Study Sheet Exam 1 Questions Flashcards
(93 cards)
What are some of the unique characteristics of birds?
Feathers
Beak/Bill (toothless)
Syrinx
What are some characteristics of birds that are not exclusive?
2-legged, bipedal vertebrate
Gizzards
Wings
Flight
Lay eggs
Endothermic
What traits do birds have that evolved for flight?
• Lightweight, (mostly) hollow bones
• Fusion in hand bones, head,pelvis, feet (lightening and strengthing skeleton)
• Furcula (Wishbone)
• Uncinate Processes
• Carpometacarpus
• Tibiotarus
• Tarsometatarsus
•Keeled sternum in birds that can fly (muscle attachment)
Summarize the importance of the Furcula
The furcula, or wishbone, compresses and rebounds like a powerful spring in rhythm to the beat of the wings. The wing itself is a highly modified forelimb that, with a few remarkable exceptions, is nearly incapable of functions other than flight.
Summarize the importance of the Uncinate Process
Horizontal, backward-curved projections—called uncinate processes—on the ribs overlap other ribs and so strengthen the walls of the body.
Summarize the importance of the Carpometacarpus
fused hand bones, supports and maneuvers the large and powerful primary flight feathers.
Explain Adaptive Radiation and give an example of traits that show this
A phenomenon where great diversity develops due to the evolution of various species adapting to different ecologies and behaviors
Examples:
Beak sizes and shapes
Leg length
Wing shape
Summarize the importance of the Nasofrontal Hinge
Allows for the ability to flex or bend the upper half of the bill. ( Cranial kinesis )
Summarize the importance of the Trabeculae
Complex system of bone struts
Summarize the importance of the Rhamphotheca
Horny sheath covering the jaws ( may have sharp cutting edges)
What are some areas of greatest diversity in birds? Give some examples for each.
Tropical Andes of South America
What is natural selection?
is the differential survival of individual organisms with advantageous traits.
(If the traits are heritable, then survivial will result in adaptive evolutionary change among generations.
Well adapted individuals live longer and produce more offspring.)
What is convergent evolution? Give an example.
the independent evolution of similar adaptations in unrelated organisms
Penguins and Auks ….
What is biogeography?
is the study of the geographical distributions of plants and animals. For more than a century, biogeographers have divided Earth into six major faunal regions corresponding roughly to the major continental areas.
What are endemic species? Give an example.
Each faunal region has its characteristic birds: so-called endemic taxa or species, which are found nowhere else, and other birds that represent major adaptive radiations of more widespread taxa.
What are avifaunas?
regional assemblages of bird species—are mixtures of species of varied ages and origins
List out some of the shared characteristics between birds and reptiles.
• Scales
• Lay eggs
• Skull of both articulate with the 1st neck vertebrae by means of a single ball and socket device- the Occipital Condyle
• Simple middle ear with/ one ear bone - the Stapes
•Ankle is located in the middle of the tarsal bones (foot)
What are archosaurs? What are their defining traits?
are a specific group of reptiles that include alligators and crocodiles, dinosaurs, and pterosaurs
• Distinctive hole in side of skull, in front of eye socket, called antorbital fenestra
• Advanced parental care behavior
Which reptile did birds originate from?
Archaeopteryx lithographica
What are vanes? Why are they characteristic in Archeopteryx?
the planar surfaces of feathers, on either side of the feather shaft
Archeopteryx’s primary (flight) feathers had asymmetrical vanes.
Most modern birds that fly have asymmetrical vanes, especially strong fliers
What is a phylogenetic tree?
is a diagram that depicts evolutionary relationships (a phylogeny) among organisms
• Branches represent historic species evolving through time
•Nodes are points where branches split off, indicating a speciation event producing new lineages
• Clades represent all descendents (living or extinct) with a common ancestor.
What do clades represent?
Represent all dependents (living or extinct) w/ a common ancestor
Which of these are clades? Which are not? Why?
Green and blue are clades because…
Red and orange are not clades because…
What are homologs? Give an example.
Similarities inherited from a common ancestor
Examples:
Wings of all birds are homologs