1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
IgorC [24]
2 years ago
10

Can you pourpse any other explanations for Lamarck's observations about the use and disuse of organs

Biology
1 answer:
Colt1911 [192]2 years ago
3 0

Yess it is one of the best things in the past but it will take a while to get the door whithout and I love the way y us u

You might be interested in
N which vertebrates did feathers first evolve?
Lapatulllka [165]
<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>
3 0
3 years ago
Explain why the chromosomes in the haploid cells that are produced by meiosis I look different than those produced by meiosis II
scoundrel [369]
In meiosis one, homologous chromosomes only separate resulting in two cells. In meiosis II, the cells divide further, separating sister chromatids and resulting in four cells. So the cells are just even smaller with less chromosomes in each one.
5 0
3 years ago
Read 2 more answers
Which of these definitions have been paired with the correct type of cell?
patriot [66]

Answer:

B. Neurons are cells that conduct electrical impulses.

Explanation:

Red blood cells carry oxygen throughout the body. White blood cells protect against pathogens and aid in blood clotting after injury. Blood cells cannot contract.

Neurons generate and conduct electrical impulses. So this one is correct.

Epithelial cells line the cavities and surfaces of blood vessels and organs, protect underlying tissue, regulate the exchange of chemicals, and secrete various substances. They do not react to stimuli, however neurons do.

Smooth muscles helps the skeleton move, smooth muscle is found in blood vessels and some organs, and cardiac muscle helps the heart beat and pump blood. They are however, not components of blood.

3 0
3 years ago
A joint condition that is characterized by the breakdown of cartilage is
DIA [1.3K]

The best answer would be:

 

Osteoarthritis

 

<span>It is when the person experiences too much weight bearing activities, which may cause the wear and tear breakdown of the joints. This worn bone may be a foreign material when identifying the joint erosion.</span>

8 0
3 years ago
How do scientists disagree on the number of biomes that exist?
Masja [62]
They have different research so they have to come together and calculate together.
8 0
2 years ago
Read 2 more answers
Other questions:
  • The harmless scarlet kingsnake has scales in a coloration and pattern resembling the scales of the dangerous coral snake. The sc
    11·2 answers
  • When do the people living in houses on the edge of the ecosystem spray general purpose insecticide to kill a wide rangeOf insect
    10·1 answer
  • Extrapyramidal effect of metoclopramide.
    13·1 answer
  • the valence of aluminum is + 3 and the valence of chlorine is -1 the formula for aluminum chloride is correctly written as
    13·1 answer
  • Which of these characteristics is common only at the embryonic stage of fish and humans, and is suggestive of a common ancestor
    15·1 answer
  • Using the words "selection pressure" and "fitness", explain how natural selection causes populations to change over time.
    14·1 answer
  • I'm just asking this question cause I'm curious how long is a giraffes neck
    15·1 answer
  • The backbone vertebrae, skull, and rib cage make up the _______ skeleton. Among other types of cells, bone marrow produces _____
    10·1 answer
  • What is scientific learning?​
    10·2 answers
  • Plant cells have some organelles that are different from those found in animal ce11s. List these organelles, and explain why you
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!