Touch and pressure are sensed by four types of mechanoreceptors:

Meissner’s corpuscles

Merkel cells

Ruffini corpuscles

Pacinian corpuscles

TLS Online TPP Program

#Id: 7036

#Unit 11. Evolution and Behavior

 Alfred Russel Wallace - Who was collecting specimens in the Malay Archipelago, had independently conceived of natural selection.

TLS Online TPP Program

#Id: 7037

#Unit 11. Evolution and Behavior

Darwin’s evolutionary theory - Evolution as such is the simple proposition that the characteristics of organisms change over time. 

Geometric increase 

Limited food & Space

Struggle for existence 

Variation 

Natural selection

Inheritance of useful characters

Speciation 

TLS Online TPP Program

#Id: 7038

#Unit 11. Evolution and Behavior

Darwin’s evolutionary theory - Common descent

TLS Online TPP Program

#Id: 7039

#Unit 11. Evolution and Behavior

Gradualism is Darwin’s proposition that the differences between even radically different organisms have evolved by small steps through intermediate forms, not by leaps

TLS Online TPP Program

#Id: 7040

#Unit 11. Evolution and Behavior

Populational change is Darwin’s hypothesis that evolution occurs by changes in the proportions (frequencies) of different variant kinds of individuals within a population.

TLS Online TPP Program

#Id: 7041

#Unit 11. Evolution and Behavior

 Natural selection was Darwin’s brilliant hypothesis, independently conceived by Wallace, that accounts for adaptations, features that appear “designed” to fit organisms to their environment.