Chapter 10 Flashcards
What is evolution? 10.1
Evolution is the process of biological change by which descendants come to differ from their ancestors.
Carolus Linnaeus 10.1
- Swedish botanist from the 1700s
- Developed a classification system for all types of organisms
- Organisms were grouped by similarities but also reflected evolutionary relationships ….
However - thought hybridization created new species
Georges Louis Leclerc de Buffon 10.1
- French naturalist from the 1700s
- Proposed that species shared ancestors instead of arising separately
- Suggested that the Earth was much older than 6000 years…similar to Charles Lyllel
What are species? 10.1
A species is a group of organisms so similar to one another that they can reproduce and have fertile offspring.
Eramus Darwin 10.1
- Born in 1731; respected English doctor, poet, and Charles Darwin’s grandfather
- Proposed that all living things were descended from a common ancestor and that more complex forms of life arose from less-complex forms…….theory later expanded by Darwin
Jean-Baptiste Lamarck 10.1
- French Naturalist
- Proposed all organisms evolved toward perfection and complexity
- Believed all species evolved
- Proposed that changed in an environment caused an organism’s behavior to change - Use of Organs Theory
ex. long neck in giraffes - Didn’t propose how traits were passed on to offspring and his theory was flawed
Who were the four people that influenced Darwin? 10.1
Carolus Linnaeus
Georges Louis Leclerc de Buffon
Erasmus Darwin
Jean-Baptiste Lamarck
What are fossils? 10.1
Fossils are traces of organisms that existed in the past.
What did George Cuvier, a French zoologist propose? 10.1
- Observed that each stratum held its own specific type of fossils and the fossils in the deep layers were different from the upper layers
- Based this on the Law of Superposition
What is the theory of catastrophism? 10.1
Volcanoes, floods, and earthquakes are examples of catostrophic events taht were once believed responsible for mass extinction and the formation of all landforms.
- Proposed by French zoologist Charles Cuvier
What is the theory of gradualism? 10.1
Canyons carved by rivers show gradual change. Gradualism is the idea that changes on Earth occurred by small steps over long periods of time.
- Proposed by Scottish geologist James Hutton
What is the theory of uniformitarianism? 10.1
Rock strata demonstrate that geologic processes, which are still occurring today, add up over long periods of time to cause great change.
- Proposed by Charles Lyell
What is variation? 10.2
Variation is the difference in the physical traits of an individual from those of other individuals in the group to which it belongs.
Where can variation occur? 10.2
- Among different species members - interspecific variation
- Among members of the same species - intraspecific variation
What is adaptation? 10.2
Adaptation is a feature that allows an organism to better survive in its environment, and they can lead to genetic change in a population over time.
ex. Galapagos turtles
What is artificial selection? 10.3
Artificial selection is the process by which humans change a species by breeding it for certain traits.
What is needed for artificial selection to occur? 10.3
- Humans - selecting agent
- Heritable traits
What is heritability? 10.3
Heritability is the ability of a trait to be passed down from one generation to the next.
What is natural selection?
What is the selecting agent for natural selection?
10.3
Natural selection is a mechanism by which individuals that have inherited beneficial adaptions produce more offspring on average than do other individuals.
- Natur
What is a population? 10.3
A population is all the individuals of a species that live in an area.
What are the 4 principles of natural selection? 10.3
- Variation - varying differences in individuals in a population
Overproduction - organisms tend to produce more offspring than can survive to maturity
Adaptation - traits of survivors will become more common in a population
Descent with Modification - favored trait is passed down and the naturally selected individuals tend to reproduce more than others
What does natural selection act on? 10.3
Natural selection acts on phenotypes/ physical traits rather than genetic material itself.
What are the four evidences for evolution? 10.4
Fossils
Geography
Embryology
Anatomy
How do fossils support evolution? 10.4
- Fossils of animals show a pattern of development from early ancestors to their modern descendants
- Intermediate or missing link species show how organisms evolved new adaptations
Problems with this: - Different decay rates of fossils or no fossils at all
How does geography support evolution? 10.4
- Shows similarities among species living in different areas
- “Descent with modification”
What is biogeography? 10.4
Biogeography is the study of the distribution of organisms around the world.
How does embryology support evolution? 10.4
- Most embryos look very similar and have gill slits and tails suggesting a common ancestor.
How does anatomy support evolution? 10.4
- Homologous and Analogous structures
What are Homologous structures? 10.4
Homologous structures are features that are similar in structure but appear in different organisms and have different functions.
ex. forelimbs of tetrapods such as bats, humans, and moles
What are Analogous structures? 10.4
Analogous structures form a similar function but are not similar in origin.
ex. bat wings and insect wings
What are Vestigial structures? 10.4
Vestigial structures are remnants of organs or structures that had a function in an early ancestor.
ex. ostrich wings, human tailbone, appendix
What is paleontology?
10.5
Paleontology is the study of fossils or extinct organisms which continues to provide new info and supports current hypotheses on how evolution occurs.
How does DNA and protein play a part in determining relationships among different organisms? 10.5
- As organisms evolve, the differences in the amino acids and proteins they make should change gradually
- The more amino acid differences there are between 2 organisms, the more distantly related they are.
Molecular and genetic evidence 10.5
DNA sequence analysis - depends on the fact that the more related 2 organisms are, the more similar their DNA will be
Pseudogenes - these sequences of DNA nucleotides act as vestigial structures that can determine a common ancestor
Homeobox genes - control the development of specific structures and indicate a distant common ancestor
Protein comparisions - molecular fingerprinting shows similarities in a unique set of proteins in organisms
