Exam 1 Flashcards
What two parts are apart of Binomial Nomenclature?
Genus species
What is a root?
the most common ancestor of all the taxa in the tree
What are nodes?
A branching point from the ancestral population
What is terminal taxon?
A clade, species, or lineage that appears at the tip of a phylogenetic tree
What is a classification bracket?
it is used to infer the likelihood of unknown traits in organisms based on their position in a phylogenetic tree
What is an outgroup?
a more distantly related group of organisms
What is an ingroup?
The group of taxa being analyzed
What is a clade?
A group of organisms with a common ancestor
What is it called when a group of organisms descended from a common evolutionary ancestor or ancestral group, especially one not shared with any other group?
Monophyletic
Structures, behaviors, and molecules that are similar (while also differing in appearance and function) because the are derived from a common ancestor
Homologous
A trait shared by two or more taxa
Synapomorphies
What is a derived trait called?
Apomorphy
What is an ancestral character state for a particular clade?
Plesiomorphy
What are the Eons?
Hadean, Archean, Proterozoic, Phanerozoic
What are the Eras in the Phanerozoic Eon?
Paleozoic, Mesozoic, Cenozoic
What are the Periods in the Cenozoic Era?
Cambrian, Ordovician, Silurian, Devonian, Carboniferous, Permian, Triassic, Jurassic, Cretaceous, Paleogene, Neogene, Quaternary
How long ago did Chordates appear?
540 mya
What Period did chordates appear?
Cambrian
How long ago did vertebrates appear?
535 mya
What period did vertebrates appear?
Cambrian
When did jawed vertebrates appear?
420 mya
What period did jawed vertebrates appear?
Silurian
When did tetrapods appear?
365 mya
What period did tetrapods appear?
Devonian
When did amniotes appear?
318 mya
What period did amniotes appear?
Carboniferous
Chordates evolved within _____
Deuterostomes
What are the 3 taxa of chordates?
Cephalochordata, Urochordata, Vertebrata
What are the differences between vetebrates and chordates?
- vertebrates have an endoskeleton
- Vetebrates can be terrestrial or aquatic animals
- Most vetebrates use jaws for feeding, the others are suspension feeders
What are the four fundamental chordate characteristics? (synapomorphies)?
- Notochord
- Dorsal, hollow, single nerve cord/neural tube
- Muscular post-anal tail
- Endostyle (or Thyroid Gland)
What are the three germ layers?
Ectoderm, Endoderm, Mesoderm
What does the neural tube develop into?
The brain and spinal cord
Why is it so important that the notochord is not collapsible in length?
It allows for lateral flexion and prevents the body from collapsing during locomotion
What is the only adult remnant of the notochord in mammals?
nucleus pulposus of the invertebral discs
What germ layer does the dorsal hollow nerve cord develop from?
embryonic ectoderm
What germ layer does the notocord develop from?
Mesoderm
What is the process of formation of the dorsal hollow nerve cord called?
Neurulation
What class are hagfish?
Myxini
What class are lampreys?
Petromyzontidae
Which two animals are Agnathans?
hagfish and lampreys
What class are sharks and rays?
Chondrichthyes
what class are bony fish?
Osteichthyes
What are ray-finned Osteichthyes?
Actinopterygii
What are lobe-finned Osteichthyes?
Sarcopterygii
What class are frogs, toads, and salamanders?
Amphibia
Which classes are amniotes?
Reptilia, Aves, Mammalia
What class are snakes, lizards, crocodiles, and turtles?
Reptilia
What class are birds?
Aves
What are some vertebrate characteristics?
Vertebrae
Cranium/braincase
head + sense organs + brain, complex endocrine organs
muscularized gut tube
multichambered heart
cartilage and bone
pharyngeal arches
somites
Epidermal placodes
Neural crest cells
What are the stages of development?
- Zygote
- Early cleavage stages (morula, blastula)
- Gastrulation (Gastrula)
- Neurulation
- Organogenesis
What does the fusion of egg and sperm make?
