Comparing Survivorship of Americans in the 1800s and Modern Times, Study notes of Biology

Download Comparing Survivorship of Americans in the 1800s and Modern Times and more Study notes Biology in PDF only on Docsity! Human  Populations:    Type  I,  II,  III    Survivorship  Curves     SC  Academic  Standards:  4.L.5A;  5.L4A;  6.L.4B;  7.EC.5A,B;  H.B.6A,C.   NGSS  DCI:    5-­‐ESS3.C;  MS-­‐LS2A,C,D;  MS-­‐ESS3.C;  HS-­‐LS2.A,C.   Science  and  Engineering  Practices:    S.1A.1;  S.1A.2;  S.1A.3;  S.1A.4;  S.1A.5;  S.1A.6;   S.1A.7   Crosscutting  Concepts:  Patterns;  Scale,  Proportion,  and  Quantity;  Stability  and   Change;  and  Systems  Models.   Focus  Question(s):    How  is  survivorship  of  modern  Americans  different  from   the  survivorship  of  Americans  living  in  the  1800’s?      How  can  survivorship   curves  be  used  to  predict  population  growth  dynamics?   Conceptual  Understanding:    Ecosystems have carrying capacities, which are limits to the numbers of organisms and populations they can support. Limiting factors include the availability of biotic and abiotic resources and challenges such as predation, competition, and disease. A complex set of interactions within an ecosystem can keep its numbers and types of organisms relatively stable over long periods of time. Fluctuations in conditions can challenge the functioning of ecosystems in terms of resource and habitat availability Each plant or animal has a unique pattern of growth and development called a life cycle. Some characteristics (traits) that organisms have are inherited and some result from interactions with the environment. In all ecosystems, organisms and populations of organisms depend on their environmental interactions with other living things (biotic factors) and with physical (abiotic) factors (such as light, temperature, water, or soil quality). Disruptions to any component of an ecosystem can lead to shifts in its diversity and abundance of populations.     Background:    Demography  is  the  study  of  population  dynamics  -­‐  how  populations   grow  and  decline.    The  worldwide  human  population  is  currently  experiencing  a   population  growth  phase,  and  presently  is  increasing  at  an  exponential  rate   (though  it  is  slowing  slightly,  human  growth  rate  is  still  positive).    Today,  the  human   population  is  just  over  6  billion  people,  and  is  expected  to  double  in  about  35  years   (300  years  ago,  the  human  population  used  to  double  every  600  years!)    By  the  year   2050  we  could  have  10-­‐12  billion  people  on  earth!      We  are  unsure  of  the  carrying   capacity  of  the  earth;  some  scientists  fear  we  have  already  surpassed  it.     Populations  grow  as  more  members  are  added  (through  births  and  immigration)   and  populations  decline  as  members  are  deleted  (through  deaths  and  emigration).     Stable  populations  have  a  balance  between  birth  (and  immigration)  rates  and  death     (and  emigration)  and  are  said  to  have  a  zero  population  growth  rate  (G=0,  where   G  is  the  Growth  Rate  of  a  population).    Predation  and  Competition  also  help  to  keep   population  sizes  stable.         Today  we  will  look  at  survivorship  /  mortality  curves,  and  construct  a  static  life   table.    A  survivorship  curve  traces  the  decline  in  number,  over  time,  of  a  group  of   individuals  born  at  the  same  time  (a  cohort).    It  can  be  thought  of  as  the  probability   of  an  individual  surviving  to  various  ages,  or  the  average  Life  Expectancy.    Life   expectancy  is  different  from  the  Maximum  Life  Span  (i.e.  the  American  robin,   Turdus    migratorius,  can  live  to  be  7  years  old  but  the  probability  of  a  newly  hatched   robin  doing  so  is  less  than  1  %.    Many  live  only  a  year  or  two.    Life  expectancy  is  1-­‐2   years,  maximum  life  span  is  7  years).         The  life  expectancy  of  human  populations  has  increased  significantly  in  the  past   100  -­‐  300  years  due  to  improved  nutrition,  preventative  medicine,  life-­‐style  changes,   improved  sewage  control  and  hygiene  and  new  technologies  such  as  refrigeration   and  pasteurization.    In  the  early  days  of  Rome,  life  expectancy  was  only  22  years!    In   America  in  1900,  the  life  expectancy  was  about  48  years;  in  2010  it  was  78.9  years.                   