Evolution

Adaptive Radiation

The speciation and adaptation of an array of species Species show different morphological and physiological traits

Galapagos

Darwin’s Finches Darwin noticed varieties of finches on the Galapagos Kept specimens, but didn’t record which islands they came from Back in England, recognized they were closely related, but different species Finches evolved from an ancestor that came from mainland S.America

Darwin’s Finches

Convergent and Divergent Evolution

Convergent Pattern of evolution in which similar traits arise because different species have independently adapted to similar conditions Divergent Pattern of evolution in which species that were once similar to an ancestral species diverge, or become more distinct

Convergent

Divergent

Mass Extinctions

Large scale dying out of a large percentage of all living organisms in an area over a relatively short period of time There have been 5 global mass extinctions

The Big 5 EraTimeExtinctionCause Cretaceous – Tertiary 65.5 Ma50% of all Genera, 75% of all species Dinos killed off, mammals and bird evolved as dominant Asteroid or Comet, volcanic events Triassic- Jurassic 205 Ma48% of all Genera Large amphibians, other non-dinos Dinos evolved as dominant (no competition) Small impacts, gradual climate change, massive volcanic eruptions Permian- Triassic 251 Ma83% of all Genera Many insects killed off, Archosaurs become dominant Mother of all mass extinctions Impact? Volcanism, climate change, Combination? Late Devonian Ma 50% of all GeneraMany causes, ocean anoxia, global cooling caused by ocean volcanism Ordovician- Silurian Ma 57% of all Genera Many invertebrates extinct Movement of Gondwana

Co-evolution

Coevolution The change of a species triggered by the change of a related object