Which combination of characteristics in a population would provide the greatest potential for evolutionary change?
a. large population, few mutations
b. small population, many mutations
c. small population, few mutations
Small population, many mutations are the combination of characteristics in a population would provide the greatest potential for evolutionary change.
b. small population, many mutations
<u>Explanation:</u>
Stabilizing selection in development is a kind of common choice that supports the normal people in a populace. In little, reproductively detached populaces, extraordinary conditions exist that can create fast changes in quality frequencies absolutely autonomous of transformation and normal determination.
Natural Selection prompts a transformation change when a few people with specific qualities in a populace have higher endurance and regenerative rate than others and give these inheritable hereditary highlights to their posterity. The power of Natural Selection aside, populace size is as yet a factor to be considered.
<span>Wings have evolved several times independently. In flying fish, the wings are formed by the enlargement of the pectoral fins. Some fish leap out of the water and glide through the air, both to save energy and to escape predators. If they were already gliding, then any mutation that would result in an increase of the gliding surface would be advantageous to the fish that has it. These advantageous may allow these fish to out-compete the others.
Wings have also evolved in bats, pterosaurs, and birds. In these animals, the wings are formed by the forelimbs. In some lizards that have evolved gliding flight, however, the "wings" or gliding surfaces may be quite different. The lizard Draco, for example, has gliding surfaces formed by an extension of the ribs. A number of extinct reptiles have similar gliding surfaces. Frogs that glide have expanded webbing on their hands and feet. Gliding ("flying") squirrels and marsupial sugar gliders have flaps of skin that lie between the front and rear limbs. These gliding animals all have one thing in common: a gliding surface that is formed by enlarging some parts of the body.
In pterosaurs, the wing is formed by an elongated finger and a large skin membrane attached to this finger. In bats, the wing is formed by the entire hand, with skin membranes connecting the elongated fingers. In birds, flight feathers are attached to the entire forelimb, while the fingers have fused together. In all of these animals except birds, the wing is a solid structure. In birds, however, the wing is formed by a large number of individual feathers lying close to each other and each feather is in turn formed by filaments that interlock.
Biophysicists have determined that flight most likely evolved from the tree down. That means most active flyers evolved flight from an animal that was already gliding. Gliding was therefore probably an indispensable intermediate stage in the evolution of flight. Since gliding has evolved in so many different groups of animals, it follows that the ancestors of birds, bats, and pterosaurs were almost certainly gliders.
Unfortunately, the fossil records of the immediate gliding ancestors of birds, bats, and pterosaurs are all missing. The first known bat and bird fossils are recognizable as flyers. The same is true of pterosaurs. Therefore the origin of these flyers remain a mystery and a subject of often acrimonious debate. There are people who claim that dinosaurs evolved insulation, which then evolved into feathers, but the evidence for that is lacking. The so-called proto-feathers found on some dinosaurs are indistinguishable from the collagen fibers found in the skin of most vertebrates. Some of the supposedly feathered dinosaurs, such as Caudipteryx and Protarchaeopteryx, are actually flightless birds. The same is probably true of Microraptor fossils, which are (as Alan Feduccia says) probably "avian non-dinosaurs."
Even though the immediate ancestor of birds remains a mystery, there is a fossil known as Longisquama insignis, which lived during the late Triassic. It has featherlike structures on its back. It was probably a glider of some sort. So, this animal may well be the distant ancestor of Archaeopteryx, the oldest known bird.
In sum, flying almost certainly evolved from animals that were already gliding, or from the tree down, not from the ground up. The dinosaurian origin of birds requires that dinosaurs evolved feathers from insulation and flight to have evolved from the ground up. Both of these requirements are extremely unlikely to have occurred in evolutionary history, because dinosaurs are almost certainly ectothermic (or "cold-blooded") and therefore they never evolved insulation, and because feathers are too unnecessarily complex to have evolved as insulation. Flight from the ground up is also dangerous because large animals that attempt to fly from the ground may crash and seriously injure or even kill themselves. We all know how dangerous an airplane can be if it loses power and crashes. Small and light weight animals, OTOH, that were already gliding can survive if their attempt to fly fails. Finally, if flight evolved from gliding, then why do animals glide? The answer is that gliding is energetically much cheaper than to descend a tree, walk along the ground, and then climb up another tree. Besides, it is almost certainly much safer to glide from one tree to another than to be walking on the ground for many arboreal animals.
See link below for details of why dinosaurs are considered ectothermic according to the available scientific evidence.</span>Source(s):<span>http://discovermagazine.com/1996/dec/aco...</span>
Answer:
Your answer is A) Sedimentary. The rocks and pebbles you see on a daily basis are most likely limestone, which is an abundant sedimentary rock.
The examples of positive feedback loops are as follows:
- contractions during the process of giving birth
- Blood clotting
<h3>WHAT IS POSITIVE FEEDBACK LOOP:</h3>
- Positive feedback loop is that in which a change in a given direction causes additional change in that same direction.
- The contractions during the process of giving birth is an example of positive feedback loop because the contractions further stretch the walls and continues until birthing occurs.
- Also, the clotting of blood causes the stoppage of blood flow.
Therefore, the examples of positive feedback loops are as follows:
- contractions during the process of giving birth
- Blood clotting
Learn more about positive feedback loops at: brainly.com/question/11312580
Answer:
1) It's called taxonomy
2) There are 7
3) The basic difference between them is Monera are unicellular and prokaryotic cellular structures, whereas Protista are unicellular and eukaryotic cellular structure. Cell organelles are absent in Monera, but Protista is well-defined and has membrane-bound organelles.
4) Reptiles and Fish belong to kingdom Animalia