A  Dominican  woman  lived  to  a  ripe  old  age  of  127  (the  maximum  human  life  span).       Disease  often  limited  population  size  prior  to  the  late  1800s.  Although  reproductive   rates  were  high,  child  mortality  rates  were  also  high,  so  the  population  remained   relatively  steady.  With  the  development  of  medicine,  vaccines,  and  improvements  in   sanitation,  there  was  a  decrease  in  infant  and  childhood  mortality.  This  drop  in   mortality  can  be  seen  as  an  increase  in  survivorship.    In  brief,  survival  rates  are  up   and  mortality  rates,  especially  infant  mortality  rates,  are  down:    this  leads  to   population  growth.       As  human  populations  progress  through  time  their  population  growth  rates  follow   predictable  patterns  called  the  demographic  transition  (where  birth  rates  are  high   but  death  rates  are  also  high  at  early  stages,  but  by  the  end  of  the  progression  both   birth  and  death  rates  are  low).    First  world  nations  have  passed  through  the   transition  already;  many  third  world  countries  are  in  the  midst  of  the  transition   currently.  The  goal  of  many  human  rights  organizations  is  to  help  developing   countries  pass  through  the  transition  and  enter  the  4th  ,  post-­‐industrial,  stage,  where   growth  rate  is  low  and  stable,  leading  to  a  stable  (non-­‐growing)  population  size  –   the  sooner  all  populations  are  at  ZPG  (zero  population  growth)  the  better  off  our   world  will  be  as  we  approach  the  end  of  our  finite  resources.    As  the  United  States   has  progressed  through  the  industrial  revolution  and  the  demographic  transition   model  over  the  last  150  years,  changes  in  the  life-­‐styles  of  citizens  have  been   reflected  in  their  age  at  death.    Factors  such  as  diseases  and  accidents  have  changed   in  their  relative  impacts.    One  way  to  study  these  changes  in  human  demographic   patterns  is  to  visit  a  local  cemetery  and  collect  data  recorded  on  tombstones-­‐  from   this  you  can  create  a  survivorship  curve.   Previous  Knowledge:  (sociology):    It’s  is  good  to  have  a  little  sociological   background  on  your  area:  There  are  great  variations  in  life  expectancy  between   different  parts  of  the  world,  mostly  caused  by  differences  in  public  health,  medical   care,  and  diet.  The  impact  of  AIDS  on  life  expectancy  is  particularly  notable  in  many   African  countries.    In  the  United  States,  particularly  the  southeast,  in  the  1700’s   there  were  a  couple  scarlet  fever  epidemics  (1735-­‐40,  1786);  during  the  civil  war   (1860-­‐1865)  typhoid  epidemics  and  malaria  claimed  lives;  there  was  a  flu  epidemic   in  1857-­‐59  and  in  1918-­‐19  (the  Spanish  Flu  of  1917/18  infected  1/5  of  world   population,  with  3%  dying  from  flu).     And,  from  Sundstrom,  William,  et  al.  "Industrialization  and  Fertility  in  the  19th   Century:  Evidence  from  South  Carolina."     http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CCI QFjAA&url=http%3A%2F%2Fweb.utk.edu%2F~mwanamak%2FJEHarticle.pdf&ei= 0S8sVPDkE4eyyQTQzIG4AQ&usg=AFQjCNFM7BmNn6zy4b1tTO2SFk-­‐YAQin-­‐ Q&bvm=bv.76477589,d.aWw     “By  the  dawn  of  the  20th  century,  fertility  rates  in  the  United  States  had   undergone  a  century  of  steady  decline.  In  1800,  white  American  females   could  expect  to  bear  7.0  children  on  average;  by  1900,  this  number  was  3.6.   The  factors  behind  the  19th  century  decline  have  been  the  subject  of  a   lengthy  literature  highlighting  the  importance  of  intergenerational  bequests,   the  economic  value  of  children,  and  the  cultural  context  for  American  family   formation.   There  are  a  number  of  mechanisms  by  which  industrialization  may  have   altered  a  household's  fertility  outcome.  First,  several  models  of  economic   growth  and  fertility  decline  highlight  the  role  of  human  capital  in  increasing   the  incentives  of  households  to  invest  in  child  quality  over  quantity,  thereby   reducing  the  number  of  children  born.  Second,  industrialization  may  have   induced  a  rise  in  the  implicit  costs  of  raising  children.  In  particular,   industries  with  high  rates  of  female  employment  increased  the  opportunity   cost  of  female  time.  