Answer:
Evolution in nature by natural selection only modifies the structures present in the ancestors and favors the better adapted structures.
Explanation:
An engineer can design the bones and muscles of the forelimbs of given organisms as per their needs and give rise to new unique structures for each of these organisms.
On the other hand, evolution in nature allows the modification of existing traits by the accumulation of variations. The adaptive variations in the traits are then favored by natural selection. Therefore, forelimbs of mammals such as horses, whales, and bats have evolved by modification of the forelimbs present in their common ancestors.
The limitation of modification of existing structures does not allow the formation of a completely new structure.
Answer:
0.78
Explanation:
Fitness measures the probability of survival and reproduction of a particular phenotype or genotype in a population.
Relative fitness measures how fit one genotype or phenotype is with respect to the most fit genotype or phenotype in a popualtion. It is calculated as = survival rate of that group / maximum survival rate observed in that population
Here,
Total number of yellow birds = 263
Yellows birds that survived = 150
Survival rate of yellow birds = 150/263 = 0.57
Total number of grey birds = 413
Grey birds that survived = 303
Survival rate of grey birds = 303/413 = 0.73
Grey birds have more survival rate than yellow birds so their survival rate is maximum in the population.
Fitness of yellow phenotype relative to grey phenotype = survival rate of yellow birds / survival rate of grey birds
= 0.57 / 0.73
= 0.78
Hence, fitness of the yellow phenotype relative to the grey one is 0.78.
Answer: Her times at lunch were always faster, no matter what type of meal she ate.
Explanation:
Before cells could be seen by using a microscope, people believed that diseases were caused by spiritual effects.