BIO 141: Evidence for Evolution (3)

Hierarchical organization of life

Life is organized in nested groups of organisms

Linnaean System

Kingdom, Phylum, Class, Order, Family, Genus, Species

what does the theory of descent with modification predict

the observed hierarchical organization of life

Homology

characters in different organisms have similar underlying molecular and anatomical structures, or are based on similar developmental processes

t or f today we recognize that homologies exist because of shared ancestry

true

example of homology

homologous arm bones in vertebrates, mole, horse, dolphin

t or f shared ancestry indicates shared development path

true

what is the function of the pharyngeal pouches

if we were fish, this is where our gills would develop

t or f false in the early stage of an human embryo, do we have a tail

true, but in the next stage it goes away

t or f all organisms use DNA or RNA as their genetic material

true

Vestigial trait

a useless or rudimentary version of a structure that has an important function in other organisms. Sometimes used for a new function

t or f whales have a floating pelvis/femur

true

example of vestigial trait

spotted dolphin embryo at 24 and 48 days, hindlimbs buds come and go

vestigial traits in human

the coccyx is a rudimentary tail bone

humans also have vestigial muscles that make our few remaining hairs stand up, if you get scared hair might stand up

provide one sentence summary for each of this topics

1. biogeographical patterns

2. artificial breeding

3. intermediate forms

4. imperfections

5. transitional fossils

6. hierarchical organization of life

7. homology

8. vestigial traits