s Strategies

•  Eating through the phyla