Macroevolution class two

Macroevolution

refers to major events on the history of life

what 3 things drives macroevolution

1. Plate tectonics

2. Mass extinctions

3. Adaptive radiations

Why is earth in constant motion

Rocky crust of the earth sits atop of molten mantle which allows the crust to drift along the surface

Theory of plate tectonics

Earth’s crust is broken into peices/plates

Continental drift

earth plats are in constant motion

3 types of plate boudnries

1. Convergence: moving towards each other

2. Divergent: Moving away from each other

3. Transform: Sliding past

Supercontinent

Believed that at 3 points in history of earth all land masses were joined together

• most recent with pangea

What is evidence of supercontinent

Marsupials (opossum)

Mass extenctions

Large scale losses of many species at once

• Reasons may include loss of habitat changing climate

• Vast majority of species that have existed in life and are now extint

5 main mass extintions

1. Ordovician

2. Devoian

3. Permian

4. Triassic

5. Cretaceous

How does mass extinction allow for macroevolution

Each mass extinction completley disrupts the complex web of relationships between organisms that inhabit the same habitat. Allows new forms of life to emerge

Adaptive radiations

evolutionary periods in which many species evolve from a common ancestory

• occurs after has extinctions because many ecological roles or chiche are avaible to be filled

drastic changes in species morphology can arise from what

mutations in genes that control development

Homeotic genes

genes that control body plan development

Taxonomy

Sciences of clasifying organisms and naming them

• currently 8 levels

8 levels of taxonomy

1. Species

2. Genus

3. Family

4. Order

5. Class

6. Phylum

7. Kindgom

8. Domains

Binomial nomenclature

unique two part name

includes the genus and specific species name

Phylogenetic trees

a way to arrange organisms in accordance with their relatedness

• relatedness is determined by similar morpholical features and simialrties in genetics

Clades

groups of organisms with a common ancestor