Origin of Animals

Question 1

How old are the oldest fossils of multicellular organisms?

Answer 1

1.2 billion years old (algae)

Question 2

How long ago did the first multicellular organism that can move on their own evolve?

Answer 2

3/4s to 1 billion years ago

Question 3

Oldest animal fossil

Answer 3

760 million year old sponge, otavia antiqua, size of a grain of sand

Question 4

Snowball Earth Hypothesis

Answer 4

sever ice age over all of earth occurred around 750 to 570 million years ago, as the earth thawed fossils show that a great radiation of multicellular organisms occurred

Question 5

Late Proterozoic Period

Answer 5

570 mya, larger soft bodied animals appeared, none were carnivorous

Question 6

Cambrian Period

Answer 6

540 to 485 mya, began with an explosion of new animal species caused by coevolution of predator and prey species, most extant animal phyla and body plans evolved

Question 7

Hox genes

Answer 7

control body plan and appendages, mutations of this gene occurred in the Cambrian period allowing evolution of new body plans