exam 3 animal with hard parts

soft bodied animals feeding

• filter feeding

• poison and tangle pray

• pharynx

soft bodied animals defense

toxins and camouflage

types of heard parts

• spicules in sponges

• skeletons

• jaws

• shells

• exoskeletons

• endoskeletons

• gravity sensors

• lenses of eyes of trilobites

biominerlization

formation of minerals with an organic matric

biominerals

• calcium salts

• calcium phosphate

• silica salts

• metal oxides

organic materials contribute to hardness

• melanin

• variety of other proteins

• chitin

melanins

pigment

chitin

complex polysaccharide

formation of biomineralized materials

• regulate Ca2+ &CO3-

epithelial tissues

surface for crystals to grow on

precipitation

deposition of inorganic components

biomineralization will only evolve if

costs are less than benefits

Cambrian esplosion

1. increased atmospheric O2

2. increased calcium carbonate in water

3. evolution of new genes

4. evolution of predators = evolutionary arms race

evolution of new genes

• duplication and modification of existing genes

• horizontal gene transfer (swap genes)