Apparently because of the costs associated with increase brain size, there is an upper limit as to how large bird brains can evolve.
Larger than expected brain sizes are associated with lower mortality rates. (This could be the result of large-brained birds having an increased intelligence that gives them an advantage in finding food, or escaping predators, though the data do not address this.)
There is no correlation between brain size and mortality rate. (This could be because of conflicting selective pressures. For example, any advantage of having a relatively large brain, perhaps increased intelligence, may be counter balanced by a disadvantage of having a relatively large brain.
Birds with brain sized that are larger than expected have relatively high mortality rate. (This could result from the metabolic costs associated with maintaining that relatively large brain, though the data do not address this.)
Unicellular green algae
Multicellular green algae
Have HOX genes that regulate gene expression
Have digits that permit grasping
Have mammary glands
Have DNA with introns
Have the same number of chromosomes
If hypothesis #1 is correct, one would not expect regional genetic/molecular differences among humans.
If hypothesis #1 is correct, the genetic variability in east-central Africans should be greater than that in other regions.
If hypothesis #2 is correct, there should be distinctive differences in the mitochondrial DNA (mtDNA) in populations of human endemic to different regions in the world. This would not be the case if hypothesis #1 is correct.
If hypothesis #2 is correct, the mtDNA of all males in a population endemic to any one region in the world should be the same.
If hypothesis #2 is correct, one cannot conclude that all humans are of the same species. Taxonomists would need to divide humans into multiple species.
Support for the southerly migration occurring first could come from the observation that there is greater genetic diversity in the mitochondrial DNA of Asians than of Europeans
If the northerly migration, which proceeded through what is now the Middle East and then on to Europe, occurred after the Asian migration then modern Europeans must be more similar genetically To Africans then Asians are to Africans.
Evidence of human/Neanderthal interbreeding could come in the form of human mitochondrial genes being found in Neanderthal DNA as the result of crossing over during meiosis.
Neither chose A, B, or C is reasonable.
Adult has a cranium
Larva has a hollow nerve cord position on the “back”, or dorsal surface, of the organism
Adult has a longitudinal, flexible rod that provides skeletal support
Adult has a lateral line system (organ)
Larva has pharyngeal slits in the region just posterior to the mouth
A vascular system
Chloroplast to permit utilizing suns energy
Cell plates for a more efficient mode of cell division
Flagellated sperm cells
Ferns are non-vascular plants
Bryophytes are the ancestor of gymnosperms
Bryophytes do not display the “alternation of generations” life cycles found in more advanced plants (gymnosperms and angiosperms)
A cell plate that grows during cytokinesis. The cell plate is composed of the constituents of the cell wall and plasma membrane.
Grasses are angiosperms (flowering plants). This is true. The represent that most primitive of angiosperms because they lack flowers.
They are more closely related to placental mammals than to marsupial mammals
What issues from the female’s reproductive tract at birth are eggs, not motile young. That is to say they are oviparous.
They have fur, a distinguishing characteristic of mammals, but do not nurse their young
They are “cold-blooded”
Is the ancestor of modern bony fish (the most diverse group of extant fish)
Is a rare modern representative of a lineage of fish previously thought to be extinct
Is a species of reptile that has apparently not changed (or evolved) in the last 300 million years
Is the ancestor of tetrapods
Is the oldest fossil vertebrate
Is was found in the Burgess Shale
It existed at the time of Pangaea
It evolved from a lineage of flying fish
It had a paper-thin jaw similar to that of modern birds
It had a long, bony tail
The photosynthetic partner is a protist
The coral animal supplies carbohydrates to its symbiotic partner
The animal partner is dead and supplies its symbiotic partner with a hard protective casing composed of carbonates
The photosynthetic partner relies on the animal partner for oxygen
Land plants, unlike their aquatic relatives, need structural support to maintain their “posture” in air. After colonizing land, plants evolved collagen which contributes to that support by acting as a “glue” to hold neighboring cells together.
Cuticles serve plants by limiting inbreeding
The evidence that all angiosperms had a common ancestor includes the observation that they all share basic similarities in their flowers and fruits. For example, all flowers are constructed of 4 whorls of modified leaves that serve as sepals, petals, stamens, and carpels.
Evidence that gymnosperms and bryophytes have a common ancestor is that they both have flagellated sperm that are similar in structure
Land plants probably evolved from a flagellated protist
Once invertebrates colonized land, they evolved an exoskeleton
Bony fish (teleost) have a swim bladder which they use a storage chamber for liquid waste (urine)
The lateral line system permits fish to orient in water
Bony fish predated cartilaginous fish
The Burgess Shale is known for its fossil demonstration of the Cambrian Explosion. The ancestors of many modern invertebrate phyla had their origins in the Cambrian Explosion. The origins of the phylum which includes modern vertebrates however were absent; they evolved later.
Amphibians evolved from a lineage of fish. Pre-adaptation s of those “proto-amphibians” for making the transition to life on land included eggs with water-tight membranes
The ancestors of the mammals living at about 65 m.y.a were reptiles other than dinosaurs
Usually, amphibians deposit their eggs outside the body and subsequently they are fertilized. Reptiles and birds, in contrast, are not as dependent on an aquatic environment for successful reproduction. They have eggs with membranes/shells that give the zygote some protection from arid conditions. A consequence of this difference between amphibians on the one hand and reptiles and birds on the other is that in the latter two taxa, fertilization must be internal
The pharyngeal slits of aquatic chordates have been modified to form the ribs of land vertebrates.
A sporophyte life stage that is more prominent than a gametophyte life stage
Cell walls of chitin
They are heterotrophs
They live symbiotically with algae
They feed on plant starches and sugars
They feed at night on suspended matter in the water
They are protists
One might reasonably interpret the apparent “mixture of features” to indicate that modern humans evolved from Neanderthals
One might reasonably interpret the apparent “mixture of features” to indicate that humans interbred with Neanderthals
If the mtDNA analysis found that the Neanderthal DNA had greater variability than that found in the H. SAPIENS sampled, then phylogeny A below must be correct
Plate tectonics resulted in large scale volcanic activity
The earth cooled significantly
The concentration of oxygen in the atmosphere plummeted
The ocean levels reach its highest level ever seen on Earth
Continental shelves, the home to the majority of marine organisms, diminished significantly in area
At about 350 million years ago, tetrapods began to appear on land. Tiktaalik is a representative of what may have been an animal form transitioning from a largely aquatic existence to a terrestrial one. When Tiktaalik was alive, it lived in an arctic setting and therefore was not exposed to heavy predation.
A preadaptation of Tiktaalik for its existence on land was its having a water-tight skin, much like reptiles today that would permit it to exist in the relatively arid terrestrial environment, compared with the moist marine environment.
During the time that dinosaurs existed on Earth as the dominant vertebrate group, Pangaea broke apart by plate tectonic movements. The earth warmed and massive tropical forest covered much of its surface and provided large amounts of food to fuel their metabolic needs.
Part of the reason for dinosaur dominance for a considerable amount of time is that they were cold-blooded like today’s reptiles. Having a low metabolic rate and relying on ambient temperature to warm their bodies, they did not require much fuel