Under  the  assumption  that  the  child  production  process   is  female  time-­‐  intensive,  this  would  have  reduced  the  incentive  to  bear   children.  Third,  the  movement  away  from  agricultural  and  at-­‐home   production  to  centralized  production,  in  addition  to  more  restrictive  child   labor  laws,  may  have  reduced  the  economic  return  to  children,  again   lowering  parental  demand  and  fertility  rates.  Fourth,  industrialization  was   associated  with  increased  urbanization  and  the  crowding  that  occurred  may   have  increased  the  explicit  costs  of  raising  children  through  higher  housing   and  food  costs  without  an  associated  increase  in  the  benefit.  Finally,  the   developing  economy  in  the  United  States  witnessed  decreases  in  child   mortality  rates,  especially  after  1880.”       http://io9.com/5920871/how-­‐we-­‐died-­‐200-­‐years-­‐ago-­‐compared-­‐to-­‐how-­‐we-­‐die-­‐ today     Question  1:    Do  people  living  in  modern  times  (1900’s)  have  a  longer  life   expectancy  versus  people  living  in  the  1800’s?     Hypothesis:       Null  Hypothesis:       Question  2:    In  the  1800’s,  who  had  a  longer  life  expectancy,  men  or  women?     Hypothesis:       Null  Hypothesis:       Procedure:    (*Note:  you  may  want  to  divide  the  class  into  4  groups,  one  group  finds   50  tombstones  of  males  you  died  before  1900,  one  group  looks  for  50  tombstones  of   females  …  and  so  on).     1. Select  100  tombstones  of  people  (50  males  and  50  females)  that  died  before   1900  (so,  they  lived  in  the  1800’s)  and  record  their  ages  at  death  and  the  sex   of  the  individual.     2. Next,  choose  100  tombstones  of  people  (50  males  and  50  females)  who  died   after  1980  (living  the  bulk  of  their  life  in  the  1900’s,  though  some  may  have   lived  in  the  2000’s  as  well  –  that’s  ok)  and  record  their  ages  at  death  and  the   sex  of  the  individual.     3. Then,  construct  a  static  life  table  from  these  data  using  the  attached  data   sheet.    Determine  values  for  the  number  of  individuals  who  were  alive  at  age   0-­‐9  years    (interval  1),  10  -­‐  19  years,  20  -­‐  29  years  and  so  on.    Also,  determine   the  number  of  individuals  who  died  during  each  interval  (the  opposite  of  a   survivorship  curve  is  a  mortality  curve).    A  survivorship  curve  is  prepared  by   plotting  the  logarithm  of  the  number  of  survivors  against  age.     4. Finally,  Plot  the  %    survivorship  versus  age  intervals  for  the  different   populations.    (Note:  typically  this  is  graphed  as  log  10  (%S)  but  the  curve   comes  out  about  the  same  so  you  can  choose  to  graph  it  normally,  %  S  on  Y   and  age  interval  on  X,  or  use  semi-­‐log  graph  paper  with  %S  on  Y  and  age   interval  on  X.         Age   Interval   (years)   Age  at  Death   (years)     (List  the  separate  ages   of  death  for  each   individual  who  died  in   this  age  interval.  The   total  goes  in  the  next   column)   #  who   died   during   interval   Survivorship   (#  still  alive)   %  Survivorship     (  #  still  alive  /   total  number  of   people  in   cohort)  x100   0-­‐1           2-­‐9           10-­‐19           20-­‐29           30-­‐39           40-­‐49           50-­‐59           60-­‐69           70-­‐79           80-­‐89           90-­‐99           100+           TOTAL   50   50   0   0   Table  3:    MALES  who  died  after  1980  (Lived  in  1900s):       What  was  the  average  age  of  death  (average  life  expectancy)?  ____________       Maximum  life  span  ?________________               Age   Interval   (years)   Age  at  Death   (years)     (List  the  separate  ages   of  death  for  each   individual  who  died  in   this  age  interval.  The   total  goes  in  the  next   column).   #  who   died   during   interval   Survivorship   (#  still  alive)   %   Survivorship     (  #  still  alive  /   total  number   of  people  in   cohort)  x100   0-­‐1           2-­‐9           10-­‐19           20-­‐29           30-­‐39           40-­‐49           50-­‐59           60-­‐69           70-­‐79           80-­‐89           90-­‐99           100+           TOTAL   50   50   0   0   Table  4.    FEMALES  who  died  after  1980  (Lived  in  1900s):     What  was  the  average  age  of  death  (average  life  expectancy)?  ____________     Maximum  life  span  ?________________       Now,  Plot  the  survivorship  versus  age  intervals  for  both  males  and  females  who   died  before  1900  on  ONE  graph.             Data  Analysis:  From  the  data  table,  graph  %S    (Y  axis)  versus  Age  Interval  (X  axis).     All  4  data  sets  should  go  on  the  same  graph.     Here  is  a  sample  of  what  a  completed  data  table  should  look  like:       Age   Interval   (years)   Age  at  Death   (years)     (List  the  separate  ages   of  death  for  each   individual  who  died  in   this  age  interval)     #  who   died   during   interval   Survivorship   (total  #  still   alive)         50  total:   %   Survivorship     ((  #  still  alive  /   total  number   of  people  in   cohort  )  x100)   0-­‐1   2  months   1   49   98%   2-­‐9   3,    5   2   47   94   10-­‐19    11   1   46   92   20-­‐29   20   1   45   90   30-­‐39    31,    32,      38   3   42   84   40-­‐49   48,    48   2   40   80   50-­‐59   50,    57   2   38   76     And  so  on  –  until  you  have  50  ages  at  death     All  ages  added   together  =       x   x   x   Average    life   Expectancy  =   total  of  all   ages  /  50   names     x   x   x   Total   50  ages     50   0   0     Students  may  find  it  useful  to  begin  with  a  data  table  like  the  one  on  the   following  page.         With-­‐out  Care         With  Care                                               Total  #  of  bubbles  =   _____       Total  #  of  bubbles  =  _____       Average  Age  at  Death  =  ____       Average  Age  at  Death  =  _____     Table  1.    Bubble  survival  rate  with  and  without  care.                                                 Bubble  number  one  lived    _____  sec.                                                               Age  at  Death            and     Survivorship*               Time  (seconds)    Without  Care   With     Without  Care*     With*   Time  Zero      X      X   total  #  bubbles  =     total  =   0-­‐4           5-­‐9           10-­‐14           15-­‐19           20-­‐24           25-­‐29           30-­‐34           35-­‐39           40-­‐44           45-­‐49           50-­‐54           55-­‐59           60-­‐64           >  65           Table  2:   Age  at  Death    and  Survivorship*       *subtract  the  number  that  died  in  the  interval  from  the  total  #  of  bubbles  to     get  how  many  are  still  alive  (survivorship)     Now  make  two  graphs:    one  of  Age  at  Death  versus  Time  Interval  (bar  graph)     and  one  of    Survivorship  versus  Time  Interval  (Line  Graph).    Each  Graph   contains  two  data  sets.           Reflection  Questions:   • What  type  of  survivorship  curve  (I,  II,  or  III)  did  you  find  for  your  data?     What  does  this  reflect?        (Type  I)     • Did  your  data  show  a  difference  in  age  at  death  between  males  and   females?  For  which  cohort?    Why  do  you  think  this  happened?     • What  was  the  average  life  expectancy  for  people  living  in  the  1800’s?   ________        For  people  living  in  the  1900’s?    __________     • Why  did  American  families  living  in  the  colonial  period  want  and  need   to  have  large  families?  (to  help  work  the  farm  –  most  people  lived  on  farms   and  grew  their  own  food  (no  grocery  stores).     What  are  some  factors  that  led  to  low  life  expectancies  in  the  American   Colonial  period?    (In  the  1700’s  there  were  a  couple  scarlet  fever  epidemics   (1735-­‐40,  1786);  during  the  civil  war  typhoid  epidemics  and  malaria  claimed   lives;  there  was  a  flu  epidemic  in  1857-­‐59  and  1918-­‐19  (Spanish  Flu  infected   1/5  of  world  population  with  3%  dying).     • Why  are  life  expectancies  throughout  the  world  so  different?       (There  are  great  variations  in  life  expectancy  between  different  parts  of  the   world,  mostly  caused  by  differences  in  public  health,  medical  care,  and  diet.   The  impact  of  AIDS  on  life  expectancy  is  particularly  notable  in  many  African   countries).     Models  and  Explanations:    In  this  lab  we  explored  survivorship  curves  and   population  growth  rates.    A  student  who  demonstrates  understanding  of  these   concepts  can  explain  why  population  growth  rates  are  different  today  than  they   were  over  100  years  ago,  and  can  explain  why  modern  Americans  have  a  Type  I   survivorship  curve.    