﻿EXTINCTION 
  AND 
  EXTEEMINATION 
  TOLMACHOFF 
  275 
  

  

  nated 
  by 
  man 
  in 
  a 
  very 
  short 
  time, 
  we 
  might 
  say 
  instantaneously, 
  in 
  

   a 
  catastrophic 
  way. 
  But 
  even 
  as 
  to 
  this 
  animal 
  we 
  are 
  not 
  quite 
  

   certain 
  as 
  to 
  the 
  real 
  cause 
  of 
  extinction. 
  It 
  inhabited 
  a 
  small 
  area 
  in 
  

   numbers 
  that 
  apparently 
  formed 
  a 
  remnant 
  of 
  a 
  species 
  that 
  was 
  once 
  

   abundant. 
  Its 
  propagation 
  had 
  doubtless 
  been 
  greatly 
  impaired 
  and 
  

   its 
  body 
  was 
  highly 
  specialized 
  with 
  respect 
  to 
  its 
  environment. 
  It 
  

   was 
  probably 
  already 
  well 
  advanced 
  toward 
  extinction 
  and 
  the 
  Bering 
  

   expedition 
  only 
  accelerated 
  its 
  end. 
  

  

  EXTINCTION 
  AND 
  EXTERMINATION 
  DISTINGUISHED 
  

  

  In 
  connection 
  with 
  the 
  extinction 
  of 
  Steller's 
  sea 
  cow, 
  exterminated 
  

   by 
  man, 
  let 
  us 
  consider 
  the 
  difference 
  betv^een 
  extinction 
  and 
  exter- 
  

   mination. 
  The 
  words 
  are 
  often 
  used 
  indiscriminately, 
  the 
  lack 
  of 
  dis- 
  

   crimination 
  causing 
  some 
  confusion 
  in 
  the 
  consideration 
  of 
  this 
  ques- 
  

   tion. 
  Extermination 
  is 
  the 
  killing 
  by 
  man, 
  by 
  other 
  animals, 
  or 
  by 
  a 
  

   change 
  of 
  climate, 
  flood, 
  or 
  any 
  other 
  outside 
  agent 
  — 
  all 
  directly 
  or 
  

   indirectly 
  affecting 
  an 
  individual 
  or 
  group 
  of 
  individuals. 
  Extinction 
  

   is 
  a 
  dying 
  out 
  ; 
  and 
  the 
  word 
  applies 
  to 
  a 
  species 
  or 
  to 
  any 
  other 
  larger 
  

   or 
  smaller 
  taxonomic 
  group. 
  If 
  the 
  word 
  is 
  used 
  in 
  referring 
  to 
  a 
  

   group 
  of 
  individuals, 
  as 
  to 
  a 
  number 
  of 
  animals 
  of 
  the 
  same 
  species 
  

   living 
  in 
  a 
  forest, 
  on 
  an 
  island, 
  or 
  in 
  some 
  other 
  restricted 
  area, 
  its 
  

   meaning 
  would 
  be 
  limited 
  geographically. 
  With 
  many 
  species 
  extinc- 
  

   tion 
  is 
  the 
  passive 
  reaction 
  of 
  the 
  organism 
  against 
  several 
  difi^erent 
  

   destructive 
  agents, 
  and 
  the 
  extinction 
  of 
  the 
  species 
  may 
  be 
  due 
  to 
  

   extermination. 
  Some 
  papers 
  on 
  extinction 
  deal 
  only 
  with 
  extermi- 
  

   nation. 
  A 
  good 
  example 
  is 
  a 
  paper 
  by 
  Osborn, 
  "The 
  causes 
  of 
  extinc- 
  

   tion 
  of 
  mammalia," 
  ^^ 
  in 
  which 
  the 
  numerous 
  possible 
  causes 
  of 
  exter- 
  

   mination 
  of 
  mammals 
  are 
  considered 
  in 
  great 
  detail. 
  The 
  difference 
  

   between 
  these 
  phenomena 
  has 
  been 
  emphasized 
  in 
  an 
  article 
  by 
  Smith 
  

   Woodward. 
  In 
  his 
  words, 
  "Local 
  extinction, 
  or 
  the 
  disappearance 
  of 
  

   a 
  group 
  of 
  restricted 
  geographical 
  range, 
  may 
  be 
  explained 
  by 
  acci- 
  

   dents 
  of 
  many 
  kinds, 
  but 
  contemporaneous 
  universal 
  extinction 
  of 
  

   widely 
  spread 
  groups, 
  which 
  are 
  apparently 
  not 
  affected 
  by 
  any 
  new 
  

   competitors, 
  is 
  not 
  so 
  easily 
  understood." 
  ^^ 
  He 
  does 
  not 
  try 
  to 
  ex- 
  

   plain 
  "the 
  universal 
  extinction" 
  except 
  in 
  connection 
  with 
  the 
  old 
  

   age 
  of 
  a 
  race. 
  His 
  "local 
  extinction" 
  and 
  "general 
  extinction" 
  cor- 
  

   respond 
  exactly 
  to 
  extermination 
  and 
  extinction 
  as 
  both 
  these 
  words 
  

   have 
  been 
  used 
  in 
  the 
  present 
  paper. 
  

  

  Extermination 
  that 
  might 
  affect 
  two 
  species, 
  one 
  a 
  prolific 
  group 
  

   and 
  the 
  other 
  a 
  group 
  already 
  in 
  process 
  of 
  extinction, 
  if 
  it 
  were 
  to 
  go 
  

   on 
  incessantly, 
  would 
  produce 
  the 
  same 
  result 
  in 
  both 
  species 
  — 
  both 
  

   would 
  become 
  extinct. 
  If, 
  however, 
  extermination 
  were 
  checked, 
  the 
  

  

  " 
  American 
  Naturalist, 
  Vol. 
  xl, 
  pp. 
  769-795, 
  829-859, 
  1906. 
  

  

  2» 
  A. 
  Smith 
  Woodward, 
  Address 
  of 
  the 
  President 
  to 
  the 
  Geological 
  Section 
  of 
  the 
  British 
  Association 
  for 
  

   the 
  Advancement 
  of 
  Science. 
  Science, 
  Vol. 
  xxx, 
  p. 
  327, 
  1909. 
  

  

  82322—30 
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