them, evolution(进化) of fruit colours, Anumans, on and then drop the seeds in other places later. This helps the fruit spread and grow in different places. To attract animals, some fruit develops colours I can that are easy for animals to see....
1. D Horseshoe Crabs-445 million years old "They have nine eyes in total..."可知,马蹄蟹(horseshoe crabs) 有九只眼睛。 2. D Nautiluses-500 million years old "That is long before dinosaurs appeared on Earth."可知,鹦 鹉螺(nautiluses)在恐龙出现在地球上之前就已经 存在了。 又根据 Sponges...
Three major hypotheses, based upon mechanisms of sexual selection, intersexual food competition and reproductive role division, have been advanced to explain the evolution of sexual dimorphism in body size and morphology of animals. Genetic models suggest that all of the hypotheses are plausible, and ...
根据第二段The experts point to animals such as the dwarf elephant that once lived on the Mediterranean island of Cyprus.The animal is now extinct.When it lived ,however,it was only the size of a small horse.Elephants that live today in Africa and Asia are much larger than ...
The evolution to the amniote egg, an egg with a hard shell, allowed the reptiles to reproduce on land. Since they were the only vertebrate land animals at that time, there was no serious competition with other animals. There was little natural selection till the Carboniferous Rainforest ...
"What they suggest, based on the information they do have, is that its visual system is a kind of compromise (妥协) between to low light and also visual keenness," says Jennifer Hoyal Cuthill at the University of Essex, UK. That isn't a mistake — it is evolution two competing ...
There are many different species of animals on Earth. This shows that evolution has led to a great deal of ___. A. diversity B. similarity C. sameness D. uniqueness 相关知识点: 试题来源: 解析 A。本题考查名词词义辨析。“diversity”表示“多样性”;“similarity”表示“相似性”;“sameness...
domestication. Indeed, kangaroos showed a very similar pattern of behaviour we have seen in dogs, horses and even goats when put to the same test. We hope that this research draws attention to the cognitive (认知的) abilities of kangaroos and helps promote more positive attitudes towards them....
Our understanding of the evolution of sex chromosomes has increased greatly in recent years due to a number of molecular evolutionary investigations in div
shorter back legs reduce the drag and it can hold on for a few seconds longer and that might be the difference between survival and death. what colin realized was that he had measured evolution in action, survival of the fittest. natural selection playing out, not over thousands of years, ...