rill-: ()i:n;i.\ A\n i'aoia rio.s of lii'i: 



EXAMPLES 



OF CONVERGENT 



ADAPTATION 



Aiiinials Imm-oiih' Ntnirlunill.N iHliipli'cl 

 to tin- ciiviromiii'iit in wliicli llii-y live, 

 iiiid forms not i-lost-ly ri'liitt'd — in fiii-t 

 very disliintly rrliiti-il luul living in 

 widfly M'lmnitccl pnrts of llii> k1<>'"'~ 

 may tiiki- on I'xactly ^iIuilat• ailiipla 

 lions when artrd ni>on liy similar en 

 vironnn-nts. 



Tliis is t-Hsily stvii in adaptations 

 for aqnatic locomotion. In each in 

 slanro tlio mtrliunical ri'sistanrt' of 

 tin' watiT to rapid motion is overcome 

 li_\ lonu and sli'iidcr liodv linc^ and 

 ^idcwisc tiattcniiit; of llic lail: rapid 

 propnlsion is accomiilislicil li_\ >iniioiis 

 niovcmcnt of this lonj; l)0(l> . and 

 swooping puddle work of llic t:iil. 

 aided by movement of the fore and 

 hind appendages which take on more 

 or less perfectly the form of fins. 



The three upper drawings repre- 

 sent restorations of tliree extinct re))- 

 tiles, — ichthyosaur, primitive sea liz- 

 ard, and sea crocodile; the foiirth be- 

 low, is an extinct amphibian; the fifth 

 a mammal (a primitive whale) — and 

 we know that rapid-swimming fishes 

 also have the same adai)tations. 



Such development of similar struc- 

 tures and habits responsive to simi- 

 lar external forces, implies similar- 

 ity in the physicochemical energies 

 of protoplasm and chromatin and 

 orderliness in their behavior, as well 

 as constant similarity in the working 

 of selei-tion 



^MBOSPONOrLUS 



■^^SMii.' 



GEOS*URUS 



^-„;^ 



^^ 



CRETACEOUS 



\^^ 



CRICOTUS PERMO- 



CARBONIFEROUS 



