Ch. 13 How Populations Evolve Flashcards
Evolutionary Adaptation
An inherited characteristic that enhances an organism’s ability to survive and reproduce in a particular environment
Evolution
Genetic change in a population or species over generations; all the changes that transform life on earth; the heritable changes that have produced Earth’s diversity of organisms
What was Darwin’s main idea?
Species change overtime and living species have arisen from earlier forms
Fossils
A preserved remnant or impression of an organism that lived in the past
What did Darwin write?
“On the Origin of Species by Means of Natural Selection”
How does petrification/fossil develop?
Minderals dissolved in ground water, seep into tissues of a dead organism and replaces the organic matter
Fossile Record
The chronicle of evolution over millions of years of geological time engraved in the order in which fossils appear in rock strata
- position in strata = age
Biogeography
The geological distribution of species
- historical contest of evolution
Comparative Anatomy
The comparison of body structures in different species
- anatomical similarities = common descent
Homologous structure
Structures that are similar in different species of common ancestry
What does “Evolution is a remodeling process” mean?
Ancestral structures originally function in one capacity are modified with new functions
- descent with modification
Comparative Embryology
The study of structures that appear during the development of different organisms
- closely related = similar stages in embryonic development
Molecular Biology
The study of molecular basis of gene and gene expression
- universality of genetic code
What are 4 evidence that validates the evolutionary view of life?
1) Biogeography
2) Comparative anatomy
3) Comparative embryology
4) Molecular biology
5) Fossils
How does population affect natural selection?
All species tend to produce excessive # of offspring, so natural resources are limited and there is a struggle to survive
Natural Selection
Differential success in reproduction by different phenotypes resulting from interactions with the environment; evolution occurs when natural selection produces change in relative frequencies of alleles in a population’s gene pool
- gradual change in characteristics of population (Favored accumulates)
- screens variation
Nature determines which organisms live/die
- depends on adaptations
- survival of the fitness
Artificial selection
Selective breeding of domesticated plants/animals to promote the occurrence of desirable inherited traits in offspring
- modifying species
- over short time
Man determines who lives/dies
- selective breeding and could explain earth’s diversity
What accounts for evolution of new species?
Heritable changes gradually accumulate
Theory of Evolution
Developed to explain the changes of organisms through time
- how organisms of past become organisms of today
Why was there a belief of “species are fixed and unchanging”?
Religion and short lifespan –> no observation or explanation
Who was Jean Baptiste Lamarck
First to oppose to species are not fond yet that changed.
- Law of Use and Disuse (muscles only)
- Law of inheritance of acquired characteristics
What are Charles Darwin’s 5 assumptions?
1) There are more organisms born than can possibly survive
2) Limited amount of resources available
3) Variations exist among members of a species (differences)
4) Organisms with favorable variations to environment are well adapted and survive
5) These organisms mate and pass variation to offspring
Do humans obey natural selection?
No
Populations
A group of individuals of the same species living in same geographic area
- smallest units that can evolve
- problem solutions: adapt, move, die
- change gradually over successive generations based on how adapted
