History of Life on Earth
How do scientists know about the existence of organisms millions of years ago?
By discovering & studying fossils
All vertebrates have this
a backbone
What is a vestigial structure?
Vestigial structures are structures that an organism has that are no longer used or needed in the way their ancestors used them.
What is the definition of an adaptation?
Over time animals change or evolve in ways that increase their chances of survival in their environment.
What happened to horse height over time, from 55 mya to today?
How many mass extinctions have there been in the past?
5
Name five species without a backbone.
snails, slugs, sea sponges, starfish, kelp, worms, or ants, octopus, and others
Name 3 bones found in the front limbs of humans and cats that are homologous structures.
humerus, ulna, radius, carpals, metacarpals, phalanges
What type of adaptation is thick fur on a polar bear?
structural adaptation
Has three body segments and three pairs of legs.
Insect
Which appeared first: Amphibians or land plants?
Land plants
Describe what an exoskeleton of an invertebrate is.
hard outer covering or shell to protect the insides
Name one vestigial structure in humans AND its purpose/function for our ancestors.
tailbone - helped balance & swinging, palmaris longus - climbing/swinging, auricular muscles - listen for nearby danger, wisdom teeth - chew/break down tough plant matter
Huddling by male penguins to conserve heat is an example of what?
behavioral adaptation
What is the reason for the Tasmanian tiger's extinction? (aka thylacine)
Humans caused the thylacine's extinction by hunting and habitat destruction.
Which fossilized horse front limb would be found in an older rock layer - a front limb with 2 toes or with 3 toes?
a front limb with 3 toes
- Stand upright
- Movement
- Supports other bones
- Protects the spinal cord
These are similar structures in organisms with shared ancestry. They evolved from a common ancestor but may not have the same function.
During the heat of the day in the desert, many lizards burrow underground to keep cooler. This is an example of a...
Behavioral adaptation
What is the main difference between herbivores, carnivores, and omnivores?
Herbivores - eat only plants
Carnivores - eat only other animals
Omnivores - eat plants & animals
The third mass extinction happened ~250mya, what percentage of species went extinct?
96%
What is the percent of the world's animals are vertebrates?
About 5%
What vestigial bones do whales have that suggest their ancestors were land mammals?
pelvis and hind (back) limbs
What is a physiological adaptation?
A body process that helps an organism to survive / How the animal’s body functions on the inside. Including changes in cells, chemicals, and processes inside an animal’s body.
An animal whose body temperature is maintained by it's surroundings.
cold-blooded animal