Chapter 1 Flashcards
Convergent Evolution
- occurs when natural selection acts on unrelated species in similar ways, causing them to evolve to become similar
Evolution
- change
- driven by natural selection
Describe proximate causes
immediate, mechanical causes
Describe ultimate causes
historical causes, especially with natural selection
biological evolution
inherited change in the properties of groups of organisms over the course of generations; descent with modification
Population
- a group of conspecific organisms that occupy a more or less well defined geographic region and exhibit reproductive continuity from generation to generation
- Interactions are more frequent among these individuals than with members of other populations of the same species
Diverge
two evolving lineages become different
hypothesis
informed conjecture or statement of what might be true
Scientific theory
- comprehensive, coherent body of interconnected statements, based on reasoning and evidence, that explain some aspect of nature (usually many aspects)
- Remember that theory is defined in a way of honor, that so much overwhelming evidence contributes to it that it is known with lots of certainty, rarely doubted
- Well supported description of the causes and processes that explain diverse observations
Uniformitarianism
the proposition that natural processes that operated in the past are the same as in the present
implies gradual rather than catastrophic change
Inheritance of acquired characteristics
- former belief that modifications of an individual during its lifetime, due to its behavior of or its environment, could be transmitted to its descendants
- Proven false
- Lamarckism
The Origin of Species
Contains two major theories
1 – descent with modification: all species, living and extinct, have descended, without interruption, from or or a few original forms of life
2 – natural selection: chief cause of evolutionary change
Describe 5 components of Darwin’s theory of evolution
- Evolution is change over time
- Common descent
- Gradualism
- Populational change
- Natural selection
Natural Selection
- Individuals with certain alleles (due to mutations) and the corresponding trait (coloration ex) have higher fitness in a given environment
- Less common
Gene Flow
- Genetic info shared between individuals in the same population or species; maintains a species
What do animals acquire when they are well-suited to their environment?
they have increased fitness (ability to survive and reproduce)
better fit traits are more likely to pass on to offspring from those well-suited in their environment