Zygote
What does the zygote undergo before mitosis begins
cleavage
Differentiation is done via _____
determination
Changes in gene expression are called?
differentiation
Which cells do not change?
Stem cells
The ongoing differentiation that results in the development of form and structure in the embryo is called
morphogenesis
What is controlled death of cells called?
Apoptosis
What process produces the three germ layers?
Gastrulation
Hagfish are monoecious, what does that mean?
They have both ovaries and testes but only one are functional
What is different about hagfish development?
They have no larval stage, no metamophosis, and develop directly
What is the only living vertebrate with no freshwater ancestor?
Hagfish
Lampreys have blocks of cartilage on top of the ____
notochord
Lampreys have ____ gill pouches
7
What are two examples of Chondrichthyes?
Elasmobranchs ( sharks and rays) and Holocephalans (chimaeras)
What replaces the notochord in adult chondrichthyes?
cartilaginous vertebral column
What are the two main groups of Osteichthyes?
Actinopterygians (ray finned) and Sarcopterygians ( lobed finned)
What are the four extraembryonic membranes
- Chorion
- Amnion
- Allantois
- Yolk sac
Amniotic egg has membranes outside the embryo to:
feed it
collect waste
put layer of water around embryo= amnion
facilitate gas exchange
What does the extoderm develop into?
Outermost layer; epidermis, nervous system
What does the endoderm develop into?
Innermost layer; lining of gut tube, digestive glands, liver, pancreas, lining of urinary system, gills, lungs
What does the mesoderm develop into?
Middle layer; muscles, skeleton, connective tissues, circulatory system, urogenital system
What is the coelom?
the fluid filled body cavity containing internal organs
What are the three arches called?
Arch 1: Mandibular arch
Arch 2: Hyoid arch
Arch 3: Branchial
Where did researchers choose to start their search for Tiktaalik?
Ellesemere island, Canada
What features was the team of researchers looking for when looking for a fossil that showed the transition from water to land?
Eyes at the top of the head
Weight baring joints/ limb structure
lungs and gills
skull and neck mobility
In the book, they talked about how they discovered that the first critical step in the evolution to bipedal animals was in the arms and hands and not in the brain. What study aided them in making this conclusion?
Early hominins
How old is Tiktaalik?
375 mya
Where was Tiktaalik found?
Canadian Arctic
What are the ideal characteristics to look for in rocks to potentially find fossils?
Sedimentary rocks (limestone, sandstone, shale)
Fine grained sediments
Low-heat, low pressure formation
Aquatic or marine environments
layered (stratified) rocks
Describe the anatomy of the appendicular (limbs) skeleton that all limbed animals share today.
shoulders (blade and collerbone), Hips (ilium, pubis, ischium), Arms (humerus, radius and ulna). Legs (femur, tibia and fibula)
which part of the human body reconnected Dr. Shubin to the cadaver he was dissecting?
Hands
What is the origin of the name Tiktaalik and why did researchers decide to use that name for this fossil?
It comes from the Inuktitut language meaning “large freshwater fish”. They chose it because of where it was discovered and Tiktaalik is easier to pronounce than some of the other choices.
Why did researchers decide to travel to the arctic for their expedition?
It had exposed rock of the right time frame that had previously been located near the equator, making it a formidable spot to find the fossils they were looking for.
What time period is Tiktaalik from?
Late Devonian
During what time period did they expect to find the origin of fingers and toes?
Devonian
Why would the development of wrist bones have been beneficial to the survival of a Tiktaalik population?
greater flexiability of movement, navigation of shallow waters, pushing up on land
Tiktaalik is the intermediate between which two groups?
limbless fish and vertebrates
What does ZPA stand for and what is it?
Zone of polarizing activity, it instructs development of the limb bud
What happens when there is a wing bud with an extra ZPA?
Duplicated structures
increased sonic hedgehog signaling
In what animal was the sonic hedgehog gene first observed?
fruit fly (drosophilia melanogaster)
What does retinoic acid cause the ZPA to do?
enhances the expression of sonic hedgehog gene