1. Option D2: Species and Speciation

2. Definitions _________– all genes in a population at a given time
_____- version of a gene
____________– the measure of a specific allele in proportion to the entire population
Expressed as a proportion or _________
Allele frequency is different than the number of _____________ in a population expressing that allele

4. Evolution of a species
Evolution of a species involves a change in the ______________of a __________ over several generations
Allele frequencies are only a __________
__________, __________ or _______________ can occur (cause new entries into gene pool or exits from pool)
If suitable for _________, then gene will be passed on (increasing allele frequency)
In time, previous less suitable genes will be “________” of gene pool

5. _________ – any group of organisms that can reproduce fertile offspring
Have similar ____________ (lineage)
Have similar ____________________
____________ distinct from other organisms
What are some issues with this explanation of a species?

6. Barriers Between Gene Pools (How to get really weird animals and plants….)
Genetic isolation
____________________– islands, mountain ranges, etc.
___________ (reproductive) Isolation- two species whose _______________do not intertwine ( pollen from one type of flower released before pistil of other flowers have emerged)
_______________– mating behavior selects certain characteristics (mating ritual of one organism not seductive enough)
Any of these will lead to new __________ given enough time

7. Speciation
Formation of a new ________ that no longer breeds with the ______________

8. Allopatric Speciation
When speciation occurs because of _________________
Islands are a great example of this

9. Sympatric Speciation
_________ do overlap, but speciation occurs because of another influence (temporal, or behavioral)
Could be mating ________, _______, or other courtship behavior
ex. Mutation of pheremone that only attracts a few females

10. Polyploidy Sex cells – __________ Somatic cells - __________
______________ – condition where there are more than 2 homologous chromosomes due to improper cell division
Most common in __________ (makes them hardier)
These extra chromosomes can make them _______________with the original. Can lead to _________ or ____________ of species if more favorable.

11. Adaptive Radiation
Many similar but distinct species ___________ from one single species
Happens when the organism is ___________ and in a ________ of opportunity
In Darwin’s Finch the beaks adapted for ______ _____________
Lemurs in Madagascar live in _______________ (desert, trees, ground)

12. Convergent vs. Divergent Evolution
Divergent is simply speciation due to ____________ to new _____________ (ex. Ancestor squirrel split by grand canyon to White-tailed antelope sq. and Harris’s antelope sq.)
Convergent Evolution is when different organisms evolve _______________ due to similar selective __________ (marsupial anteater in Australia; mammal anteater in S.A. bioluminescence in marine organisms and fungi)

13. Theories on pace of evolution
___________ – species slowly change through a series of intermediate forms
Supporters say __________ for enough organisms exist to show these slow _________ changes
Supporters also say that you don’t see most organisms ________________ now

14. _______________ – rapid speciation due to new niche formation or geographic isolation
Support by fossil record showing organisms (cochroaches, sharks) that have __________ significantly over millions of years
Also supported by ______ in fossil record

15. Polymorphism
When more than one ________ of a species is present in a population
_________________– one form is distinctly disadvantaged
__________________- if both forms provide a distinct advantage for survival

16. Transient Polymorphism
Allele frequency changes in response to _____________
Can change back

17. Sickle Cell Anemia is balanced polymorphism
In malaria stricken areas – both forms offer a ________ (balanced)
HbA allele codes for blood cells that __________, but susceptible to ___________
HbS allele can’t carry O2, but __________ to malaria
HbAHbS person gets best of __________
When not in a location where malaria is endemic, not a suitable characteristic (transient)

18. Cystic fibrosis
Cf gene causes _______ buildup, but normal gene is susceptible to ________