characteristics I.Shared of life A. Energy- organisms interact with their environment to acquire and use energy
Matter in - CO2 and nutrients Matter out - O2 and biomass Energy in - light Energy out - heat
I.Shared characteristics of life B. CellsBasic membrane bound units
1.Prokaryotic cellLack of a nucleus 1.Eukaryotic cell-
-has a nucleus Called cell theory C. Replication -cells come from other cells
I.Shared characteristics of life D. Information- organisms contain hereditary information in units
called genes - DNA
Controls the development and maintenance of all organisms. Similar in all organisms .
I.Shared characteristics of life
E. Response to Environment
- Feedback mechanisms
1.Negative feedback
-accumulation of an end product of a process slows that process
2. Positive feedback
-Less common - end product speeds up a pathway
I.Shared characteristics of life F. Evolution 1. Definition:
- Change in genetic composition of a population of a population over time
2. Background
a. Artificial selection
- evolution, when humans select for desired traits (ex. Corn- changed to be the way it is now by humans, not natural development)
b. By the 1800's, scientists knew that only simple fossils were found in older rock, and complex fossils only in younger rock. c. New Life forms appeared and some disappeared
3. Darwin studied interesting species on the Galapagos islands
3. Darwin studied interesting species on the Galapagos islands a. Beak shape of the finches was adapted to the food
source on the islands
b. Structure and function are correlated
4. Darwin referred to evolution as
- Descent with modification
a. All organisms are related through a history of descent b. Over time, as new species form, they begin to diverge from one another. c. He proposed that the mechanism was natural selection
5. Evolution by Natural Selection
a. Individuals in populations varied and that the variation was heritable b. Populations producing were more offspring than could survive c. Species tended to be suited to their environment d.Conclusion: -Individuals with traits suited to a particular environment are more likely to survive and reproduce -Leads to change over time, evolution -Fitness means the ability to survive and reproduce
% of light colored moths
Industrial Revolution
Time Clean Air Act
6. Natural Selection in Action
Natural Selection- Key Points
Selection acts on individuals but evolution occurs in populations Selection depends on the environment There must be heritable variation in a population for natural selection to act
7. The central idea of biological evolution is that all life on Earth shares a
-common ancestor
a. Explains similarities between all life forms
B. Explains differences between all life forms
6. What is modified?
Evolution only occurs when there is a change in within a population over time. These genetic differences are heritable
III. The tree of life
A. Definition
- A family tree of all organisms that shows their evolutionary relationships
B. Three main branches (domains) 1. Archaea
-ancient prokaryotes (live in extreme environments)
2. Bacteria
-prokaryotes (live in non-extreme environments)
3. Eukarya
1. Protists 2. Fungi 3. Animal 4. Plants
C. We depict the relationships between organisms using a phylogenetic tree.
1. Phylogeny- reconstruction of evolutionary relationships by studying inherited relationships
1. Root of the tree:
- Ancestral lineage
2. Tips of the branches: - Decedents of that ancestor 3. As you move from the root to the tips, you are moving forward in time.
4. Speciation: formation of a new species
5. A clade is a grouping that includes a common ancestor and all the descendants (living and extinct) of that ancestor.
yes
yes
no
no
E. Building a phylogenetic tree 1. Characters
2. Shared Derived Characters
F. Scientific names 1.Genus 2.Species
Homo sapiens