This  student  can  also,  given  some  life  history  details  of  an     organism,  such  as  size,  reproductive  patterns,  fecundity,  and  life  span,  predict  if  the   species  will  show  a  Type  I,  II,  or  III    survivorship  curve.       Bibliography:   Campbell  Biology  (9th  edition).  (2010).    Benjamin  Cummings  Publishing.     Condran,  G.  and  E.  Crimmins.    1980.    Mortality  differentials  between  rural  and  urban  areas   of  states  of  the  northeastern  United  States  1890-­‐1900.    Journal  of  Historical  Geography   6  (2):  179-­‐202.     Dethlefsen,  E.S.  and  K.  Jensen.    1977.    Social  commentary  for  the  cemetery.    Natural  History   86(6)  32-­‐29.     Kuntz,  S.    1984.    Mortality  change  in  America,  1620-­‐1920.    Human  Bio.  56:  559-­‐582.     Lee,  R.    (2003).  The  Demographic  Transition:  Three  Centuries  of  Fundamental  Change.     Journal  of  Economic  Perspectives  17:(4)  -­‐  167–190.     Pike,  L.,  Krebs,  J.,  Stoeckmann,  A.,  Steinmetz,  J.,    Ludlam,  J.,  Malakauskas,  D.;  Malakauskas,  S.;   and  Vanderhoff,  N.    (2013).  Biology  103L  Environmental  Biology  Laboratory,  3rd  edition.     Francis  Marion  University  custom  publishing,  Florence  SC,  USA.             Pike,  L.,  and  B.  Fox.    (2002).    Project  Intermath  (COMAP):  Survival  of  Early  Americans.     Retrieved  October  1,  2014  from   http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&ved=0CCwQFjAC &url=http%3A%2F%2Fwww.cengage.com%2Fmath%2Fbook_content%2F0495011592_gi ordano%2Fstudent_cd%2Filaps%2Fsurvival_americans.pdf&ei=RxMsVNe9IsylyATmgYLoD Q&usg=AFQjCNFZlKSYocXf2C-­‐gUiTHEuxMND5iDw&bvm=bv.76477589,d.aWw     Pianka,  E.    (1970).  On  r  and  k  selection.  The  American  Naturalist  104  (940):  592-­‐597         Age   Interval   (years)   Age  at  Death   (years)     (List  the  separate  ages   of  death  for  each   individual  who  died  in   this  age  interval.    The   total  goes  in  the  next   column).   #  who   died   during   interval   Survivorship   (#  still  alive)   %   Survivorship     (  #  still  alive  /   total  number   of  people  in   cohort)  x100   0-­‐1           2-­‐9           10-­‐19           20-­‐29           30-­‐39           40-­‐49           50-­‐59           60-­‐69           70-­‐79           80-­‐89           90-­‐99           100+           TOTAL   50   50   0   0   Table  2.        FEMALES  who  died  before  1900  (Lived  in  1800s):     What  was  the  average  age  of  death  (average  life  expectancy)?  ____________         Maximum  life  span  ?________________       Now,  Plot  the  survivorship  versus  age  intervals  for  both  males  and  females  who   died  before  1900  on  ONE  graph.           Age   Interval   (years)   Age  at  Death   (years)     (List  the  separate  ages   of  death  for  each   individual  who  died  in   this  age  interval.  The   total  goes  in  the  next   column)   #  who   died   during   interval   Survivorship   (#  still  alive)   %  Survivorship     (  #  still  alive  /   total  number  of   people  in   cohort)  x100   0-­‐1           2-­‐9           10-­‐19           20-­‐29           30-­‐39           40-­‐49           50-­‐59           60-­‐69           70-­‐79           80-­‐89           90-­‐99           100+           TOTAL   50   50   0   0   Table  3:    MALES  who  died  after  1980  (Lived  in  1900s):       What  was  the  average  age  of  death  (average  life  expectancy)?  ____________       Maximum  life  span  ?________________               Age   Interval   (years)   Age  at  Death   (years)     (List  the  separate  ages   of  death  for  each   individual  who  died  in   this  age  interval.  The   total  goes  in  the  next   column).   #  who   died   during   interval   Survivorship   (#  still  alive)   %   Survivorship     (  #  still  alive  /   total  number   of  people  in   cohort)  x100   0-­‐1           2-­‐9           10-­‐19           20-­‐29           30-­‐39           40-­‐49           50-­‐59           60-­‐69           70-­‐79           80-­‐89           90-­‐99           100+           TOTAL   50   50   0   0   Table  4.    FEMALES  who  died  after  1980  (Lived  in  1900s):     What  was  the  average  age  of  death  (average  life  expectancy)?  ____________     Maximum  life  span  ?________________       Now,  Plot  the  survivorship  versus  age  intervals  for  both  males  and  females  who   died  before  1900  on  ONE  graph.