Probably because they are large and tough.
Larger animals tend to be higher up in the food chain and are less likely to be eaten when born. A mouse needs to have dozens of offspring a year to insure that one of then will get to continue the species. A human or and elephant need only have a few offspring in a lifetime to continue the species.
Migration helps animals survive in extreme conditions by providing them with access to food, a less harsh climate, or better protected area in which to breed or to have offspring. Many animals migrations are linked to those of other animals, for example some animals at the top of the food chain will follow packs of other animals they use as a main source of food.
Within a population of animals there are variations and differences. So when an environmental change occurs those animals that are better suited to that environment survive and are able to reproduce sucessfully. Those animals that cannot survive as well under the new conditions tend to reproduce less and die out, leaving just the offspring of those who could tolerate and thrive in the new environment. Thus passing on this ability to survive to their offspring leaving a population well suited to the new environment.
false
the animals have less nutrients.
He meant that animals have to expend energy in order for them to gain enough food to survive and reproduce. The less efficient their attempts to gather food, the less energy they'll have for raising fertile offspring, the lower the chances that their genes will be represented in subsequent generations. Through reproduction, animals indirectly compete with all other members of their species, who are also trying to gather food, find mates and get their genes represented in the next generation.
Animals that urinate less conserve more water so would be better adapted to survive.
Organisms that are less fit can die before they reproduce. This is statistically more likely for such organisms. Organisms that are less fit have problems getting mates as they are passed over in greater numbers than fit organisms. Organisms that are less fit can not bring the offspring to term and provide as well for the offspring as fit organisms can. Organisms that are less fit pass on to their progeny the genetic insults that they carry, thus their offspring are less fit also. And many other reasons could be thought of here, so you think of some reasons yourself.
Water,sunlight,and soil.As an example,a desert is dry and has much sunlight and less nutrients,and the rain forest has more water,less sunlight and more nutrients than a desert. A small amount of plants and animals can survive in the desert.While more plants and animals survive in the rain forest.
different animals live in different places around the world according to what they need to survive. Like: water, food, shelter, and space. The more crowded an area is the less likely the animals are to survive, so animals automatically spread out. but it also depends on the climate that an animal needs to survive. Like a python couldn't survive here because it is too cold but it can survive in Florida where it is really warm.
Because fitness means exactly that. The ability to survive and reproduce - pass on genes.
Absolutely not... typically they will produce a multiple more than what will survive in order to maximize survivability... genetically speaking this increases the 'fitness' of the organism. Turtles and other reptiles will produce dozens of offspring only to have a small percentage survive, but reptiles take very little care of their young (the majority of the fates of the offspring are left up to chance and the strengths of individual offspring). Mammals will produce less (typically 1/2 of the number of nipples for feeding is the average birth number at one time). Mammals produce less because they take more care of their offspring and leave less to chance.Spider unfortunately (in this authors humble opinion), have WAY too many offspring! :)Have a great day,Synapse your fingers to the beat,Synaptophyllic
No, trees provide oxygen for us to survive. If they did not live longer we would have less oxygen. Also certain animals live and eat off of trees and we eat animals, without the trees those animals would die off and we may survive but more likely perish. Hope it helped