Quiz #1 Flashcards
Lectures 1-5
Name the types of evidence you need to in order to use the “biological concept of species”.
- Ability to interbreed
- Niche
- Morphology
Periods when large numbers of species and families are forever lost in the fossil record are called
Mass extinction
How to write scientific names for species
Two names: first capitalized, all underlined
Cells of multicellular organisms differ from the cell of a unicellular organism in three aspects which are
- Cells of multicellular animals are smaller
- Cells of multicellular animals are more dependent
- Cells of multicellular animals are more specialized
Scientific Method
- observation
- question
- hypothesis
- prediction
- testing
- theory
What was the theory before natural selection?
Creationism
-Religious belief that nature and all aspects of the universe originated from god
What are Darwin’s 5 theories?
- Perpetual change
- Common descent
- Multiplication of species
- Gradualism
- Natural selection
Perpetual Change
Living organisms are not constant or immutable, they change.
Example: how insects become resistant to pesticides
Problems with this theory: Fossil records may be biased because soft structured animals are not in them,
Common Descent
There is a common ancestor for all living forms, current or extinct.
-Homologous and Analogous relationships
Example: using a cladogram
Multiplication of Species
A branching tree that diversification ancestral form splits into two or more derived forms.
Example: variation that occurs due to geographical barriers which creates new species
Four main concepts of species
- Typological
- Biological
- Evolutionary
- Phylogenetic
Typological concept of species
- Based on morphological similarity. They look similar, then they’re grouped as a species.
- Assumes species do not change which is false
Biological concept of species
- Based on similarity, niche, and ability to interbreed and produce viable offspring
- Limitations for asexual species
Phylogenetic concept of species
- Based on the evolutionary concept and in any recognizable genetic variation resulting from isolation
- Limits because hard to recognize with just the eye
Evolutionary concept of species
Based on biological concept plus evidence of ancestry
-Limits species who do not have ancestry information
Micro-evolution
Variation within species
Macro-evolution
Variation among species
3 elements to recognizing species
- An official name (binomial system)
- An official description (in publication)
- An official type of preserved specimen
Gradualism
Change among species occurs as a gradual process over time
Limits because species can change suddenly or not at all
Natural Selection
Change is driven by natural selection and the survival of the fittest
Four key observations:
1. Populations are fertile
2. Resources are limited so numbers remain ~same
3. Variation seems hereditary
4. Differential survival and no identical descendants
Adaptive Radiation
Formation of various species from a common ancestral form
also occurs after massive extinctions
What caused the massive extinction of dinosaurs?
Could be:
- Global warming
- Asteroid/ meteor rain
- Lack/change in food source
Animals four distinctive characteristics
- Heterotrophic
- Multicellular
- Eukaryote
- Have no cell walls
Why aren’t all animals pluricellular?
There are zygotes (fertilized gamete) that are a single cell
Taxonomy
The discipline that names the species. Important for distinguishing what is a species
Systematics
looks at relationships between species and compares how closely related species are by cladogram
Multicellular animals
-Animals can be big and complex
As size increases, the surface to volume ration decreases which limits metabolism
-Cells are smaller, more dependent
-More specialized
Unicellular animals
- Small and simple
- Small surface area
- Require high surface to volume ratio
Four main tissues
- Epithelial: internal and external surfaces
- Connective: binding & support (ligaments)
- Muscular: contractile cells
- Neural: reception and conduction of stimuli
Sponge Phylum
Porifera
3 body shapes of sponges
- Asconoids
- Syconoids
- Leuconoids
Asconoids
- Simplest organization of sponges
- Tube shaped
- Lined with choanocytes
Syconoids
- More complicated sponge body
- Single osculum
- Layered in syconoids
- Choanocytes line radial canals
Leuconoids
- Most complex sponge body
- Numerous osculums
- No spongocoel
- Flagellated chambers lined with choanocytes
Choanocytes
- Main cell
- Flagellum moves water for filtration
