<u>Answer:</u>
Recent evidence suggest that feathers evolved from scales and suggest that 'feathers and pycnofibers' could be homologous.
<u>Explanation:</u>
- One of the major difficult issue related to bird evolution is the evolution of feathers.
- Feathers are considered as the most 'complex integumentary structures' which are found in vertebrates.
- Evolutionary developmental biology suggests that the 'planar scale structure' is been modified for developing into feathers by 'splitting' to form web like structures.
- Scales and Feathers consist of 'two distinct form of keratin' so it was thought that 'each type was exclusive skin structure' but recent study suggests that they are developmental expressions of same skin structures.
The correct answer is option C, that is, behavioral isolation.
The phenomenon of behavioral isolation takes place when two populations possess the tendency of interbreeding, but exhibit distinctions in courtship rituals or other kinds of behavior. For example, the western and eastern meadowlarks are very identical birds whose habitat overlap in the middle of the United States.
However, the members of the two species will not mate with each other, possibly as they use different songs in order to fascinate males. The eastern meadowlarks will not respond to the songs of western meadowlarks, and vice versa.
Lion, Spotted hyena, African wild dog, Leopard, Cheetah, and probably crocodillians. Hope this helped!
Answer:
b
Explanation:
the worm is living while the leaf is not
Spiders have malpighian tubules<span> to absorb salts and wastes while humans have microscopic subunits in the kidneys called </span>nephrons to filter blood. Malpighian tubules<span> remove wastes from insects by producing urine and solid nitrogenous waste, which are then excreted from the body.</span>
