Chapter 5 - Evolution Flashcards
What is Species Diversity?
The number of different species in an ecosystem
What is Genetic Diversity?
The amount of variation between individuals in a singular species
What are the two main reasons we use Taxonomy?
- To help identify organisms
- To help scientists deal with the diversity of life and represent relationships between organisms
What is a species?
A group of organisms with similar features who can interbreed with one another
What is a Genus?
A classing or grouping of multiple similar species
What is the order of Levels of classification from most broad to least broad?
Kingdom
Phylum
Class
Order
Family
Genus
Species
What is Eubacteria?
- No nucleus
-True bacteria
-Cell wall w/ peptidoglycan
-Can reproduce asexually
What is Archaea?
-No nucleus
-Not a true bacteria
-Some genes are closer related to humans than Eubacteria
-Cell wall without peptidoglycan
What are two ways we define pieces of evidence for evolution we’ve found?
Direct (Fossils, continental drift)
Indirect (Biochemstry findings, Embryology)
What is a half-life? How does this help with dating fossils?
A half-life is the time it takes for an isotope to turn into a stabler daughter isotope and decay. This helps with fossil dating because scientists can take a sample of fossil and see how decayed it is to give a window of how old the fossil
The older the fossil the more _______ compared to its descendants
Primitive
What are our three findings from fossil evidence?
- Different species lived on earth at various times
- The more complex an organism is, the further removed it is from its ancestor
- Ancestors and descendants tend to live in the same geographical area
What is a transitional fossil?
A fossil that acts as the ‘missing link’. A fossil that bridges the gap between an ancestral group and a group of descendants.
Why might an acestor fossil not be located in the same place its descendant is?
They may have evolved pre-drift, meaning that the drift caused them to move geographically, and if it had not happened they’d be in the same geographical area
What might a descendant being located in the same place as its ancestors tell you?
It may tell you it is relatively young, and evolved post-drift
What does endemic mean?
Endemic means a species found in one location only
Why might islands have little to no native mammals or reptiles?
Because mammals and reptiles would have a difficult time getting to the island compared to winged organisms who would be easily able to get there and evolve from there.
What is a homologous feature?
Features with similar structure from the same ancestor with different present functions.
Bird wing vs. Human arm
What is an analogous feature
A feature that has similar uses but different structures. They did not come from a common ancestor.
Dragon fly wing vs. Bird wing
How does embryonic development point towards evolution?
There are homologoues features in the womb, such as tails that turn into tail bones. We share these embryonic feature with many other closely related species. This points towards us being from a common ancestor
What is a vestigial feature?
A feature that does not have any use anymore. Like an appendix, or hip bone in a whale. The hip bone points towards whales coming from an ancestor that may have walked on all fours, pointing towards a common ancestor
Would the sequence of the amino acid in a protein be able to tell you if two organisms are closely related?
Yes
What would be a vestigial gene?
A vestigial gene is genes an organism might have, but may be defective and unable to carry out their task.
E.g; humans have a gene to create our own Vitamin C, but we have no need to create or any need for vitamin C
What was Lamarcks theory?
An organism could will itself to change to its environment, and that change would be passed down onto the next generation
Why was Lamarck wrong?
Use or disuse of a feature does not change the genetic makeup of an organism. And the Genetic makeup is what gets passed down to the next generation
What were four points Darwin discovered?
- Species descended from fossils
- Species evolve differently if isolated
- Species evolve differently depending on the environment
- Fossils may be moved by geological forces
What are the five points of Natural Selection?
- Overproduction
- Competition
- Variation
- Natural selection
- Inheritance of successful traits
What are mutations?
Changes in the coding of DNA
How do mutations occur?
Environmental changes, radiation, and in the duplication of cells
When is mutation a big deal?
In large populations with high reproductive rates
What are three misconceptions about mutations?
“Mutation occurs when needed”
- No it will not
“Evolution is pure chance”
- Pur chance and Surivival of the fittest
“Harmful mutations will accumulate”
- No, they are not in favor of nature and will quickly be snuffed out
