The answer is Permian-Triassic extinction.
The Permian-Triassic extinction was 252 million years ago. It is known as The Great Dying because about 95% of all species died out due to environmental changes (volcanic eruptions, dry climate, melting of ice sheets, etc). This is also the only event in which many insect species wiped out.
Answer:
All vascular plants have water-conducting tissue and are better adapted for life on land than the bryophytes; they are also characterized by a dominant sporophyte generation.
Answer:
The tail and the caudal fin are the chief locomotory organs of fish and are used for rapid swimming during which tail is lashed from side to side by "alternate contraction and relaxation" of the myomeres on the two sides of the vertebral column.
Explanation:
Answer:
Testing positive for HIV means a high chance of death and a good chance of lower reproduction rates. But some people are immune to HIV, which makes them more evolutionarily fit, likely to live longer, likely to reproduce more, which would increase the frequency of the immune allele in the population. Over time, this increase in frequency of the gene that causes immunity could spread across the human race and cause it to evolve.