LEC 8/27 Speciation

True, you need variation for adaption.

pop or group of pop, members potentially interbreed & produce FERTILE offspring, appearance is not important

process by which new species come into being

they originate as modified descendants of other species

Genetic isolation, pop diverge genetically, reproduction isolation

gene flow between two pop is interrupted (pop becomes genetically isolated from each other

genetic diff gradually accumulate between the 2 pop

some of these genetic diff (traits) will be reproductive barriers (traits that prevent 2 individuals from interbreeding with each other

Temporal isolation, habitat isolation, behavioral isolation.

mating or flowering occurs at difft seasons or times of day

pop live in difft habitats and do not meet

little or no sexual attraction between males and females

structural diff in genitalia or flowers prevent copulation or pollen transfer

female and male gametes fail to unite in fertilization

Hybrid inviability and hybrid sterility

hybrid zygotes fail to develop or fail to reach sexual maturity

hybrids fail to produce functional gametes

gene flow is reduced due to a geographical barrier “other country” squirell example

switch in the use of a resource by some individuals reduces gene flow “same country” ex with ants and apples

True

systematists, evidence and results

are the detectives of life’s history

observable characters need to be derived (unique) and shared

produce a tree-like diagram called phylogeny or cladogram