Unit 9: Evidence of Evolution Flashcards
What are examples of adaptations that help prove evolution?
1.) Antibiotic resistance
2.) Weeds and insects that have become
resistant to pesticides
3.) Flea and tick resistance to medications
4.) Peppered Moths of England
Besides adaptation what is evidence of evolution?
1.) Fossils
2.) Anatomy
3.) Embryology
4.) Biochemistry
What are fossils?
preserved remains of an ancient organism
How can the age of a fossil be determined?
Relative dating, Radioactive dating
Are the oldest fossils at the top of bottom?
Bottom
What can fossils provide us evidence about?
1.) The anatomy (size, shape, bone structure)
2.) Where an organism once lived (habitat)
3.) What an organism ate
What is anatomy?
The bone and organ structure of an organism
What is a homologous structure?
Structure with a common evolutionary origin
Same bone arrangement, same function, or both
Organisms with homologous structure share a common ancestor
What is a analogous structure?
Structure that do not have a common evolutionary origin
Not similar in bone arrangement, but similar in function
Organisms with analogous structures have different ancestors
What are examples of homologous structures?
Lizard, bird, human, Whale
What are examples of analogous structures?
Whale, turtle, Fish, Penguin
What is vestigual structure?
a structure in a present day organism that no longer has a purpose, but was probably useful to an ancestor
What are vestigual structures in humans?
1.) Appendix
2.) Tail bone
3.) Goosebumps
4.) Wisdom teeth
What is embryology?
the earliest stage of growth and development in an animal
What is biochemistry?
Using biological molecules to see evolutionary relationships
Similar patterns
in Proteins and Amino Acids
What do Phylogenic trees show?
evolutionary relationships based on DNA similarities.
What’s a synonym for adaptation?
Variation
What will increase or decrease an organism’s chances of survival in an environment?
Some variations (adaptations)
What are the 3 different types of Natural Selection that act on variations?
1.) Stabilizing
2.) Directional
3.) Disruptive
What is stabilizing selection?
Favors AVERAGE individuals
Reduces variation in a population of organisms
Medium colored shells are favored and light and dark shells are reduced!
What is directional selection?
Favors one of the extreme variations
Example: Dark shells survive
What is disruptive selection?
Favors both extremes of a variation
2 new species evolve
Example: Light and dark shells survive
Starlings produce an average of five eggs in each clutch. If there are more than five, the parents cannot adequately feed the young. If there are fewer than five, predators may destroy the entire clutch. As a result, five eggs becomes the most common clutch size.
What type of selection?
Stabilizing
A scientist measures the circumference of acorns in a population of oak trees and discovers that the most common circumference is 2 cm. There are very few acorns with circumferences of 3 cm or circumferences of 1 cm. Only the 2 cm circumference acorns survive. What type of selection?
Stabilizing
Black rabbits (BB) and white rabbits (WW) are both able to survive because they can camouflage into the white and black rocks in their environment. However, the intermediate gray rabbits (BW) do not survive. This results in only white and black rabbits.
What type of selection?
Distruptive
A population of birds with various size beaks eats seeds. Small seeds can be eaten by birds with small beaks. Larger, thicker seeds can only be eaten by birds with larger, thicker beaks. During a drought, only large thick seeds exist so only the large, thick-beaked birds survive.
What type of selection?
Directional
Women often have complications during labor while giving birth to very large babies, whereas very small babies tend to be undeveloped. As a result, medium sized babies are the ones that end up surviving to adulthood.
What type of selection?
Stabilizing
What are species?
Organisms that can breed and produce fertile offspring
What is specitation?
the evolution of a new species
How does speciation happen?
When 2 similar populations of organisms can no longer interbreed
What is geographic Isolation?
Occurs when 2 populations are separated by geographic barriers such as rivers, mountains, or bodies of water
Eventually the split populations become 2 separate species
What is Divergent Evolution?
A pattern of evolution where 1 species evolves into different species with similar traits
The species share a
Common ancestor.
What is adaptive evolution?
When 1 species evolves into many different species because of different environments
What type of evolution does homologous structures show?
Divergent evolution
What is convergent evolution?
A pattern of evolution where unrelated organisms evolve into forms that resemble each other because of similar lifestyles.
These 2 species do not share a common ancestor. They have similar traits because they live in similar environments.
What type of evolution does analogous structure show?
Convergent evolution
What is Gradualism?
species evolve through a slow, steady change in adaptations
What is punctuated equilibrium?
species evolve quickly, in rapid bursts, and then there are long periods with no change
Who is Charles Darwin?
A British naturalist
1831 – Took a job as a naturalist on the HMS Beagle and embarked on a 5 year journey
Famous for his theory of evolution
Wrote “On the Origin of Species”
Where did Darwin conduct his studies?
Galapagos islands
What are the Galapagos islands?
In the Pacific Ocean, near the equator
Are owned by the country of Ecuador
Have many unique animals and plants
Who is Jean-Baptiste Lamarack?
French scientist
Lamarck believed that organisms could change during their lifetimes by choosing to use or not use various parts of their bodies.
He believed organisms have a desire to become more complex and perfect.
What is Lamarks Giraffe Example?
Lamarck argued that giraffes necks would grow a little bit longer because it would try to reach the leaves on the top of the trees.
What did Darwin notice about the organisms on galapagos island?
That they looked like other organisms around the world but had certain adaptations to help them live on the island.
What is Mimicry?
An adaptation where one species looks like another
Usually a harmless species will try to look like a dangerous species to avoid predators.
What is camouflage?
An adaptation that allows an organism to blend in with its surroundings.
What is natural selection?
When an organism with a favorable variation survives and passes on that variation to the next generation.
It brings about a change in a population of organisms
What is the process that causes populations to change over time?
Natural selection
How does natural selection work?
1.) A population of organisms has variations
(different traits).
2.) Some variations are favorable.
3.) More offspring are born than survive.
4.) Those that survive have the favorable traits.
5.) A population will change over time.
What is artificial selection?
Breeding organisms with specific traits in order to produce offspring with the same trait
What is fitness?
how well an organism can survive and reproduce in its environment
