Evolution-Day 2 Flashcards
What is divergent evolution?
Divergent evolution is when population become less and less like each other.
*Most of evolution is divergent
What is convergent evolution?
Convergent evolution is when over time population become more like one.
*Features in adaptation to a common ancestor
*Convergent does not mean that they shared a common ancestor
What is parallel evolution?
Parallel evolution is when populations are evolving at the same rate and slowly becoming the same
Why do different organisms develop similar characteristics even though they are from different ancestral paths?
Organisms develop these similar characteristics due to being in similar environments or experiencing similar environmental and selective pressures.
COMMON FEATURES DO NOT MEAN THAT THEY CAME FROM A COMMON ANCESTOR
What are the evidences for evolution?
- Direct observation
- Fossil records-Vestigial Structures
- Fossil records-Transition Forms
- Fossil records-Ancient Resmblance
- Anatomy- Homologous vs Analogous
- Anatomy-Embryonic Development
- Biogeography
- Molecular and DNA
What is direct observation?
The collection of information of cahnges being observed. Ex: sut made trees darker, moths got darker
Describe Vestigial structure evidence.
Evidence for evolution; These structures are found in species, but no longer use them
Ex: snakes have leg bones that they no longer use
Describe Transitional form evidence.
Evidence for evolution; Fossils that show intermediate states between an ancestral form and that of its descendants. Fossils that connect ancestral species with their descendants through a series of tiny steps
*The archeopteryx is a transitional fossil in between dinosaurs
Describe ancient resemblance
If they look similar to each other, chances are that they have a common ancestor from not too long ago.
*Horses and zebras
Describe homologous structures in anatomy.
Structures that are similar in multiple species and show that organisms descended from a common ancestor.
Same ancestry does not necassarily mean that a bodily structure will have the same function
Describe analogous structures in anatomy.
Analgous structures are those that are the same among different species that are not related.
*Butterflies and bats (do not come form common ancestor)
*Usually found in convergent
Describe the anatomy- embryonic development evidence.
Organisms that share a common ancestry share similar developmental genes that result in smiliarities in their embryonic development.
Describe biogeography
The geographic distribution of organisms on the planet follow patterns. Tectonic plates and all that stuff. Evidence for evolution- animals that once had a common ancestor evolved separately as the continents moved apart
