SELECTION & ADAPTATION Darwin´s theory explains why

individuals are usually well adapted to their environment

ADAPTATION = an inherited trait present in a population because the trait helps individuals to survive and reproduce in a specific environment

DARWIN´S EVIDENCE FOSSILS Darwin believed evolution occurred due

to differences in the fossil record (all existing fossils)

Darwin noticed

patterns of gradual

change in the fossil

record

DARWIN´S EVIDENCE BIOGEOGRAPHY Darwin studied locations of organisms

Similar environments cause the evolution of organisms in similar ways

Similar organismsSimilar

enviornmentsDIFFERENT locations

DARWIN´S EVIDENCE DEVELOPMENTAL BIOLOGY Common patterns and structures of

developing embryos could mean common ancestors

All vertebrate embryos have a tail at some time

during development

DARWIN´S EVIDENCE ANATOMY Many internal similarities exist in bodily

structure

The forelimbs of many vertebrates are composed of the same basic

groups of bones = HOMOLOGOUS STRUCTURES

DARWIN´S EVIDENCE BIOCHEMISTRY Change over time can be traced through

changes in DNA

Close relatives have few

differences in amino acids

Very different species have many

differences in amino acids

DARWIN´S STRENGTHS1. EVIDENCE – Darwin was the first person

to propose evolution AND give supporting evidence (others had proposed evolution but didn´t have proof)

2. MECHANISM – Darwin´s theory of natural selection gave a reason for evolution to occur

3. IMPORTANCE OF VARIATION – Darwin showed variation in species everywhere (species did not stay the same forever). This diversity is the starting point of evolution.