Key Terms:
Macro evolution- major changes over evolutionary time
Geological record-
adaptive radiation- a group of organisms forms new species, whose adaptations allow them to fill new habitats or roles in their communities
"evo-devo"- a field that combines evolutionary and developmental biology
Paedomorphic- retaining juvenile traits into adulthood
homeotic genes- are master control genes that determine basic features, such as where pairs of wings or legs develop on a fruit fly
phylogeny-evolutionary history of a species or group of species
convergent evolution- analogous similarities in similar environments
systematics- classifies organisms
phylogenetic tree-a hypothesis of evolutionary relationships within a group
molecular systematics-compares ncleic or other molecules to infer relatedness of taxa
molecular clocks- can be calibrated in real time by graphing the number of nucleotide diffferences against the dates of evolutionary branch points known from the fossil record
different genes evolve at different rates
evolution is not goal directed
natural selection results fromthe interactions between organism and their environment
if the environment changes, apparent evolutionary trends may cease or reverse
Thursday, March 3, 2011
Tuesday, March 1, 2011
Chapter Fourteen
Key Terms:
Species- a group of organisms whose members can breed and produce fertile offspring, but who do not produce fertile offspring with members of other groups
Speciation- Emerging of a new species
Taxonomy- the branch of biology that names and classifies species and groups them into broader categories
Biological species concept- defines a species a a population or group of populations whose members have the potential to interbreed in nature and produce fertile offspring
morphological species concept- classifies organisms based on observable phenotypic traits
Ecological species concept- defines a species by its ecological role or niche
Phylogenetic species concept- defines a species as a set of organisms representing a specific evolutionary lineage
Reproductive barriers- serve to isolate a species gene pool and prevent interbreeding
allopatric speciation- populations of the same species are geographically separated, separating their gene pools
sympatric speciation- new species may arise within the same geographic area as a parent species
polyploidy- the multiplication of the chromosome number due to errors in cell division.
Reading Journal
1) Who developed the binomial system? Carolus Linnaeus developed the binomial system of naming organisms using physical characteristics to distinguish over 11,000 species
2) How do reproductive barriers arise? Post zygotic, Pre zygotic, through nature and through environment; natural selection, and organisms that are best adapted, not the strongest.
3) What happens when isolate populations renew contact? in hybrid zones, members of different specie meet and mate to produce hybrid offspring
Five Facts:
1) 80% of all living plant species are the descendants of ancestors that formed by polyploid speciation.
2) hybridization between two species accounts for most of these species
3) Reinforcement is when hybrids are less fit than parent species,natural selection strengthens reproductive barriers
4) The time between speciation events averaged 6.5 million years and rarely took less than 50,000 years.
5) Medium ground finches and cactus finches occasionally interbreed
Taxonomy is a branch of biology that names and classifies species and groups them into broader categories. Swedish physician and botanist Carolus Linnaeus introduced the binomial system of naming organisms. This system is the basis of taxonomy. Most organisms are based on observable phenotypic traits. Also, according to the phylogenetic species concept, a species is the smallest group that shares a common ancestor, and also forms one branch on the tree of life.
Reproductive barriers isolate a species' gene pool and prevents interbreeding. Some examples of isolation barriers include temporal isolation, habitat isolation, behavioral isolation, mechanical and gametic isolation.
Speciation is the emerging of new species. Allopatric speciation are when populations of the same species are geographically separated, separating their gene pools. Sympatric speciation is when new species may arise within the same geographic area as a parent species.
A laboratory study has documented the beginning of reproductive isolation in Fruit flies. The fruit fly population adapted to a new food source; researchers have identified the specific gene involved.
Hybrid zones are regions where members of different species overlap and produce some hybrid offspring. In a stable hybrid zone, a limited number of hybrid offspring continue to be produced.
Adaptive radiation is the evolution of an animal or plant group into a wide variety of types adapted to specialized modes of life. It can occur when populations are provided with expanded opportunities following mass extinctions, colonization of a diverse new environment, or the evolution of new structures.
The time interval between speciation events varies, from a few thousand years to tens of millions of years. Speciation rates can be seen from a punctuated equilibrium model and a gradualism model.
Here is the Blue-Footed Boobie. It is classified as...:
Youtube video for Speciation:
http://www.youtube.com/watch?v=-vmOBgiwwq8
Species- a group of organisms whose members can breed and produce fertile offspring, but who do not produce fertile offspring with members of other groups
Speciation- Emerging of a new species
Taxonomy- the branch of biology that names and classifies species and groups them into broader categories
Biological species concept- defines a species a a population or group of populations whose members have the potential to interbreed in nature and produce fertile offspring
morphological species concept- classifies organisms based on observable phenotypic traits
Ecological species concept- defines a species by its ecological role or niche
Phylogenetic species concept- defines a species as a set of organisms representing a specific evolutionary lineage
Reproductive barriers- serve to isolate a species gene pool and prevent interbreeding
allopatric speciation- populations of the same species are geographically separated, separating their gene pools
sympatric speciation- new species may arise within the same geographic area as a parent species
polyploidy- the multiplication of the chromosome number due to errors in cell division.
Reading Journal
1) Who developed the binomial system? Carolus Linnaeus developed the binomial system of naming organisms using physical characteristics to distinguish over 11,000 species
2) How do reproductive barriers arise? Post zygotic, Pre zygotic, through nature and through environment; natural selection, and organisms that are best adapted, not the strongest.
3) What happens when isolate populations renew contact? in hybrid zones, members of different specie meet and mate to produce hybrid offspring
Five Facts:
1) 80% of all living plant species are the descendants of ancestors that formed by polyploid speciation.
2) hybridization between two species accounts for most of these species
3) Reinforcement is when hybrids are less fit than parent species,natural selection strengthens reproductive barriers
4) The time between speciation events averaged 6.5 million years and rarely took less than 50,000 years.
5) Medium ground finches and cactus finches occasionally interbreed
Taxonomy is a branch of biology that names and classifies species and groups them into broader categories. Swedish physician and botanist Carolus Linnaeus introduced the binomial system of naming organisms. This system is the basis of taxonomy. Most organisms are based on observable phenotypic traits. Also, according to the phylogenetic species concept, a species is the smallest group that shares a common ancestor, and also forms one branch on the tree of life.
Reproductive barriers isolate a species' gene pool and prevents interbreeding. Some examples of isolation barriers include temporal isolation, habitat isolation, behavioral isolation, mechanical and gametic isolation.
Speciation is the emerging of new species. Allopatric speciation are when populations of the same species are geographically separated, separating their gene pools. Sympatric speciation is when new species may arise within the same geographic area as a parent species.
A laboratory study has documented the beginning of reproductive isolation in Fruit flies. The fruit fly population adapted to a new food source; researchers have identified the specific gene involved.
Hybrid zones are regions where members of different species overlap and produce some hybrid offspring. In a stable hybrid zone, a limited number of hybrid offspring continue to be produced.
Adaptive radiation is the evolution of an animal or plant group into a wide variety of types adapted to specialized modes of life. It can occur when populations are provided with expanded opportunities following mass extinctions, colonization of a diverse new environment, or the evolution of new structures.
The time interval between speciation events varies, from a few thousand years to tens of millions of years. Speciation rates can be seen from a punctuated equilibrium model and a gradualism model.
Here is the Blue-Footed Boobie. It is classified as...:| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Pelecaniformes |
| Family: | Sulidae |
| Genus: | Sula |
| Species: | S. nebouxii |
Youtube video for Speciation:
http://www.youtube.com/watch?v=-vmOBgiwwq8
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