Exam 1 (Evolution) Flashcards
Evolution
progressive change of organisms as they descend from ancestral species-is a fact
modern synthesis
- Darwin’s theory of natural selection, combined with other mechanisms of evolution
- explanation for phenomena in such diverse fields as paleontology and developmental biology, medicine and psychology.
Questions that Evolutionary Biology helps answer
–Distribution and abundance of species
-Diversity of Life
Procession of Life (or Tree of Life)
- Fit of Form and Function
- What of Humans?
Darwin and Wallace’s theory of evolution
by natural selection was the first plausible, widely-accepted mechanism for evolutionary change.
Clinical significance of evolutionary biology to medicine (HIV)
- that two separate lineages of this retrovirus passed into the human population from African Apes in the mid 20th century.
- enabled us to develop a therapy for HIV
- “triple therapy” HIV treatment is an example of evolutionary medicine.
- Antibiotic resistance since the 20th century
What produces adaptation?
natural selection is the only mechanism capable of producing adaptation.
taxonomy
branch of biology concerned with naming and classifying living things.
Carolus Linnaeus
- He developed the two part system of binomial nomenclature we use today.
- His genera were clustered into increasingly broader categories; families, classes, phyla, and kingdom.
- Although he did not believe in evolution by descent, this pattern clearly suggests some mechanism by which different forms of life are related to each other as a series of diverging, heirarchial, branches.
Malthus
- published “An Essay on the Principle of Population” in 1798.
- people tend to have more children than can possibly survive, and human populations have historically been kept in check by famine, starvation, and disease
Hutton
-Hutton proposed that it was possible to explain geological land formations by processes that are currently in operation, such as erosion and sedimentation.
gradualism
process that happen over a really long period of time erosion of streams and sediment on side of river deltas
Charles lyell
uniformitarianism-the idea that geological processes in operation now operated similarly in the past, at about the same rate.
Jean Baptiste de Lamark
developed the first comprehensive model of evolution.
The Voyage of the Beagle
- inspiration for Darwin’s theory of natural selection from voyage on HMS Beagle in 1831
- Species diversity, especially in the Galapagos islands (most of the species only live there and no where else in the world)
Origin of Species makes this argument
- All organisms produce more offspring than can possibly survive
- All organisms vary for a wide variety of different attributes and features-they also vary in reproductive success: some have more offspring than others.
- Some variation is heritable.
- Some of this variation must influence reproductive success
- Given that the above are true…desirable characteristics will thus be preferentially passed to offspring
Some of the original evidence for evolution
Embryology
Vestigial and Homologous Structures
Biogeography
The Fossil Record
Embryology
Closely related species go through similar stages of development, although the adults may not resemble each other very closely.
Vestigial Structures
Many species retain structures that only make sense in light of their ancestry.
These structures are typically reduced and nonfunctional,
Homologous Structures
structures that are similar in their fundamental layout and construction, although they may serve very different purposes
Biogeography
The distribution of living plants and animals suggests that organisms diversify into the ecological niches available to them-and when geography blocks dispersal, similar adaptations occur in unrelated taxa occupying the same type of habitat.
DDT resistance in mosquitoes
Indiscriminate spraying led to the rapid evolution of pesticide resistance. Five Anopheles species were resistant by 1956 and 38 by 1968.
1) Chemical adaptation: enzymes evolve that break down the pesticide.
2) Behavioral adaptation: They evolved to move from inner, sprayed walls to outer, unsprayed walls. They evolved sensitivity and avoid the pesticide.
Adaptation examples
- Tyrannosaur vs. Spiniosaur
- Strepsitera- adapted and specialized to fit between the terga of bees and wasps.
Galapagos finches
- 13 finch species
- Offspring of various parents have been counted, and the shifting relationships between traits such as beak size and body size vs. fitness have been documented
-drought struck yr 2, they didn’t mate or produce eggs
because the plants didnt produce seeds
- specifically Caltrop (need at least a 11mm beak to open)
- yr 3 population had decimated, evolved by natural selection, beak size (longer and deeper)
