In 1859, Charles Darwin set out his theory of evolution by natural selection as an explanation for adaptation and speciation. He defined natural selection as the "principle by which each slight variation [of a trait], if useful, is preserved".
Is an organism in its earliest stage of development. In humans, this is the stuff and defined as the developing organism from the fourth day after fertilization to end of the week. After that unborn baby is usually referred to as the fetus.
I believe the answer is B.
Answer:
a. Species A survived because of its widespread range including some areas that were not as affected by mass extinction.
Explanation:
The species distribution might confer extinction resistance during massive extinction events. One of the most important reasons for a species -or any other taxonomic group- to survive massive extinction is its wide distribution area.
The broad geographical range of a group -as Species A in the example- enhances the survival chances during mass extinctions. When the event occurs, it severely affects most individuals of a certain area. If the species is restricted to that area, then the species will probably disappear, no matter the number of individuals living there.
But if the species is widely distributed, there are more survival chances. The extinction event will only affect a few regions, but not all of them, meaning that some of the individuals of the species will be able to survive.
Probably as only a few individuals of species A got to survive, they must have suffered the effects of genetic drift after the disaster, causing a reduction in genetic variability.
<span>The question is the following: "Smokers have a greater chance of developing deadly diseases" and I assume we are asked to determine whether it's true or false. It is a true statement - and we can see it on the packaging of cigarettes in many countries. Some of these diseases are cancer (for example lung cancer) and diseases of the blood stream.</span><span />
