Natural Selection Chapter #2 Flashcards
Fossils
preserved remain of an organism ICE TAR AMBER SEDIMENTARY
Mineralization (petrification)
When a structure trapped in sediments is replaced by minerals
Relative dating
Uses mathematical formulas to study the amount of radioactive isotopes in a fossil
Why do isotopes decay?
Atoms with different number of neutrons the wrong number of neutrons, it is not stable
Where are radioactive isotopes found?
Natural processes like solar radiation and star formation
Half-life
the amount of time it takes half a radioactive isotope to decay into a stable element
C-14 becomes N in … years
5730( recent bones)
U-238 becomes Pb in …. years
4.5 billion years ( old bones)
Evolution
All of the changes that have transformed life over an immense time
Gradualism
the theory that the Earth has been slowly shaped by natural forces
Who tried to explain how modern life forms differed from fossils
Jean Baptista Lamark
Radiometric dating
Uses mathematical formulas to study the amount of radioactive isotopes in a fossil
Who had the theory of gradualism
Charles lyell
Examples of gradualism
Canyons- made from rivers that have eroded
Volcanoes- form islands, volcanoes change earth
Idea of inheritance of acquired traits
By using of not using certain body parts, an organism develops certain characteristics. These enhanced characteristics would be passed on to the offspring. An example is a kangaroo’s powerful hind legs were the result of ancestors strengthening their legs by jumping, the leg strength was then passed to the offspring.
Why is the idea of acquired traits wrong
This idea is wrong because an acquired characteristic would have to modify DNA of specific genes for it to be inherited and there is no evidence that this happens
Father of evolution
Charles Darwin
What observations did Darwin make about the island animals compared to those in South America and what did Darwin infer about his observations?
Darwin noticed the plants and animals in south america had a definite character . The animals found in south america distinct from those found in europe. Some of the fossils found were gigantic versions of the modern animals. Darwin inferred mainland species changed after they colonized the islands and adapted to their new environment.
Using Lyell’s theories how did Darwin explain the fossils he found in the Andes mountains
Lyell believed mountain ranges can be thrusted up centimeter by centimeter because of earthquakes occurring over millions of years. When Darwin found fossils ocean organisms in the Andes he reasoned that earthquakes lifted the rock bearing those marine fossils from the sea floor.
Two key conclusions Lyell ( and Darwin) based on geologic evidence
- The slow process of mountain building and erosion suggests the earth is solid.
- The gradual process occurring over spans of time could cause change on Earth. Darwin would apply the idea of gradual change to the evolution of Earth’s life forms
Back in England Darwin was well known as
a famous naturalist
Thomas Malthus
Writes an essay on human populations. Essay explains how human suffering was due to the fact that populations grow faster than resources can be produced
Darwin did not immediately publish his ideas; it wasn’t until another naturalist _____ came up with the same ides for evolutionary changes
Alfred Wallace
Darwin published the book
The origin of Species
The species alive today descended from
ancestral species
When organisms spread into new habitants the accumulate modifications or ______ in a process called______
adaptations; descent with modification ( evolution)
Describe what adaptations help a jack rabbit survive in it environment
Jack rabbits benefit from fur that blends well in the desert and ears that help keep its body cool. The white fur of a jack rabbit provides camouflage in the snowy regions of the snow shoe hare’s range
artificial selection
Selective breeding of domestic animals and plants
Darwin’s second major point is natural selection is defined as
The process by which individuals with inherited characteristics well suited to the environment leave more offspring on average than other individuals. Certain traits can give individuals advantages over others of the same species in the environment.