Adaptations & Evidence of Evolution

Types of Adaptations

Mimicry and Camoflague

Mimicry

Copies the appearance or behavior of other species.

Ex. Viceroy and monarch butterflies

Camoflague

Blends in with surroundings.

Ex. Moths, chameleons, tigers, octopus

Types of Evidence

Fossil Record, Anatomical Record, and Molecular Record

Fossil Record

Shows change over time

Anatomical Record

Comparing body structures

• Homology + vestigial structures

• Embryology + Development

Molecular Record

Comparing protein & DNA sequences

• The more similarities, the more closely related

The 3 Structure Types

Homologous, Analogous, and Vestigial

Homologous Structure

• Same origin (divergent evolution)

• Same structure

• Same development in embryo

• Different functions

This is valid evidence of evolution and common ancestors.

Analogous Structure

• Looks similar

• Same function

• Different structure

• Different origin (convergent evolution)

This is NOT evidence of evolution.

Vestigial Structure

Structures that have lost use over time and now serve NO purpose.

Ex. The tail bone in humans.

True or False? Organisms with similar structures while developing tend to be closely related.

True

What is the name of the group of fossils that are used as evidence for evolution because they show intermediate forms of a species as well as the gradual changes and accumulation of adaptations?

These types of fossils show a middle form of two different species

Transitional Fossils

Relative Dating

• Can determine which fossil is older

• Process: Comparing the depth of a fossil

Absolute Dating

• Can determine the age of a fossil in years

• Process: Measuring the decay of carbon

Which is more precise: relative or absolute dating?

Absolute Dating

Index Fossil

These are important in relative dating- they are easily recognizable, abundant, has a wide geographic range (found in many places), but has a limited time range that it existed on Earth.

Ex. Trilobite

Which is older: the fish, shell, or ammonite?

Ammonite

Characteristics of a Herbivore’s Teeth

The teeth of herbivores are long, flat, and grow continuously. These teeth grow continuously because herbivores usually spend most of their time chewing. Since herbivores eat plants, their teeth does not need to be as sharp. 

Characteristics of a Carnivore’s Teeth

Carnivores have well-developed incisors that help them hold on to their prey. Their molars and premolars are jagged, used for tearing. 

Characteristics of a Omnivore’s Teeth

Since omnivores eat both meat and plants, their molars are flat for grinding. Meanwhile, an omnivore’s canines are less developed than a carnivore’s.